week 1 Flashcards
(169 cards)
1
Q
What is meant by the anatomical terminology?
hypo-
hyper-
epi-
supra-
sub-
osteo-
chondr-
endo-
ecto-
-cyte
-itis
-ectomy
A
- under or below
- above
- upon, on, over, near, at, before, after
- above or after
- under
- bone
- cartilage
- within
- outer, external
- relating to a cell
- inflammation or a disease characterised by inflammation
- excision (surgical removal)
2
Q
What is meant by the anatomical terminology?
lateral
medial
dorsal
proximal
distal
cranial
caudal
palmar
plantar
axial
abaxial
rostral
caudal
A
- further away from the middle of the body or midline of the body.
- Opposite of lateral towards the middle of the body
- Belly side or underside of an organism
- back or topside of the body, top of the hand
- close to the beginning of a structure with an end and a beginning
- close to the end of a structure with an end and a beginning
- towards the head
- towards the tail
- palm or the anterior surface of the hand
- relating to the soul of the feet
- Towards the central line of the body or any parts
- Away from the long axis of the body or any parts
- Front of the brain
- back of the brain
3
Q
What are the 3 planes and how do they lie? Type of sagittal plane?
A
Dorsal plane- parallel to the back
Transverse plane- perpendicular to the long axis of the body. Splits into top and bottom.
Sagittal plane- divides the body into right/left halves
Median plane- type of sagittal plane that divides the body into exactly equal left and right parts.
4
Q
What is palpation?
A
Palpation is a technique used during a physical examination. The hands are used to assess structures or objects.
5
Q
How to carry out a palpation? And what should you be able to work out?
A
In order to palpate you fix the animal’s skin against your finger pads (not finger tips) and move around within the limits of the skin’s stretch. Release, then re-site your fingers and palpate the next region. It is important to apply even pressure and to move slowly. Don’t allow the skin to slip otherwise all you will feel is the fur/hair moving.
When palpating structures you should be able to describe several components of the structures including: Size, Shape, Texture (firmness), Location (relationship to adjacent structures)
From these you should be able to identify/differentiate between: Bone, Muscle, Tendon, Abdominal organs, Fluid filled structures e.g. joint capsules/bladder, Other soft tissues structures e.g. lymph nodes.
6
Q
What skills are involved in manipulation? and what are you trying to work out?
A
When manipulating structures you are predominantly moving joints within the tissues. You try to identify: Location of joint, Type of joint, Direction of movement, Range of movement, Freedom of movement, Relationship to adjacent structures
7
Q
What is meant by the term cortex and medulla in terms of gross anatomy of bones?
A
cortex - tube of solid bone
medulla - central cavity filled with bone marrow (fat in older animals)
8
Q
What terms are used to describe the shaft of a bone and the ends of a bone?
A
shaft - diaphysis
ends
- metaphysis (flared region adjacent to epiphysis)
- epiphysis (rounded end)
9
Q
What type of bone is found in the outer layer of a bone and in the inner layer of a bone?
A
outer layer - cortical (compact) bone
inner layer - cancellous (trabecular, spongy) bone
10
Q
What is meant by the terms trunk, limbs, visceral bones?
A
trunk is the central part of the body includes: vertebral column, ribs, sternum, skull
limbs are the appendicular part of the body. Includes: shoulder and pelvic limb
Visceral bones are bony formations in soft tissues rather than being part of the skeleton like the os penis bone
11
Q
Bones can be classified depending on where they occur, what 2 terms are used to describe this and what do they mean?
A
Axial skeleton
the bones forming the axis or centre of the animal eg bones of the head, neck, vertebral column, ribs, (pelvis) and tail.
Appendicular skeleton
Regions that are attached eg Bones of the forelimbs
and hindlimbs.
12
Q
What are the 2 examples of visceral bones? and in which animals are they found?
A
Os penis in the dog and cat
Os cordis in the heart of ruminants
13
Q
What are the two ways bone develop and what type of bones develop by each method?
A
Chondral ossification – bones ossify from a cartilage precursor
Eg most limb bones: humerus, radius, ulna, carpal bones, femur, tibia, tarsal bones
Membranous ossification – bones ossify directly from mesenchymal cells
Eg scapula, most bones of the skull
14
Q
What are the classifications for bones based on what they look like? And what bones do they involve?
A
Long bones- includes femur, tibia and fibula
Short bones- include tarsals and carpals
Flat bones- protect internal organs or provide a connection point for your muscles
Sesamoid bones- small, round bones that are embedded within tendons or ligaments
Irregular bones- unique shapes and can’t be classed as the others such as the vertebrae.
15
Q
Key features of long bones?
A
Cylindrical shape
Main part of bone is a column providing strength, expanded ends providing transfer of load
Resist compression when loaded, act as levers and resist tension during muscle contraction
Humerus, femur, radius, tibia
16
Q
Key features of short bones?
A
Many sides, similar dimensions throughout (length, breadth, height)
Found in groups of bones that act to transmit and disseminate forces through joints (distribute weight and force more evenly and reduce concussive forces)
One surface is always non-articular – for ligament attachment and vasculature
Carpal and tarsal bones
17
Q
Key features of irregular bones?
A
Surprisingly enough these have an irregular shape
Usually have various jutting processes for muscle and ligament attachment
Most typical examples are the vertebral bones
18
Q
Key features of flat bones?
A
Thin, flat bones
Act as attachments for soft tissues, and protect underlying tissues
Bones of the skull, scapula, pelvis, ribs
19
Q
What are pneumatic bones?
A
Bones which contain air spaces
Flat bones of the skull – form the paranasal sinuses
20
Q
key functions of sesamoid bones?
A
Function is to provide additional strength and reduce wear over joints
Protect tendon over a bony prominence (navicular bone)
Redirect course of tendon (patella)
Attachment for tendon (patella)
Weight-bearing function (equine fetlock)
E.g. equine navicular bone
21
Q
What is meant by the terms for bones?
diaphysis
epiphysis
metaphysis
cortical/ compact bone
medullar cavity
cancellous/spongy/ trabecular bone
periosteum
articular surfaces
A
Diaphysis- shaft or central part of a long bone
Epiphysis- the end part of a long bone
Metaphysis- the neck portion of a long bone between the epiphysis and the diaphysis.
Cortical/ compact bone- Area of denser material used for providing strength.
Medullary cavity- central cavity in long bones containing bone marrow
Cancellous/spongy/ trabecular bone- bone tissue with a mesh like structure
Periosteum- the membrane of blood vessels and nerves that wraps around most of your bones.
Articular surfaces- any surface of a skeletal formation that makes direct contact with another skeletal structure.
22
Q
What is the function of the humeral and femoral head, tubercles/trochanters and tuberosities, fossae, condyles and epicondyles
A
Humeral and femoral head- Involved in forming a ball and socket joint in the shoulder and hip.
Tubercles, trochanters and tuberosities- act as an attachment site for several muscles.
Fossae- depression or hollow area in a bone. Provide space for muscle attachment, housing structures like nerve and blood vessels.
Condyles and epicondyles- Play a crucial role in the movement and stability of the human body. Allow for movement.
23
Q
Describe the structure and function of the periosteum, compact bone, cancellous bone and medullary cavity?
A
Periosteum
structure - Fibrous connective tissue membrane consisting of two layers: an outer fibrous layer and an inner cellular layer
function - Covers the external structure of bones with the exception of joint surfaces, which are covered by articular surfaces. Supplies bones with blood, nerves and cells that help them grow and heal.
Compact bone
structure - solid bone consisting of concentric bone arranged around a central osteon (provide strength and support to the bone, and help in repair and remodelling of bone tissue).
function - The compact bone is the main structure in the body for support, protection and movement.
Cancellous bone
structure - Light and porous, honeycomb like structure. The bone matrix or framework is organised into three- dimensional latticework of bony processes called trabeculae, arranged along lines of stress. The spaces between are often filled with marrow and blood vessels.
function - Provides strength and support to the overlying bony cortex whilst minimising weight. Vital reservoir for developing red blood cells, platelets, and white blood cells. Usually surrounded by a shell of compact bone which provides greater strength and rigidity, enables the bone to dampen sudden stress.
Medullary cavity
structure - A hollow central space found within the shaft (dialysis) of long bones. Its walls are formed by a thin layer of spongy bone which is surrounded by a thick layer of compact bone. The medullar cavity is lined with a thin vascular membrane called the endosteum and contains bone marrow.
24
Q
What are the different tissue types?
A
- epithelial tissue
- nervous tissue
- connective tissue
- muscle (contractile tissue)
25
What does nervous tissue consist of?
- nerve cells (or neurones)
- neurological cells
in the CNS - astrocytes, oligodendrocytes, microglial cells, ependymal cells
in the PNS - satellite cells, Schwann cells
26
What are the function of neurones and neurological cells?
Neurones:
- receive and facilitate nerve impulses
- classified based on function and structure
Neuroglial cells:
- supporting cells, e.g. facilitate conduction of nerve impulse, immune function, maintenance of neurones
27
Connective tissue functions?
Wide variety of various functions including:
- mechanical and structural support
- supports and connects the various parts of the body by 3-dimensional framework also known as stroma (Stroma = Greek for layer, bed covering)
- separates tissues and organs.
- Originate from cells of the mesodermal (middle tissue) layer of the embryo.
28
What are the key functions of connective tissue?
support, movement, protection, fat (energy) storage.
29
What are the 5 main categories of connective tissue and what are the subgroups?
1. Loose connective tissue
2. Dense connective tissue
i) Regular
ii) Irregular
3. Cartilage
i) Hyaline
ii) Elastic
iii) Fibro~
4. Bone
i) Lamellar
ii) Trabecular
5. Blood
30
What is loose connective tissues other name? and compare it to DCT?
Give some examples of LCT and states its structure and function?
areolar connective tissue
- fewer fibres than DCT
- more cells and ground substances in ECM
- less rigid and more easily distorted, but due to the presence of collagen, it can still provide resistance when stretched creating a tough barrier
Examples: mucosal and submucosal connective tissues of blood vessels, muscles, nerves and organs such as kidney and liver.
Structure: cells found within a network of mostly collagen fibres.
Function: loose packing, support, nourishment to associated structures, tissue sliding.
31
Where are dense connective tissue found, what is its structure and function?
Location: tendon, ligament, cornea of the eye, arteries.
Structure: matrix composed of collagen, elastin fibres.
Function: tensile strength and stretch resistance.
32
what cells are found in cartilage and what do they do? Compare to bone?
The cells in cartilage are called chondrocytes.
They produce a matrix which is made up of type II collagen, glycoproteins and water
Unlike bone, cartilage does not contain calcium phosphate and it is therefore more flexible then bone.
Cartilage is continually broken down and renewed throughout life, just like bone.
33
What is the function of cartilage?
Function: all provide flexibility with rigidity, fibrocartilage can withstand considerable pressure.
Note: typically poorly supplied with blood.
34
What are the 2 types of bone? and what is their structure and function?
There are two types:
Lamellar (compact) bone
Trabecular (spongy) bone
Structure:
Collagen network – tensile strength.
Crystalline – compressive strength.
Bone cells – maintenance of bone.
Function: provides strength and support
35
What are the 3 main components of connective tissue structure? and what do they do?
Three main components:
Cells
Collagen fibres
Ground substance – special proteins.
Cells separated from each other by abundant extracellular matrix.
36
what are the different names of cell types embedded within connective tissue?
Cartilage = chondrocytes
Bone = osteoblasts/osteocytes/osteoclasts*
Muscle = myocytes
Tendons = tenocytes (elongated fibrocytes)
*Osteoclasts are derived from monocytes (a white blood cell (WBC) lineage)
37
What is the importance of ECM in connective tissue? and what does it consist of and what are their importance's?
Structure of ECM gives connective tissue its morphological and functional characteristics.
ECM consists of:
Collagen and elastin fibres
collagen – strong, flexible but inelastic (several types, type I most common).
reticular fibres – fine collagen type III fibres, networks of these fill space between tissue and organs
elastin – elastic properties – percent varies according to tissue function
Ground substance (non-fibrous protein and other molecules)
amorphous gel-like substance surrounds cells
components include: hyaluronic acid, proteoglycan
Water
38
are cells tightly packed in connective tissue
Connective tissue does not consist of tightly packed cells
Much of tissue volume made up of extracellular space
This space filled with extracellular matrix (ECM)
39
What is ECMs function and what is it produced by?
Function: structural support of cells, also guides their division, growth and development
Produced by specialist cells in the tissues, names of cells end with suffix that identifies function:
~blasts – create matrix
~cytes – maintain matrix
~clasts – break down matrix for remodelling
40
What is the name of a fat cell or a muscle cell?
adipocyte, myocyte
41
Compare a fibrous ECM to a liquid ECM, what happens to the structure of the connective tissue?
Fibrous
- rich in structural proteins like collagen and elastin, forming a dense network of fibres.
- provides rigidity, tensile strength, and resistance to stretching
- fewer cells relative to matrix, cells are embedded sparsely amongst the fibres
- supports load-bearing and mechanical functions, maintain tissue integrity under stress
Liquid
- mostly water, with dissolved proteins, nutrients, gases and waste
- fluid and flexible, no structural fibres
- higher relative presence of cells suspended in the fluid
- support transport, immune response, and regulation
42
What gives rise in the formation of the embryo to various tissues including blood, muscles, tendons, cartilages etc.
Mesoderm produces embryonic mesenchyme as it differentiates. Mesenchyme is the term for the loose tissue “stuff” in an embryo that gives rises to various tissues e.g. blood vessels, muscles, tendons, cartilage, etc.
43
What are the 3 embryonic components and what do they produce?
Embryonic components include:
Ectoderm – epithelium of extreme ends of the tract (as well as outer epithelium and nervous system)
Mesoderm – becomes the musculoskeletal system including smooth muscle
Endoderm – becomes intestinal epithelium
44
summary of embryology unanswered
summary of embryology
45
What are the 4 tissue types in embryology?
- Epithelial (skin, lung and GIT lining).
- Neural (nervous system, derived from embryonic ectoderm, hence termed neuroectoderm).
- Contractile (all muscles, derived from embryonic mesoderm).
- Connective (everything not in 1, 2 & 3! Derived from embryonic mesoderm).
46
What is embryonic connective tissue, where is it primarily found and what is its features?
Loose connective tissue formed during early embryonic development
Found primarily in the umbilical cord
Features:
hydrophilic ECM
jelly-like
also known as mucoid connective tissue or Wharton’s Jelly
47
embryonic tissue unlabelled
answered
48
What is reticular connective tissue and what does it form?
Reticular connective tissues:
Contain reticular and elastic fibres that predominate (main element) in irregular connective tissues
Reticular fibres (type III collagen): form the stroma of the lymphoid system (i.e. lymph nodes, spleen)
Elastic fibres: intervertebral disks and wall of the aorta
49
What are the 2 types of adipose tissue and what are their roles? give the structure and function of adipose tissue!
Two types:
Brown adipose tissue – heat
White adipose tissue – energy store
Structure: little ECM surrounding cells, cells full of lipid
Function: packaging, protection, insulation
50
label adipose tissue
51
What are the 2 components of welfare?
physiological components, behavioural components
52
What are the day 1 competencies encompassing behaviour?
Do no harm
Apply behavioural first aid
53
What is involved in analysing locomotion?
evaluate what is normal/abnormal
assess gait patterns
identify gait adaptations – e.g. lameness
performance indicators
Welfare indicators
54
What to consider before assessing locomotion?
Consider:
space available
surface conditions
firm, level, non-slip
(firm surface: assess muscular, soft surface: soft tissue)
firm surface enables you to listen to footfalls and assess gait pattern
age of animal – e.g. arthritic dog, gangly foal?
any medical conditions
handler
speed of gait (slow or fast)
55
Compare human observation and technical equipment in assessing locomotion?
Human observation:
Can be subjective, biased
Frame rate - human eye can miss detail
Low technical effort and convenient
Requires experience
Low cost
Technical equipment:
Measurable
Objective, less bias
Requires dedicated:
equipment
space
resources
personnel
Higher cost
But is quantification important?
56
What is meant by Gaits?
Gaits are specific patterns of the footfalls during locomotion (e.g. walk, trot, canter)
Gaits change with speed
Gaits have a characteristic sequence of footfalls
Strides take place within a gait
57
What is a stride and what are the 2 components of a stride?
Stride
Complete cycle of movement
e.g. from the setting down of foot to the next setting down of the same foot
Phases of a stride:
stance phase (weight bearing limb)
swing phase (non-weight bearing limb)
58
What are the 4 types of Gaits
walk/trot/canter/gallop
59
Characteristics of a walk
Four-beat
Symmetric
Sequence of foot-falls:
RH-RF-LH-LF
Never >3 nor <2 limbs weight-bearing at any one time.
Centre of gravity always between a triangle of weight-bearing feet.
60
Characteristics of a trot
Two-beat.
Biologically very ancient pattern seen in fish.
Symmetric.
Diagonal gait.
Body supported alternately by left & right diagonal pairs.
Period of suspension between successive stance phases.
Marked axial twisting – resisted by design of axial system (acquired via evolution).
61
characteristics of a canter
Three-beat
Asymmetric
Rocking horse motion:
RH RF+LH LF
LH LF+RH RF
One moment of suspension: after single forelimb leaves the ground, prior to single hindlimb contact
Lead leg – left or right lead
One diagonal pair
Other two limbs out of phase
62
characteristics of a gallop
Fast, four-beat
Asymmetric gait
Horses usually lead with their inside leg around a turn (called the lead leg)
Moment of suspension
63
What are the 3 types of gallops? And what are their footfall?
Three types of gallop:
Transverse:
LH RH LF RF *
(*One moment of suspension)
Rotary:
RH LH * LF RF *
(**Two moments of suspension)
Counter-rotary:
The opposite of rotary, i.e. anticlockwise footfalls
64
examples of when animals are in each type of gallop.
Transverse gallop is used by:
Dogs at low speed
Horses (odd-toed ungulates)
Cattle (large even-toed ungulates)
Rotary gallop used by:
All cats
Dogs at high speed
Gazelle, antelope (small even-toed ungulates)
Running rodents
Note in the horse this is called “disunited canter”
Counter-rotary used by:
Greyhounds on the track, since they race anti-clockwise
65
Why do we change gait?
Physical necessity: limb "flies off ground“
Pendulum effect (limb an inverted pendulum)
Centrifugal force acting upwards
Froude number = ratio of inertial force:gravitational force (>1 = suspension phase)
Metabolic advantages:
optimal speed for each gait at which energy cost is minimal
Treadmill study – measured amount of oxygen consumed at different gaits
respiratory pattern
locomotion and respiratory coupling
Mechanical advantages:
reduced bone strain
66
What sensations are involved in the neurological basis of limb coordination and what motor responses are involved in response to stimuli?
Sensation:
Vision
Vestibular system (inner ear) – balance orientation
Mechanoreceptors (touch)
Nociceptors (pain)
Proprioceptors (body position)
Motor response to stimuli:
Nervous system: voluntary and involuntary control, reflexes
Central pattern generators – generate rhythmic motor patterns (inc respiration)
Responsible for producing gaits: walk, trot, canter etc…
Brainstem
Cerebellum – balance
Constant monitoring of muscle length and tension (muscle spindles and golgi tendon organs)
67
What are the Functional adaptation to high-speed locomotion: Equine? and how is this achieved?
Increase stride length:
elongation of distal limb
mobile scapula
increase length of limb
whiplash effect – small motion upper limb > flick of lower limb
Minimise mass of limb:
most of work done by animal during locomotion involves accelerating and decelerating limbs
muscles positioned proximally (near pivot-point)
reduced number of bones in limb
adaptations = lower mass (inertia) of lower limb
Conservation of energy:
‘Whiplash’ effect of limb
Long tendons:
Transfer load, shock absorbers, energy store
Stable joints:
limit range of movement but little extra support required
(low mass = low inertia)
Relatively rigid spine/sacroiliac junction:
Large gut
Large body mass
Transfer of energy from powerful hind quarters
Minimises up-and-down movements of body during locomotion (conserves energy)
Inertia is the tendency for an object to resist any change in its motion.
68
What are the Functional adaptation to high-speed locomotion: Canine?
Elongation of limbs
mass proximal
Digitigrade:
need claws for catching prey
claws may assist with grip
(humans = plantigrade, horses = unguligrade)
Flexible back:
arches & straightens over wide range - increases stride length
No restriction from gut.
Tail:
assists with balance when out-of-balance
69
What are the clinical consequences of adaptations: Equine?
Low safety margins: bones and tendons
- fractures
- tendon strains
Little soft-tissue cover distal limbs
poor wound/fracture healing
Little soft tissue to absorb impact loads
joint injuries/osteoarthritis
70
dog muscles unlabelled
labelled
71
microscope unlabelled
labelled
72
How to initially set up a microscope?
1. Turn on the light and increase the brightness to give a wite light output.
2. Rotate the objective Lense to the lowest setting x4
3. Place the side on the stage using the retaining mechanism to hold it in place. Raise or lower the stage to bring the image into focus.
Set the eyepieces to the correct width for your eyes so you can look down both together comfortably. Move the, in and out as if you are holding a pair of binoculars and try to create a single round image.
73
How to focus the slide?
1. Look down the eyepieces with both eyes open and slowly raise or lower the stage to bring the specimen into focus. Use the coarse adjustment control initially and then the fine.
2. One eyepiece is not adjustable, and one is adjustable (part of it rotates): lose the eye over the adjustable one. Now focus using the fine control until a sharp image is in focus.
3. Now open the other eye above the fixed eyepiece and close the first eye. Without touching the gross focus knob, and just using the adjustment on the eyepiece itself, rotate to obtain a sharp image through that eye. Now open both eyes.
74
how to focus the condenser?
1. Check that the lowest power objective lense is in place
2. Close the lamp iris on the base of the microscope (where the light comes up) until the edges of the iris appear on the field of vision.
3. Focus the iris by adjusting up and down the substage condenser until the light gives a sharp-edged hexagon shape, which should be in the centre of the stage.
4. Open the lamp iris on the base of the microscope until the iris edges just disappear from your field of view
5. Adjust the condenser aperture to produce the best image
For the condenser apparatus match the number on the condenser aperture ring to the power of the objective used
75
what to do when moving up the objectives?
1. By moving up the objectives you will be increasing the magnification of the objects in view, this will hopefully also increase the resolution as well.
2. Do not adjust the stage
3. How Select the required objective by rotating the nosepiece, not by holding the objective itself
4. Move it around to the next lens in sequence
5. Use the fine focus to obtain an in-focus image
6. Continue this process until the magnification is suitable for the objects you wish to view
7. To move the stage around and examine the stage adjuster dials, one will do up and down one will do left and right.
76
What objectives are required for parasites, urine, cellular material/microbes?
Objectives required
Parasites x4
Urine x10-x40
Cellular material/microbes x10 up to x100 (Oil immersion)
77
What is meant by the term resolution/ magnification?
Resolution is the ability of a microscope to distinguish detail.
Magnification is the ability of a microscope to produce an image of an object at a scale larger than its actual size.
78
What is the need of a skeleton?
Structural
Supports the body
Protection
Protects vital organs against trauma
Locomotion
Provides rigid rods and levers through which muscles can act to effect movement
Mineral reservoir
Multitude of organic ions (e.g. Calcium, Phosphorous)
79
What are the limitations of bone?
Rigid
Hard/brittle
Unable to expand from within.
- Limited growth potential – can only expand at existing surfaces
80
What are the 2 components of bone tissue? and what are the 3 types of cells in bone? and what are the spaces in bone called?
Matrix
- Organic
- Inorganic
Cells
- Osteocytes
- Osteoblasts
- Osteoclasts
Vascular spaces
81
What is the organic component of bone matrix called? What is it and what is synthesised by and how is it secreted? and what is embedded in and what are their roles?
Osteoid" - Ground substance in which numerous collagen fibres are embedded
Synthesized by osteoblasts
Secreted onto existing bone surface
Collagen type I ~90% (trace type V)
Strong, inert fibrils: Important structural component
Embedded in a ground substance of water and:
Glycoproteins - Osteonectin, Osteocalcin : Binds collagen & mineral
Proteoglycans - Biglycan, decorin : Bind growth factors
Bone sialoproteins - Osteopontin, thrombospondin : Associated with cell adhesion
82
What is found in the inorganic components of the bone matrix and what is its roles?
Bone minerals
60-70% dry weight
Confer hardness and rigidity
Make bone radio-opaque
Composed largely of crystals: Hydroxyapatite (Ca10(PO4)6(OH)2), Carbonate, Calcium phosphate.
83
When does mineralisation of bone occur and how long does it take?
Mineralisation
Commences as soon as osteoid secreted
Reaches 70-80% final in ~ 3 weeks
Takes years to complete
84
What are the two ways in which Collagen fibres are deposited in different organizational structures in bone?
Woven bone – haphazard collagen. "Quick and dirty" formation: Young growing animal, fracture repair, etc. Mineralises quickly
Lamellar bone (parallel fibre bone)– thin layers of osteoid within which collagen fibres are parallel. Structurally superior. Collagen fibres deposited in different organizational structures
85
What is an osteon and how can you tell the difference between primary and secondary osteons and fibrolamellar bone (when distinguishing in a specimen)? Have a go at bone tissue labelling?
Osteon is the basic unit of compact bone, composed of concentric layers of bone tissue and a central canal with blood vessels.
Fibrolamellar bone - mix of woven bone + primary osteons. No cement line around primary osteons. In growing regions especially cortex. Disorganised matrix + embedded vessels.
Primary osteons - cement line not present. Few concentric lamellae. Formed during original bone growth. Clean, small, orderly.
Secondary osteons - cement line present. many concentric lamellae. Formed through cortical bone remodelling. Appearance large circular, sharply defined.
white arrow - primary
black arrow - secondary
fibrolamellar bone - wiggly bracket
86
When are primary osteons formed and what do they contain?
Cortical bone
Primary osteons are formed during appositional bone growth, when the bone increases in diameter
They run parallel to the long axis of the bone, contain one or more vascular canals and are always surrounded by woven bone.
87
label a secondary osteon
answer
88
What are osteoblasts, osteocytes and osteoclasts derived from and what are their characteristics?
Osteoblasts
Derived from mesenchymal stem cells
Synthesize and secrete osteoid
Active in mineralization process
Osteocytes
Scattered within matrix
Interconnected by dendritic processes
Derived from osteobalsts but stopped synthesis of matrix and dividing
Reside within "lacunae“ which are interconnected by "canaliculi"
Long-lived
Maintain matrix
Osteoclasts
Responsible for bone resorption
Large cells, multiple nuclei
Release protons leads to acid environment leads to demineralization
Secrete proteases – destroy organic matrix
Derived from bone marrow
89
Process of bone modelling and remodelling
Cellular mechanisms:
Coordinated action osteoclasts and osteoblasts
Bone excavated – Osteoclasts excavate cylindrical tunnel – form a cutting cone (50nano m/day).
Bone replaced - Osteoblasts follow, form concentric lamellae of lamellar bone on walls, surrounding a centrally in-growing blood vessel. Form a secondary osteon.
Facilitates:
change in bone shape
change in bone material
repair of damaged bone
release of mineral ions
90
What is meant by a stress fracture?
"Stress fracture" defines a syndrome involving localised bone injury associated with fatigue damage subsequent to repetitive loading.
Underlying cause of lameness in wide range of conditions in racehorses.
Behind most catastrophic fractures in racehorses.
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On a stress strain curve what is meant by the terms, stress, strain, elastic region, yield point, plastic region?
Stress = force per unit area
Strain = percentage of elongation
Elastic region = measure of elasticity
Yield point = point at which the structure will no longer return to its original shape
Plastic region = structure deformed and moving towards failure
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What does microdamage of bone cause?
- structural damage, various levels
- cell death
- vascular disruption
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What is involved in the fracture cycle?
high strains - microdamage - remodelling - increased porosity .... repeat
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what type of growth occurs in bones?
interstitial growth = internal expansion
95
hyaline/ articular cartilage are involved in and when are they found?
Joint surfaces including synovial joints, sternum,
Precursors to bones in embryonic skeleton
Present inside bones, serving as a center of ossification or bone growth.
Predominantly type II collagen
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What is hyaline cartilage designed to do? and what are its implications for disease and repair?
Cartilage is designed to:
withstand and distribute load
act as an elastic shock absorber
provide a wear resistant surface to articulating joints
be self maintaining
Avascular – devoid of blood vessels
Aneural – devoid of nerves
Alymphatic - devoid of lymphatics
Implications for disease and repair
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What is white fibrocartilage and where is it found?
- Specialised cartilage in areas requiring tough support or great tensile strength eg intervertebral disks, symphyses
- Lines surfaces of bony grooves for tendons eg flexor digital sheath, palmar surface navicular bone.
- Interface ligament/tendon and bone
- Contains more collagen vs hyaline cartilage
- Contains type I and type II collagen (type II in hyaline and elastic cartilage)
- Fibrocartilage lacks a perichondrium
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Where is yellow/elastic cartilage found?
Yellow/elastic cartilage
Found in the pinna of the ear and several tubes, such as the walls of the auditory and eustachian canals and larynx, epiglottis, arytenoids.
Keeps tubes permanently open, similar to hyaline but contains elastic bundles (elastin) scattered throughout the matrix.
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How to chondrocytes multiply and how do they obtain nutrition and o2?
Chondrocytes are the only cells found in cartilage.
They produce and maintain the cartilage matrix.
Exist in low density
Obtain nutrition and O2 by diffusion (cartilage avascular)
Chondrocytes continue secreting new matrix when embedded in matrix internal expansion (interstitial growth)
Chondrocytes are capable of division within matrix
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How do chondrocytes vary in depth?
Chondrocytes in different zones of cartilage have distinct biochemical, biomechanical & physiological properties
Chondrocyte morphology varies with depth
superficial, middle, deep, calcified. Tend to get bigger and more complex as you get deeper but less of them.
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What are the two-phase composites of articular cartilage? and how are they organised and what do they contain?
Two-phase composite
3-D latticework of type II collagen fibres
Orientation of fibres divided into zones
Deeper (interface with bone) layer calcifies
2. Hydrated gel
Chondrocytes
No blood vessels, lymphatics or nerves
Deeper portion calcifies
Hydrated gel:
Fills (expands) space between collagen fibres
Held together by other "structural" molecules: collagen XI, collagen IX, fibromodulin, decorin,COMP
Aggrecan - proteoglycan
core protein
glycosaminoglycan chains
~ 10,000 –ve groups
attract cations (Na+)
osmotic pull water
Aggrecan linked to long hyaluronan to form long chain
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Tissue distribution of type 1 cartilage
skin, tendon, organs, mature scar tissue, artery walls, cornea, endomysium, fibrocartilage, surrounding muscle fibres, organic part of bones and teeth
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Tissue distribution of type 2 cartilage
hyaline cartilage (50% composition), vitreous humour
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Tissue distribution of type 3 cartilage
reticular fibres (organ stroma), granulation tissue
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Tissue distribution of type 4 cartilage
basal lamina, eye lens, filtration system of capillaries and glomerula
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Tissue distribution of type 5 cartilage
interstitial tissue (associated with type 1), placenta
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What does connective tissue develop from?
Develops from the embryonic mesenchymal tissue
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What is the function of mesenchymal cells and what are their characteristics?
Give rise to most tissues.
Mesenchyme cells are the little pink dots they are associated via cell processes, mechanism by which the cells communicate with each other The mesenchyme is surrounded by extensive ECM (contain proteoglycans, glycoproteins, fibres and other molecules).
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Characteristics of connective tissue
Often has fibroblast or fibrocytes. Contains ECM. Fibres are often collagenous, elastic or reticular and surrounding that is the ground substance different to that in bone. This is a very generic extra cellular matrix substance that also contains hyaluronic acid (soft, slippy). Proteoglycans and glycoproteins are often in the ECM too.
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Where are the following fibres found? Collagen fibres, elastic fibres and reticular fibres?
Collagen fibres
Crimp, arrangement
Tension
Tendon, fascia, capsules, cartilage, bone
Elastic fibres
Capsules, lungs, arteries
Stretch to 150%
Reticular fibres
Stroma (supportive)
Liver, kidney, spleen, lymph nodes, bone marrow where they provide structure so the organ retains its shape, size and doesn’t collapse in on itself.
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What is the main structural protein in connective tissue? and what is it structure and main components?
Collagen exists as a triple helix. This is the main protein found in most of these connective type tissues. Consists of a polypeptide triple helix structure this is a very firm structure. Amino acids there are have covalent bonds that are very strong and less likely to come apart than other bonds.
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What are Glycosaminoglycans? What do they do and what are they involved in?
Glycosaminoglycans are polysaccharide chains they are massive molecules that are negatively charged. They attract positively charged molecules. They are great for osmosis as they can draw and hold water. They are good at withstanding compressive forces, when you squash them, they're able to squash into a small shape then expand back into a big shape.
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Clinical uses of glycosaminoglycans
Clinical uses
Reduces inflammation
Enhances function
Mechanisms not fully understood
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What is hyaluronic acid characteristics and what is it involved in?
Resists compression
Major component of hyaline cartilage
Major component of synovial fluid
Affects viscosity together with lubricin
Major component of skin
Involved in many aspects of tissue repair
Facilitates cell migration and proliferation
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What do proteoglycans do and what is there importance?
Proteoglycans are also within the connective tissue they bind things and are very good at plasticity and elasticity, they help the tissue move quite freely. They are very good at trapping water, very good in collagen where water is expelled and brought back then trapped.
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importance of glycoproteins
Very important membrane proteins. It is very important and ensures that the cell membranes are firm and maintain their structure. They are also very important in cell-to-cell communication and interactions. They help bind together other components of connective tissue such as fibres, cells and ground substance.
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importance of laminin
Major proteins in the basal lamina
Influence
Cell differentiation
Migration
Adhesion
Phenotype
Survival
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What is fibronectin secreted by and what is it involved in?
Secreted by many cells, primarily fibroblasts
Involved in
Cell adhesion, growth, migration and differentiation
Wound healing
Embryonic development
Higher percentage in the body of an embryo than an adult.
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What is the interstitium and what is its roles?
Network of collagen fibers and fluid-filled spaces that underlies the skin and surrounds the gut, muscles, and blood vessels. A type of loose connective tissue.
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What is loose connective tissues role in the stroma?
Tissue in the stroma helps the organs keep shape and often in the functioning of that specific tissue.
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What does loose connective tissue contain that reduces damage away from main tissues? and what collagen fibre is it mainly made up of?
Loose connective tissue contains a reservoir of water, which is useful for the organ as it can take water away from the reserve. This creates less damage than taking it away from main tissues. Mostly type III collagen.
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Compare the fibres and cellularity of dense connective to loose connective tissue? What is the 2 types of order of these fibres and in which structures do you find these?
Dense connective tissue in comparison is usually more fiber rich, and we also tend to use it for areas where we need a lot of protection like the sclera of the eye, skin and dura matter. Also used in places where we need orderly bundles of fibers like tendons and ligaments. Often type I collagen as this is a little bit stronger than other types of collagen. Very few cells in dense connective tissue.
Disordered bundles of parallel fibres
Sclera
Skin
Dura mater
Parallel ordered bundles
Tendon
Ligaments
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Characteristics of tendon/ligament
Parallel collagen fibers give tendons and ligaments their strength. Several bundles are together so hopefully if one breaks the others will be fine.
Surrounded by peritenon (connective tissue sheath surrounding tendons/ligaments)
They contain
Nerves
Vessels
Fibrocytes/tenocytes
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What are the 2 types of supportive connective tissue? and what is the importance of their composition?
Bone and cartilage
Sparse cellularity
Collagen fibres give tensile strength
Composition of ground substance give characteristic mechanical properties
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What are fibrous joints? What are their importance and what are the 3 types and examples for each?
Fibrous joints are a type of joint where connections between bones are connected by fibrous connective tissue. These are important because they strongly unite adjacent bones and thus serve to provide protection for internal organs, strength to body regions, or weight-bearing stability. Sutures, syndesmoses and gomphosis are the three types of fibrous joints. Connective tissues help make up the joints. The skull also known as the cranial sutures, are fibrous joints that connect the bones of the skull type of sutures. Syndesmoses is a type of fibrous joint in which two parallel bones are united to each other by fibrous connective tissue e.g. split bones. Gomphosis is the specialized fibrous joint that anchors the root of a tooth into its bony socket with the maxillary bone (upper jaw) or mandible (lower jaw) of the skull.
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What are cartilaginous joints?
What are the 2 types and examples for each?
What are their importance?
Cartilaginous joints are another type of joint that are connected entirely by cartilage.
Synchondrosis e.g. between skull & hyoid bone
Symphysis e.g. two halves of pelvis
Cartilaginous joints allow more movement between bones than a fibrous joint but less than highly mobile synovial joint. They also form the growth regions of immature long bones and the intervertebral discs of the spinal column. Synchondrosis joints are cartilaginous joints which bones are joined together by hyaline cartilage. They may be temporary or permanent. A symphysis joint is a joint in which the body (physis) of one bone meets the body of another. Symphysis joints are joined by fibrocartilage, giving it a much greater ability to resist pulling and bending forces compared with synchondrosis joints and hyaline cartilage.
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What are synovial joints? and why are they significant?
A synovial joint is a connection between two bones consisting of a cartilage lined cavity with fluid, which is known as a diarthrosis joint. These joints are the most flexible type of joint between bones.
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What are involved in a synovial joint?
Articular cartilage
Subchondral bone
Epiphyseal bone
Synovial membrane
Synovial fluid
Capsule and ligaments
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What is subchondral bone and what is its importance?
Chondral means cartilage. So subchondral bone is the bit of bone that is connected to the cartilage. The bone provides nutrients and oxygen and gets rid of waste products from the cartilage. Therefore, the blood vessels that supply the bone also supply the cartilage. The subchondral bones job is to distribute the weight loads put on it to ensure that the bone doesn’t break. It has an undulating junction (wavelike shape), so that the cartilage can also undulate and they can fit together like a jigsaw (there's no glue).
Forms joint surfaces
Supports cartilage
Distributes loads to epiphyseal, metaphyseal, cortical bone
Variable thickness
Undulating junction with cartilage (no fibres cross)
Rich supply blood vessels, lymphatics, nerves
The subchondral bone tries to absorb the impact load so that the bone in the middle doesn’t have to withstand high forces.
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What is epiphyseal bone and what is its importance?
Epiphyseal bone is the bone at the end. It is good at undergoing modelling and remodelling. It is near the cartilage, if it gets damaged it can repair a lot easier than the bone in the middle. It is able to withstand the load.
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characteristics of synovial fluid
Clear, slightly yellowish, slippery, viscous fluid
Fills joint space
Ultrafiltrate of plasma
Contains similar ions & small molecules
High concentration of hyaluronan
Lubrication (soft tissues)
Nutrition
Volume usually low
Slight negative pressure (-1.25mmHg)
Helps stabilize joint
Pathology - high volume, distend joint (>51mmHg)
Reduced joint stability
Increased distance for nutrients to diffuse
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analysis of synovial fluid. normal and abnormal signs for cytology and biochemistry
Cytology - normal
Usually low cell count (<5x109cells/litre)
Some neutrophils, lymphocytes and mononuclear cells
Abnormal
high Neutrophils for bacterial and fungal infections
high Eosinophils for autoimmune disease
Biochemistry - normal
pH <6.9
Total protein 10-20g/l
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What are biomarkers and how do they involve synovial fluid?
Biomarkers are physical, chemical, or biological characteristics that can be measured in the body. Synovial fluid will show what is going on in the bone and cartilage surrounding it.
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Importance of cytokines in joint diseases
If certain cytokines are present, it could suggest certain types of diseases. These are released by cells for communication. Each specific cytokine could suggest certain and different diseases. Looking for differences in levels in different joints.
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Characteristics and importance of synovial fluid.
What are its two main cell types (synoviocytes)
Synovial membrane makes the synovial fluid and is highly vascularised it has lots of villi (massive SA) and that’s so it can secrete all this fluid into the joint. Relatively very easy to break this membrane, so you must be careful not to make a big hole causing synovial fluid to leak out of the joint.
"A": macrophage-like (eat debris and clean up the joint)
"B": fibroblast-like (synthesize macromolecules) collagen and hyaluronan
These are not exclusively just synoviocytes
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Function of synovial membrane
Function
Produce synovial fluid:
Filter plasma
Synthesize essential molecules
such as collagen and hyaluronan
Nutrition – brings blood vessels close to cartilage surface
Clear debris from joint
also has nerves as well
136
What is the importance of the joint capsule?
Supports synovium
Stabilizes joint
Contains nerves which are important in proprioception – monitor joint position and movement
137
What are collateral ligaments?
Collateral ligaments are important stabilizing structures found in joints, particularly the knee and elbow. They help prevent excessive side-to-side movement and provide support during motion.
Provide stability between bones forming a joint
Tendon-like but higher ratio of elastin to collagen: allows some more stretch
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Importance of tendon sheaths and bursae in joints.
These can be found depending on the joint. Tendon sheaths can cover tendons to make sure they are not rubbing against any sharp bones or things like that. Bursae cushions and protects soft tissues passing over hard points
139
What is joint homeostasis?
Joint homeostasis is keeping everything in the joint the same. Load-bearing is okay. Non-load bearing is where the joint can’t move. Fluid can’t move so the cartilage isn’t fed so it breaks down and so on. So, some bearing is very important
140
what are the constituents of bone cells?
What are their histological features and function/characteristics?
osteocytes, osteoblasts and osteoclasts.
Osteocytes
Histological feature - in lacunae: canaliculi
Function/ characteristic - control the activity of osteoclasts and osteoblasts
Osteoclasts
Histological feature - multinucleate, on surface
Function/ characteristic - breaking down bone tissue
Osteoblasts
Histological feature - periosteum and endosteum
Function/ characteristic - bone formation
141
what are the constituents of bone matrix?
What are their histological features and function/characteristics?
Collagen I, proteoglycans and glycoproteins.
Histological feature - eosinophilic (stains readily with eosin) in HE sections (Haematoxylin and eosin)
Function/ characteristic - maintaining the strength and integrity of bones
142
what are the constituents of bone mineral?
What are their histological features and function/characteristics?
calcium, carbonated hydroxyapatite
Histological feature: N/A
Function/ characteristic: gives bone their compressive strength
143
what are the constituents of bone collagen type/s?
What are their function/characteristics?
collagen I
Function/ characteristic: provides flexibility and strength
144
what are the constituents of cartilage cells?
What are their histological features and function?
Chondrocyte
Histological feature: lacunae
Function: produces collagen and the ECM
145
what are the constituents of cartilage matrix: hyaline, elastic, fibrocartilage?
What are their histological features and function?
Aggrecan
HF: surrounds the lacunae containing the chondrocytes
F: gives form and strength to cartilage through a mesh-like structure of fibrils
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what are the constituents of cartilage collagen type/s: hyaline, elastic, fibrocartilage?
What are their histological features and function?
Type II
HF: n/a
F: provides cushioning and reduces friction between the bones
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What is the costochondral junction?
The costochondral junction is the point where the ribs connect to the costal cartilage in the front of the rib cage.
148
What are calcium, phosphorus, magnesium, sodium and potassium's function in bone tissue?
Calcium and phosphorus are involved in maintaining strong bones and teeth.
Magnesium helps with the structural development of bones.
Sodium and potassium are present in smaller amounts, these minerals are important for maintaining bone structure and the body’s fluid balance.
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What are the roles of calcitonin, calcitriol and parathyroid hormone in calcium regulation?
Calcitonin is a hormone produced by the thyroid gland that regulates calcium levels in your body by decreasing it.
Calcitriol increases blood calcium levels by promoting absorption of dietary calcium from the GI tract.
Parathyroid hormone (PTH), regulates calcium and phosphate. PTH effects are present in the bones, kidneys, and small intestines. As serum calcium levels drop, the secretion of PTH by the parathyroid gland increases.
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Characteristics of long bones and examples
Long bones
- Characterized by their elongated shape and are typically longer than they are wide
- Hard, dense bones that provide strength, structure and mobility
- They have two ends and contain yellow and red bone marrow
- Examples include bones of the arms and legs.
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Characteristics of short bones and examples
Short bones
- They are roughly cube shaped. Equal width and length
- Primarily composed of spongy tissue covered by a thin layer of compact bone.
- Provide stability and support with little movement.
Examples include the carpal bones, tarsal bones and the patella.
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Characteristics of flat bones and examples
Flat bones
- Type of bone that is thin, flattened and slightly curved.
- Composed of a spongy bone sandwiched between two thin layers of compact bone.
- They serve as the point of attachment for muscles or protection for your internal organs
- Examples include frontal bone of skull, scapula, sternum and ribs.
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Characteristics of irregular bones and examples
Irregular bones
- Unique shape that cannot be classified as long, short, or flat bones.
- Consist of thin layers of compact bone surrounding a spongy interior
- Examples include vertebrae, the hip, and some bones found in the skull.
Perform various functions including, protecting nerve tissue and providing support for the pharynx and trachea.
154
Characteristics of sesamoid bones and examples
Sesamoid bones (derived from the Greek word for sesamoid seed hence the small size)
- Bone embedded with a tendon or a muscle.
Examples include the patella in the knee
155
Characteristics of visceral bones and examples
Visceral bones
- Bony formations in an organ.
- They can be found in the heart tongue, or penis of certain animals.
- The lower jaw, some elements of the upper jaw, and the brachial arches, including the hyoid bone, are also considered visceral bone.
156
What are the 3 types of joints? and what are the different classes within these? and give examples
Fibrous joints include sutures (joints found between the bones of the skull), syndesmoses (joints found between long bones that allow for slight movement between parallel points), gomphoses (joints between the teeth and their sockets in the jawbone)
Cartilaginous joints include the pubic symphysis, costal cartilages (connecting ribs and the sternum), intervertebral discs (between vertebrae in spine)
Synovial joints include the shoulder, hip, elbow, ankle, knee, neck, wrist.
157
What is meant by the diaphysis, metaphysis and epiphysis? and what are their functions?
Diaphysis is the central elongated shaft of the bone. Provides strength and support. It contains the central medullary cavity filled with bone marrow, crucial for the production of blood cells.
Metaphysis is the neck portion of a long bone between the epiphysis and diaphysis. It contains the growth plate the part of the bone that grows during childhood, and as it grows it ossifies near the diaphysis and epiphysis.
Epiphysis is the end part of a long bone, initially growing separately from the shaft. The primary function of the epiphysis is to allow for movement at the joints. The articular cartilage of the epiphysis provides a smooth, low-friction surface for the bones to move against each other.
158
What is compact bone? and what is its functions?
Compact bone (Cortical bone)
- Dense and strong type of bone that forms the outer layer of bones.
Provides structural support and protection due to its high density and minimal porosity.
159
What is the medullar cavity? and what is its functions?
- Hollow central space within the shafts of long bones.
- Contains bone marrow, which plays a role in the production of red and white blood cells and platelets.
Surrounded by a thin layer of spongy bone and a thick layer of compact bone.
160
What is Synoviocentesis ?
Synoviocentesis is a diagnostic procedure that involves the collection of synovial fluid from a joint or tendon sheath.
161
What are the reasons for carrying out synoviocentesis?
Reasons for carrying out synoviocentesis are to investigate joint disease or whether there are any indications of infection in the joint space itself.
162
What is involved in the typical preparation for synovioventesis?
Typical preparation includes clipping the limb and scrubbing the area with an antiseptic solution with a minimum of 3-5 mins of contact time. Joint surface is prepared by swabbing or splashing alcohol solution on the surface.
163
EDTA tubes are needed for collecting samples for further analysis, what are their purpose?
chelating agent that can remove metals from the blood
164
How to carry out synociocentesis of metacarpophalangeal joint (fetlock)?
Flex the fetlock joint
Insert the needle through the proximal part part of the lateral collateral sesmoidean ligament in a frontal plane with the needle parallel to ground
Look at aspiration 1 image
165
How to carry out synociocentesis of distal interphalangeal joint (coffin)?
Palpate the condyles of the second phalanx of the dorsal aspect
Insert the needle (19 or 20G) proximal to the coronary band, on the midline or 1cm medial or lateral to it.
direct the needle distally (and axially if an off-midline approach is used)
look at aspiration 2 image
166
What do you analyse of the joint fluid?
Turbidity (cloudiness)
Colour
Viscosity (take a drop between finger and thumbs, pull them apart and see how long the fluid takes before it snaps)
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onto direct smears part of bone and joint anatomy and histology SDL
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