A&P Y1

Question 1

Skeletal system functions?

Answer 1

Skeletal system functions?

.Supporting the body- protection for vital organs, soft tissues will attach onto. Holds the animal upright.

.Storage - storage of mineral particularly calcium & phosphorus.

. Production -red marrow produces red blood cell, white blood cells and other elements of blood. Produced in long bones. In young in all bones.

.Protection - rib cage for heart and lungs, skull for brain, vertebrae for spinal cord, pelvis for reproductive organs.

.Leverage of movement

From week 1 theory

Question 2

Bone tissue?

Answer 2

.Bone tissue?

.has a strong roll in homeostasis because of the calcium stored in the bone.

.Calcium is needed for correct muscle function and need a constant reserve. Bone can release calcium into the blood stream when needed.

.Bone tissue also bone marrow red & yellow. Yellow stores lipids.

.larger at component of skeletal system and second cartilage

.Cane repair itself with osteoblasts cells.

.Bones can thicken and gain strength from regular exercise and a balanced diet. Horses can get bone splints from ever exercise in young race horses. Bones been strained too quickly. Lump form to help support tissue.

From week 1 theory

Question 3

Bone classification?

Answer 3

Bone classification?

.Long bones - provide muscle attachement for joints. Involved in movement. Normally in limbs.

.Irregular bones - all different e.g. vertebrae, some in skull.

.Short bones - normally in-between joints. Horse short bones in carpus. High movement needed. Rotational movement.

.Flat bones - thin and flattened for protection of organs e.g. ribs, skull

.Sesamoid bones - over joints not forming. Provide strength to tendons and ligaments . E.g knee cap.

From week 1 theory

Question 4

Bone tissue formed?

Answer 4

Bone tissue formed?

.Two components of bone tissue are cells and extracellular matrix that is a substance that surrounds the cells called ground substance and fibres.

.Extracellular matrix (non cellular) component filled the space between the cells. Secreted by bone cells. Made up of an inorganic and organic parts below

-Inorganic salts (ground substance) - larger 60% of bone weight in adults. Calcium carbonate and calcium phosphate give bone hardness and rigidity also flexibility so they don’t break as easy.

-Organic part (fibres) - 90% type 1 Collagen fibres give bone toughness, it allows pressure to be withstanded. These salts are deposited in a matrix of collagen fibres. 10% of organic composition non- collagenase proteins. Produce collagen fibres. Maintenance of bone tissue.

From week 1 theory

Question 5

Histology of bone?

Answer 5

Histology of bone?

.Bone cells are responsible for development, maintenance and breakdown of bone tissue.

Types

.Osteogenic (Osteoprogenitor) cells - develops into an Osteoblast. Derived from mesenchyme (stem) cells that are able to multiple because they have osteogenic potential. It happened via the process of mitosis and differentiation into bone cells. Found in the periosteum and endosteum.

.Osteoblasts - First cells to developed from osteoprogenitor cells. regenerate bone when needed. They cover majority of bone surface in huge numbers. forms bone tissue. Secrete extracellular matrix. Formation of organic matrix - osteoid . Bone development - while bones are in their osteoblast stage they are responsible for secreting osteoid that will then be calcified and mineralised to form the extracellular matrix and the bone tissue. High rate of metabolism. Abundant ER, ribosomes, golgi apparatus, mitochondria.

.Osteocytes - once osteoblasts have matured (produces osteoid ect) they become osteocytes . maintains bone tissue. Fewer metabolic activity.

.Osteoclasts - functions in resorption, the destruction of bone matrix when needs to be replaced. Large multinucleated cells (more than one nucleus). Near bone surface. Derived from macrophages (immune cell) and are taken to the bone tissues by blood vessels and detect bone that needs to be broken down then osteoclasts secrete hydrogen ions that create an acidic environment that will dissolve minerals, salts within the bone matrix and remove organic matrix these process brokers down the bone tissue needed to be replaced. Functions - only carried out when bone tissue needs replacing. needs to work with the osteoblasts to form new bone. If over active can cause osteoporosis - this brakes down bone tissue too quickly.

From week 1 theory

Question 6

Bone structure types?

Answer 6

Bone structure types?

Two types below

.Cortical (compact, hard bone) -Made up of osteons. Looks like lots of rings around circles on bone under microscope. These circles are the lamellae layers forming a cylinder of bone matrix. All of the layers are called Lamellae (hollow cylinders) forming one matrix tube and fit together to form a osteon.

.Cancellous (spongy, traecular bone) - In-between trabeculae (holes) is red marrow (haematopoietic) that is red blood cells or yellow (fatty) marrow that is a reserve for fat. Made up of trabeculae. Looks like holes within bone.

.Flat bones - layer of hard bone on the inside, then they have a layer of spongy bone and then another layer of hard bone on the outside.

.Irregular bones - are mainly spongy bone with a thin layer of compact bone on the outside.

.Long bones - spongy at ends and compact in the middle.

.Short bones are mainly spongy bone and covered by compact bone on the outside.

From week 1 theory

Question 7

Compact bone?

Answer 7

Bone structure - compact bone?

.Structural unit - osteon or haversian system.

.Made up of a number of repeating units we call osteon (haversian system). Osteon are a hollow cylinder bone matrix and they all fit together.

.Looks like lots of rings around circles on bone under microscope. These circles are the lamellae layers forming a cylinder of bone matrix. All of the layers are called Lamellae (hollow cylinders) forming one matrix tube and fit together to form a osteon.

.Lamellae - lines run in 90 degree angle. Line run In opposite direction to the next lamellae.

.Osteon - are formed in the lamellae tube way because the upright position gives it extra support. Thousands of tubes along with collagen fibre provide toughness to bone.

.Central (haversian) canal - a hole in the middle of the Osteon. This hole (canal) allows blood vessels, nerve fibres to pass through the Osteon.

.Lacuna - the dots seen under microscope seen on compact bone. Small holes and they contain the osteocytes within them.

.Volksmann’s canal - they connect the different osteons together to provide a blood supply from the periosteum (on outside of bone) into the central/ haversian canals.

.Canaliculi - are small channels that connect the osteocytes to the central/ haversian canal. They connect the lacunae and central canal for nutrient and waste distribution.

.Endosteum - covers outer inside of compact bone in the middle (the part that touches the medullary cavity). Stem cells lie within this the endosteum and periosteum.

From week 1 theory

Question 8

Spongy (Cancellous) bone?

Answer 8

Spongy (Cancellous) bone?

.Made up of trabeculae looks like a sponge. Arranged in this way to provide max strength and can arrange them self for strain and stress areas.

.Within the trabeculae they still have Lamellae in them and have the osteocytes in the lacunae in the same way as the compact bone does.

.Canaliculi are present that provide communication network and allow the osteocytes to receive nutrients and blood they need.

.Within spongy bone the bone tissue will vary in quantity from about 10% - 70% depending on where the bone.

.Within the holes and gaps is where the high about of yellow and red bone marrow.

From week 1 theory

Question 9

Long bone structure?

Answer 9

Long bone structure?

.Proximal epiphysis (top) - spongy bone. Generally sit within joint capsules and joint cavities and need to be able to glide over one another for the joint to be able to function effectively. The articular cartilage covering the epiphyses has a smooth surface that allows this to happen.

.Diaphysis (middle) - is made up of compact bone and inside the centre of the compact bone is the medullary cavity and this contains bone marrow.

.Distal epiphysis (bottom) - spongy bone. Generally sit within joint cavities and need to be able to glide over one another for the joint to be able to function effectively. The articular cartilage covering the epiphyses has a smooth surface that allows this to happen.

From week 1 theory

Question 10

Periosteum?

Answer 10

Periosteum?

.Surface membrane connective tissue that covers all outside of bones.

From week 1 theory

Question 11

Foetal skeleton?

Answer 11

Foetal skeleton?

.Earliest stages of development begins with a cartilaginous tissue framework then the stem (mesenchymal) cells will start to turn (differentiate) into chondrocytes (mature cartilage cells). That’s what form the cartilage model of the skeleton.

.During the second half of embryo genesis (foetal development) the bones will under go the process called endochondral ossification. The extracellular matrix of this cartilage will start to form intermediary cartilage tissue that form the frame of the skeleton.

.These chondrocytes will start to grow and then the tissue will become vascularised (start to get a blood supply) to the cartilage frame and that will transport osteoclasts (cells that breakdown tissue) will start to break down the cartilaginous matrix and in its place we start to see osteoblasts that form bone tissue instead. That is the process of ossification.

From week 1 theory

Question 12

Bone development stages?

Answer 12

Bone development stages?

.Primary ossification will happen within the diaphysis (centre) of long bones becoming bone tissue first then spreads along the rest of the diaphysis.

.Secondary ossification - happens later on in the distal & proximal epiphyses of the bones.

.Epiphyseal plate - is formed from cartilage remaining between the expanding primary and secondary ossification centres (plate separating the epiphyses and diathesis).

.Articular cartilage - on the outside of the epiphyses. Will remain throughout maturity. Is a layer of cartilage. Provides a smooth surface for the ends of bones so joints can easily glide over each other.

From week 1 theory

Question 13

Ossification?

Answer 13

Ossification?

.Bone forming by osteoblasts.

From week 1 theory

Question 14

Bone development stages?

Answer 14

Bone development stages?

1) Hyaline cartilage framework (foetal)

2) Primary ossification centre inside the medullary cavity that expands the length of the diaphysis.

3) Secondary ossification centre in the proximal & distal epiphyses.

After you’re left with compact bone in the diaphysis shaft, spongy bone in the epiphyses, epiphyseal plate dividing the two and the articular cartilage covering the ends of the bones.

From week 1 theory

Question 15

Epiphyseal (growth) plates?

Answer 15

Epiphyseal (growth) plates?

.Reason - allows elongation of the bones and bone development to continue.

.Young animal - have the epiphyseal plates remaining to allow for elongation and growth of the bones. They will continue to grow and develop through the process of mitosis (cellular multiplication) we will get more cartilaginous tissue growing in that region.

.As the animal matures, near the edges of the epiphyseal plates will start to ossify and we will get new bone formation.

.New bone formation increasing the length of the shaft at both ends.

.Thickness of the physis decreases as the cartilage is broken down for ossification ending the bone lengthening process. It can no longer grow and expand but Can still see bones growing in thickness and diameter when under stress

.Periosteal (appositional) - bone grows in thickness not in length.

.Endosteum - osteoclasts on here will be breaking down old bone on the inside but the medullary cavity will stay the same size.

From week 1 theory

Question 16

Medullary cavity?

Answer 16

Medullary cavity?

.Inside the middle of compact bone. Contains bone marrow and means the bone is lightweight.

From week 1 theory

Question 17

The axial skeleton?

Answer 17

The axial skeleton?

.Skull - Incisors, molars, incisive bone, nasal bone, frontal bone, Temporomandibular joint, Occiput, Temporal bone, facial crest, mandible, maxilla.

.Vertebrae column - equation cervical (C7), thoracic (T18), lumbar (L6) L5 in Arabs, sacral (S5), coccygeal (C15-20). Protects the spinal cord and allows attachments for muscles and tendons to support the weight of the body e.g has to hold the abdominal cavity up in the horse.

.Ribs and sternum

From week 1 theory

Question 18

The appendicular skeleton?

Answer 18

The appendicular skeleton?

.Bones that bring about locomotion

.Shoulder blade
.Pelvic
.Limbs

.Thoracic (forelimb) limb -a shock absorber and a weight carrying limb. Approx 60% of their weight is distributed to the forelimbs. Straighter than hind limbs for more support.

.Pelvic (hind) limb - approximately 40% of body weight support. Main function is creation of power of locomotion. They are the driving force that push the animal forwards.

From week 1 theory

Question 19

Intervertebral discs?

Answer 19

Intervertebral discs?

.Approximately 10% of the length of the spine.

.Cartilage in-between the vertebrae

.Acts as a shock absorber, cushioning the vertebrae from damage e.g. when running.

From week 1 theory

Question 20

Rib cage?

Answer 20

Rib cage?

.Sternum - ventral part of rib cage. First 8 (true) ribs articulate with the sternum directly by forming a bony attachment.
The other 10 (false ribs) have an indirect attachment, they are attached via costal cartilage attachment between the ribs and the sternum.

.Rib-head, body, costochondral junction, costal cartilage.

.Articulate with thoracic vertebrae

.Articulate with sternum either directly or indirectly

From week 1 theory

Question 21

Articulation?

Answer 21

Articulation?

.An articulation, or joint is usually formed of fibrous connective tissue and cartilage.

From week 1 theory

Question 22

Further reading?

Answer 22

Further reading?

E-book on wuc library

.Chapter 4: the skeletal system in anatomy and physiology of farm animals (fails and magee, 2018)

-functions of bones
-terminology
-classification of bones according to gross appearance

From week 1 theory

Question 23

Body movement?

Answer 23

Body movement?

.Body movements happen when muscles contract across joints, moving one bone towards another.

From week 1 theory bones video on moodle

Question 24

Joint types?

Answer 24

Joint types

3 Types;

-Fibrous joints - connect bones with dense fibrous connective tissue. No joint cavity. They don’t move e.g in skull.

-Cartilaginous joints - connect bones with cartilage. Don’t move very much. No joint cavity. 2 types - synchondroses and symphyses.

-Synovial joints - freely moveable.
6 special features;

.Articular cartilage that covers the opposing bone surfaces

.Band-like ligaments

.A joint cavity filled with fluid

.Synovial fluid lubricant (acts like grease on a hinge).

.A fibrous joint capsule

from week 1 theory Bones video on moodle

Question 25

How much joints can move

Answer 25

How much joints can move .Synarthroses - non-moving joints e.g surface of skull. .Amphiarthroses - partly-moving joints e.g. pelvic area. .Diarthroses - fully movable joints e.g. limbs from week 1 theory Bones video on moodle

Question 26

Synovial joints?

Answer 26

Synovial joints? Structure Types; .Plane joint - unite bones using cartilage (they use gliding movements) .Hinge - uniaxial movement .Condylar - biaxial movement .Pivot - uniaxial movement .Ball and socket - multiaxial movement (rotational movement) the more flexible a joint is, the more unstable and fragile it is. .Saddle - biaxial movement e.g hands and feet. from bones video on moodle week 1 theory

Question 27

Identify the scientific anatomical names?

Answer 27

Identify the scientific anatomical names? 1. Fetlock = metacarpophalangeal and metatarsophalangeal joints 2. Long Pastern = Proximal phalanx 3. Pedal bone = distal phalanx 4. Hock = Tarsus Joint From week 1 practical sheet

Question 28

Identify the layman’s terms

Answer 28

Identify the layman’s terms 1. Middle phalanx = short pastern 2. Metacarpophalangeal joint = fetlock 3. Mandible = lower jaw 4. 3rd Metatarsal bone = cannon bone from week 1 practical sheet

Question 29

Give definitions for the following anatomical terms:

Answer 29

Give definitions for the following anatomical terms: 1. Proximal = situated nearer to the point of attachment 2. Distal = situated away from the point of attachment 3. Medial = situated near the median plane of the body or the midline of an organ 4. Lateral = away from the midline of the body (side) 5. Dorsal = the back or upper side of an organism or parts of an organism 6. Ventral = bottom half and include the chest, abdomen, shins, palms, and soles 7. Cranial = towards the head 8. Caudal = towards the tail from week 1 practical sheet

Question 30

Give an example of each of the following in the equine skeleton

Answer 30

Give an example of each of the following in the equine skeleton • A long bone = femur • A short bone = carpal bone • A flat bone = scapula • An irregular bone = pelvic bone • A sesamoid bone = there are two in the horse. Proximal are found at the back of the fetlock or metacarpophalangeal and metatarsophalangeal joints and the distal sesamoid bone (navicular bone) is behind the pedal bone. From week 1 practical sheet

Question 31

2nd, 3rd, 4th metacarpal and tarsal bones are

Answer 31

2nd, 3rd, 4th metacarpal and metatarsal bones are 2nd and 4th = splint bones 3rd = Cannon bone From week 1 practical sheet

Question 32

Stifle joint

Answer 32

Stifle joint .Patella bone (kneecap) infront of it

Question 33

Skeletal structures on a horse for exam

Answer 33

Skeletal structures on a horse for exam • Cranium • Mandible • Cervical vertebrae (first and last vertebrae) • Thoracic vertebrae (first and last vertebrae) • Lumbar vertebrae (first and last vertebrae) • Sacral vertebrae (first and last vertebrae) • Caudal vertebrae (first and last vertebrae) • Scapula • Humerus • Sternum • Elbow joint • Radius • Ulna • Carpus • 2nd, 3rd 4th Metacarpal bones • Metacarpophalangeal joint • Proximal sesamoid bones • Proximal phalanx • Middle phalanx • Distal phalanx • Distal sesamoid bone (navicular bone) • 1st -18th rib • Ilium = part of hip bone • Tuber ischium = part of pelvis • Tuber coxae = part of pelvis • Tuber sacrale = part of pelvis • Hip joint • Femur • Patella • Stifle • Fibula • Tibia • Tarsus • 2nd, 3rd , 4th Metatarsal bone From week 1 practical sheet

Question 34

Muscle Function

Answer 34

Muscle Function 1. Produce movement 2. Maintain posture 3. Stabilise joints 4. Control cavity pressures 5. Maintain body temperature 6. Energy Storage 7. Control entrance and exits to body From week 2 lecture

Question 35

Muscle Types

Answer 35

Muscle Types .Smooth .Cardiac .Skeletal From week 2 lecture

Question 36

Smooth Muscle

Answer 36

Smooth Muscle AKA: .Nonstriated .Involuntary muscle Surrounds: .Blood Vessels .Digestive tract .Urinary system .Reproductive system .Respiratory system .Involuntary movement From week 2 lecture

Question 37

Cardiac Muscle

Answer 37

Cardiac Muscle Composed of cardiac muscle cells: .Cardiomyocytes/Cardiocytes .Contracts without nervous stimulation .Striated .Fatigue resistant  From week 2 lecture

Question 38

Skeletal Muscle

Answer 38

Skeletal Muscle .Striated .Voluntary control .Movement  From week 2 lecture

Question 39

Skeletal Muscle Gross structure

Answer 39

Skeletal Muscle Gross structure .Origin - Least moveable .Body - Contracts .Insertion - Moveable From week 2 lecture

Question 40

Basic Structure of Skeletal Muscle

Answer 40

Basic Structure of Skeletal Muscle Belly: .Many muscle cells .Connective tissue between muscle fibres .Nerves throughout .Photo on laptop From week 2 lecture

Question 41

Skeletal Muscle Organisational Hierarchy

Answer 41

Skeletal Muscle Organisational Hierarchy .Skeletal muscles have a hierarchical structure .The muscle (organ) is composed of fascicles .Fascicles are composed of fibres  From week 2 lecture

Question 42

Skeletal Muscle Fibres

Answer 42

Skeletal Muscle Fibres .Long, multinucleated cell .Visible striations .Sarcolemma - Tubular sheath which envelops the fibres of skeletal muscles. .Myofibrils - Elongated protein strands with thick and thin filaments From week 2 lecture

Question 43

Skeletal Organisational Hierarchy

Answer 43

Skeletal Organisational Hierarchy .Fibres are composed of myofibrils  - Arranged in parallel .Myofibrils are composed of sarcomeres  - Arranged end to end .Sarcomeres are the functional unit of the muscle cell from week 2 lecture

Question 44

Skeletal Muscle Tissues

Answer 44

Skeletal Muscle Tissues Three connective tissue layers; .Epimysium .Perimysium .Endomysium From week 2 lecture

Question 45

Skeletal Muscle – fibre alignment

Answer 45

Skeletal Muscle – fibre alignment .Parallel – ‘strap muscle’ - Greatest potential for muscle shortening - Relatively weak .Pennate/penniform - Increased power - Less distance to contract - Unipennate - Bipennate - Multipennate  From week 2 lecture

Question 46

Skeletal Myofilaments

Answer 46

Skeletal Myofilaments .Actin - Thin filaments - Double helix - Myosin binding site .Myosin - Thick filaments - Multiple chains - Globular heads - Bind to Actin Myofilaments don’t shorten, simply slide over each other From week 2 lecture

Question 47

The Sarcomere

Answer 47

The Sarcomere .Is the contractile unit of muscle .Muscle contracts (shortens) .Then relaxes (lengthens) From week 2 lecture

Question 48

Muscle contraction

Answer 48

Muscle contraction .Rest - Thick and thin filaments do not overlap completely .Contraction - Length of sarcomere is reduced - A bands don’t change length - I bands shorten - H zone disappears .Sliding filament theory - Thick and thin filaments don’t change shape - Degree of overlap increases .Myofibril: A cylindrical organelle running the length of the muscle fibre, containing Actin and Myosin filaments. .Sarcomere: The functional unit of the Myofibril, divided into I, A and H bands. .Actin: A thin, contractile protein filament, containing 'active' or 'binding' sites. .Myosin: A thick, contractile protein filament, with protrusions known as Myosin Heads. .Tropomyosin: An actin-binding protein which regulates muscle contraction. .Troponin: A complex of three proteins, attached to Tropomyosin. .Sarcoplasmic Reticulum: A specialised type of smooth ER that regulates the calcium ion concentration in the cytoplasm of striated muscle cells. From week 2 lecture

Question 49

Tropomyosin and troponin

Answer 49

Tropomyosin and troponin .Tropomyosin - Rod shaped protein - Regulatory protein in thin filament - Blocks actin’s active sites .Troponin - Helps position tropomyosin to actin - Binds calcium ions .Both help control myosin – actin interactions From week 2 lecture

Question 50

Muscle contraction

Answer 50

Muscle contraction Step 1: A nervous impulse arrives at the neuromuscular junction, which causes a release of a chemical called Acetylcholine. Acetylcholine causes the depolarisation of the end-plate, causing calcium ions (Ca2+) to be released from the sarcoplasmic reticulum into the sarcoplasm. The presence of Acetylcholine causes the depolarisation of the motor end plate which travels throughout the muscle by the transverse (T) tubules, causing Calcium (Ca+) to be released from the sarcoplasmic reticulum within the muscle fibre into the sarcoplasm of the muscle fibre. Step 2: In the presence of high concentrations of Ca2+, the Ca2+ binds to Troponin, changing its shape and so moving Tropomyosin from the active site of the Actin. The Myosin filaments can now attach to the Actin, forming a cross-bridge. In order for myosin filaments to be able to attach to the actin, they need to be activated. This happens when a molecule of ATP binds to the myosin head. This is hydrolysed into ADP and inorganic phosphate. The energy from this reaction lifts the myosin head into the cocked position to form a cross-bridge.  Step 3: The breakdown of ATP releases energy which enables the Myosin to pull the Actin filaments inwards and so shortening the muscle. The contraction of myosin's S1 region is called the power stroke. The power stroke occurs when the ADP and inorganic phosphate molecules are released.  This occurs along the entire length of every myofibril in the muscle cell. Step 4 & 5: The Myosin detaches from the Actin and the cross-bridge is broken when an ATP molecule binds to the Myosin head. When the ATP is then broken down the Myosin head can again attach to an Actin binding site further along the Actin filament and repeat the 'power stroke'.  Freom week 2 lecture notes

Question 51

Sliding filament theory

Answer 51

Sliding filament theory .Interaction between Actin and Myosin molecules .Myosin head centre for reactions - Binding to and hydrolysing ATP to ADP .Energised Myosin binds to Actin forming cross bridge .What causes filaments to slide? - Attachment myosin head to binding sites on thin filaments and sliding begins. - Each cross bridge attaches and detaches several times during contraction, generating tension that helps to pull the thin filaments toward the centre of the sarcomere. - As this occurs simultaneously in sarcomeres throughout muscle cell, cell shortens. .Based on the interaction of the actin & myosin molecules that make up the thick & thin filaments Myosin consists of a long fibrous tail region with a globular ‘head’ sticking off to the side The tail is where the individual myosin molecules join together to form the thick filament The myosin head is the centre for the reactions that power muscle contractions It does this by binding to & hydrolysing ATP to ADP with the resultant release of energy Energised myosin binds to a specific site on actin forming a cross-bridge From week 2 lecture

Question 52

Sliding filament theory steps

Answer 52

Sliding filament theory steps .Release stored energy .Relaxation myosin head .Change of angle of attachment .Myosin bends in on itself .Tension on actin filament .Pull actin filament to centre sacromere The stored energy is released which causes the myosin head to relax. This relaxation changes the angle of attachment of the myosin head to the myosin tail. As the myosin bends in on itself, it exerts tension on the thin actin filament to which it is bound. Hence it pulls the thin filament to the centre of the sarcomere. The bond between the low energy myosin and the actin is broken when a new molecule of ATP binds to the myosin head. The cycle repeats and the newly energised head can now contract again. From week 2 lecture

Question 53

Sliding filament theory

Answer 53

Sliding filament theory .Thick filament – approx 350 heads .Form and re-form 5 cross bridges / sec .NB: Myofilaments don’t shorten .It can now attach to a new binding site on another actin molecule farther along the thin filament Each thick filament has approximately 350 heads Each head can form and re-form about 5 cross bridges per second, driving filaments past each other A muscle cell will only store enough ATP for a few contractions Some myosin heads will always be in touch with actin to avoid thin filaments sliding backward Myofilaments don’t shorten, simply slide over each other Week 2 lecture

Question 54

Functional Classification

Answer 54

Functional Classification .Flexors - aims to close a joint angle .Extensors - aims to open a joint angle .Adductors - towards midline .Abductors - away from midline .Agonist – prime mover, provides major force .Antagonist – works against another muscle, e.g. bicep and tricep .Synergist – helps support movement e.g. brachialis to biceps brachii in flexing elbow From week 2 lecture video part 1

Question 55

Types of Contraction

Answer 55

Types of Contraction .Isotonic - Concentric - Eccentric - Antagonistic against larger force .Isometric - Stationary contraction against resistance .Concentric - During concentric contraction, the biceps shortens and pulls the weight towards the shoulder joint. .Two situations can lead to an eccentric movement from this point; - The biceps is loaded with a force greater than the one it produced during concentric contraction (e.g. more weight added to the dumbbell). - You intentionally start relaxing your biceps. .In both situations, the force produced by the muscle is insufficient to hold the biceps brachii in a fully contracted state. This will cause the muscle fibers to forcefully lengthen, which is called eccentric contraction. From week 2 lecture From week 2 lecture notes

Question 56

Bicep

Answer 56

Bicep .Aims to flex the elbow. .Brachial policy helps to support the bicep. From A&P Muscle Tissue Week 2 (Part 1) video

Question 57

Tricep

Answer 57

Tricep .Aims to extend the elbow From A&P Muscle Tissue Week 2 (Part 1) Video

Question 58

Skeletal muscle insertion

Answer 58

Skeletal muscle insertion .Some muscles share the same insertion site but have their own origins. From A&P Muscle Tissue Week 2 (Part 1) Video

Question 59

Skeletal muscle origins

Answer 59

Skeletal muscle origin .Is the part where the nervous impulse starts and brings the insertion closer to the origin during a contraction. From A&P Muscle Tissue Week 2 (Part 1) Video

Question 60

Skeletal muscle terminology

Answer 60

Skeletal muscle terminology .Hypertrophy - a large linning of the fibres. .Hyperplasia - increase in amount of fibres present From A&P Muscle Tissue Week 2 (Part 1) Video

Question 61

ATP?

Answer 61

ATP .Provides energy for contraction .Decrease in available ATP causes fatigue. From week 2 lecture video part 2

Question 62

Tone?

Answer 62

Tone? .Tension within muscles at rest . Involuntary .Prevents paralysis with nervous systems help. From week 2 lecture video part 2

Question 63

Smooth muscle?

Answer 63

Smooth muscle? .No striations .Fusion form cell - it's spinal shape helps it perform peristalsis .Central nucleus .Nerve type - mechanical and electrical .Ca2+ needed for contraction and relaxation. .Smooth muscle cells - respond to stimuli with relaxation or contractions. starts from mechanical stimuli (stretch) e.g. food. From week 2 lecture video part 2

Question 64

Cardiac muscle

Answer 64

Cardiac muscle .Striations and lines .Intercalated discs .Electrical transmission .Loads of ATP production .Excitation and contraction .Calcium needed for contraction From week 2 lecture video part 2

Question 65

Extensors of the shoulder

Answer 65

Extensors of the shoulder .Brachiocephalicus muscle - Is the extensor of the shoulder. It raises and advances the shoulder. .Supraspinatus muscle - May assist in extending the shoulder but acts chiefly as a stabilising muscle of the shoulder joint. From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 131.

Question 66

Flexors of the shoulder

Answer 66

Flexors of the shoulder .Latissimus dorsi - Very strong flexor of the shoulder. .Infraspinatus - may flex, abduct and outwardly rotate the shoulder. .Deltoideus - flexor and abductor of the shoulder joint. From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 132.

Question 67

Adductors of the shoulder

Answer 67

Adductors of the shoulder .Pectoral muscles - strong adductors of the forlimbs From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 132.

Question 68

Extensor of the elbow

Answer 68

Extensor of the elbow .Tricep brachii - strongest extensor of the elbow. Can also flex the shoulder. From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 132.

Question 69

Flexors of the elbow

Answer 69

Flexors of the elbow .Bicep brachii - chief action flexion of the elbow but can extend it also. .Brachialis - strictly a flexor of the elbow From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 133.

Question 70

Extensors of the carpus

Answer 70

Extensors of the carpus .Extensor carpi radialis - largest extensor of the carpus .Extensor carpi ulnaris (Ulnaris lateralis) - can also flex the carpus From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 133.

Question 71

Flexors of the carpus

Answer 71

Flexors of the carpus .Flexor carpi radialis .Flexor carpi ulnaris From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 134.

Question 72

Extensors tendon of the digit

Answer 72

Extensors tendon of the digit .Digital extensor muscle (extensor digitorium communis) - extensor of all joints of the digit including the metacarpophalangeal joint (fetlock) and may assist in extending the carpus and in flexion of the elbow. From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 134.

Question 73

Flexors tendon of the digit

Answer 73

Flexors tendon of the digit .Deep digital flexor (flexor digitorum profundus) From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 135.

Question 74

suspensory ligament

Answer 74

Suspensory ligament .Connective tissue instead of muscle like most animals. Origin from the palmar aspect of the proximal metacarpus and insert on the proximal sesamoid bones. .It supports the metacarpophalangeal joint. From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 135.

Question 75

extensors of the hip

Answer 75

extensors of the hip .Biceps femoris .Semimembranous .Middle gluteal muscle From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 141.

Question 76

flexors of the hip

Answer 76

flexors of the hip .Rectus femoris .Iliacus .Psoas major .Sartorius From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 141.

Question 77

extensors of the stifle

Answer 77

extensors of the stifle .quadricep femoris - insert on the patella and are the primary extensor of the stifle. includes rectus femoris as one of the heads etc From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 142.

Question 78

flexors of the stifle

Answer 78

flexors of the stifle .Bicep femoris .semitendinosus .semimembranosus From Fails and Magee (2018) 'Anatomy and Physiology of Farm Animals. Chapter 7, page 142

Question 79

Tissue types

Answer 79

Tissue types .Epithelial - Covers & protects body from environment .Nervous - Controls body activities .Muscle - Movement by contraction .Connective - Supports & holds structures together From week 3 lecture

Question 80

Connective tissues types

Answer 80

Connective tissues types .Skin .Blood .Bone .Tendon - take longer to heal as poor blood suppy .Ligament - take longer to heal as poor blood suppy .Cartilage - doesn't heal as has no blood supply .Fascia - under skin and around organs From week 3 lecture

Question 81

Classification of Connective Tissue

Answer 81

Classification of Connective Tissue .Embryonic .Specialised .Proper -Loose irregular -Dense regular -Dense irregular From week 3 lecture

Question 82

Structure of Connective Tissue (CT)

Answer 82

Structure of Connective Tissue (CT) .A supporting tissue with a wide range of forms, roles and functions. .Composed of: -Cells -Fibres - extracellular matrix -Ground substance- extracellular matrix .Most fixed cells - Tend to synthesise (make) and maintain the extracellular matrix (ECM) in which they sit. - Most common connective tissue cell = fibroblast (immature or “precursor” cell) - Also: Chondroblasts, osteoblasts, adipocytes (fat cells) .Also migrating immune cells -e.g. mast cells, macrophages, plasma cells From week 3 lecture

Question 83

Structure of connective tissue Fibres

Answer 83

Structure of connective tissue Fibres 1) Collagen fibres (most abundant protein in body) -Provide tensile strength -Produced by fibroblasts -Form bundles (3 types) 2) Elastic fibres -Provide stretching and recoil -Form cross-linked networks 3) Reticular fibres -Provide a supporting framework for organs From week 3 lecture

Question 84

Structure of Connective tissue Ground Substance

Answer 84

Structure of Connective tissue Ground Substance .Semi-fluid gel “glue”, Colourless and transparent -Carbohydrate (sugar) molecules called “polysaccharides” -Form chains called “glycosaminoglycans” = GAG chains -GAG chains attach to core protein, forming “proteoglycans” - looks like a hair brush. -These bristley structures knot together forming “glycoproteins”. Functions: -Traps water, which then resists compression (think jelly!) -Also provides gel/fluid for nutrients to diffuse through From week 3 lecture

Question 85

The Extracellular Matrix = Ground Substance + Fibre

Answer 85

The Extracellular Matrix = Ground Substance + Fibre Ground Substance .Glycosaminoglycans (GAGs) .Proteoglycans .Glycoproteins Role of ground substance: -Diffusion -Nutrients -Resistance to compression Fibres .Collagenous (white) .Elastic (Yellow) .Reticular Role of Fibre: -Tensile Strength -Elastic Recoil -Defined Structure From week 3 lecture

Question 86

Dense Regular Connective Tissue

Answer 86

Dense Regular Connective Tissue .Regular collagen bundles .Tightly packed cells .High tensile strength .Protection mechanisms are common From week 3 lecture

Question 87

Tendons (Dense Regular connective Tissue)

Answer 87

Tendons (Dense Regular connective Tissue) .Connect muscles to bone .High tensile strength .Taut when muscle contracts .Slackens during muscle relaxation .Poor blood supply From week 3 lecture

Question 88

Ligaments (Dense Regular connective Tissue)

Answer 88

Ligaments (Dense Regular connective Tissue) .Connect bone to bone .High tensile strength .Always remains taut! .Poor blood supply .Less elastin than tendons .Microstructure similar to tendons .Cells known as desmocytes. .Cellular component greater than tendons From week 3 lecture

Question 89

Bone Tissue (Specialised Connective tissue)

Answer 89

Bone Tissue (Specialised Connective tissue) .Calcium carbonate and calcium phosphate (inorganic) - 60% of bone weight in adults. - These salts are deposited in a matrix of collagen fibers (organic) - Salt crystals give bone hardness and rigidity. Collagen fibers give bone toughness. From week 3 lecture

Question 90

Cartilage (Specialised Connective tissue)

Answer 90

Cartilage (Specialised Connective tissue) Types; .Hyaline, elastic, fibrous .Highly specialised connective tissue .Single cell type – Chondrocyte .Secretes a rubbery matrix .Ground substance – chondroitin From week 3 lecture

Question 91

Hyaline Cartilage

Answer 91

Hyaline Cartilage .Most common .Synovial joint surfaces (articulating surfaces) .Blueish white appearance .AKA articular cartilage .Nose, ears, trachea etc From week 3 lecture

Question 92

Joints function

Answer 92

Joints function .Articulations between adjacent bones that enable movement From week 3 lecture

Question 93

Joint Structural Classification

Answer 93

joint Structural Classification .Fibrous joints - dense connective tissue .Cartilaginous joints -Cartilage union .Synovial joints -Fluid filled cavity between bones From week 3 lecture

Question 94

Joint Functional Classification

Answer 94

Joint Functional Classification .Synarthroses -NO joint movement Amphiarthroses -Small amount of joint movement .Diarthroses Wide range of joint movement (Monoaxial, biaxial, triaxial) From week 3 lecture

Question 95

Fibrous joints

Answer 95

Fibrous joints .Bones joined by fibrous tissue .3 types; .Sutures – overlapping or interlocking .Syndesmoses – connected by fibrous tissue .Gomphoses – peg-in-socket .Sutures & Gomphoses - Immovable joints. Junctions between bones filled by a small amount of fibrous connective tissue. .Syndesmoses - amphiarthroses, fibrous connections, not designed for mobility. From week 3 lecture

Question 96

Cartilaginous joints

Answer 96

Cartilaginous joints .Bones united by cartilage .Most slightly movable 2 types: .Synchondroses - sites of bone growth. Connected by hyaline cartilage membrane. Mostly temporary - Epiphyseal plates of developing bones. Some permanent. .Symphyses - articular surfaces covered with fibrocartilage. Fibrocartilage connection. Shock absorption. Pelvic symphysis and intervertebral joints. From week 3 lecture

Question 97

Synovial joints

Answer 97

Synovial joints .Articular cartilage .Joint cavity .Joint capsule .Synovial fluid .Reinforcing ligaments .Inner membrane secretes synovial fluid .Joint capsule fibrous and continuous with periosteum - Contributes to joint stability - Composed of collagen - Highly vascularised - Afferent pain receptors From week 3 lecture

Question 98

Types of synovial joints

Answer 98

Types of synovial joints .Hinge = Folding movement - metacarpophalangeal joint, Ginglymus joint. .Plane / gliding = Sliding movement - intercarpal joints, Arthrodial joint. .Pivot = Monoaxial, Rotation movement - atlantoaxial joint. .Condyloid = Biaxial movement - antebrachiocarpal joint, Knuckle shaped surface. .Saddle .Ball and socket = Wide ranging, Triaxial, multidirectional - coxofemoral. From week 3 lecture

Question 99

Synovial Joints stability maintained by

Answer 99

Synovial Joints stability maintained by .Shape .↑ surface area .Surrounding muscle .Intra articular ligaments .Lateral & medial collateral ligaments .Negative hydrostatic pressure. From week 3 lecture

Question 100

Ligaments

Answer 100

Ligaments .Ligaments - Capsular, Extra-capsular, Intra-capsular .Fat pads .Bursae Why are ligaments in / around a joint? -Tough and unyielding -No resistance to normal joint movement -Prevent excessive / unnatural joint movement -Become taught at normal limit of ROM -Cross-fibre structure limits of elasticity From week 3 lecture

Question 101

Stifle Joint

Answer 101

Stifle Joint .One of the most complex joints in the horse. Ability to ‘lock’ allowing one limb to rest. .Surrounded by - ligaments to secure and stabilise. .Menisci (fibrocartilage disks) .Femorotibial joint - Ginglymus joint - Uniaxial. Slight abduction/adduction and rotation – how is movement controlled? .Femoropatellar joint - Gliding joint From week 3 lecture

Question 102

Forelimb (Thoracic limb) Joints

Answer 102

Forelimb (Thoracic limb) joints .Shoulder Joint .Elbow Joint .Carpus .MCP Joint .PIP Joint .DIP Joint From week 3 lecture

Question 103

Hindlimb (Pelvic Limb) joints

Answer 103

Hindlimb (Pelvic Limb) joints .Hip Joint .Stifle Joint .Hock Joint .MTP Joint .PIP Joint .DIP Joint From week 3 lecture

Question 104

Scapulohumeral joint

Answer 104

Scapulohumeral joint .Ball and socket/spheroid .All directions, but in the horse mainly flexion and extension with some adduction and abduction From week 3 Joint names, type and function pdf

Question 105

Humeroradial joint

Answer 105

Humeroradial joint  Hinge joint  Flexion and extension From week 3 Joint names, type and function pdf

Question 106

Carpometacarpal joint

Answer 106

Carpometacarpal joint  Composite plane joint  Very little movement From week 3 Joint names, type and function pdf

Question 107

Metacarpophalangeal joint

Answer 107

Metacarpophalangeal joint  Composite hinge joint  Flexion and extension From week 3 Joint names, type and function pdf

Question 108

Proximal intercarpal joint

Answer 108

Proximal intercarpal joint  Composite condylar joint  Flexion and extension From week 3 Joint names, type and function pdf

Question 109

Coxofemoral joint

Answer 109

Coxofemoral joint  Ball and socket/spheroid  All directions, but in the horse mainly flexion and extension with some adduction and abduction From week 3 Joint names, type and function pdf

Question 110

Atlanto-occipital joint

Answer 110

Atlanto-occipital joint  Condylar joint  Flexion and extension: ‘nodding’ From week 3 Joint names, type and function pdf

Question 111

Atlanto-axial joint

Answer 111

Atlanto-axial joint  Pivot joint  Rotational movement From week 3 Joint names, type and function pdf

Question 112

Femoropatellar joint

Answer 112

Femoropatellar joint  Gliding joint  Gliding From week 3 Joint names, type and function pdf

Question 113

 Distal interphalangeal joint/pastern

Answer 113

 Distal interphalangeal joint/pastern  Saddle joint  Flexion and extension From week 3 Joint names, type and function pdf

Question 114

Femorotibial joint

Answer 114

Femorotibial joint  Condylar joint  Flexion and extension, some adduction and abduction From week 3 Joint names, type and function pdf

Question 115

Tarsocrural/tibiotarsal joint

Answer 115

Tarsocrural/tibiotarsal joint  Cochlear joint  Flexion and extension From week 3 Joint names, type and function pdf

Question 116

Tarsometatarsal joint

Answer 116

Tarsometatarsal joint  Composite plane joint  Little movement From week 3 Joint names, type and function pdf

Question 117

Radiocarpal joint

Answer 117

Radiocarpal joint  Composite condylar joint  Flexion and extension From week 3 Joint names, type and function pdf

Question 118

Mesotendon

Answer 118

Mesotendon .Blood vessels, nerves and lymphatic vessels reach the tendon through the mesotedon. From Anatomy & Physiology of Farm Animals, Chapter 6: Joints Figure 6-3 (Fails and Magee, 2018)

Question 119

Hyperextension

Answer 119

Hyperextension .Movement in which the angle between segments is increased beyond 180 degrees (a straight line). .The metacarpal and metatarsals of the horse are hyperextended during normal standing position (physiological hyperextension) .Other joints do not normally hyperextend unless stressed, fatigued or poor conformation. From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 106 (Fails and Magee, 2018)

Question 120

Types of synovial joints

Answer 120

Types of synovial joints .Simple joints - involve only two articulating bones .Composite (compound) joints - include more than two bones within the same joint capsule From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 106 (Fails and Magee, 2018)

Question 121

Scapula

Answer 121

Scapula .The scapula has no true bony connection with the thorax. It is held in place by a num- ber of muscles and ligaments. This type of joint is sometimes called a synsarcasis. From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 108 (Fails and Magee, 2018)

Question 122

Medial patellar ligament

Answer 122

Medial patellar ligament .In the horse, the medial patellar ligament is attached to the medial aspect of the patellar via a large hook-shaped fibro- cartilage. The combined cartilage and tendon create a stout loop that can be locked over the medial ridge of the femo- ral trochlea at will. In this position, the stifle is held in extension with minimal muscular effort; this anatomic arrangement therefore con- tributes to the ability of the horse to stand while sleeping. .Sometimes can become locked (upward fixation of the patella) From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 114 (Fails and Magee, 2018)

Question 123

A dislocation

Answer 123

A dislocation .Also known as a luxation, is a condition in which articular surfaces undergo a significant loss of congruency (less severe dislocations are subluxations). Dislocation of a joint nearly always includes stretching or tearing of ligaments, and if the dislocation is severe enough, the joint capsule also may tear .Because of the excessive stretching or tearing of ligaments, recovery from a dislocation may be less satisfactory and take longer than recovery from a properly treated fracture. From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 117 (Fails and Magee, 2018)

Question 124

A Sprain

Answer 124

A Sprain .Is a condition in which the ligaments are stretched, but the joint is not persistently subluxated following removal of the displacing force. .The term strain is sometimes used in place of sprain, although strain is used more frequently to denote excessive stretching of a muscle or tendon. Although a considerable amount of swelling may follow a sprain, the affected joint usually recovers spontaneously if rested adequately. From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 117 (Fails and Magee, 2018)

Question 125

Joint infection

Answer 125

Joint infection .Lacerations such as those from barbed wire may extend into a joint cavity, causing loss of synovial fluid and exposing the interior of the joint to the external environment. .An injury of this nature is serious and may be difficult to treat, The danger is not from the loss of synovial fluid (which is rapidly replaced), but from infection of the joint cavity. Synovial fluid is a good medium for bacterial growth, and the many recesses of most joint cavities make drainage and treatment of an infected joint difficult. There is danger of permanent damage to the articular cartilage from infection. .Puncture wounds to joints may also result from penetration by a sharp object such as a nail, wire, or wood sliver. Such wounds are especially dangerous; since the wound is often not obvious, it usually drains poorly, and the environment into which the bacteria are introduced is fre- quently anaerobic (not exposed to air). In such conditions, a puncture wound can precipitate a particularly severe infection. From Anatomy & Physiology of Farm Animals, Chapter 6: Joints page 117 (Fails and Magee, 2018)

Question 126

Integumentary System

Answer 126

Integumentary System Skin - epithelial and connective tissue. Has a layer of adipose tissue for fat storage. Secretes pheromones during mating season. Hair - keratin version of skin Glands - evaporation of sweat allows the body to cool Horns - keratin version of skin Hooves - keratin version of skin Claws - keratin version of skin From week 4 lecture

Question 127

Integumentary System - Role

Answer 127

Integumentary System - Role Protective barrier -Reduced water loss -Invasion from microbes -Abrasive trauma .Metabolic actions .Excretion of wastes .Thermoregulation .Sensory receptor .Communication From week 4 lecture

Question 128

Thermoregulation

Answer 128

Thermoregulation Hot -vasodilation - arterioles dilate so more blood enteres skin capillaries and heat is lost -sweating - sudorific glands secrete sweat which removes heat -pilorelaxation - hairs flatten -stretching out - by opening up Cold -Vasoconstriction - arterioles get smaller to reduce blood going to skin. Keeping core warm. -shivering - rapid contraction and relaxation of skeletal muscles this generates body heat. Heat produced by respiration. -piloerection - Hairs stand up on skin to trap warm air. -curling up - making yourself smaller so smaller surface area From week 4 lecture

Question 129

Meniscus?

Answer 129

Meniscus? .Pad in-between stifle joint From week 3 lecture

Question 130

Skin layers

Answer 130

Skin layers .Epidermis - stratified squamous epithelial tissue .Dermis .Hypodermis From week 4 lecture

Question 131

Epithelial tissue types

Answer 131

Epithelial tissue types Simple -Simple squamous -Simple Cuboidal Epithelium -Simple Columnar Epithelium Stratified -Stratified Squamous Epithelium -Stratified cuboidal -Pseudostratified columnar Transitional .Can stretch such as bladder From week 4 lecture

Question 132

Epidermis stratum types

Answer 132

Epidermis Stratum types .Stratum corneum - outer layer -Dead, flattened cells -Filled with keratin -Continuously replaced -Prevents evaporation -Absorbs water .Stratum lucidum -Variably present -Stains poorly -Dead, flattened keratinocytes .Stratum granulosum -Spindle shaped cells -Basophilic keratohyalin granules .Stratum spinosum -Desmosomes -Keratinisation site .Stratum basale - Under layer of epidermis, connect epidermis to dermis. -Undifferentiated -Mitotically active - mitosis happens here -Cuboidal or columnar cells -Closely applied to underlying dermis From week 4 lecture

Question 133

Epidermis

Answer 133

Epidermis .Outer layer .Avascular .Stratified squamous epithelium .Very few nerve endings From week 4 lecture

Question 134

Dermis

Answer 134

dermis .Functional part of skin Contains; .Arteries .Veins .Capillaries .Lymphatics .Sympathetic nerves -Motor innervation -Vessels -Glands -Arrector pili muscle cells .Sensory nerves From week 4 lecture

Question 135

Dermis layers

Answer 135

Dermis layers .Papillary layer - upper layer .Reticular layer - lower layer 80% of dermis From week 4 lecture

Question 136

Hypodermis

Answer 136

Hypodermis .Superficial fasicia .Subcutaneous .Areolar/loose connective tissue .Panniculus adiposus -Species dependent distribution and abundance .Insulation .Aiding in the anchoring of skin .Protection against trauma .Movement of skin w/o tearing .Storage of fat, water, salt From week 4 lecture

Question 137

Hair

Answer 137

Hair .Wiskers sensitive to touch Parts; .Hair follicle -Dermal papilla -Hair bulb -Double layered root sheath -Internal epithelial root sheath -External epithelial root sheath -Sebaceous glands Contains; .Medulla - central cavity .Cortex -Several layers of cornified cells -Spread of melanin determines colour .Cuticle .Compressed keratinised epithelial cells .Arrector pili muscles -Around hair -Smooth muscle fibres -Sympathetic innervation From week 4 lecture

Question 138

Skin Glands

Answer 138

Skin Glands .Sebaceous glands -Holocrine – releases sebum -Derived from external root sheath -Empty into hair follicle -Arrector pili contraction compresses glands .Sudoriferous glands -Sweat glands -Tubular/eccrine -Entire body .Only horses sweat readily - the albumin in horses' sweat makes it foamy. -Sensitive to circulating adrenalin -Rich in protein -Hypertonic From week 4 lecture

Question 139

Modified Epidermis

Answer 139

Modified Epidermis .Hooves .Horn From week 4 lecture

Question 140

Hoof

Answer 140

Hoof .Hoof continuous with the epidermis at coronary band .Exterior protects and dissipates concussion .Hoof epidermis forms horn -Tubules -Intertubular horn -Lamellae Hoof capsule .Protects the distal end of the limb .Keratinized epithelium over modified dermis .Wall, periople, sole and frog Hoof wall .Grows down from the coronary band .Vertically arranged horn tubules surrounded by intertubular horn Hoof Sole .Tubular horn .Non weight bearing .33% water Hoof Frog .Keratinised stratified squamous epithelium .Papillae slightly longer than solar corium .Softer tissue and 50% softer then other sole tissue From week 4 lecture

Question 141

Hoof corium

Answer 141

Hoof corium .Corium (dermal layer) contains blood vessels and nerves, sensitive .Nourishment and attachment for epidermis .Corium -Perioplic -Coronary -Lamellar -Frog -Sole From week 4 lecture

Question 142

Hoof Laminar junction

Answer 142

Hoof Laminar junction .Primary and secondary dermal & epidermal laminae .600 primary laminae .Each primary has 150 – 200 secondary laminae .Proximodistal orientation From week 4 lecture

Question 143

Smooth Endoplasmic Reticulum Definition

Answer 143

Smooth Endoplasmic Reticulum Definition .It is a subset of the endomembrane system of the endoplasmic reticulum. Its main functions are the synthesis of lipids, steroid hormones, the detoxification of harmful metabolic byproducts and the storage and metabolism of calcium ions within the cell. .Smooth ER is prominent in cells of the liver that process harmful chemicals, in cells of the endocrine system such as those in the adrenals that produce steroid hormones, and in excitable cells such as neurons and muscle cells that use Ca2+ signaling. From week 4 https://biologydictionary.net/smooth-endoplasmic-reticulum/

Question 144

Rough Endoplasmic Reticulum

Answer 144

Rough Endoplasmic Reticulum .This organelle is primarily concerned with the synthesis, folding and modification of proteins, especially those that need to be delivered to different organelles within the cell, or secreted from the cell. .The ER can be morphologically divided into two structures–cisternae and sheets. From week 4 https://biologydictionary.net/rough-endoplasmic-reticulum/

Question 145

Mitochondria

Answer 145

Mitochondria .Organelles within eukaryotic cells that produce adenosine triphosphate (ATP), the main energy molecule used by the cell. For this reason, the mitochondrion is sometimes referred to as “the powerhouse of the cell”. .Mitochondria produce ATP through process of cellular respiration—specifically, aerobic respiration, which requires oxygen. The citric acid cycle, or Krebs cycle, takes place in the mitochondria. This cycle involves the oxidation of pyruvate, which comes from glucose, to form the molecule acetyl-CoA. Acetyl-CoA is in turn oxidized and ATP is produced. From week 4 https://biologydictionary.net/mitochondria/

Question 146

Cell Nucleus

Answer 146

Cell Nucleus .The cell nucleus is responsible for producing two main products to support the efforts of each cell. The first, messenger RNA, or mRNA, is the product of transposing a gene coding for a specific protein from the DNA structure to the RNA structure. This shorter mRNA strand can exit the nucleus and enter the cytoplasm. When a ribosome picks up this mRNA, it will translate this mRNA into the language of proteins and create a long strand of amino acids. This strand will then be folded into a functional protein, which may serve one of a thousand different roles. From week 4 https://biologydictionary.net/cell-nucleus/

Question 147

Centriole

Answer 147

Centriole .A centriole is a small structure made of microtubules which exists as part of the centrosome, which helps organize microtubules in the body. A centriole is the main unit that creates and anchors microtubules in the cell. .During normal cell functions, motor proteins attach to both the microtubules and an item to be transported. The motor proteins crawl along the microtubules, dragging whatever substance or compartment with them. Not all cells contain centrioles, and other methods are used for creating microtubules. .A centriole is made of nine sets of microtubules, each in groups of three known as triplet microtubules. From week 4 https://biologydictionary.net/centriole/

Question 148

Ribosomes

Answer 148

Ribosomes .Ribosomes are ‘protein factories’ and are the site of protein production in cells. These organelles ‘read’ the instructions stored in DNA molecules and use these to assemble polypeptide chains (long chains of amino acids). These are then folded into the secondary, tertiary, and quaternary structures that allow the protein to fulfill its specific function. From week 4 https://biologydictionary.net/cell-organelles-plants-and-animals/

Question 149

Golgi Apparatus

Answer 149

Golgi Apparatus .Newly synthesized proteins are sent to the Golgi apparatus after they leave the rough ER. The Golgi apparatus (a series of flattened, membrane-bound sacs) is like the ‘mailroom’ of the cell and packages new proteins into tiny, membrane-bound vesicles for distribution. Once packaged, the proteins are sent off to the outer cell membrane, where they either leave the cell or become part of the lipid bilayer. From week 4 https://biologydictionary.net/cell-organelles-plants-and-animals/

Question 150

Vacuoles

Answer 150

Vacuoles Some animal cells contain vacuoles, which are typically small organelles used to transport substances in and out of the cell. They are often used to contain and dispose of waste products. From week 4 https://biologydictionary.net/cell-organelles-plants-and-animals/

Question 151

Lysosomes

Answer 151

Lysosomes .Lysosomes are spherical organelles filled with digestive enzymes, and they have several functions within cells. They are used to break down old or surplus cell parts, destroy invading pathogens, and also play a key role in programmed cell death (AKA apoptosis). From week 4 https://biologydictionary.net/cell-organelles-plants-and-animals/

Question 152

The Cell Membrane

Answer 152

The Cell Membrane The main function of the cell membrane is to create a physical barrier between the interior of the cell and the external environment. However, it also controls the movement of substances in and out of the cell. The cell membrane consists of a semipermeable lipid bilayer that is studded with channels and receptors to allow certain molecules through. Therefore, the cell membrane helps to keep toxins out of the cell, while ensuring that valuable resources (such as nutrients) can enter. It also allows waste and metabolic products to leave the cell. From week 4 https://biologydictionary.net/cell-organelles-plants-and-animals/

Question 153

Cytoplasm

Answer 153

Cytoplasm The cytoplasm is a jelly-like substance that fills up the spaces inside cells. It cushions and protects the organelles, and also gives cells their shape. The cytoplasm is composed of water, salts, and other molecules required for cellular processes. From week 4 https://biologydictionary.net/cell-organelles-plants-and-animals/

Question 154

Eukaryotic cells

Answer 154

Eukaryotic cells .Animals, plants, fungi and protoctists are all constructed of eukaryotic cells .Ranging from single to multicellular organisms From week 4 further reading https://www.nottingham.ac.uk/nursing/sonet/rlos/bioproc/prokaryotes/4.html

Question 155

Eukaryotes: examples

Answer 155

Eukaryotes: examples .An amoeba - is a water and soil dwelling unicellular protozoan. .Fungi - include your typical mushrooms, but also include the likes of Tinea pedis, which causes Athlete's Foot. .Plants - range from single celled algae and the most delicate of flowers, to giant trees thousands of years old. The diversity of animals includes: insects, fish, amphibians, reptiles, birds and mammals. From week 4 further reading https://www.nottingham.ac.uk/nursing/sonet/rlos/bioproc/prokaryotes/4.html

Question 156

What is the Nervous System?

Answer 156

What is the Nervous System? .‘the network of nerve cells and fibres which transmits nerve impulses between parts of the body’ Functions .Collects information - Internal - External .Regulates movement .Regulates secretions from glands (endocrine system) .Consciousness From week 5 lecture

Question 157

Anatomy of the Nervous System

Answer 157

Anatomy of the Nervous System .Brain .Spinal cord -Grey matter -White matter .Peripheral nerves .Neuron Central nervous system (CNS) - is separated into central and peripheral nervous system .Brain - the meninges cover brain and spinal cord .Spinal Cord Peripheral nervous system (PNS) - is divided into afferent and efferent nervous systems -Nerves extending from the central axis to the periphery -Cranial nerves -Spinal nerves -Sensory (afferent) nerves From week 5 lecture

Question 158

Nervous system terminology

Answer 158

Nervous system terminology Afferent = bringing info from environment to CNS Efferent = convey info from CNS to environment Somatic = sends info to CNS from outside environment Visceral = sends info to CNS from inside environment Somatic = Voluntary Autonomic = Involuntary Sympathetic = ‘fight or flight’ Parasympathetic = ‘rest and digest’ From week 5 lecture

Question 159

Autonomic nervous system (ANS)

Answer 159

Autonomic nervous system (ANS) .Viscera -Smooth muscle -Cardiac muscle -Some endocrine glands .Sympathetic ‘Fight-or-flight’ .Parasympathetic ‘Rest-and-digest’ .Sensory and motor function From week 5 lecture

Question 160

CNS - (Fore) Brain

Answer 160

CNS - (Fore) Brain Cerebrum/Cerebral Cortex .Two hemispheres -Gyri -Fissure/sulci .Grey matter = cerebral cortex, control .White matter = sensory and motor pathways Parts .Thalamus -Relay centre between cerebrum and brainstem/spinal cord .Epithalamus -Pineal gland - Melatonin -Circadian rhythm -Sleep induction .Hypothalamus -Hypophysis/pituitary gland -Regulates autonomic nervous system -Involved in homeostasis From week 5 lecture

Question 161

Limbic System

Answer 161

Limbic System .Thalamus .Hypothalamus .Frontal lobe .Olfactory lobe .Amygdala .Hippocampus From week 5 lecture

Question 162

CNS – (Mid/Hind) Brain

Answer 162

CNS – (Mid/Hind) Brain .Cerebellum .Brainstem -Medulla, Pons and Midbrain From week 5 lecture

Question 163

CNS - Spinal Cord

Answer 163

CNS - Spinal Cord .Runs from brain stem to lumbar region of the spine .Made up of gray and white matter .Gray matter = more cell bodies .White matter = more myelinated axons .Ascending -Sensory -Originate in spinal cord -Travel to brain -Proprioception -Pain -Touch .Descending -Motor -Originate in higher brain -Travel to spinal cord -Voluntary muscle control From week 5 lecture

Question 164

Reflex Arc

Answer 164

Reflex Arc .Simple reflex -Withdrawal reflex -Circuit of 3 neurons: sensory – inter – motor -Receptors pick up stimulus -Effector organs produce outcome From week 5 lecture

Question 165

Nerve Cells - Neurons

Answer 165

Nerve Cells - Neurons .Functional unit of nervous system .Carrier of electrical messages .Long life .Lack of ability to regenerate .High metabolic rate .Conduct impulses usually in one direction only From week 5 lecture

Question 166

Structure of a Neuron

Answer 166

Structure of a Neuron Cell body (soma) - Biosynthetic centre Dendrite - Input region Axon - Conducting region - Transmits nerve impulses Synapse - Communication Schwann cells - Form myelin sheaths around axon - Myelin acts as insulator Nodes of Ranvier - Where myelin sheaths are interrupted From week 5 lecture

Question 167

Neurons

Answer 167

Neurons .Charged cells .2 major functions -Irritability -Conductivity .Nerve impulse -Altering Na+ and K+ concentration From week 5 lecture

Question 168

Impulse Transduction

Answer 168

Impulse Transduction .Transmission of messages along axon .Impulse is self-propagating .Highly complicated – involves movement of electrically charged particles .Messages travel at >100 m/s From week 5 lecture

Question 169

Polarity

Answer 169

Polarity .Plasma membrane of neuron is polarised – i.e. opposite charges on either side .Negative charge inside .Positive charge outside .Resting potential = -70 mV From week 5 lecture

Question 170

Ion concentration

Answer 170

Ion concentration .Resting nerve cell: - Inside cell: High K+ and low Na+ - Outside cell: opposite .Electrical, chemical or mechanical stimulation causes increase in permeability to Na+ .K+ moves out, Na+ moves in From week 5 lecture

Question 171

Action potential

Answer 171

Action potential Continuous conduction - Stimulus reaches threshold level - result in transmission of action potential (AP) .Saltatory conduction -Myelin sheath insulates against charge -Nodes of Ranvier only part where impulses can transmit -Depolarisation wave passes from one node to the next -Faster than continuous and requires less energy From week 5 lecture

Question 172

Synapses

Answer 172

Synapses .Synapse - Junction between 2 neurons or 1 neurone and an effector .Effector is a gland  neuro-glandular junction .Effector is muscle  neuro-muscular junction .AP cannot cross synapse Stages .Pre-synaptic neuron -Neuron terminating at synapse .Post-synaptic neuron -Neuron beginning at synapse .2 types of synapses: -Electrical -Chemical From week 5 lecture

Question 173

Synapses Electrical and chemical

Answer 173

Synapses Electrical and chemical .Electrical -Gap junctions – pre and post synap. neurons close together -Between axons and cell bodies, dendrites and dendrites, and 2 cell bodies -Rapid communication .Chemical -Most synapses -Rel. wide space between pre and post synap. Neurons -Space = synaptic cleft From week 5 lecture

Question 174

Neurotransmitters

Answer 174

Neurotransmitters .Neurotransmitter (NT) -Chemical crossing synaptic cleft -Stored in synaptic vesicles within synaptic knob -Release stimulated when impulse reaches synaptic knob -Diffuses across gap – binds to receptor sites on post-synaptic membrane -Affects permeability of post-synaptic membrane .After depolarization – repolarization .Excess NT removed from synaptic cleft .Signals either excitatory (stimulating AP) or inhibitory - EPSP = Excitatory PostSynaptic Potential - IPSP = Inhibitory PostSynaptic Potential .EPSP -Depolarise membrane (more +ve) -Bringing neurone closer to firing AP .IPSP -Hyperpolarise membrane (more –ve) -Inhibit firing of AP .Not all or nothing -Continuous in post-synaptic neurones -Integration of all PSP’s needed before impulse is transmitted along postsynaptic axon From week 5 lecture

Question 175

Types of neurotransmitters

Answer 175

Types of neurotransmitters Two main ones .Acetylcholine -Released by motor neurons -Also some in brain and some in autonomic NS -Released by cholinergic neurons .Noradrenaline (norepinephrine) -Released by sympathetic neurons -In brain and spinal cord -Released by adrenergic neurons From week 5 lecture

Question 176

Cerebral cortex 4 lobes

Answer 176

Cerebral cortex 4 lobes .Parietal lobe .Frontal lobe .Occipital lobe .Temporal lobe From week 5 lecture

Question 177

Eye Visual information receptors

Answer 177

Eye Visual information receptors .Rods and cones appear on the surface of the retina .Rods are highly sensitive and function in dim light .Cones function in daytime vision, colour vision and to improve sharpness. From week 5 practical - Equine Senses (PowerPoint)

Question 178

Equine Vision

Answer 178

Equine Vision .Monocular/Binocular .Vertical field of vision = 178 degrees .Blind spot extending approx 2 meters in front of the horse .Blind spots 10- 20 degrees either side .Total field of vision near 350 degrees .Colour vision - dichromatic vision From week 5 practical - Equine Senses (PowerPoint)

Question 179

Stereopsis and Acuity

Answer 179

Stereopsis and Acuity Stereopsis: The ability to see in stereo and perceive depth Substantial binocular overlap allowing for the possibility of stereopsis Acuity: Limited ability to focus on objects less than a meter away From week 5 practical - Equine Senses (PowerPoint)

Question 180

Chemoreception

Answer 180

Chemoreception .Gustation (taste) .Olfaction (smell) .These senses are neurologically linked From week 5 practical - Equine Senses (PowerPoint)

Question 181

Olfaction (smell)

Answer 181

Olfaction (smell) .The vertebrate cerebral hemisphere developed from the roof of the olfactory lobe .Large vomeronasal organ – responsive to species specific molecules found in body secretions Roles of olfaction -Stimulating/highlighting oestrus -Suppressing younger male hormonal development -Communication -Stallion competition -Marking territories -Imprinting -Detecting/recognizing food From week 5 practical - Equine Senses (PowerPoint)

Question 182

Gustatory (taste)

Answer 182

Gustatory (taste) .Taste = interactions of chemical stimuli with chemoreceptors .Chemoreceptors = papillae, found on the tongue .Used during mutual grooming .Regulates digestive processes and associated behaviour From week 5 practical - Equine Senses (PowerPoint)

Question 183

Selection and acceptance of flavours

Answer 183

Selection and acceptance of flavours .Goodwin et al., (2005) .Suggest selection of food on basis of the following; -Visual cues -Odour -Taste -Texture -Availability -Variety From week 5 practical - Equine Senses (PowerPoint)

Question 184

Tactile

Answer 184

Tactile (Touch/ contact/pressure) .Free-living equids use tactile stimulation for forming bonds and relaxation. .Can react to pressures too light for humans to feel .Twitching From week 5 practical - Equine Senses (PowerPoint)

Question 185

Why do horses need to touch?

Answer 185

Why do horses need to touch? .Bonding .To check out tonality of con-specifics .To differentiate between objects - Especially for the foal - In relation to foliage textures From week 5 practical - Equine Senses (PowerPoint)

Question 186

Skin receptors

Answer 186

Skin receptors .Thermoreceptors .Mechanoreceptors .Nociceptors .Distribution thought to be evolutionary decided .Gate control theory .Twitching From week 5 practical - Equine Senses (PowerPoint)

Question 187

Vibrissae

Answer 187

Vibrissae .Wiskers From week 5 practical - Equine Senses (PowerPoint)

Question 188

Auditory

Answer 188

Auditory .Funnel shaped ears .Move in unison or independently .Move around a lateral arc of 180 degrees .Can respond to sounds from up to 4400m away (McGreevy, 2002) .Laying ears flat offers protection from very loud noises From week 5 practical - Equine Senses (PowerPoint)

Question 189

Conclusion - The Senses

Answer 189

Conclusion - The Senses Sensory Modality: Example .Olfaction: Pheromones (group cohesion, territory marking, individual recognition) .Tactile: Touch and vibrational cues including substrate-coupled (spider on web) .Auditory: Sound (bird and cricket song) .Visual: Courtship dances, aggressive stances of equids, firefly light patterns. .Gustatory: Electric eels communicate with one another through charged pulses. From week 5 practical - Equine Senses (PowerPoint)

Question 190

Right Cerebral Hemisphere

Answer 190

Right Cerebral Hemisphere .With rounded lobes and intricate folds, the cerebral cortex is the largest and most recognizable part of the brain. From perception to decision making, language, and consciousness, human experience Hives here. There are about 16 billion neurons and 60 billion glia in the cerebral cortex, arranged into six layers that guide the development of useful neural circuits. These six layers of the cerebral cortex contain the cell bodies of neurons and constitute the brain's signal processing ''grey matter'. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 191

Left Cerebral Hemisphere

Answer 191

Left Cerebral Hemisphere The cerebral cortex is divided into two nearly symmetric hemispheres, which are joined by a thick bridge of white tissue called the corpus callosum. Each hemisphere is comprised of four lobes containing discrete regions that carry out specific functions. Some functions are shared by redundant areas in both hemispheres. while other functions are focused in a single hemisphere. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 192

The meningeal layers

Answer 192

The meningeal layers .Are three membranes lying underneath the skull that envelop and protect the brain. The outermost membrane, the dura mater (Latin for tough mother), is leathery and thick and provides the strongest protection for the brain underneath the skull. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 193

Brain Stem

Answer 193

Brain Stem All of the nerve fibers connecting the forebrain, cerebellum, and spinal cord pass through the brainstem. The brain stem directs essential activities like heart rate and breathing. It is also involved in the sleep-wake cycle, attention, temperature regulation, vision, hearing, and motor control of muscles in the face and neck. The brain stem is divided into three structures stacked one on top of the other: the midbrain (or mesencephalon), pons, and medulla oblongata. Each of these structures contains clusters of neurons governing specific core functions for body and life maintenance. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 194

Limbic System

Answer 194

Limbic System The limbic system is a large group of brain structures responsible for motivation, emotion, learning, and memory. Structures in the limbic system include the olfactory bulb (smell), hippocampus (memory). amygdala (fear and reward), hypothalamus (hormones and sleep), basal ganglia (motivation and voluntary motion). and cingulate gyrus (gateway to the limbic system from the cerebral cortex). From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 195

Hypothalamus

Answer 195

Hypothalamus The hypothalamus provides a link between the central nervous system (the brain and the spinal cord) and the endocrine system (glands that release hormones). The hypothalamus controls the pituitary gland, which releases hormones that regulate various bodily functons. Signals from the hypothalamus keep body temperature n check, regulate thirst and hunger, oversee the tick-tocking of our circadian rhythms, and promote bonding between family members, particularly mothers and their children. The hypothalamus also helps to bridge subconscious signals from the brainstem with signals from the cerebral cortex. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 196

Thalamus

Answer 196

Thalamus The thalamus, located in the middle of the brain, relays information about most of our senses out to the rest of the brain, and is generally considered "grand central station for the sorting of sensory information before it connects on to the cortex. Vision, hearing, touch, proprioception, and taste signals are all routed through the thalamus before being sent to their respective processing centers in the cerebral cortex. However, the thalamus is not just a messenger for our eyes and ears: it also receives feedback input from the cerebral cortex, which helps it filter sensory information in -real time- before forwarding it along. The thalamus is further connected to other brain regions—like the hippocampus and the brainstem—and may also be important for coordinating signals between various lobes of the cerebral cortex that control attention. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 197

Ventricles

Answer 197

Ventricles The ventricles are four cavities inside the brain that house and produce cerebrospinal fluid (CSF), which protects, nourishes, and cleans up after the brain. The ventricles are responsible for keeping the CSF flowing and fresh. In fact, the brain floats in this CSF —and if ft didn't, it would collapse under its own weight. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 198

Pituitary gland

Answer 198

Pituitary Gland The pitur[ary gland produces and releases hormones controlling various bodily functions and behaviors. It is a key component of the endocrine system and helps relay signals from the hypothalamus to glands throughout the body. For example, the hypothalamus sends signals to the pituitary gland; the pituitary gland then releases hormones into the bloodstream; these hormones reach additional glands in the body, spurring the release of other hormones: and those final hormones circulate back up to the hypothalamus, which interprets the meaning of those hormones for the brain n order to regulate behavior. The regulation of stress, growth, and reproduction are three of the various responsibilities of the pituitary gland. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 199

Basal Ganglia

Answer 199

Basal Ganglia The basal ganglia are a group of brain structures that control voluntary movements, habitual behaviors, and emotions. The basal ganglia are comprised of six structures: caudate nucleus, globus pallidus, nucleus accumbens, putamen, substantia nigra, and subthalamic nucleus. The location of the basal ganglia—underneath the cerebral cortex but on top of the brainstem reflects its role as an intermediary between our higher thoughts, our sensations, and our reflexes. Parkinson's disease. Tourette's syndrome, Huntington's disease and addiction can all be traced back to problems with the basal ganglia. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 200

Cerebellum

Answer 200

Cerebellum The cerebellum (Latin for "little brain-) may be small, but it contains about 70 billion neurons (five times as many neurons as the physically larger cerebral cortex). Highly convoluted (resembling a cauliflower), the cerebellum has recently taken center stage in its importance for honing our most practiced talents, from playing the piano to hitting a home run. The cerebellum helps improve motor skills by detecting errors in movements and making minute adjustments to the next movement. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 201

Corpus Callosum

Answer 201

Corpus Callosum The corpus callosum is a thick, wide bundle of neural connections linking the left and right hemispheres of the cerebral cortex. Neurons in either hemisphere stretch their axons (neural wires) through the corpus callosum to communicate with neurons in the opposite hemisphere. Specialized cells called glia wrap fatty deposits. known as myelin, around these axons to provide insulation for electrical signals, akin to the rubber insulation found on electrical wires. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 202

Olfactory Bulb

Answer 202

Olfactory Bulb The olfactory bulb is a specialized area of the cortex that processes our sense of smell. Sensory neurons in the nose detect odors and send signals via the olfactory nerve through the skull to the olfactory bulb. Once there, these signals are sorted by clustered circuits called glomeruli. A series of neural circuits then relay signals back into the brain to identify smells or recognize particular smells according to memories of past smells. In rodents and -lower organisms," the olfactory bulb is the major brain region besides the hippocampus that incorporates newborn neurons into its circuits. In humans (who are less dependent on adapting their sense of smell for survival), this process of neurogenesis is significantly reduced. From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 203

Cranial Nerves

Answer 203

Cranial Nerves The cranial nerves are a group of twelve nerves (bundles of axons) controlling muscles in the neck and head. Ten of the twelve cranial nerves originate in the brainstem, while the remaining two originate in the cerebral cortex (the olfactory and optic nerves. I and II, respectively). From https://www.brainfacts.org/3d-brain#intro=false&focus=Brain-cerebral_hemisphere-right

Question 204

Breeding Styles

Answer 204

Breeding Styles Mare .Long day breeder .Seasonally polyoestrous .Spontaneous ovulatory (cyclic) .Mature 10-24 months Stallion .Can produce sperm all year round (but less in winter) .5-20yrs old: Can breed 2-3 times per day

Question 205

Female Reproductive Anatomy

Answer 205

Female Reproductive Anatomy .Ovaries .Infundibulum .Fallopian/ uterine tubes/ oviduct .Uterine horns .Uterine body .Cervix  .Vagina .Vulva

Question 206

Vulva

Answer 206

Vulva Function? .Protection of vaginal entrance Outer area: .Labia on either side of vulval opening .Vulval seal .Muscle covered by pigmented skin containing sweat and sebaceous glands Inner area: .Lined by mucous membrane continuous with vagina .Vulva constrictor muscle: .Maintains vulval seal .Exposes clitoris during oestrus (winking to attract the male)

Question 207

Clitoris

Answer 207

Clitoris .Situated in clitoral fossa .3 clitoral sinuses - (ventral, medial, lateral) .Risk area for harbouring -venereal disease (VD) -bacteria and infections

Question 208

Perineal Conformation

Answer 208

Perineal Conformation .A = ideal conformation 80% below pelvic floor .Poor perineal conformation caused by low ischium or low pelvis

Question 209

Vagina and Vestibule

Answer 209

Vagina and Vestibule .Mare: 18-23 cm long .Runs from vulva to cervix .Vestibular seal -Secretion of acidic to neutral secretions  -Bactericidal and spermicidal

Question 210

Cervix

Answer 210

Cervix Projects caudally into vagina - separates vagina and uterus Cervical seal Tight thick-walled sphincter muscle Lining consists of series of crypts (folds)

Question 211

Uterus

Answer 211

Uterus Uterus is a hollow muscular organ which joins cervix and fallopian tubes  Lining highly folded  Endometrial folds Size affected by age and parity

Question 212

Uterus Wall

Answer 212

Uterus Wall 3 layers: Perimetrium - Myometrium Endometrium

Question 213

Fallopian Tube/Oviduct

Answer 213

Fallopian Tube/Oviduct .Infundibulum -Catches ova .Ampulla -Fertilisation site .Isthmus -Increased muscle -Transport of sperm

Question 214

Ovaries: Female Gonads

Answer 214

Ovaries: Female Gonads .covered by tunica albuginea .Primary organs of reproduction in the female .Paired structure .Ovulation fossa - where the eggs are released .Size varies Outside .Mesovarium .Ovulation fossa Inside .Tunica albuginea .Medulla -Vascular  .Cortex - Follicles  .Interstitial cells - Endocrine function

Question 215

Male Reproductive Anatomy

Answer 215

Male Reproductive Anatomy .Testes .Epididymis .Ductus deferens .Scrotum .Accessory glands .Penis .Prepuce

Question 216

Testosterone

Answer 216

Testosterone .Necessary for all normal male repro functions .Spermatogenesis .Maturation of sperm .Accessory gland function .Development of the male

Question 217

The Penis

Answer 217

The Penis .Is a Copulatory organ .Inside the prepuce 3 parts: .Glans penis -Urethral process .Body /  shaft -Corpora cavernosa -Blood sinusoids .Corpus spongiosum -Contains penile urethra .Roots Penis Body: .Haemodynamic tissue .Lower corpus cavernosus urethra -Urethra -Bulbospongiosus muscle .Upper corpus cavernosus penis -Muscle and erectile tissue

Question 218

Accessory Glands

Answer 218

Accessory Glands Ampulla: •High levels of ergothionine  •(= anti-oxidizing agent) •Mainly in pre-sperm fraction Prostate:  •Alkaline secretion as part of pre-sperm fraction •Rich in proteins, citric acid and hydrolytic enzymes Vesicular: Bulbourethral: .Produce bulk of ejaculate .Medium for transport of sperm .Semen provides favorable conditions for nutrition of sperm .Buffer against adverse conditions in female gentle tract e.g will stop other horses sperm afterwards from not being able to work

Answer 219

Ampulla: •High levels of ergothionine  •(= anti-oxidizing agent) •Mainly in pre-sperm fraction Prostate:  •Alkaline secretion as part of pre-sperm fraction •Rich in proteins, citric acid and hydrolytic enzymes

Question 220

Testes

Answer 220

Testes .Gametogenic (site of sperm production) & steroidogenic (site of endocrine/hormone production) .Contained in scrotum & covered by tunica albuginea .Ideal temperature: 35 - 36°C .Temperature regulation through: -Cremaster muscles .Gametogenic function: -Seminiferous tubules -Lined with Sertoli cells -No. of Sertoli cells varies with season .Endocrine function: -Leydig cells -Located in intertubular area -Leydig cells: sperm production & puberty

Question 221

Male Epididymis

Answer 221

Male Epididymis .Convoluted tubules in 3 sections -Caput, Corpus, Cauda .Lining highly folded with microvilli .Function -Site of sperm maturation -Storage

Question 222

Vas Deferens/ Ductus Deferens

Answer 222

Vas Deferens/ Ductus Deferens .Connects epididymis of testes to urethra .Folded lining to maximise sperm storage .Contractions of muscular wall propel sperm and fluid from testes to penis

Question 223

Ejaculation

Answer 223

Ejaculation .Emission of spermatozoa from tail of epididymis through vas deferens into pelvic urethra .Contraction of smooth muscle within walls .Secretions of accessory glands mixed with spermatozoa .Ejaculation through further muscular contractions .Autonomic reflexes involving sympathetic and parasympathetic divisions

Question 224

Sperm

Answer 224

Sperm .Produced within seminiferous tubules and nursed by Sertoli cells .3 areas of sperm cell: -Head -Midpiece -Tail

Question 225

Spermatogenesis

Answer 225

Spermatogenesis .Spermatocytogenesis -Development spermatogonia from germ cells -Spermatogonia differentiate into primary spermatocytes .Meiosis stages -Primary spermatocytes  secondary spermatocytes -Secondary spermatocytes  spermatids .Spermiogenesis -Differentiation of spermatids into spermatozoa

Question 226

Equine Maturity age

Answer 226

Equine Maturity age .Male - 14 months .Female - 18 months

Question 227

Free portion of the penis (bulb of the penis). Expands up to 3x it’s size during copulation:

Answer 227

Free portion of the penis (bulb of the penis). Expands up to 3x it’s size during copulation: .Glands penis - seen in resting position

Question 228

Receives immature sperm from the rete testes. Testicular fluid is reabsorbed here to concentrate the sperm:

Answer 228

Receives immature sperm from the rete testes. Testicular fluid is reabsorbed here to concentrate the sperm: .Epididymus (caput part)

Question 229

Site of sperm and testosterone production. Contains seminiferous tubules (site of sperm production) and intertubular Leydig cells which secrete testosterone:

Answer 229

Site of sperm and testosterone production. Contains seminiferous tubules (site of sperm production) and intertubular Leydig cells which secrete testosterone: .Testis

Question 230

Site of sperm maturation:

Answer 230

Site of sperm maturation: .Epididymus (corpus part)

Question 231

Predominant site of sperm storage prior to ejaculation via the vas deferens:

Answer 231

Predominant site of sperm storage prior to ejaculation via the vas deferens: .Epididymus (cauda part)

Question 232

Contains corpus cavernosum and corpus spongiosum tissue. In a resting position, lays retracted in the prepuce (sheath):

Answer 232

Contains corpus cavernosum and corpus spongiosum tissue. In a resting position, lays retracted in the prepuce (sheath): .Body/ shaft of penis

Question 233

Muscle responsible for holding the penis inside the pelvic cavity when in a resting position:

Answer 233

Muscle responsible for holding the penis inside the pelvic cavity when in a resting position: .Retractor muscle

Question 234

Singular gland, responsible for secreting an alkaline secretion as part of the pre-sperm fraction to clear out the urethra prior to ejaculation:

Answer 234

Singular gland, responsible for secreting an alkaline secretion as part of the pre-sperm fraction to clear out the urethra prior to ejaculation: .Prostate gland

Question 235

Mare breeding

Answer 235

Mare breeding .Seasonal breeder .Seasonally poly oestrous .Spontaneous ovulatory (cyclic) .Mature 10 - 24 months

Question 236

Breeding cycle

Answer 236

Breeding cycle .Oestrous: whole cycle .Pro-oestrus: period preceding oestrus .Oestrus: period of sexual receptivity .Metaoestrus: period following oestrus .Dioestrus: period of sexual inactivity .Anoestrus: winter months no cycle

Question 237

Mare’s Cycle

Answer 237

Mare’s Cycle .21 day cycle (proestrus-dioestrus) .Ovulation is day 0 .Oestrus 5 +/- 2days .Pregnancy 335 days

Question 238

Reproductive Hormones

Answer 238

Reproductive Hormones .Gonadotropin-releasing hormone (GnRH) .Follicle-stimulating hormone (FSH) .Luteinising hormone (LH) .Oestrogen .Progesterone .Prostaglandin F2a (PGF2a)

Question 239

Gonadotrophin releasing hormone

Answer 239

Gonadotrophin releasing hormone .Released in tonic AND pulsatile manner .80% GnRH via hypothalamic – pituitary portal vessels to anterior pituitary -Stimulates production of gonadotrophins (LH and FSH) .20% GnRH goes to CNS - affects behaviour

Question 240

Follicle Stimulating Hormone (FSH) and Luteinising Hormone (LH)

Answer 240

Follicle Stimulating Hormone (FSH) and Luteinising Hormone (LH) .Produced by anterior pituitary gland .FSH: Follicular development .LH: Ovulation of dominant follicle

Question 241

Role of Luteinising Hormone (LH)

Answer 241

Role of Luteinising Hormone (LH) .Final follicular development  message to ovulate -Possible role in selection of dominant follicle .Causes ovulation -LH receptors on follicular theca cells increase as LH -concentration increases .Starts production of oestradiol (behaviour) -Theca cells involved with oestradiol production .Involved in initial formation and maintenance of CL? (LH receptors on CL)

Question 242

Oestrogens (Oestradiol (E))

Answer 242

Oestrogens (Oestradiol (E) .Ovarian steroid oestrogen .Produced by follicle .Produced by developing follicles through interaction between theca cells and granulosa cells .Monophasic – 1 peak – 24-48 h prior to ovulation .Production linked to FSH and LH – synchronise oestrus

Question 243

Corpus Luteum

Answer 243

Corpus Luteum .Develop from follicle cells .Temporary endocrine gland .Progesterone .No fertilisation -PGF2a synthesis (uterus) -Stimulates luteolysis

Question 244

Progesterone

Answer 244

Progesterone .Steroid .Produced by Corpus Luteum (CL), pulsatile manner .24 – 48h post ovulation, max reached 5 – 6 days, maintained until day 15-16 .Inhibitory effect  LH

Question 245

PGF2α

Answer 245

PGF2α .Difficult to measure – short half life .Pulsatile release .Increase between day 14 and day 17 post ovulation if no pregnancy detected .Secreted by uterine endometrium .Causes luteolysis of CL

Question 246

Stallion breeding style

Answer 246

Stallion breeding style .Can produce sperm all year round (but less in winter) .5-20yrs old: Can breed 2-3 times per day

Question 247

Spermatogenesis

Answer 247

Spermatogenesis .Spermatocytogenesis -Development spermatogonia from germ cells -Spermatogonia differentiate into primary spermatocytes .Meiosis -Primary spermatocytes  secondary spermatocytes -Secondary spermatocytes  spermatids .Spermiogenesis -Differentiation of spermatids into spermatozoa

Question 248

Sperm

Answer 248

Sperm .Produced within seminiferous tubules and nursed by Sertoli cells .3 areas of sperm cell: -Head -Midpiece -Tail

Question 249

Endocrine system

Answer 249

Endocrine system .Use of chemical messages (hormones) .Regulation and control of various functions are performed through chemicals. .Released by endocrine glands .Control of physiological processes .Involved in homeostasis and adaptation .Works in collaboration with the nervous system

Question 250

Endocrine vs. Nervous

Answer 250

Endocrine vs. Nervous .Endocrine -Release of chemical (hormone) into bloodstream -Effect can be on many target cells spread throughout the body -Effect will take place over a relatively prolonged time (ranging from seconds to days) .Nervous -Release of chemical (neurotransmitter) across a synapse -Effect restricted to innervated target cells -Effect generated within milliseconds

Question 251

Endocrine Glands

Answer 251

Endocrine Glands .Ductless .Hormones secreted directly into the bloodstream

Question 252

Hormones

Answer 252

Hormones .Endocrine - further away cells -Affects distant cells -Insulin, epinephrine (aka, adrenaline) .Paracrine - closer cells -Affects neighboring cells .Only those organs having the specific receptors respond to the hormone .Organic compounds .Target specific -Chemical messengers arrive at target cells -Specific receptor sites on target organs -Triggers chain reaction

Question 253

Hormone concentrations

Answer 253

Hormone concentrations .Hormones do not make cells do anything new -Affect rate at which functions are performed .Some remain fairly constant -Thyroid hormones (little variation) .Others respond to certain stimuli -Epinephrine (stress/exercise) .Others change in relatively constant cycles -Reproductive hormones .The greater the concentration of hormone in the blood – the ---greater the rate of diffusion.

Question 254

Metabolism & Excretion

Answer 254

Metabolism & Excretion .Half life -Time taken for the concentration to reduce by one half .Down regulations -No. of hormone receptors decreases after exposure to certain hormones.

Question 255

Hypothalamus

Answer 255

Hypothalamus .Small in size .Located in the skull .The site of production for a large number of hormones .Controls a number of other glands .Hormonal or nervous control .The “control centre” .It lies in the centre of the brain .Interface – nervous and endocrine -Senses need for anterior pituitary hormones -Forms posterior pituitary hormones -Integration of autonomic nervous system function

Question 256

Pituitary Gland

Answer 256

Pituitary Gland .Master gland .Located in the skull .Variety of functions -Adrenocorticotropic Hormone (ACTH) -Growth Hormone (GH) -Anti-Diuretic Hormone (ADH) -Thyroid Stimulating Hormone (TSH)

Question 257

Hypothalamic Control of Anterior Pituitary Hormones

Answer 257

Hypothalamic Control of Anterior Pituitary Hormones .Releasing hormones (releasing factors). Secreted like neurotransmitters from neuronal axons -TRH (thyrotropin releasing hormone) - turns on TSH -CRH (corticotropin releasing hormone) - turns on ACTH -GnRH (gonadotropin releasing hormone) - turns on FSH and LH -PRF (prolactin releasing hormone) - turns on PRL -GHRH (growth hormone releasing hormone) - turns on GH .Inhibiting hormones -PIF (prolactin inhibiting factor) - turns off PRL -GH (growth hormone) inhibiting hormone - turns off GH

Question 258

Thyroid Glands

Answer 258

Thyroid Glands .Behind the larynx .Growth hormone .Thermoregulation .Calcium storage .PARATHYROID GLANDS

Question 259

Thyroid and Parathyroid

Answer 259

Thyroid and Parathyroid Thyroid .Thyroxine (T4) and tri-iodothyronine (T3) -Influence metabolic rates, growth, and .Calcitonin: reduces blood Ca ion concentration -Inhibits osteoclast activity -Regulates bone growth in young animals Parathyroid .Parathyroid hormone (PTH): works with calcitonin to maintain Ca blood homeostasis. -Stimulates osteoclasts -Inhibits osteoblasts

Question 260

The Pancreas

Answer 260

The Pancreas .Abdominal Cavity .Primary regulator of blood sugar levels .Production of insulin (β-cells) and glucagon (α-cells)

Question 261

Adrenal Glands

Answer 261

Adrenal Glands .Located on the kidneys .Metabolism .Behaviour -Fight or flight

Question 262

Adrenal Hormones

Answer 262

Adrenal Hormones 1.Glucocorticoids – cortisol, corticosterone, cortisone -Present in low levels -Increase in response to stress -Increase blood glucose levels -Stimulate hepatic gluconeogenesis -Mobilising fatty acids from the adipose tissue ready for conversion to glucose. -In large quantities they depress the inflammatory reaction 2. Mineralocorticoids – aldosterone -Acts on distal convoluted tubule of the kidney -Regulates acid/base balance 3. Adrenal sex hormones -insignificant quantities

Question 263

The Gonads: Sex Organs

Answer 263

The Gonads: Sex Organs .Ovaries .Testes .Reproductive cycle .Drive sexual behaviour

Question 264

Control & Feedback Mechanism

Answer 264

Control & Feedback Mechanism .Negative feedback -Maintain levels within normal range .Three main methods of stimuli -Humoral Stimuli - chemical e.g blood sugar levels -Neural Stimuli - fight or flight -Hormonal Stimuli (secreted from a different endocrine gland)

Question 265

Endocrine summary

Answer 265

Endocrine summary .Endocrine and nervous system linked to control homeostasis of internal environment .Pituitary acts as ‘master’ gland .Glandular secretions -Target specific -Trigger specific actions -Controlled by negative feedback