small animal musculoskeletal (wk 1) Flashcards
fat storage is a function of bone - true or false?
true - lipids are stored as yellow marrow in long bones
which muscle type is NOT striated - skeletal, smooth or cardiac?
smooth muscle
which is the effects of resistance training vs endurance training on myofibres (muscle fibres)?
1. increased number of blood vessels, mitochondria, mitochondrial proteins and oxidative enzymes
2. increased diameter of muscle fibres and myofibrils, increased number of myofibrils
1 - endurance training (cardio)
2 - resistance training (big muscles)
which of the following will NOT cause decreased skeletal muscle tone?
1. low blood potassium levels
2. low glucose levels
3. dysfunction of acetylcholinesterase
- dysfunction of acetylcholinesterase - this is the thingie that removes the acetylcholine and causes the muscle to relax
normal numbers of cervical, thoracic, lumbar and sacral vertebrae on an average dog and cat? *caudal/tail vertebrae is variable
7 cervical, 13 thoracic, 7 lumbar, 3 sacral - think 7, 13, 7, 3.
true or false - there are joints between the vertebral bodies
true - a mix of different types too
A dog has damage to the nerve that supplies the triceps brachii muscle. The nerve damage means that the triceps brachii cannot contract.
What would you expect to see clinically?
1. inability to bear weight on the affected limb.
2. inability to flex the carpus.
3. inability to move the limb forwards when walking.
- inability to bear weight on the affected limb - contraction of the triceps is what extends the elbow, and weight bearing is performed with joints held in extended position.
You are at the pub after a hard day of Kuracloud lessons. Which proximal limb muscle needs to contract for you to get your hard-earned drink to your mouth?
1. Biceps brachii m.
2. Brachiocephalicus m.
3. Trapezius m.
4. Triceps brachii m.
- Biceps brachii m. contraction - this causes elbow flexion needed to lift drink
muscle contraction - does the insertion move towards the origin, or vice versa?
insertion point moves towards origin, origin point of the muscle stays put
what’s the normal name for the gastrocnemius muscle?
the calf muscle
What would be the expected consequence of rupture of the gastrocnemius tendon (runs from knee to ankle)?
1. Extension of the stifle.
2. Flexion of the stifle.
3. Extension of the tarsus.
4. Flexion of the tarsus.
- Flexion of the tarsus
What would be the expected consequence of rupture of the cranial cruciate ligament?
1. Increased adduction of the tibia
2. Increased gliding of the tibia cranial to the femur
3. Increased rotation of the tibia relative to the femur
- Increased gliding of the tibia cranial to the femur
is gliding or rotation possible in the normal elbow?
nope
is rotation possible in a normal hip joint?
yes - it’s a ball and socket joint, can do everything except gliding
is a head nod normally seen with forelimb lameness, or forelimb and hindlimb?
mostly forelimb
what does effusion mean?
abnormal amounts of fluid within a joint space
what does laxity mean?
abnormal looseness or instability of a joint
what does subluxation mean?
partial dislocation of a joint - where the joint surfaces are still in partial contact but not properly aligned
what does crepitus mean?
a grating or crackling sensation when moving a joint
which image depicts collateral ligaments?
B - collateral ligaments are located medially and/or laterally
What is the function of collateral ligaments?
1. Prevention of hyperextension/hyperflexion
2. Prevention of medial/lateral angulation
3. Prevention of cranial and caudal movement
- Prevention of medial/lateral angulation - they’re located on the sides of the joint
which joint does not allow flexion and extension?
1. carpus
2. atlantoaxial joint
3. shoulder
- atlantoaxial joint (the close to the skull vertebrae)
true or false - all of the following are unable to rotate: atlantoaxial joint, elbow, stifle, shoulder, carpus and tarsus?
true - only the hip can
which of the following allows pendular (abduction and adduction) movements?
- hip, shoulder, carpus, atlantoaxial, elbow, tarsus, stifle?
only atlantoaxial (it’s a pivot joint)
is the pelvis part of the axial or appendicular skeleton?
appendicular (included with the hindlimbs/forelimbs)
Which forelimb structures bear weight in the normal standing dog/cat?
1. Digits 1-5 and their pads, the metacarpal pad, the carpal pad
2. Digits 1-5 and their pads, the metacarpal pad, the carpal pad
3. Digits 1-4 and their pads, the metacarpal pad
4. Digits 2-5 and their pads, the metacarpal pad, the carpal pad
5. Digits 2-5 and their pads, the metacarpal pad
- Digits 2-5 and their pads, the metacarpal pad - digit 1 is the dew claw, it’s not on the ground
what is supination (pronounced soup-in-nation)?
to turn or hold a hand/limb/foot so that the palmar/plantar surface faces upwards or outwards (think your hands face upwards when holding a bowl of soup)
what is pronation?
the opposite of supination - to turn or hold a hand/foot/limb so that the palmar/plantar surface faces downwards or inwards
What are the structures within the stifle joint that stop cranial and caudal movement of the tibia relative to the femur?
1. The cruciate ligaments
2. The collateral ligaments
3. The menisci
4. The infrapatellar fat pad
- The cruciate ligaments
are the cruciate ligaments named based on:
a. their origin
b. their insertion
b. their insertion - the cranial cruciate ligament inserts on the cranial aspect of the tibia and originates caudolaterally
which is thick vs thin muscle fibre components?
1. made up of bundles of myosin
2. made up of actin, tropomyosin and troponin
- thick muscle fibres - made up of myosin
- thin muscle fibres - made up of actin, tropomyosin and troponin
Which electrolyte, released by the sarcoplasmic reticulum, is essential for the binding of myosin to actin (and subsequent muscle contraction)?
1. Calcium
2. Magnesium
3. Potassium
4. Sodium
- Calcium
An action potential is necessary to trigger muscle contraction. What is an action potential?
a fast and transient change in the membrane potential of a cell
Which neurotransmitter binds to skeletal muscle to open sodium channels and trigger an action potential in the muscle?
1. Acetylcholine
2. Adrenaline
3. Nerve growth factor
4. Noradrenaline
- Acetylcholine
what is potassium’s influence of muscle contractions if low amounts are present in the blood?
hypokalaemia - muscle weakness (low potassium in blood = fewer positive ions crossing over membrane = lower resting membrane potential = harder to trigger depolarisation)
what is potassium’s influence of muscle contractions if high amounts are present in the blood?
hyperkalaemia - increased muscle contractions (increased positive ions in the blood = more cross over to cell = increased membrane potential = easier to trigger depolarisation/action potentials)
what is sodium’s influence on muscle contractions if low amounts are present in the blood?
hyponatraemia - muscle weakness (it’s the opening of the sodium channels that stimulates depolarisation, so there’s decreased stimulation of muscle contraction)
what is sodium’s influence on muscle contractions if high amounts are present in the blood?
hypernatraemia - increased muscle contractions (spasms, twitching - the opening of sodium channels stimulates depolarisation, so there’s increased stimulation of muscle contraction)
what is glucose’s influence on muscle contractions if low amounts are present in the blood?
hypoglycaemia - decreased muscle contraction (not enough ATP production = decreased ability for myosin to bind to actin)
what is glucose’s influence on muscle contractions if high amounts are present in the blood?
hyperglycaemia - no effect on muscle contraction
what is glucose’s role in muscle contraction?
glucose –> ATP to provide energy for muscle cells (ATP is used in the binding of myosin to actin, which draws muscle filaments together, causing contraction)
is the opening of potassium channels triggering:
a. depolarisation
b. repolarisation
b. repolarisation (return of the membrane potential to its resting level stops the action potential, and ends muscle contraction)
is the opening of sodium channels triggering:
a. depolarisation
b. repolarisation
a. depolarisation (which causes the action potential which causes the muscle contraction)
Calcium is required for transmission of action potentials across the neuromuscular junction, which in turn trigger muscle contraction. Calcium is also necessary for myofibril contraction through its interaction with troponin.
However, calcium also blocks sodium channels involved in depolarisation of nerves and muscle fibres. what is calcium’s effect on muscle contraction if high levels in blood?
hypercalcaemia - muscles unable to contract (calcium blocks sodium channels involved in depolarisation)
Calcium is required for transmission of action potentials across the neuromuscular junction, which in turn trigger muscle contraction. Calcium is also necessary for myofibril contraction through its interaction with troponin.
However, calcium also blocks sodium channels involved in depolarisation of nerves and muscle fibres. what is calcium’s effect on muscle contraction if low levels in blood?
hypocalcaemia - uncontrollable muscle contraction (think tetanus) because less sodium channels are blocked = increased depolarisation
Calcium is one of the most abundant electrolytes in the body and is mostly stored in bones. Too much calcium in the blood (hypercalcaemia) might be caused by:
a. destruction of bone
b. new bone formation
a. destruction of bone
When a tissue is damaged, it releases/leaks compounds, such as enzymes, proteins and metabolites, into the blood. We can test for products of muscle breakdown in the blood and urine - what does increased myoglobin indicate?
muscle damage - this causes the myoglobin (protein that carries and stores oxygen in muscle) into the blood where it is then filtered by kidneys. myoglobin causes the urine to be dark red/brown coloured
what projection is this radiograph?
a. craniocaudal
b. craniopalmar
c. dorsoventral
d. lateral
d. lateral
what is structure B?
lateral fabella
what projection is this radiograph?
a. cranioplantar
b. craniocaudal
c. dorsoventral
b. craniocaudal
what is structure C?
common calcaneus tendon
what is structure A?
patella ligament
the nerve that passes through the area indicated by the yellow dashed line innervates muscles that:
a. abduct the hips
b. adduct the hips
c. extend the hindlimb
d. flex the hindlimb
b. adduct the hips - it’s the obturator nerve that passes through the obturator foramen, trauma to this region would cause the affected limb to splay out (eg calving injuries)
what is structure A?
6th lumbar vertebrae
what is structure B?
the ilium
what is structure C?
the ischium
structure surrounded by the solid yellow line?
the acetabulum
structure pointed to by the two yellow arrows - is it a:
a. fracture
b. the sacroiliac joint
c. the hip
b. the sacroiliac joint
where is the occipital bone?
top right
where is the frontal sinus?
air pocket thing rostral to brain?
where is the tympanic bulla?
bottom right
true or false - the wing of the ilium is also referred to as the tuber coxae in dogs
true (that would explain why I was confused as to what the tuber coxae was)
where is the proximal physis?
here - the physis is the cartilaginous disk separating the epiphysis from the metaphysis. it is responsible for the growth of long bones
locate the antebrachiocarpal joint in this puppy’s radiograph
here - not to be confused with distal epiphyseal lines
