VAP TEST LECTURES 1-9 (no embryology) Flashcards
Flexion
shorten limb and reduce (less than 180 degrees) flexor angle
Extension
lengthen limb to increase flexor angle
Walk
four beat gait. LH, LF, RH, RF
Trot
two beat gait. LH and RF then LF and RH
Canter
three beat gait. LH and RF then LF then RH
Transverse gallop
four beat gait with all 4 feet suspended at one point. Very fact but not for long. LH, RH, LF, RF
Rotating gallop
four beat gait in dogs/cheetahs. LH, RH, RF, LF
Pace
two beat gait can be trained in horses. Walk in same side pairs. Natural in camels
One beat gait
totting, pronking. Springboks do to demonstrate fitness
Plantigrade
walking on soles of feet
Digitigrade
walking on balls of feet
Unguligrade
walking on hooves
Powered rolling
pangolin
Trunchobracial junction
- Detachment of the forelimb from the body i.e no bony articulation
- Connected by muscle instead e.g serratus ventralis attaches thorax to the limb (therefore difficult to measure horses’ heights)
- Scapula ‘glides’ over lateral thoracic wall and rotates to increase stride length during exercise
Which species has vestigial clavicle
Cat/rabbit
Horse names for: carpus, metacarpophalangeal joints, region between this and hoof, distal interphalangeal joint
the knee, the fetlocks, the pastern, the pedal/coffin joint
Difference in humerus in muscular animals
larger tuberosities for greater muscle attachment
Types of muscle
- Skeletal striated (very regular muscle fibres)
- Cardiac striated (less orderly)
- Smooth (no fibres. Cells)
Muscle architecture
- 1 muscle -> many fascicles
- 1 fascicle -> many muscle fibres
- 1 fibre -> 1 multinucleate syncytium (a long cylindrical tube from cells joined together)
Within each fibre: many intracellular longitudinal myofibrils each divided into repeating transverse sarcomeres. Each sarcomere can contract a certain distance and all added together works out range of muscle.
Extrinsic muscle meaning
Trunk to limb (often strap since no leverage)
Intrinsic muscle meaning
Within limb (often pennate i.e tendons arranged to have lots of short myofibrils so cant contract far but can contract forcefully)
Epimysium
fibrous elastic tissue that surrounds each muscle. Outer layer
Fascial tunnels
EXTERNAL CONNECTIVE TISSUE
Tight fibrous tubes that contain muscles in a fixed volume – useful for venous and lymphatic return
- Divert semi-sharp trauma (contracted muscle in tight tube is firm and protected against injury)
Synergist muscles
Prevent other muscles being impaired
Capsular muscles
Stabilise joint capsule
Ligamentar muscles
Constrain movement to keep motion in correct plane
Equation for torque
Toque = force x perpendicular distance from pivot
Tendons
A strong fibrous continuation of the epi, peri, and endo-mysia at the ends of a muscle
Dense collagen. Generally connects muscle to bone
Funicular
Cord like tendons
Aponeurosis
Broad sheet like tendons
Role of tendons
1) Direct muscular force (telegraph, focus, distribute)
2) Store and release elastic potential energy
3) Absorb sudden forces (protects muscle and bone)
4) Amplify very rapid movement (resonance)
Sesamoid bones
Form in tendons (occasionally ligaments too)
Prevent flattening and reduce friction.
Increase distance of tendon from pivot by pulling it out, increasing perpendicular distance so increasing toque
Synovial bursa
Bags of fluid to lubricate movement of tendon over bone. May connect to a joint space
Synarthroses
Immobile joints give stability
Synostosis
Type of synarthroses. Bone (mature skull, mature pelvis). Fused together bones. No movement
Synchondrosis
Type of synarthroses. - Synchondrosis: Cartilage (growth plates) within bone
Symphysis
Type of synarthroses. Fibrocartilage (early pelvic, mandibular). Some movement
Syndesmois
Type of synarthroses. Fibrous attachment between bones (early skull)
Gomphosis:
Type of synarthroses. Firbrous tooth socket
Amphiarthrosis
- Intervertebral joints -> composite joints including one symphysis and two diarthroses
Diarthrosis
Synovial joints. More mobile with fluid and cartilage
Hinge (ginglymus)
Move about one axis so in one plane e.g hock, elbow. Some hinge joints (e.g. horse elbow) are ‘snap joints’ – at a high energy state in an intermediate position. Ovoid rather than circular so collateral ligament pulled taut in intermediate. Prefer being flexed or extended. Snaps between states
Pivot (trochoid)
e.g c1/c2 joint for twisting head. One axis that is longtitudinal to bone.
Saddle (sellar)
2 axis e.g interphalangeal
Ellipsoidal
2 axis e.g antebrachiocarpal joint
Ball and socket (enarthrosis)
3 axis
Planar, sliding (arthrosis)
e.g intercarpals, intertarsals. Translation not rotation
Synovial membrane:
- Glistening pink, many vessels and nerves
- Often incomplete, no basement membrane Synoviocytes type A (phagocytic) and B (secretory)
- Often large pouches to allow movement
Synovial fluid
- Secreted by membrane
- Plasma ultrafiltrate + hyaluronate (long-chain glycosaminoglycan)
- Lubricant, nutritive (gases/glucose)
Articular cartilage
- Not just hyaline - Varies in fibrous content
- 1mm in dog, several in ungulates
- No vessels or nerves – fed by synovial fossa diffusion – 1. fluid 2. capsule 3. bone
- Arcade arrangement of collagen – tangential fibres superficially, perpendicular deeper
To remember when giving Baytril (enrofloxacin)
Causes abnormal development of articular cartilage in growing animals
Joint capsules
Fibrous capsule attaches to periosteum
Continuous with articular cartilage
Supports joint: often thickened into ligaments (‘bone-to- bone’) – e.g. collateral ligaments restrict to one plane
Much innervation: proprioception (sensation of where limbs are in space), respiratory reflexes
Ligaments
Bone to bone
Discs/menisci
o Discs and menisci are fibro- cartilage ingrowths from capsule o disc (complete): e.g jaw joints o menisci (incomplete): e.g stifle o Allocate different movements to different compartments (acts as two joints
Labra
Fibrocartilaginous lips which deepen and extend the socket in ball and socket joints– e.g. hip socket
Fat pads
lie between synovial membrane and capsule
Fibroblast
Makes fibrous tissue
Chondroblast
Makes cartilage (resting state chondrocyte in lacunae)
Osteoblast
Makes bone (resting state osteocyte in lacunae)
Types of cartilage
1) Hyaline skeletal: Simplest, may mineralise in old age. Found in upper respiratory tract and ventral ribs.
2) Elastic skeletal: Contains elastin fibres too. Found in external ear and upper respiratory tract.
3) Fibrocartilage skeletal: Alternating layers of hyaline cartilage and collagen. Found in intervertebral discs, symphyses, scuta, labra, menisci and discs.
4) Articular cartilage: Complex partly fibrous/partly hyaline form. Found in joints
5) Hyaline ‘model’ is a precursor for bone development
Osteoid
Bone matrix
1/3 is organic: type 1 collagen
2/3 is hydroxyapatite with adsorbed calcium carbonate i.e mix of calcium salts
Osteoclasts
Cells which break down bone to allow reformation and reabsorption of calcium. Bone formation/ destruction is controlled hormonally by parathyroid hormone, calcitonin and vitamin D.
Multinucleate and short lived
Axial
Spine
Appendicular
Limbs
Cranial
Skull
Post cranial
Non skull
Cancellous bone
Light, spongy bone with much less mineral. Still strong. Soft tissue between spicules. Parallel and perpendicular fibres of spicules to force applied.
Marrow and air spaces
Red marrow: haemopoietic makes blood cells
Yellow marrow: adipose tissue (fat). Found in extremities of body from halfway down arm and leg. Want lighter marrow is distal bones for movement.
Pneumatised: some animals fill bones with air e.g vulture metacarpu
Compact bone
Constantly remodelled, yielding many parallel cylinders – ‘osteons’. Each cylinder based around a Haversian canal (from osteoclast erosion). Canal carries vessels and nerves and connects to marrow cavity. Interconnected by oblique connecting tubes called Volkmann’s canals
Periosteum
lines bone
- Major role in bone formation
- Tendons, ligaments and joint capsules attach to it (not directly to bone)
- Carries blood vessels and nerves
- Major role in bone repair i.e post fracture
Parts of spine
Cervical, thoracic, lumbar, sacral, caudal
Punctuated equilibrium
Species are generally stable changing very little which is then punctuated by rapid change to create new species leaving few fossils behind (explains lack of intermediate fossils)
Hopeful monsters
Organisms with a profound mutant phenotype with potential to establish new evolutionary lineage
Convergent evolution
2 distantly related species develop similar characterics despite not being related -> independent evolution e.g due to similar conditions
E.g myoglobin in whales and moles is similar due to living in low O2 conditions
Clades
Contain ‘all descendants of a single common ancestors’ and are defined by a shared derived characteristic from the ancestor (not present in more distant relatives not in clade)
Conditions for domestication:
- Rapid growth
- Flexible diet
- Breed in captivity
- Calm
- No strict social hierarchy (therefore can separate groups)
Results of domestication
- Fat deposits
- Reduced weaponry
- Smaller brain
- Neoteny (juveline characteristics)
Dogs ancestor
20-40,000 B.C.
Derive variously from Eurasian, Indian and Chinese wolves
Sheep ancestor
11-9,000 B.C.
Mouflon, Urial
Pigs ancestor
9,000 B.C
Wild boar
Goat ancestor
8,000 B.C
Bezoar
Cattle ancestor
8,000 B.C
Auroch
Cats ancestor
8-3,000 B.C
African wild cats
Chickens ancestor
6,000 B.C
Indian red jungle fowl
Donkeys ancestor
5,000 B.C
Wild ass
Horses ancestor
4,000 B.C
Tarpan
Perimysium
Connective tissue that surrounds bundles of muscle fibres (a fascicle)
Endomysium
Thin layer of connective tissue that surrounds each muscle fibre
