Anatomy And Physiology

Question 1

Cranium structure and function

Answer 1

Structure:
- facial bones: eye sockets, nose, cheeks, jaw etc.
- opening at the base of cranium to allow spinal cord to connect to brain
Function:
-it protects the brain from damage

Question 2

Maxilla structure and function

Answer 2

Structure:
- major bone in face
- part of nasal and oral cavity
Function:
- holds top teeth in place
- supports muscles that are used in mastication and facial expressions

Question 3

Mandible structure and function

Answer 3

Structure:
- largest and strongest bone in face
- only moveable bone in skull
- attached to muscles
Function:
- involved in mouth movements
- holds bottom teeth in place

Question 4

Sternum structure and function

Answer 4

Structure:
- Elongated bone on centre of the chest
- found in 4 limbed vertebrates
- adapted for avian to allow flight
Function:
- gives definition and supports the clavicle and ribs

Question 5

Clavicle (collarbone) structure and function

Answer 5

Structure:
- curved bone of the shoulder girdle
- the furcular (wishbone)is made of 2 clavicle bones fused together
Function:
- links the scapula and the sternum in vertebrates
- holds the shoulder in place to allow weight to be transferred from upper body to head, back and chest

Question 6

Hyoid structure and function

Answer 6

Structure:
- attached to the base of skull, the mandible, the tongue, the larynx and the scapular belt.
- has a body 2 greater horns and 2 lesser
Differs in place and function differs depending on species
Function:
- Serves as an attachment structure for the tongue and muscles in the floor of the oral cavity
- when swallowing the hyoid bone, tongue and larynx move upwards rapidly

Question 7

Rib cage structure and function

Answer 7

Structure:
- there are 24 ribs but this can vary by species
- which each descending rib the cage gets a lot more bigger
- the lower part of the ribs (last 5) give freedom to allow for diaphragm movement
Function:
- protect the lungs, heart, and other internal organs of the thorax
- in snakes the ribs provide protection for the whole entire body

Question 8

Baculum structure and function

Answer 8

Structure:
- isolated bone in the penis
- derived from connective tissue
- found at the distal end of the tissue above the urethra
- it is long, thin and narrow
- it is absent in humans but present in primates
Function:
- it aids sexual reproduction by keeping stiffness during sexual penetration
- allows males to mate for longer periods which help in mating strategies
- varies in size and shape depending on species

Question 9

Plasma structure and function

Answer 9

Structure:
- Cell/Plasma membrane
- thin semi permeable wall
- separates cell contents and surroundings
- acts as a barrier to block certain ions and molecules from entering and exiting the cell
Function:
- Prevents blood clots
- Provides immunity
- helps keep healthy blood pressure and volume
- Plasma proteins maintain body’s ph balance
- carry electrolytes (potassium and sodium) to the muscles
- Transports nutrients like glucose, amino acids, lipids and vitamins around the body
- carries oxygen to organs and co2 back to lungs
- transports hormones to dedicated organs

Question 10

Erythrocytes structure and function

Answer 10

Structure:
- red due to haemoglobin inside them which allows them to carry oxygen
- microscopic, Biconcave disc, no nucleus to allow them to carry more
- develop in bone marrow
Function:
- carry nutrients to muscles
- carry oxygen to rest of the body from lungs

Question 11

Leukocytes structure and function

Answer 11

Structure:
- they are colourless, have a distinct membrane (nucleus), microscopic
- flexible cell membranes and can form extensions called pseudopodia to aid engulfing of pathogens
5 Different types of leukocytes
- Neutrophils: kill bacteria, fungi, and foreign debris
- Lymphocytes: consist of T cells, Natural killer cells and B cells to protect and make antibodies
- Eosinophils: identify and destroy parasites, cancer cells and assist the basophils with allergic responses
- Monocytes: clean up damaged cells
- Basophils: produce an allergic reaction (coughing and sneezing)
Function:
- help fight infection and part of immune system
- circulate in tissues and bloodstream to respond to injury or illness
- attack unknown organisms that enter the body
- produce antibodies to attach and destroy the organisms

Question 12

Thrombocytes structure and function

Answer 12

Structure:
- smallest blood cell
- shaped like a plate in non active form (not being used to stop blood loss)
- receive signal from damaged vessel and this activates the platelets into their “octopus” form
- they gain tentacles in active form to attach to the broken vessels
Function:
- helps to stop and control bleeding
- essential for survival during surgeries and injuries
- if an animal lacks thrombocytes in the blood it can be fatal

Question 13

Arteries structure and function

Answer 13

Structure:
- under high pressure due to blood flow
- very small lumen
- thick outer walls

Function:
- carries oxygenated blood to body cells
- pulmonary artery carry’s only unoxygenated blood

Question 14

Vein structure and function

Answer 14

Structure:
- low blood pressure
- valves to prevent backflow
- large lumen
- thin outer walls

Function:
- carries deoxygenated blood from body to heart.
Pulmonary vein take oxygenated blood

Question 15

Capillaries structure and function

Answer 15

Structure:
- one cell wall thick to allow for diffusion
- form a dense network to bathe body tissue

Function:
- oxygen and dissolved foods diffuse into cells from blood
Carbon dioxide and waste products diffuse out of the blood

Question 16

Bronchi Structure and function

Answer 16

Structure:
- has cartilage rings
- trunk of the tree
Function:
- disperses air into all areas of the lungs

Question 17

Alveoli structure and function

Answer 17

Structure:
- grape like structure to increase surface area
- give lungs a spongey appearance
- 1 cell thick walls to allow diffusion
- moist to allow gas exchange to take place more easily
Function:
- Site of gas exchange
- surrounded by capillaries to get oxygen into blood

Question 18

Function of diaphragm

Answer 18

Mechanics:
- skeletal muscles underneath the lungs
- creates a vacuum in the chest cavity
- contracts down when breathing in to draw air into the lungs
- relaxes and pushes air out of the lungs

Question 19

3 types of nervous system in the body

Answer 19

Central nervous system
- brain and spinal cord
Peripheral nervous system
- communication nerves that transmit signals to the CNS
Autonomic nervous system
- regulates involuntary physiologic processes (heart rate, blood pressure, respiration, digestion and sexual arousal)

Question 20

Central nervous system - forebrain

Answer 20

Brain - forebrain, midbrain, hindbrain

Forebrain:
- cerebral cortex:
Also known as the hemisphere or cerebrum
- deeply folded layers for protection
- outer layer of grey matter contains cell bodies of neuron’s
- Inner layer of white matter contains nerve fibre
- used for higher thinking

Thalamus:
- centre of the brain and have 2 either side (hypothalamus and thalamus)
- relay station for sensory information
- central location allows nerve fibres to spread easier throughout the brain

Limbic system:
- responsible for emotion, behaviour, motivation, long term memory and olfaction.
Made up of:
- hypothalamus
- amygdala: emotion centre of the brain
- hippocampus: role of formation for new memories and past experiences
- cingulate gyrus: plays a role in reaction to pain and regulation of aggressive behaviour
- basal ganglia: involved with rule bases learning, choosing from potential actions, working memory and attention

Question 21

Central nervous system - midbrain

Answer 21

Mid-Brain:
- In between the forebrain and hindbrain and only seen when the brain is cut into.
- it is essentially a motorway for the brain nerve fibres, carry info for hearing and sight.
- not processed just transferred to required location
- responsible for sleep, arousal, pain, consciousness and habituation
- neuron receptors: target of transmitters and drugs eg: serotonin and dopamine receptors.
- membrane receptor protein that is activated by a neurotransmitter
Reticular Formation:
- Network of neuron’s throughout the brainstem which extends into the thalamus.
- structure has no clear boundaries so it’s hard to label
- involved in physiological functions eg: pain sensitisation, alertness, fatigue, sleep and motivation.

Question 22

Central nervous system - Hindbrain

Answer 22

Hind-Brain:
Cerebellum:
- dorsal surface of hindbrain, globular covers in deep fissures, responsible for balance, coordination and movement.
The pons:
- forms a bridge of nerve fibres between midbrain and medulla oblongata and control breathing and heart rate.
Medulla oblongata:
- extends from hindbrain and merges into spinal cord.
- responsible for breathing, blood pressure, heart rate, swallowing and coughing.

Question 23

3 methods the body uses to protect the brain

Answer 23

1. Ventricular system:
   - inter-connecting valves and cavities inside the brain, filled with cerebrospinal fluid.
2. Meninges:
   - protective layers around the brain made from connective tissue and collagen fibres.
3. Blood brain barrier:
   - membrane that controls movement of substances.

Question 24

Structure and function of spinal cord

Answer 24

Structure:
- protected by spinal cord column that is made up of vertebrae.
Function:
- relay information of inner and outer responses from the body and report them to your brain.

Question 25

Autonomic nervous system - Synapses

Answer 25

Synapses: - axon terminates from the synapse, the axon passes the impulse to the dendrites and they push on the impulse to the synaptic cleft, when it reaches the synaptic cleft a neurotransmitter takes the impulse and carries it across the synapse through the chemical fluid and brings it to the post synaptic membrane.

Question 26

Autonomic nervous system - notes and (para)sympathetic

Answer 26

Autonomic nervous system - governs fight or flight response - controls internal organs - involuntary control - has 2 parts: sympathetic and parasympathetic. Parasympathetic: - controls when animal is at rest - prepares animal to conserve or save energy by completing certain activities eg: stimulating salivary glands and digestive juices, decreasing heart and respiration rates. Sympathetic: - prepares body for energy consuming activities eg: - inhibiting digestive system and salivation - increasing heart and respiration rates - encourages the liver to release glucose into bloodstream - stimulates adrenal glands to release hormones

Question 27

Endocrine system - location of glands and hormones

Answer 27

What is a gland - a group of cells specialised to release certain hormones. What is a hormone - a substance that is secreted into the blood from a tissue that makes it Hypothalamus: Structure - size of a pea, divided into 3 zones, highly complex part of the brain Location - deep within the brain, above pituitary gland Function: - Main link between endocrine and nervous system - Maintains your body in a balanced state - Produces some hormones (anti diuretic hormone) Responsible for: Body temperature, blood pressure, hunger and thirst, sense of fullness when eating, mood, sex drive and sleep Pituitary gland: Structure - divided into 2 sections anterior and posterior lobe, 1.25cm in diameter, connected to hypothalamus by pituitary stalk Location - base of the brain Function - anterior lobe makes and releases - follicle stimulating hormone, luteinising hormone, prolactin, growth hormone. Posterior lobe releases - anti diuretic hormone, oxytocin. Responsible for growth, metabolism, reproduction, response to stress and trauma, lactation, water and sodium, labour and childbirth. Pancreas: Structure - leaf shaped/tapered organ, five parts of pancreas, contain 2 glands. Location - in the abdomen behind stomach and in front of spine. Function - 2 main functions, exocrine function to aid digestion, endocrine function to regular blood sugar levels. Consists of islets of langerhans that create and release hormones eg: glucagon and insulin. Adrenal glands: Structure - triangular shaped, come as a pair Location - above the kidneys Function - secrete hormones to regulate metabolism and immune system, produce hormones eg: aldosterone, glucocorticoids - cortisol mostly, adrenaline and noradrenaline Thyroid: Structure - 2 inches long and butterfly shape Location - found in neck Function - produces hormones that regulate the body’s metabolism, produces calcitonin to regulate calcium levels balanced and thyroxine - metabolism. Parathyroid: Structure - small and oval shaped Location - back of the thyroid Function - produces parathyroid hormone to increase calcium levels in blood. Ovaries: Structure - Paired Location - lower abdomen on each side of uterus Function - hormone production during female reproduction: oestrogen - prepares for uterus embryo to implant Progesterone - maintains pregnancy Testes: Structure - oval shaped organ, paired Location - underneath the male appendage Function - part of male reproduction, secretion of testosterone

Question 28

Hormone effects and controls mechanisms

Answer 28

Circulating hormones - released into blood and are circulated to all cells throughout the body. Examples could be a thyroxine or progesterone. Local hormones - secreted by body tissue and bind to neighbouring or local cells but do not circulate through the blood Examples are mast cells release histamine to attract the immune defence system due to body damage Hormone receptors: - chemical messengers released into blood plasma or or to cell/tissue local area - it only affects cells if it has the correct receptor - hormone receptors are molecules inside or on the surface of a cell that binds its hormone resulting in molecular change which initiates character or group of responses - these are proteins or glycoproteins

Question 29

Thermoregulation

Answer 29

Thermoregulation is the way the body controls your temperature. Too hot - hyperthermia - releases heat Too cold - hypothermia - increases heat Hypothalamus causes these changes in the body Too hot: Sweating - evaporation from skins surface to reduce temp Increased respiration heat loss - warmer air breathed out Dogs don’t sweat they pant to release heat. Vasodilation - body vessels next to skin widen Hairs on body flatten down Too cold: Vasoconstriction - blood vessels next to skin narrow Body hairs - raise to trap heat next to body Shivering - increases metabolism to release heat as by product Muscular activity - releases heat within body Release of adrenaline Brown fat stores Endotherm: An animal that controls mechanisms inside its own body - temperature homeostasis Ectotherm: Animal that gains heat from outside the body sources - directly or indirectly from the sun - able to survive from lower body temperatures - use heat from sun and rocks to increase temps - able to slow metabolism and activities to conserve heat and stop needing to use energy for food

Question 30

Stem cells structure and function

Answer 30

Stem cells are an undifferentiated and not specialised cell. Structure: - do not have tissue - specified structure. - found throughout the body in bone marrow, blood vessels, brain, skin and heart. Function: - only cells that are able to differentiate into 200+ cells such as bone, blood, fat and nerve cells - can repair damaged tissues

Question 31

Bone cells

Answer 31

Bone cells: Structure:

Question 32

Bone cells structure and function

Answer 32

Bone cells: Mature bone cells are called osteocytes which are derived from osteoblasts (bone forming cells) Structure: - a Stellate shape - found in the lacuna in bone matrix Function: - bone deposition and resorption - play a role in bone remodelling

Question 33

Blood cells: erythrocytes

Answer 33

Erythrocytes: Structure: - have no nucleus - don’t contain dna - do not divide or carry out most tasks like most other typical cells - their shape is biconcave to maximise surface area. Function: - responsible for transporting oxygen and nutrients

Question 34

Blood cells: leukocytes

Answer 34

Leukocytes: Structure: - contain a nucleus - flexible cell membranes which can form extensions (help engulf pathogens) - very small and can only be seen under a microscope Function: - part of immune system - help to protect and fight disease

Question 35

Muscle cells structure and function

Answer 35

Muscle cells: Structure: - contain myofibrils - composed of three proteins (actin, myosin and Titin) that interact to enable muscle contraction - contain sarcoplasm instead of cytoplasm Function: - specialised cells that are able to contract