NMSK Flashcards
Hypo-
Under or below
hyper-
above
Epi-
upon, on, over, near, at, before, after
supra-
above or after
sub-
under
osteo-
bone
chondr-
cartilage
endo-
within
ecto-
outer, external
-cyte
relating to a cell
-itis
inflammation or a disease characterised by inflammation
-ectomy
exision (surgical removal)
Terms used for describing moving closer and away from the middle of the body
lateral and medial
terms used for going towards the topside or belly side
Ventral and dorsal (belly side and topside respectively)
What terms are used to describe being close to the beginning or end of the structure (like a arm or leg)
proximal and distal
terms used to describe going towards the heard or towards the tail
cranial and caudal
what terms are used to describe the palm or the anterior surface of the hand/leg and what is its opposite term
palmar and dorsal
terms used to describe the bottom and top of the foot
Plantar and dorsal (respectively)
terms used to describe the front or back of the brain
rostral and caudal respectively
what term is used to describe being located or directed towards the axis and is located or directed away from the axis
Axial and abaxial respectively
what plane runs parallel to the back
Dorsal plane
what plane divides the body into top and bottom parts?
transverse plane
what plane divides the body into right and left halves? and what is this plane specifically called when the parts are exactly equal?
sagittal plan and median plane respectively
What is the tube of solid bone called that surrounds the central cavity filled with bone marrow (fat in older animals)? also what is the name of this part?
Cortex and medulla respectively
What are the 3 parts of the bone in terms of sections? and which regions are these?
Epiphysis - rounded end
Metaphysis - flared region
Diaphysis - shaft
Metaphysis is adjacent to epiphysis
What are the two types of bone?
Cortical (compact) bone and cancellous (trabecular spongy) bone
What are visceral bones?
These are bony formations in soft tissue rather than being part of the skeleton like the os penis bone and os cordis (in the heart of ruminants). os means bone in latin.
What are the two classification categories for describing where bones come from and what do they mean?
Axial skeleton and appendicular skeleton
Axial skeleton - bones forming the axis or centre of the animal
Appendicular skeleton - regions that are attached.
What are the two types of bone development and what do they mean?
chondral ossification and membranous ossification
chondral ossification - bones ossify from a cartilage precursor (most limb bones)
Membranous ossification - bones ossify directly from mesenchymal cells (scapula, most bones of the skull)
Bones can be classified on how they developed. Where would you find these two types of bones formed from these processes in terms of weight bearing and why?
Chondral ossification - found in load bearing areas. Often have specific fail/ fracture configuration.
Membranous ossification - found in non-load bearing areas. These bones are generally lighter and less dense.
What are the 6 types of bones in terms of shape and what does each individual term mean?
long b - inc femur, tibia and fibula
short b - inc tarsals and carpals
flat b - protect internal organs or provide a connection point for your muscles
sesamoid b - small, round bones that are embedded within tendons or ligaments
irregular b - unique shapes and can’t be classed as the others such as vertebrae
pneumatic b - for reducing weight in birds
What type of bone is adapted for resisting compression when loaded and acts a lever during movement and resists tension during muscle contraction and how does it do this?
Long bones.
- Main part of bone is a column providing strength
-expanded ends providing transfer of load
what type of bone is found in groups and why? and why is one of its surface always non-articular?
short bones.
They are found in groups to disseminate forces through joints
One surface is always non-articular for ligament attachment and vasculature
What type of bone has jutting processes and what are the point of these?
Irregular bones have various jutting processes for muscle and ligament attachment.
What type of bone act as attachments for soft tissues and protect underlying tissues?
flat bones
what is the name for bones that contain air sacs?
pneumatic bones
Flat bones of the skull- form the paranasal sinuses.
what is the function of sesamoid bones and how are these attached?
provide additional strength and reduce wear over joints. Protect and redirect tendons.
They are held in place by surrounding tendons or ligaments (patella, fetlock, navicular bone).
What is the name of the fibrous connective tissue membrane consisting of two layers regarding bones: an outer fibrous and inner cellular layer? and what does it do?
Periosteum.
supplies bones with blood, nerves and cells that help them grow and heal.
What is the main structure in the body for support, protection and movement? and what is it made up of?
Compact (cortical) bone. It is made up of concentric bone arranged around a central osteon
what is the purpose of an osteon?
provide strength and support to the bone, and help in repair and remodelling of bone tissue.
describe the structure of a cancellous (spongy) bone
Light and porous, honeycomb like structure. The bone matrix is organised into 3-dimensional latticework of bony processes called trabeculae, arranged along lines of stress. The spaces between are often filled with marrow and blood vessels.
what is the function of cancellous (spongy) bone?
- 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.
describe the structure of a medullary cavity and its surrounding layers
A hollow central space found within the shaft (diaysis) 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.
What is the function of the medullary cavity?
contains bone marrow, which produces blood cells and stores fats and minerals
What is a haversian canal and what is its function?
A haversian canal surrounds blood vessels and nerve cells throughout bones and communicates with osteocytes through connections called lacunae.
What are the 4 types of tissue?
Epithelial tissue
Nervous tissue
connective tissue (inc blood tissue)
muscle (contractile) tissue
What does nervous tissue consist of?
Think about which neurological cells are involved in the CNS and PNS and what do they do?
Nerve cells (neurones) + neurological cells.
CNS
astrocytes (star-shaped) - provide structural and metabolic support to neuron, blood-brain barrier maintenance, regulate neurotransmitter levels, aid in brain and spinal cord repair after injury, regulate blood flow to active brain regions
oligodendrocytes - produce + maintain the myelin sheath, provide metabolic + structural support to neurons (particularly axons), regulate of ion movement around axons for optimal signal transmission
microglial cells - primary immune cells in CNS, phagocytosis, inflammatory response (release cytokines and signalling molecules to mediate inflammation), synaptic remodelling (during development and in response to neural activity), maintenance (monitor the health of neurons and the CNS environment, maintaining homeostasis)
ependymal cells (line the ventricles of the brain and the central canal of the spinal cord) - Producing CSF (cerebrospinal fluid) which cushions the brain and the spinal cord, circulating CSF, create a selectively permeable barrier the CSF and brain tissue, neural stem activity (some ependymal cells have stem-like properties, contributing to neurogenesis (the formation of new neurons) in certain conditions.
PNS
Satellite cells - found in the ganglia of the PNS, surrounding the neuronal cell bodies. Function: provide structural and metabolic support to neurons, regulate microenvironment (nutrients, ions and neurotransmitters), involved in chronic pain signalling by interacting with sensory neurons, potential role in neural regeneration.
Schwann cells - found in the PNS, wrapping around axons (nerve fibres) . Function: form the myelin sheath, provide support and protection for unmyelinated fibres, help guide axon regrowth through Wallerian degeneration, play a role in nerve inflammation and repair.
What are the various functions of connective tissues? and where does it originate from in the trilaminar disc of the embryo?
- mechanical and structural support
- supports and connects the various parts of the body by 3-dimensional frameworks called stroma
- separate tissues and organs
Originates from cells of the mesodermal layer of the embryo
Describe the structure and function of loose connective tissue, and what does it supply?
Composed of loosely arranged collagen and elastic fibres embedded in a gel-like matrix called ground substance.
Its flexibility allows for movement and stretching without comprising the integrity of neighbouring tissues. It also plays an important role in the immune system as it houses immune cells that fight against infections and foreign particles. Additionally, it facilitates the diffusion of nutrients, gases and waste products between blood vessels and surrounding tissues.
This type of tissue forms a network that surrounds and supports blood vessels, nerves and organs.
What are the two types of dense connective tissue, describe there structure and function and where they are found?
Regular and irregular dense connective tissue.
Dense connective tissue is a type of connective tissue primarily composed of type 1 collagen fibres. Fewer cells and less ground substance compared to loose connective tissue.
Regular - fibres are arranged in a parallel and organized pattern - Mainly composed of collagen fibres, with some fibroblasts (cells that produce the collagen and other fibres) - provides strength, flexible support from one direction- Found in tendons and ligaments
Irregular - fibres are arranged in a more random, less organized pattern - Similar composition to regular dense connective tissue - provides strength in multiple directions as opposed to one
- Found in areas that require support and flexibility from various angles, such as the dermis of the skin and the fibrous capsules around organs and joints.
what are the 5 main types of connective tissue?
loose connective tissue, dense connective tissue, cartilage, bone and blood.
what are the 3 types of cartilage? Describe their structure and function and where they are found?
3 types of cartilage: hyaline, elastic and fibro.
Cartilage is made up of the following components specialised cells called chondrocytes and chondroblasts, ECM (which includes glycosaminoglycans (hydrophilic and ideal for attracting water, which contributes to the gel-like consistency of the extracellular matrix (ECM)), proteoglycans (Proteoglycans are proteins covalently linked to GAGs (except hyaluronic acid). They function in hydration, cushioning, and structural support of the ECM) and water)
- Hyaline - smooth, glossy appearance due to fine collagen fibres that are not easily visible under a microscope.
- provides smooth surfaces for joint movement, flexibility and support
- found in the nose, trachea, larynx, ends of long bones (Articular cartilage) and the fetal skeleton
- Elastic - contains a high number of elastic fibres in addition to collagen fibres, making it more flexible and resilient. - maintains the shape of structures while providing flexibility
- found in the ear (auricle), the epiglottis (part of the larynx), and the eustachian tubes
- Fibro - contains thick bundles of collagen fibres, making it very strong and able to withstand heavy pressure - provides strong support and withstands compression
- found in the intervertebral discs, the menisci (knee), and the pubic symphysis (joint between the two pelvic bones)
What are the two types of bone tissue? and describe their structure and function? And also where it is found?
lamellar bone and trabecular bone
- Lamellar- type of mature bone characterised by its organized structure, consisting of parallel layers or lamellae of collagen fibres. - makes up the compact bones in the skeleton, such as the long bones of the legs and arms.
replaces woven bone during the process of bone remodelling, ensuring the strength and integrity of the skeletal system. - Trabecular bone- Lighter less dense type of bone found within the interior of bones. It has a porous, honeycomb like structure composed of trabeculae, which are thin rods and plates of bones that form a meshwork - Found at the end of long bones and in the vertebrae. Like at the ends of the femur - Network of spongy bones acts as a shock absorber cushioning the impact forces during locomotion.
What is blood made up of? Where is it located and what is its role?
Blood (fluid connective tissue)
- Made up of red and white blood cells., plasma and platelets.- Located within your bones, bone marrow. - transportation of substances into and out of the body, regulation of internal body temperature, involved in the immune response
compare loose connective tissue to dense connective tissue
LCT has fewer fibres (still has collagen and elastin), more cells and ground substance, less rigid and more easily distorted (still provides resistance when stretched creating a tough barrier).
what do chondrocytes do?
produces a matrix in cartilage (ECM) which is made up of type 2 collagen, glycoproteins and water. They synthesize GAG, elastin and collagen to provide cartilage with strength, flexibility, and resilience, regulation of cartilage during embryonic development and postnatal growth, response to mechanical stress.
What does cartilage not contain that makes it more flexible than bone?
calcium phosphate
What is the composition of blood and to what levels?
Approximately 55% plasma, 45% erythrocytes (red blood cells), 1% leukocytes (white blood cells) and thrombocytes (platelets)
How are cells separated in connective tissue?
separated by abundant ECM.
What are the 3 main components of connective tissues?
cells, collagen fibres and ground substances (special proteins).
What are the name of the cells embedded in cartilage, bone, muscle, tendons?
Cartilage= chondrocytes
Bone= Osteoblasts/osteocytes/osteoclasts
Muscle= myocytes
Tendons= tenocytes (elongated fibrocytes)
Osteoclasts ae derived from monocytes ( a white blood cell (WBC) linage)
What does ECM consists of? And what is its function? What are the 3 types of specialist cells that maintain the matrix?
ECM consists of collagen (several types, type 1 most common) and elastin fibres, ground substance and water.
It gives connective tissue its morphological and functional characteristics. Provides structural support of cells, also guides their division, growth and development.
- blasts - cytes and - clasts.
- blasts create matrix
- cytes maintain matrix (control activity of blasts and clasts)
- clasts break down matrix for remodelling
What is the difference between fibrous ECM and liquid ECM in structure, function and properties?
Structure
- Fibrous ECM is composed mainly of fibrous proteins like collagen, elastin and fibronectin. These proteins form a dense, mesh-like network.
- Liquid ECM is found in fluids like blood plasma. It contains a mix of soluble proteins, electrolytes, and other molecules.
Function
- Fibrous ECM provides structural support and tensile strength to tissues. It’s crucial in areas that experience high mechanical stress, such as tendons, ligaments and skin.
- Liquid ECM facilitates the transport of nutrients, waste products, and signalling molecules throughout the body. It also helps maintain homeostasis and providing a medium for cellular communication.
Properties
- Fibrous ECM is highly rigid and strong, capable of withstanding stretching and pressure. It also plays a role in cell adhesion, migration and differentiation.
Liquid ECM is more fluid and less structured compared to fibrous ECM. It allows for easy movement and flow of its components.
In embryonic development what layer of the germ layer does connective tissue come from?
The mesoderm (middle layer)
Where was loose connective tissue found primarily in early embryonic development? What features did it have?
In the umbilical cord.
Features: hydrophilic ECM, jelly-like, also known as mucoid connective tissue or Wharton’s jelly.
what is reticular connective tissue?
Connective tissue is a form of connective tissue with reticular fibres (collagen type III) as the main component.
It contains reticular and elastic fibres that are the main element in irregular connective tissues. Reticular fibres form the stroma of the lymphoid system (lymph nodes and spleen). Elastic fibres line intervertebral discs and the wall of the aorta.
What are the 2 types of adipose tissue and what is their function? describe their structure and function?
Brown adipose tissue - involved in heat control (insulation)
White adipose tissue - energy storage
Structure: little ECM surrounding cells, cells full of lipid
Function: packaging, protection, insulation
Factors to consider before accessing locomotion?
Before you start accessing locomotion.
Consider:
- Space availability
- Surface conditions (firm, level, non-slip) firm surface allows you to access muscular, soft surface: soft tissue and allowing you to listen to footfalls
- Age of animal
- Any medical conditions
- Handler
Speed of gait
How to access locomotion?
- Visual observations
- Locomotion analysis equipment (high speed treadmills, video cameras, data analysis software, force plates)
Assess quality and divergence from the norm
What is a stride? and what are the 2 phases involved in a stride?
A stride is a complete cycle of movement. E.G. from the setting down of a foot to the next setting down of the same foot
2 phases
- stance phase (weight bearing limb)
- swing phase (non-weight bearing limb)
What is the beat of a walk and sequence of foot falls?
4 beat. RH-RF-LH-LF
What is the beat of a trot and sequence of foot falls?
2 beat LH+RF then LF+RH
What is the beat of a canter and sequence of foot falls?
3 beat RH,RF+LH,LF or LH,LF+RH,RF
What is the beat of a gallop and sequence of foot falls?
fast 4 beat
Transverse gallop
Horses, cattle, deer, dogs at low speed, LH,RH,LF,RF, suspension phase
Rotatory gallop
Dogs at high speed, cheetahs, gazelle, running rodents RH,LH suspension phase ,LF,RF, suspension phase
Counter-rotatory is opposite of rotatory gallop - greyhounds on the track
what neurological sensations are involved in limb coordination?
vision
vestibular system - balance
mechanoreceptors - touch
nociceptors - pain
proprioceptors - body position
What motor responses are used in limb coordination?
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 - The brainstem plays a crucial role in limb coordination by acting as a relay centre for many essential motor functions. It integrates and processes signals between the brain and the spinal cord to facilitate smooth, coordinated movements of the limbs.
Cerebellum - balance (continuously processing information related to body position, movement, and coordination)
Constant monitoring of muscle length and tension (muscle spindles and golgi tendon organs)
Equine adaptations to high speed locomotion
- increased 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 work done by animal during locomotion involves accelerating and decelerating limbs, muscles positioned proximally (near pivot-point), reduced number of bones in limb, adaptations to lower mass (inertia) of lower limb
- conservation of energy: whiplash effect of limb, long tendons (transfer load, shock absorbers, energy store), stable joints
- relatively rigid spine/sacroiliac junction: large gut, large body mass, transfer of energy from powerful hind quarters, minimise up-and-down movements of body during locomotion (conserves energy)
Functional adaptations to high-speed locomotion: canine
- Elongation of limbs with mass being proximal
-digitigrade: need claws for catching prey, claws may assist with grip
- flexible back: arches & straightens over wide range - increases stride length
- tail: assists with balance when out-of-balance
clinical consequences of adaptations: equine
- low safety margins: bones and tendons (fractures and tendon strains)
- little soft-tissue cover of distal limbs (poor wound/fracture healing)
- little soft tissue to absorb impact loads (joint injuries/osteoarthiritis)
what are the 2 components of welfare?
physiological components and behavioural components
Try and label dog muscle unlabelled in brainscape folder
look at dog muscle labelled answer
How to initially set up a microscope?
Initial set up of a microscope
1. Turn on the light and increase the brightness to give a white 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. 4. 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.
how to focus the condenser to make sure the image is in focus?
- Check that the lowest power objective lense is in place
- 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.
- 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.
- Open the lamp iris on the base of the microscope until the iris edges just disappear from your field of view
Adjust the condenser aperture to produce the best image
what objective lenses are required for urine, parasites and cellular material/microbes?
Objectives required
Parasites x4
Urine x10-x40
Cellular material/microbes x10 up to x100 (Oil immersion)
What is meant by resolution and 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.
What are the roles of a skeleton?
Structural (supports the body), Protection of vital organs, locomotion, mineral reservoir
What is bone tissue made up of?
organic matrix (osteoid), inorganic matrix, cells (osteocytes, osteoblasts, osteoclasts), vascular spaces
What is osteoid? What secretes it and where?
Osteoid is a ground substance in which numerous collagen fibres are embedded. It is synthesised by osteoblasts and secreted onto existing bone surface.
What is embedded in osteoid? and what is there role?
collagen type 1 - important structural component around 90%
glycoproteins - binds collagen and minerals
proteoglycans - bind growth factors
bone sialoproteins - associated with cell adhesion
What does the inorganic matrix of bone tissue do and what is it composed of?
Bone minerals 60-70% dry weight. Confer hardness and rigidity. Make bone radio-opaque. Composed largely of crystals: hydroxyapatite, carbonate, calcium phosphate
What is mineralisation and what is the timeline of mineralisation?
Mineralisation (process at which the sites of newly formed organic bone matrix (osteoid) becomes filled with minerals) commences as soon as osteoid secreted. Reaches 70-80% final in 3 weeks. Takes years to complete.
What are the two ways that collagen fibres are deposited in bone formation?
Woven bone - haphazard collagen. quick and dirty formation: young growing animal, fracture repair, etc. mineralises quickly. crossed fibres
Lamellar bone (parallel fibre bone) - thin layers of osteoid within which collagen fibres are parallel. Structurally superior. Collagen fibres deposited in different organizational structures.
What happens to woven bone?
Woven bone normally mature to stronger lamellar bone.
What are osteons and osteoid?
Osteoid is the unmineralized organic portion of the bone matrix, whereas an osteon is the structural unit of compact bone.
Osteons are the method to take the blood vessels through the bone.
what is the difference between primary and secondary osteons?
Primary osteons are formations characteristics of mature bone.
Secondary osteons are formed by replacement of existing bone. These appear differently as osteoclasts when remodelling bone cells first resorb or eat away a section of bone in a tunnel called a cutting bone.
Describe the structure of osteonal bone?
Osteonal bone is bone tissue that contains blood vessels surrounded by concentric rings of bone tissue.
What is fibrolamellar bone?
Fibrolamellar bone is an impermanent primary bone tissue found in fast growing juvenile mammals. Consists of woven bone interspersed with lamellar bone. It is highly vascular and contains many primary osteons and blood vessels, allowing for rapid bone deposition and growth. Provides strength and flexibility
When are primary osteons produced and what do they contain and what are they surrounded by?
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 bones.
What structure is found at the edge of a secondary osteon?
the cement line
what is found in a secondary osteons?
- haversian canal in the centre (containing blood vessels, lymphatics and nerves)
- osteocytes in lacuna
- canaliculi containing cytoplasmic processes of osteocytes
- cement line
How are secondary osteons formed?
by coordinated action of osteoclasts and osteoblasts
what derives osteoblasts and what do they do? when are they active?
derived from mesenchymal stem cells
synthesise and secrete osteoid
active in mineralisation process
Where are osteocytes found how do they communicate with each other? and what is there role?
Found within the lacunae. They communicate with each other and with other bone cells through canaliculi. In charge of bone remodelling they control osteoblasts and osteoclasts.
What is osteoclasts role and what is its characteristics? also what is it derived from?
- responsible for bone resorption, release protons creates acid environment causing demineralisation. Also secretes proteases which destroy organic matrix
- large cells, multiple nuclei
- derived from bone matrix
What are the steps involved in bone modelling and remodelling?
- Osteoclasts destroy/remove some of the bone
- Osteoblasts then secrete osteoid and concentric lamellae forms making walls of lamellar bone surrounding a blood vessels
- Secondary osteon is created
What type of bone comes first in the healing process?
Woven bone always come in first for the healing process but then you hope that it will develop to a lamellar bone.
What is a stress fracture?
Stress fracture defines a syndrome involving localised bone injury associated with fatigue damage subsequent to repetitive loading.
What is meant by strain?
percentage of elongation
What is meant by stress?
force per unit area
what is meant by yield point on a stress strain graph?
point where structure no longer returns to original shape
what is meant by plastic region on a stress strain graph?
Plastic region = structure deformed and moving towards failure
What do stress fractures cause and why?
They cause microdamage:
Structural damage of various levels, cell death and vascular disruption.
Why does remodelling bone eventually contribute to failure?
Remodelling causes increased porosity (empty spaces in a material). Then high strains causes microdamage then the cycle repeats till failure.
Where is cartilage found and what is its function?
Cartilage is more pliable than bone. It is found in joints as its function is to provide flexible interface between bones and smooth bearing surface. Flexible support in outer ear, sternum, larynx, cartilage rings of trachea etc.
What type of growth is cartilage able to undergo?
interstitial growth (internal expansion)
What makes up the matrix of cartilage?
Collagen fibers – Mainly Type II collagen, which provides tensile strength and structure.
Proteoglycans – Large molecules like aggrecan, which attract water and help maintain cartilage’s gel-like consistency for shock absorption.
Hyaluronic acid – A glycosaminoglycan that forms complexes with proteoglycans to retain water and provide resilience.
Glycoproteins – Such as chondronectin, which help anchor chondrocytes to the matrix.
Water – Makes up 60-80% of cartilage, aiding in resilience and load distribution.
Where is articular cartilage found and why? describe in terms of nerves, blood vessels and lymphatics? what does this cause?
Mechanically unique, hydrated and slippery connective tissue that covers the ends of bones in synovial joints. It is designed to: withstand and distribute load, act as an elastic shock absorber, provide a wear resistant surface to articulating joints
self maintaining
-avascular
-aneural
-alymphatic
implications for disease and repair
What are the 3 types of cartilage?
articular/hyaline, fibrocartilage, elastic
What colour is fibrocartilage? Where is it found and why?
white
Specialised cartilage in areas requiring tough support or great tensile strength, lines surface of bony grooves for tendon, interface ligament/tendon and bone
It contains more collagen vs hyaline cartilage
contains type 1 and 2 collagen, lacks a perichondrium (dense layer of connective tissue that surrounds most types of cartilage accept articular and fibrocartilage)
What colour is elastic cartilage? where is it found and why?
yellow.
Found in the pinna of the ear and several tubes.
It keeps tubes permanently open, similar to hyaline but contains elastin scattered through the matrix
What is the only type of cell found in cartilage and what is its role?
Chondrocytes are the only cells found in cartilage.
Produce and maintain the cartilage matrix. Exist in low density. Must obtain nutrition and O2 by diffusion (cartilage avascular). Chondrocytes continue secreting new matrix when embedded in matrix causing internal expansion (interstitial growth). Chondrocytes are capable of division within matrix.
What is membranous and chondral ossification?
Membranous - bones ossify* from mesenchymal cells (scapula, scull bones), found in areas of high load bearing, have fail/fracture configurations that are clean
Chondral - bones ossify* from cartilage precursor (most limb bones), found in non-load bearing areas, fracture configuration looks like shattering
*ossify means to change into bone or bony tissue
What are the 6 bone shape classifications?
Long (eg. humorous)
Short (eg. carpal bones)
Flat (to protect or attach to soft tissue)
Sesamoid (provide strength and reduce tendon wear on bone/joints)
Irregular (for muscle and ligament attachment)
Pneumatic (contain air space)
What is periosteum?
What is the endosteum?
Vessel-rich, bone producing* membrane that covers all of a bone except region with articular cartilage.
*Supply blood to the bone which is required for development and remodelling
Membrane that lines the marrow cavity and lays down bone, supplied by the nutrient artery
What is the structure and function of…
cortical bone?
cancellous bone?
Solid concentric bone arranged around a central osteon. It provides structural support and protection to the bodies bones.
Bony trabecular (little beams) with spaces filled with red bone marrow. It provides structural support against stress and flex whilst staying light.
What is the structure and function of the medullary/marrow cavity?
Hollow bone filled with red and yellow bone marrow.
red marrow makes blood cells and the yellow marrow stores fat and minerals.
What is the nutrient artery?
Vessels in the periosteum supply the blood for the bones via. the nutrient arteries which carry the blood from the vessels to the endosteum.
What are the functions of these typical long bone features?
- The head
- Tubercles, trochanters, tuberosites
- Fossae
- Condyles and epicondyles
Allows a wide range of movement in joints
Elevation/raise irregularity in bone that acts as an attachment site for muscles and ligaments
Depressed irregularity in bone that acts as an attachment sight for muscles and ligaments
Condyles - Provide structural support to bone joints
Epicondyles - Allows the attachment of ligaments and tendons
What are osteoids composed of?
Water, Glycoproteins, Proteoglycans, Bone sialoproteins
What are the main issues/limitations with bone?
Rigid
Hard/Brittle
Cannot expand from within/Limited growth
What happens to woven bone over time?
Is replaced with lamellar bone (not always the case, why some fracture sites are always weaker)
As bone forms what are the two ways in which the fibres are deposited and organised?
Woven bone (haphazard) - used for growing bone or fracture repair so mineralises quickly
Lamellar bone (parallel with bone) - thin layer of osteoid* that collagen fibre grows parallel to, structurally superior.
What is fibrolamellar bone?
Contains additional fibre making it better at withstanding impact
What is the main difference between lamellar bone and woven bone?
Lamellar bone contains osteons
What is the main function of osteons?
To allow blood vessels (and nerves) to run through the bone, these can be seen as the circle in the centre of the osteoblasts
In an osteons what is the name given to the circle in the centre and what does it contain?
The Haversian canal - contains blood vessels, lymphatics (waste disposal vessels) and nerves
What is the name given to the line that runs around the outer edge of all osteons?
The cement line
Where are osteocytes found and what can be seen coming off from them?
Found within the osteoblasts with canaliculi (cytoplasmic processes) running off of them
What are secondary osteons?
Smaller osteons that come off of the primary osteons into the bone tissue
What is the main function of osteoclasts and how do they achieve this?
Breaking down the bone and bone reabsorption by releasing protons which create an acidic environment which then leads to demineralisation of the bone. They also secrete proteases which destroys any organic matter.
Where do osteocytes come from?
What method of communication of osteocytes use?
Osteocytes come from differentiated osteoblasts
Dendritic processes
Where do osteoblasts come from?
Mesenchymal stem cells
What properties do osteoclasts have?
Large cells
Lots of nuclei
Where are osteoclasts derived from?
Bone marrow
What are the 4(/5) connective tissues?
Epithelial
Nervous
Connective
Muscle (contractile)
(- Blood, but this can also be considered connective)
What are the steps involved in bone modelling and remodelling?
Osteoclasts destroy/remove some of the bone
Osteoblasts then secrete osteoid and concentric lamellae forms making walls of lamellar bone surrounding a blood vessels
Secondary osteon is created
How does repetitive strain cause failure?
More stress over time = less elasticity in the bone and more deformation = higher chance of fracture
This is referred to as cyclical loading
What is a stress fracture?
Makes the bone progressively more porous and therefore weak which leads to a large fracture.
How does remodelling of bone result in a higher chance of failure?
High strains - microdamage - remodelling - increased porosity - fracture
What does nervous tissue consist of and what is the difference between it in the CNS and PNS?
Nerve Cells and Neuroglial Cells
Neuroglial cells in the CNS:
- astrocytes
- oligodenrocytes
- microglial cells
- ependymal cells
Neuroglial cells in the PNS:
- satellite cells
- Schwann cells
What is the function of nervous tissues?
Hint: function of neurones and neuroglia cells
Neurons
- receive and facilitate nerve impulses
- classified based on function and structure
Neuroglial cells
- supporting cells by facilitating conduction of nerve impulses, immune function, maintenance of neurones
What are the 4 key functions of connective tissue?
Support
Movement
Protection
Fat/Energy Storage
What are the 5 main categories of connective tissue?
(include subgroups)
Loose (or Areolar)
Dense
- regular
- irregular
Cartilage
- hyaline
- elastic
- fibro
Bone
- lamellar
- trabecular
Blood (special kind of liquid connective tissue)
What is the structure and function of LCT, DCT, Cartilaginous and Bone tissue?
LCT
Structure = cells found within a network of collagen and elastin fibres
Function = loose packing, support, nourishment to associated structures, tissue sliding
DCT
Structure = matrix composed of collagen and elastin fibres
Function = tensile strength and stretch resistance
Cartilaginous
Structure = depends on cartilage type
Function = provides flexibility (as no calcium phosphate) with rigidity, can withstand pressure
Bone
Structure = collagen network (tensile strength), crystalline (compressive strength), bone cells ( maintenance)
Function = provides strength and support
What are the cells in cartilaginous tissue called and what is their function?
What happens to cartilage throughout it’s life (like bone)?
Does cartilage have a good vascular supply?
Chondrocytes: produce a matrix made of type ll collagen, glycoproteins and water
Broken down and renewed
No, its poorly supplied with blood
What are the differences between LTC and DCT?
Loose has few elastin and collagen fibres - Dense has lots
Loose has lots of cells and ground substance - Dense has few cells and less ground substance in the extracellular matrix
Loose is less rigid/easily distorted but is still resistance when stretched due to collagens tough barrier - Dense is rigid and hard to distort due to its dense fibre
Loose is found in mucosal + submucosal CT of blood vessels, muscle, nerves, organs (kidney, liver)
Dense is found in tendons, ligaments, cornea of eye, arteries
What happens throughout bones life and why is it hard/hardly flexible?
Constantly remodelled
Contains calcium phosphate (found as hydroxyapatite) in the extracellular matrix
What are the 3 main components that make up CT?
Cells
Collagen fibres
Ground substance (special proteins)
What is the purpose of the extracellular matrix (ECM) in CT?
Help to separate cells from each other (so not tightly packed), non-living ECM helps classify CT subgroups, structure of the ECM gives CT its morphological and functional characteristics
What does ECM contain*?
Collagen and elastin fibres
- Collagen type l most common it’s strong, flexible but inelastic.
- Reticular fibres are fine collagen type lll fibres and these networks fill spaces between tissue and organ.
- Elastin has elastic properties but the % varies depending on tissue function
Ground substance (non-fibrous protein + other molecules)
- amphora’s gel-like substance that surrounds cells
- components are hyaluronic acid and proteoglycans
Water
blood ECM has no collagen fibres
What is the function of ECm?
What produces ECM?
Is ECM inert or dynamic?
Structural support of cells, and guides their division, growth and development
Specialised cells
It is dynamic
The names of specialist cells that produce ECM end in suffixes that identify the function, what is the function of these suffixes?
-blasts
-cytes
-clasts
-blast = creates matrix
-cytes = maintain matrix
-clasts = break down matrix for remodelling
Which of the 3 embryonic layers produces connective tissue?
mesoderm
What are the 4 types of tissue in embryology? and what is it derived from?
epithelial tissue - derived from all three germ layers
connective tissue - primarily derived from the mesoderm
Muscle tissue - primarily derived from the mesoderm
Nervous tissue - primarily derived from the ectoderm
During embryonic development where is most connective tissue found and what are its main features?
What other names are given to embryonic CT?
During embryonic development, most connective tissue is found in the mesoderm.
Main features of embryonic connective tissue:
- Loosely packed cells embedded in an abundant extracellular matrix (ECM)
- Rich in ground substance, which is composed of glycosaminoglycans (GAGs) and proteoglycans, providing a gel-like consistency
- Contains mesenchymal cells, which are pluripotent and capable of differentiating into various cell types (e.g., fibroblasts, chondroblasts, - -osteoblasts, and adipocytes)
- Highly vascular, facilitating nutrient exchange and cell migration
Other names:
Mesenchyme - undifferentiated, pluripotent tissue from which most adult connective tissues originate. Found throughout the embryo, forming the basis for cartilage, bone, and muscle development
Wharton’s jelly - type of mucous connective tissue found specifically in the umbilical cord, rich in hyaluronic acid and collagen, providing cushioning and protection to the umbilical vessels.
Mucous connective tissue - subtype of embryonic CT with a jelly-like consistency. Composed of scattered fibroblast-like cells and gelatinous ECM, primarily located in the umbilical cord (Wharton’s jelly)
What does reticular connective tissue contain?
where is it found and what does it do?
composed of reticular fibres (a type of collagen, specifically type III collagen), contains fibroblasts that produce and maintain the fibres
Found in lymphoid organs, where it forms a supportive framework.
What are the two types of adipose tissue and what is its structure and function?
Brown adipose tissue - heat
white adipose tissue - energy storage
What is the structure and function of adipose tissues?
structure - Little ECM surrounding cells, cells full of lipid
Function - packaging, protection, insulation
What are mesenchymal cells surrounded by? How are mesenchymal cells associated?
Mesenchymal cells are surrounded by an amorphous ground substance composed mainly of hydrated glycosaminoglycans (GAGs), proteoglycans, and glycoproteins, along with a sparse network of reticular fibers (type III collagen). This extracellular matrix (ECM) provides a soft, jelly-like environment that allows the cells to remain loosely associated and mobile.
Loosely associated, connected through thin cytoplasmic processes that are embedded in the ECM
What does all connective tissue contain?
cells, ECM (composed of fibres, ground substance, interstitial fluid - this allows for the exchange of nutrients, gases, and waste products between cells and the bloodstream)
What are the 3 types of fibre found in CT and an example of where they are found?
Collagen fibres, elastic fibres and reticular fibres.
Collagen fibres - provide tensile strength and resistance to stretching. E.g. tendons and ligaments, bone and cartilage, dermis of the skin
Elastic fibres - provide elasticity and allows tissues to stretch and recoil. E.g. walls of large arteries, lungs, skin and elastic cartilage
Reticular fibres - form a mesh-like network that provides support and structure for soft tissues and organs. E..g. lymph nodes and spleen. liver and bone marrow.
What is the main structural protein found in connective tissue?
Collagen - consists of three polypeptide chains wound into a helical structure, which gives it strength and stability.
What structure is collagen found in? How these from collagen fibres? What type of bonds form to stabalise the fibrils and between what?
Consists of three polypeptide chains wound into a triple helix structure, which gives it strength and stability. Repeating sequence of Glycine- X-Y. X is often proline, Y is often hydroxyproline or hydroxylysine. Multiple triple helixes from into collagen fibrils, these then bundle together to form collagen fibres. Covalent cross-links between lysine and hydroxylysine stabalizes the fibrils making it more stable.
What are the main amino acids in collagen and purpose of these? and what bonds do they have?
Primarily consists of glycine (33%) - smallest amino acid allowing the chains to fit tightly together in the helical structure, proline (10-15%) - introduces kinks in the polypeptide chain, promoting the helical structure, hydroxyproline (post transitionally modified form of proline) - stabilizes the triple helix by forming hydrogen bonds, hydroxylysine (another modified amino acids) - involved in covalent cross-links between collagen molecules, adding strength and flexibility
Hydrogen bonds - form between hydroxyproline residues
Covalent cross-links - involve lysine and hydroxylysine residues, occur during maturation and strengthen the fibril network
Peptide bonds - hold the amino acids together within the chains
Van der Waals forces and hydrophobic interactions - contribute to the packing of collagen molecules into fibrils
How many types of collagen fibres are there?
28 types
Where is type 1 collagen distributed?
Skin, tendon, organs, mature scar tissue, artery walls, cornea, fibrocartilage, surrounding muscle fibres, organic part of bones and teeth, endomysium
Where is type 2 collagen distributed?
hyaline cartilage, vitreous humour
Vitreous humor is a clear gel that fills the back of the eye and helps maintain its shape and vision
Where is type 3 collagen distributed?
reticular fibres (organ stroma), granulation tissue
Granulation tissue is a type of new connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process.
Where is type 4 collagen distributed?
basal lamina, eye lens, fibration system of capillaries and glomerula
Where is type 5 collagen distributed?
interstitial tissue (associated with type 1), placenta
What does GAG stand for?
What are GAGs? and how do they work?
Glycosaminoglycans
Glycosaminoglycans (GAGs) are long, unbranched polysaccharides composed of repeating disaccharide units. They play a critical role in connective tissue function by interacting with water, proteins, and cells.
Involved in hydration and lubrication, structural support and cushioning, cell signalling and adhesion, regulation of inflammation.
GAGs are highly negatively charged due to the presence of sulfate and carboxyl groups, which attract water molecules.
This gives GAGs the ability to retain water, creating a gel-like consistency in the extracellular matrix
GAGs combine with proteins to form proteoglycans, which contribute to the ECM’s resilience and shock absorption.
Their gel-like nature allows tissues to resist compressive forces.
GAGs can bind to growth factors, cytokines, and cell surface receptors, modulating cell signaling.
GAGs can bind to growth factors, cytokines, and cell surface receptors, modulating cell signaling.
What are some clinical uses of GAG?
anticoagulants and antithrombotic, osteoarthritis and joint disorders, wound healing and tissue repair, ophthalmic applications, interstitial cytisis and bladder control, drug delivery and cancer therapy, anti-inflammatory and antioxidant applications
What are some functions of hyaluronic acid?
hydration and moisture retention (remarkable ability to hold up to 1000 times its weight in water), wound healing and tissue repair (promotes cell migration and proliferation, accelerating wound healing), anti-inflammatory and antioxidant effects, skin elasticity and antioxidant effects, skin elasticity and anti-aging, ocular functions, bladder protection, drug delivery and tissue engineering
What are the two components to welfare?
Behavioural and Physiological
What does animal behaviour give vets an insight to?
The animals emotional and welfare state
Any potential safety concerns for staff, clients and public
What are the two behavioural based day one competences that graduates must be able to demonstrate?
(Bracketed info is for my understanding don’t need to recite this)
‘Do no harm’
(By not creating a situation that causes an animal to be fearful of the veterinary clinic or of routine care procedures (eg, clipping nails), to advise and assist the client to take preventative measures to avoid an aversion to the veterinary practice and provide basic guidance to avoid development of behaviour problems.)
Apply ‘behavioural first aid’
(Identify that a problem exists, take short-term measures to ensure the safety of people and animals, and if the veterinarian is not a behaviour specialist and, thus, unable to provide support, refer the animal to a suitably experienced person.)
What’s a common indicator when assessing welfare, especially in livestock?
Locomotion
Is the animal lame? This can indicate both physiology and behavioural issues.
This is usually an indicator that the animal is in pain
This is assed through observation and scoring systems
What are some stereotypical behaviours and how are they relevant to NMSK??
Weaving = worn feet, muscle injury, arthritis
Strange weight bearing = musculoskeletal system remodels
How can behaviour impact the success of operations?
Have to consider:
pre-op/post-op management
hospital cages, box rest
will gentle exercise be possible
limb amputation adaptation and quality of life
Can stereotypies be caused due to something neurological?
yes
What is the difference between acute and chronic pain?
How can this make pain scoring difficult?
Acute = short
Chronic = long-lasting
Pain scoring cannot differ between acute and chronic pain, this can lead to the animal receiving incorrect treatment. This is why a history is essential.
What is the difference between these pain scales:
- SDS
- VAS
- NRS
- Glasgow composite pain scale
- Composite pain scale in horses
- Facial/grimace scale
Simple Descriptive Scale - 5 or 5 point scale going from mild-moderate-severe
Visual Analog Scale - 10cm line, left hand is 0 with no pain right hand is 10 with worst possible pain
Numerical Rating Scales - scale of 4, 5 or 10-point pain scale
Glasgow - for acute pain composed of 7 questions with a score of 20, guide for analgesic intervention for scores >/= 5
Facial/Grimace - scale 0-2 rating facial tenseness ie. tight lips, 0= not present, 1=moderately present, 2=obviously present
Define the terminology for these words (include and example):
Fear
Phobia
Anxiety
Stress
Fear : Unpleasant emotion caused by threat of danger, pain or harm (horse spooked when car drove past)
Phobia : Irrational fear of, or aversion to something. Type of anxiety disorder (dog trembles when balloon goes near it)
Anxiety : an uncontrollable physiological, behavioural and emotional reaction to stimuli (separation anxiety when left alone)
Stress: any situation that disturbs the equilibrium between living organisms and their environments, they can cause your body to respond differently depending on trigger
What are the 4 F’s?
What are they a sign of?
Fight - attack threat
Flight - escape threat
Freeze - stiffen up
Fidget - appears overly energetic, can’t stay still
Anxiety and fear
What are the 8 steps in the SVMS animal handling template?
species organ and evolutionary history
Individuals history and context of interaction
Assess environment and maximise comfort
asses animal body language as indicated comfort level and intent
asses your body language and behaviour
asses handler language and attitude
handling tools
safe, effective restraint
Have a go at labelling the unlabelled Maslow’s hierarchy in brainscape folder
look at labelled Maslow’s hierarchy in brainscape folder
What is the difference between emotion, mood and temperament?
Emotion: response to stimuli, short lived
Mood: positive or negative, not reliant on stimulus, longer-lasting
Temperament: individuals emotional predisposition, long lasting (genetics, life experiences)
What is neophobia?
A fear of new things
What is the difference between homeostasis and allostasis?
Homeostasis: bodies response to change
Allostasis: bodies response to the anticipation of change as well as actual changes
What are the two key components in the stress response (one is a rapid response pathway the other is slow)?
Flight or fight response - rapid
Hypothalamic-Pituitary-Adrenal axis (HPA) - takes minutes to hours
What are the 3 main types of stress?
What is the body trying to do when it responds to stress?
1.Eustress - good stress
2.Neutral stress (neustress) - not harmful
3.Distress - affects well-being
Body becomes aroused and attempts to reduce the stress
What is General adaptive syndrome (GAS)?
What are GAS’s 3 stages?
What are the 2 major body systems involved in GAS?
The General Adaptation Syndrome (GAS) is a three-stage physiological response to stress
Alarm - Resistance - Exhaustion (referenced image - GAS image in BrainScape)
Nervous and endocrine/hormonal
When the body is in the alarm response what happens?
Flight or fight:
- body prepares for physical activity
- increase in epinephrin and norepinephrine =
increase activity of sympathetic nervous system
- activation of HPA axis = increase in corticosteroids
- adrenaline, noradrenaline, corticosteroids mobilise energy reserves and raise blood glucose
- immune system repressed (susceptible to illness)
When the body is in the resistance response what happens?
Second stage of the GAS, which describes how the body reacts to stress.
Hormonal response - releases stress hormones, such as cortisol, epinephrine and norepinephrine, to sustain the energy and keep the body alert. Cortisol levels remain elevated, which increase glucose to provide energy.
Body tries to maintain homeostasis despite the ongoing stress.
Prolonged stress can cause immune system suppression and decreased sensitivity to stressors
Risk of progression to exhaustion
When the body is in the exhaustion response what happens?
Third and final stage of GAS
Depletion of energy resources, leading to chronic fatigue and weakness
weakened immune system, cortisol levels will remain high but might eventually drop due to burnout.
Physical symptoms of exhaustion, such as headaches including cognitive and emotional decline
Potential for serious health issues
What process occurs when a stress message is received?
stress perception (stressors detected by sensory organs (eyes, ears, etc) or interpretated by the brain, the amygdala assesses the situation and signals the hypothalamus which acts as a control centre and activates the SNS.
SNS sends signals through the ANS to the adrenal glands which release epinephrine and norepinephrine, which cause: increase HR, increased BR, dilated pupils, muscle tension and redirected blood flow from unnecessary organs.
If the stressor persists, the HPA axis is activated to sustain the stress response. The hypothalamus releases corticotropin-releasing hormone (CRH), this signals the pituitary gland to release adrenocorticotropic hormone, this prompts the adrenal glands to release cortisol (boosts glucose, enhances alertness and focus, reduces non-essential functions).
Once the stressor has gone, the PNS activates, causing cortisol levels to drop, HR and BR normalise, and body returns to homeostasis.
What in the body is turned off when the flight or fight repose is deactivated?
stress hormone production decreases, HR and BP normalise, breathing slows, digestive system reactivates, immune function resumes, muscle tension relaxes, pupil dilation reverses, cognitive focus shifts
What’s the HPA axis and how does it respond to stress?
Hypothalamic-Pituitary-Adrenal axis. Its a complex network involving three main components: the hypothalamus, pituitary gland and adrenal glands.
The HPA axis activates through a cascade of events: stress signal detection, pituitary activation, adrenal gland activation resulting in the stress response effects.
Hypothalamus releases CRH into pituitary gland. Pituitary gland releases ACTH via blood, this acts on cortex of the adrenal gland. Adrenal cortex releases cortisol into the circulatory system this activates the body’s cells, endocrine glands and brain.
Cortisol effects
- turns off insulin, liver starts releasing glucose, increase in energy supply
- shuts down reproductive function and inhibits production of growth hormone
- bodies energy supply can be concentrated on dealing with the stress.
What is a conditioned emotional response?
Learned emotional reaction to a previously neutral stimulus.
What is the usual order in which behavioural problems are investigated?
What are the 3 factors associated with behaviours problems?
-identify and define the behaviour
-gather background information
-observe and record the behaviour
-assess environmental and social factors
-physiological and cognitive evaluation
- rule out medical causes
-diagnose and develop an intervention plan
behavioural factors are typically influenced by 3 key factors: biological factors, physiological factors, environmental/social factors
What are the 4 categories of aggression?
What can be a contributing factor to all 4?
Defensive (fear-related) Irritable (pain-related), protective (territorial), predatory
hypertension (high-blood pressure)
What steps would a behaviour counsellor take when a behaviour problem is presented?
Takes a holistic, systematic approach:
- comprehensive history and observation
-rule out medical issues
-identify triggers and motivation
-create and implement a tailored behaviour modification plan
-provide ongoing support and adjustment to ensure long-term success
What are the ABC’s of behaviour?
✅ Antecedent → What happens before the behavior?
✅ Behaviour → The specific action or response that occurs.
✅ Consequence → What happens after the behaviour?
What behavioural advice do clients seek from general practice?
- mental health and emotional well being
-parenting and behavioural awareness
-lifestyle and behavioural changes
What is the amygdala?
What are the main 4 nuclei found in the amygdala?
What is found dispersed in the fibre tracts of the nuclei and what are the two most important groups?
What’s the main purpose of the amygdala?
The amygdala is a small, almond-shaped cluster of nuclei located deep within the temporal lobe of the brain, near the hippocampus. It is a key part of the limbic system, involved in emotion processing, memory, and behaviour regulation.
Basolateral complex (BLA) - emotional learning and associations
Central nucleus (CeA) - involved in automatic and behavioural responses, plays a role in fear conditioning
Corticomedial nucleus - olfactory processing and the regulation of appetite and sexual behaviour
Intercalated masses (ICMs) - regulatory filter for amygdala output, modulating emotional responses
Within the fibre tracts of the amygdala, you’ll find interspersed cell groups. The two most important groups are:
- the bed nucleus of the stria terminalis (BNST) - functionally linked to amygdala in stress response and anxiety regulation
-extended amygdala - incl BNST and parts of the central amygdala, playing a role in chronic stress and addiction-related behaviours.
The amygdala’s main purpose is to:
Process and regulate emotions: Especially fear, anxiety, and aggression.
Form emotional memories: It links emotions with memories, enhancing memory consolidation during emotional events.
Trigger autonomic responses: Involved in the fight-or-flight response, influencing heart rate, hormone release, and behavior.
Decision-making and social behavior: Helps interpret emotional cues and influences emotional decision-making.
How does lateral nucleus differ from the basolateral complex?
What does the lateral nucleus in the amygdala do?
What does the central medial nucleus in the amygdala do?
Basolateral complex refers to the entire region, which includes the lateral nucleus as well as the basal and accessory basal nuclei.
The lateral nucleus of the amygdala plays a key role in emotional learning and sensory integration, specifically in fear processing. It receives info from the thalamus, sensory cortices and hippocampus.
The central medial nucleus (CeM) is part of the central nucleus of the amygdala and is primarily involved in triggering autonomic and behavioural responses.
What fear responses does the amygdala trigger?
Amygdala → Hypothalamus → HPA axis:
Triggers the fight-or-flight response.
Amygdala → Brainstem:
Activates reflexive and autonomic responses (e.g., startle reflex, freezing).
Amygdala → Prefrontal Cortex:
Modulates conscious fear perception and emotional regulation.
What is fear conditioning?
Where in the brain is the primary area for fear conditioning?
Fear conditioning is a form of associative learning in which an organism learns to associate a neutral stimulus (such as a tone or light) with an aversive stimulus (such as an electric shock), leading to a conditioned fear response (e.g., freezing, increased heart rate, or stress hormone release). This type of learning is a key model for studying fear, anxiety, and trauma-related disorders like PTSD.
The amygdala, particularly the basolateral amygdala (BLA) and the central nucleus (CeA), is the primary brain region involved in fear conditioning. Here’s how it works:
-Basolateral Amygdala (BLA) – Processes and associates sensory information (e.g., the tone and shock) to form fear memories.
-Central Nucleus (CeA) – Acts as the output region, sending signals to other brain areas (e.g., hypothalamus, brainstem) to trigger fear responses (freezing, increased arousal, etc.).
Other brain regions also play important roles:
-Hippocampus – Contextual fear conditioning (associating fear with a specific environment).
-Prefrontal Cortex (PFC) – Regulates and extinguishes fear responses.
-thalamus – Rapidly relays sensory information to the amygdala.
The amygdala is essential for both acquiring and expressing conditioned fear, making it the central hub for fear-related learning and behaviour.
What is fear extinction?
Fear extinction is a form of learning in which a previously conditioned fear response diminishes when the conditioned stimulus (e.g., a tone previously paired with a shock) is repeatedly presented without the aversive outcome. Unlike forgetting or erasing the original fear memory, extinction involves forming a new inhibitory memory that suppresses the fear response.
Key Brain Regions Involved in Fear Extinction
Prefrontal Cortex (PFC) – Particularly the infralimbic (IL) cortex (in rodents) or ventromedial prefrontal cortex (vmPFC) (in humans):
-Plays a crucial role in inhibiting the amygdala during extinction.
-Strengthens extinction memories by suppressing fear responses.
Amygdala – Still involved, but its activity is modulated by the PFC:
-The basolateral amygdala (BLA) interacts with the PFC to form extinction memories.
-The central nucleus (CeA) reduces fear output when extinction is learned.
Hippocampus – Helps with context-dependent extinction (remembering whether extinction occurred in a specific environment).
what is the unconditioned pathway? Describe this pathway.
The unconditioned pathway refers to the neural circuit that processes the innate (unlearned) fear response to an aversive stimulus (like a shock or loud noise), as opposed to the conditioned pathway, which learns associations between neutral and aversive stimuli (like in fear conditioning).
Thalamus
-Receives raw sensory input (e.g., pain, loud sounds) and relays it rapidly to the amygdala.
-The sensory thalamus (e.g., medial geniculate nucleus for sounds) provides a quick but crude signal.
Amygdala (Central Nucleus, CeA)
-The central nucleus (CeA) is the primary output for innate fear responses.
-Activates downstream targets to trigger freezing, increased heart rate, stress hormones, etc.
Hypothalamus & Brainstem
-The CeA projects to the periaqueductal gray (PAG) (for freezing/defensive behaviors) and the lateral hypothalamus (for autonomic responses like increased blood pressure).
How It Works (Example: Response to a Shock)
Stimulus: A painful foot shock activates nociceptive (pain) pathways.
Fast Thalamic Route:
The shock signal reaches the lateral amygdala (LA) via the posterior intralaminar nucleus (PIN) of the thalamus (a direct, subcortical route).
Amygdala Processing:
The LA quickly activates the CeA, which orchestrates the fear response.
Fear Outputs:
Freezing: Via projections to the PAG.
Autonomic Arousal: Via the hypothalamus and vagus nerve.
Stress Hormones: Via the bed nucleus of the stria terminalis (BNST) and HPA axis.
What is the difference between the pathways of a conditioned and a unconditioned pathway?
Conditioned vs. Unconditioned Pathways in Fear Conditioning
Unconditioned Response (UR) Pathway: Mediates the innate reaction to the aversive stimulus (e.g., shock → freezing).
Conditioned Response (CR) Pathway: Develops after learning, linking a neutral stimulus (tone) to fear via the basolateral amygdala (BLA).
Key Difference
The unconditioned pathway is hardwired and does not require learning.
The conditioned pathway (involving BLA and PFC) is plastic and forms through associative learning.
What is the difference between conditioned, unconditioned and neural pathways?
Unconditioned pathways are innate, natural or reflexive pathways. They are hardwired in the nervous system and do not require prior learning. They involve unconditioned stimuli and unconditioned response.
Conditioned pathways are formed through learning and experience, they involved the association of a neutral stimulus and an unconditioned stimulus until the neutral stimulus alone triggers the response. The learned association creates a conditioned stimulus and a conditioned response.
Neural pathways have physical connections of neurons in the brain and the nervous system. They are the biological structures that carry electrical and chemical signals between different parts of the brain and the body. Neural plasticity allows these pathways to be strengthened or weakened through experience and learning.
What pathway does the neutral stimulus follow and what is the result?
Initial pathway of the neutral stimulus - pathway during conditioning - conditioned response
Initial pathway involves sensory detection by sensory organs and the associated signal being transmitted to the brain. Then processed by the thalamus , which sends it to the appropriate sensory cortex for interpretation. The stimulus is neutral so the brain perceives it but does not trigger a reflex or automatic response as it is purely recognized as a meaningless signal.
Pathway during conditioning. When the neutral stimulus is repeatedly paired with an unconditioned stimulus, the brain starts forming new associations. You then get the co-activation of pathways (the NS pathways and the unconditioned stimulus pathway fire simultaneously) this leads to the formation of an association (amygdala (emotional learning centre) and hippocampus (memory centre), neural connections strengthen. The prefrontal cortex also plays a role in forming the association. As it is involved in cognitive processing and integrating information. It helps regulate and consolidate the learned association making it more stable.
This causes the neutral stimulus to become a conditioned stimulus. It now triggers the same response as the unconditioned stimulus. The neural pathway has been altered through synaptic plasticity and Hebbian learning.
Key Takeaway
The neutral stimulus initially follows a sensory pathway without causing a significant response.
During conditioning, it becomes linked to the emotional or motor response pathway through synaptic strengthening.
The result: the once-meaningless NS now triggers a conditioned response (CR).
What is contextual conditioning and how does it work?
contextual conditioning is a form of classical conditioning in which the environment or context itself becomes part of the conditioned stimulus.
The context becomes a conditioned cue. The brain associates the environment or context with the unconditioned stimulus. eventually the context alone triggers the conditioned response. This process involves the hippocampus (memory centre) and the amygdala (links the emotional response to the unconditioned stimulus and the context). This creates a context-dependent memory. Prefrontal cortex is also important as it regulates and integrates the contextual and emotional information and is involved in decision making, interpretation and learning.
Provide definitions for the following terminology:
1. Behaviour Modification
2. Habituation
3. Systematic Desensitisation
4. Counter-conditioning
- Behaviour modification is a therapeutic approach based on the principles of operant and classical conditioning. It involves using reinforcement, punishment, or extinction to change or shape specific behaviours.
- The process of making or becoming accustomed or used to something
- Systematic desensitisation is a therapeutic technique used to reduce phobias or anxiety by gradually exposing the individual to the feared object or situation while practicing relaxation techniques.
- Counter-conditioning is a behavioural therapy technique in which a previously learned association is replaced with a new, more positive association.
Provide definitions for the following terminology:
1. Flooding
2. Reinforcement
3. Punishment
4. Associative learning
1) Flooding is a behavioural therapy technique used to treat phobias and anxiety disorders by exposing the individual to the feared stimulus at full intensity for a prolonged period.
2) Reinforcement is a principle of operant conditioning in which a consequence strengthens or increases the likelihood of a behaviour.
3) Punishment is a principle of operant conditioning in which a consequence decreases the likelihood of a behaviour occurring again.
4) Associative learning is a form of learning in which an individual links two stimuli or a behaviour with a consequence.
Examples.
1) placing a person with arachnophobia in a room full of spiders
2) giving praise for good behaviour
3) giving detention for tardiness
4) dog salivates when hearing a bell
Provide definitions for the following terminology:
1. Desensitisation
2. Sensitisation
3. Aversive
4. Pheromonatherapy
5. Clicker-training
1) Desensitization is a process of reducing emotional or physiological responses to a stimulus through gradual and repeated exposure.
2) Sensitization is a form of non-associative learning where repeated exposure to a stimulus increases the response over time.
3) An aversive is any stimulus or experience that is unpleasant, uncomfortable, or undesirable, often used in punishment-based training. E.G. shock, loud noise
4) Pheromonatherapy is the use of synthetic pheromones to influence animal behaviour and reduce stress, anxiety, or aggression.
5) Clicker training is a positive reinforcement training method that uses a small device (clicker) to mark desired behaviours.
What is genetic influence?
Genetic influence refers to the impact of inherited genes on an individual’s physical traits, behaviours, and psychological characteristics.
Match up the time period and description using the period to be matched version in BrainScape folder
Prenatal - 6
Neonatal - 2
transitional - 3
socialisation period - 4
juvenile period - 1
social maturity - 5 possibly
Summarise the following mechanisms of learning:
1. Simple, non-associative (eg habituation and sensitisation)
2. Associative (eg classical conditioning and operant conditioning)
3. Imprinting
4. Social learning
1) learning through exposure to a single stimulus without forming associations.
2) learning through forming connections between stimuli or behaviours and consequences
3) A rapid form of learning that occurs during a sensitive period and creates a lasting bond or recognition.
4) Learning by observing and imitating the behaviour of others.
What is classical learning?
What is operant learning?
Classical learning, or classical conditioning, is a type of associative learning where a neutral stimulus becomes associated with a meaningful stimulus, leading to a conditioned response.
Operant learning, or operant conditioning, is a learning process where behaviour is strengthened or weakened by consequences (rewards or punishments).
What are positive reinforcers?
What is a negative punishment?
A positive reinforcer is any stimulus that, when added after a behaviour, increases the likelihood of that behaviour happening again in the future.
Negative punishment occurs when a desirable stimulus is removed after a behaviour, which decreases the likelihood of that behaviour happening again.
What is a negative reinforcer?
What is positive punishment?
A negative reinforcer is the removal of an unpleasant stimulus to increase the likelihood of a behaviour recurring.
Positive punishment involves adding an unpleasant stimulus to decrease a behaviour.
What is an unconditioned reinforcer?
An unconditioned reinforcer (or primary reinforcer) is a stimulus that is naturally rewarding and does not require learning to be effective. E.G. sleeping.
When pain scoring what is the difference between sensitivity and specificity?
sensitivity is the ability of a pain assessment tool to correctly identify individuals who truly have pain.
specificity is the ability of a pain assessment tool to correctly rule out individuals who do NOT have pain.
Why is the analysis of locomotion important?
Allows evaluation of what is normal/abnormal
You can assess gait patterns
Becomes easier to identify gait adaptations – e.g. lameness
Highlights performance and welfare indicators
What are the pros and cons of the two ways in which locomotion can be measured and which do vets use mostly?
Human Observation (vets use)
P - low technical requirements, low cost
C - subjective/biased, human eye misses details, experience needed
Technical Equipment
P - objective, less bias, measurable
C - needs dedicated equipment, space, resources, personnel and has high cost
What are gaits?
Specific patterns of footfall during locomotion. These change with speed and have characterised sequences.
What is a stride and how is it different to a gait?
A stride takes place within a gate, it is the complete cycle of one movement* and has two phases:
The stance phase (weight bearing) and the swing phase (non-weight bearing)
*from the setting down pf foot to the next setting down of the same foot
What are the 4 gaits?
Walk, Trot, Canter, Gallop
What are the properties associated with walk?
Four-beat, Symmetric, Never >3 or<2 limbs bearing weight at one time, centre of gravity in a triangle between weight bearing feet
Footfall sequence : RH-RF-LH-LF
What are the properties associated with trot?
Two-beat, symmetric, diagonal gait, body supported alternately by L&R diagonals, period of suspension (between successive stance phases), marked axial twisting resisted by axial system
What are the properties associated with canter?
Three-beat, asymmetric, 1 moment of suspension (when forelimb leaves ground before hindlimb hits the ground), lead leg is left or right, one diagonal pair and other two limbs out of phase
RH, RF+LH, LF
OR LH, LF+RH, RF
What are the properties associated with gallop?
Four-beat, asymmetric, lead with inside/lead leg around a turn, moment of suspension
RH,LH,RF,LF
What is the moment of suspension?
Period when o feet are in contact with the ground (fast trot, canter, gallop)
Usually 1 per cycle but 2 in greyhounds and cheetahs (see image)
What are the 3 types of gallop and how many moments of suspension do they have?
Transverse = 1 (LH RH LF RF *)
Rotary = 2 (RH LH * LF RF *)
Counter-rotary = 2, just opposite of rotary
What species use transverse gallops?
Dogs at low speed
Horses (odd-toed ungulates*)
Cattle (large even-toed ungulates)
*mammals with hooves
What species uses rotary gallop?
Cats
Dogs at high speed
Gazelle, antelope (small uneven-toed ungulates)
Running rodents
Horses during disunited canter
What species uses counter-rotary gallop?
Greyhounds on the track as it’s anti-clockwise
Why do animals change gait?
Physical necessity due to the pendulum effect, centrifugal force acting upwards and fraude number* = leg moving at constant velocity:gravitational force
Metabolic advantages, so animal will move at speed which is energy efficient and that matches with the respiratory rate
Mechanical advantages to reduce bone strain
*Speed at which we change gait ie. walk to run
What are the two main neurological impacts on limb coordination?
Cerebellar Dysfunction
- The cerebellum plays a key role in fine-tuning motor movements, balance, and coordination. Damage or dysfunction here can lead to:
- Ataxia: uncoordinated, clumsy movements
- Dysmetria: inability to judge distance or scale of movement (like overshooting a target)
- Tremors during intentional movement (intention tremor)
Proprioceptive Impairment
- Proprioception is the sense of body position and movement, largely mediated by the dorsal columns of the spinal cord and peripheral nerves. Damage can result in:
- Poor limb position awareness: leading to misjudged or delayed movements
- Sensory ataxia: coordination worsens when visual input is removed (e.g., positive Romberg sign)
What are the two ways in which horses are adapted for high-speed locomotion?
Equine Species Adaptation
- relatively rigid spine/ sacroiliac junction: large gut, large body mass, transfer or energy from powerful hind quarters, minimises up-and-down movements of body during locomotion (conserves energy)
- conservation of energy: whiplash effect on limb, long tendons (transfer load, shock absorbers, energy store), stable joints (limit range of movement but little extra support required (low mass= low inertia)
How are dogs adapted for high-speed locomotion?
Canine Species Adaptation
- elongation of limbs (mass proximal)
- digitigrade ( needs claws for catching pray, also assist with grip)
- flexible back (arches and straightens over wide range- increasing stride length, no restriction from gut
- tail (assists with balance)
What are the clinical consequences in the equine adaptation to high-speed locomotion?
Equine Species Adaptation
- low safety margins: bones and tendons (fractures and tendon strains)
- little soft-tissue cover distal limbs (poor wound/fracture healing)
- little soft tissue to absorb impact loads (joint injuries/OA)
What are there two purposes of cartilage in the body?
Joints ie. flexible interface between joints
Flexible support ie. outer ear
What are the 3 types of cartilage?
Articular/Hyaline
Fibrocartilage
Elastic
What are the typical ways/forms in which you can find articular cartilage?
- joint surfaces, covering the end of the bones, like in synovial joints
- precursors of bone in the embryonic skeleton
- found in bones as a centre of ossification* for bone growth
- mostly type ll cartilage
*turning cartilage and fibrous tissue into bone
Articular cartilage is Avascular, Aneural and Alymphatic what do these three words mean?
Avascular = devoid of blood vessels
Aneural = devoid of nerves
Alymphatic = devoid of lymphatics
What are the main properties of cartilage?
Withstand and distribute load
Elastic shock absorber
Wear resistance against surfaces in articulating joints
Self maintaining
What is fibrocartilage?
Where is it found?
Specialised cartilage for areas requiring tough support or tensile strength
Intervertebral disks and surfaces of bony groves for tendons (interface ligament/tendon and bone)
What does fibrocartilage, elastin and articular contain?
Fibro: Type l and ll collagen (more collagen than articular), Type ll makes up 50% of dry weight, lacks perichondrium *
Articular: Type ll cartilage
Elastic: Type ll cartilage, elastin its matrix
- layer of dense irregular connective tissue that surrounds cartilage, especially hyaline and elastic cartilage
What does elastic cartilage look like?
Where is it found?
Yellow
Found in the pinna of the ear and several tubes like the larynx which it keeps permanently open
What is the name given to the only cells found in cartilage?
What are their functions?
How do they obtain nutrients?
Can they divide?
Chondrocytes
Keeping and maintaining the matrix, they can secrete new matrix whilst embedded in the matrix (this results in internal expansion)
Through the diffusion of O2 as cartilage is avascular
Yes, they divide within the matrix
Do chondrocytes vary in cartilage, if so, how?
Their morphology depends on their depth/zone. They have different biochemical, biomechanics and physiological properties.
What are the zones of cartilage and
Superficial
Middle
Deep
Calcified
What does the ground substance that the typical collagen framework imbeds in consist of?
Water and carbohydrates (so it’s highly hydrated)
Where do cranial nerves arise from?
I + II = cerebrum
III - XII = brainstem
How many sets of cranial nerve pairs are there? (they mirror each other hence the pairs)
12
Label the 3 foramina’s
1- optic canal
2 - orbital fissure
3 - rostral alar foramen
What are the names of the 12 cranial nerves? And which one has 3 branches and what are these 3 branches?
OLFactory
OPtic
OCCulomotor
TROchlear
Trigeminal *
Abducen
Facial
Vestibulocochlear
Glossophrayngeal
Vagus
(Spinal) accessory (spinal and cranial part)
Hypoglossal
V1 opthalmic branch
V2 maxillary branch
V3 madibular branch
What is the exit point for the cranial nerves?
Olfactory - olfactory foramina
Optic - optic canal
Oculomotor - orbital fissure
Trochlear - orbital fissure
Trigeminal - V1, 2 and 3
Abducent - orbital fissure
Facial - Stylomastoid foramen
Vestibulocochlear - internal acoustic meatus
Glossopharyngeal - Jugular foramen
Vagus - Jugular foramen
Accessory - Jugular foramen
Hypoglossal nerve - Hypoglossal canal
Identify where the cranial nerve are? using the cranial nerve unlabelled version
1 through 12 in order as below
I olfactory
II optic
III oculomotor
IV trochlear
V trigeminal
VI abducent
VII facial
VIII vestibulocochlear
IX glossopharyngeal
X vagus
XI accessory
XII hypoglossal nerve
What are the 3 groups that cranial nerves can be put into?
Special senses
(olfactory, optic, vestibulocochlear)
Innervation of head muscles
(oculomotor, trochlear, abducens, hypoglossal)
Innervation of structures originating from brachial arches
(trigeminal, facial, glossopharyngeal, vagus, accessory)
The branchial arches (also called pharyngeal arches) are structures that develop in the embryonic stage and give rise to various anatomical structures in the head, neck, and face.
What nerve provides all sensory innervation to the head?
trigeminal nerve
What are the 3 branches of the trigeminal (V) nerve?
Which is the motor branch, what are the clinical signs that there is an issue with this branch?
Opthalmic, Mandibular, Maxillary
Mandibular - masseter muscle atrophy, drop jaw
Which aspects of the face does the facial nerve impact when it comes to motor function?
Ear, eyelid, cornea, lip
What are the two part functions of the vestibulocochlear?
Cochlear = hearing
Vestibular = balance
What are the signs that there is a vestibular issue with CN-Vlll?
Head tilt, circling , nystagmus (involuntary rapid movement of one or both eyes), leaning
What motor innovation does the glossopharyngeal CN-IX provide?
Motor function to the tongue and pharynx
What are the signs that there is an issue with the glossopharyngeal cranial nerve?
Tongue = Stylopharyngeous (inability to move feed from the back of the tongue to the oesophagus
Pharynx = difficulty swallowing, respiratory noises, pharyngeal collapse
Grass can sometimes be seen through the nose
What happens if there is an issue with the vagus CN-X?
What are tests that can be done to test for problems?
Laryngeal paralysis, stridor (high-pitched breathing) , dysphagia (difficulty swallowing)
Slap test (not commonly used anymore, feeling for larynx flinch ), endoscopy, passing a nasogastric tub
Issue with the glottis
What muscles does the accessory CN-Xl control?
What are the signs that there is damage to the accessory
Sternocleidomastoid (SCM)
Function: Turns the head to the opposite side and flexes the neck.
Trapezius
Function: Elevates the shoulders (shrugging) and helps rotate and stabilize the scapula.
Signs of nerve damage
- shoulder droop on affected side due to trapezius weakness
- difficulty when shrugging the shoulder
- weakness turning the head away from the side of the lesion
- scapular winging or asymmetry
- muscle atropy over time in the SCM/ trapezius
What does the hypoglossal CN-Xll control?
How can you identify if there is an issue with CN-Xll?
Nerve is all about tongue movement.
Innervates all intrinsic and extrinsic muscles of the tongue except the palatoglossal (which is the vagus nerve)
Speech (articulation)
Swallowing
Chewing
Moving the tongue in and out, and side to side
Tongue deviation
Towards the side of the lesion in a lower motor neuron (LMN) lesion
➤ “The tongue licks the lesion.”
Opposite side deviation in some upper motor neuron (UMN) lesions
Atrophy (wasting) of the tongue muscles on the affected side
Fasciculations (small, involuntary muscle twitches) — a key LMN sign
Speech issues (dysarthria)
Slurred or imprecise pronunciation due to tongue weakness
Difficulty with swallowing (dysphagia)
Identify 1-7 of the brain and distinguish which is Grey matter and which is white?
Where has this transection been taken from?
Grey Matter
1. Cerebral Cortex (neocortex)
2. Cingulate Gyrus
3. Basal Ganglia: Caudate Nucleus
White Matter
4. Cerebral White Matter
5. Corpus Callosum
6. Internal Capsules
7. Ventricles - Lateral Ventricles
The cerebral hemisphere of the telencephalon
