Muscle function

Question 1

describe the ultrastructural appearance of striated muscle and state which bands contain actin, myosin or both

Question 2

compare striated and non striated muscle

Answer 2

Striated muscle is made of skeletal and cardiac muscle. both contain myoglobin, an oxygen storing molecule.
however skeletal muscle can be controlled voluntarily and there is direct nerve-muscle communication.

similar to the non striated smooth muscle , cardiac muscle has indirect nerve-muscle communication and involuntary control however non striated muscle does NOT have myoglobin.

Question 3

compare and contrast the structural significance of fast and slow striated muscle

Answer 3

slow twitch fibres have a rich capillary supple, they are aerobic therefore have high myoglobin levels , many mitchondria and any cytochromes
the appear darker ( red) and are fatigue resistant so they are good for standing and walking. they use fatty acids to generate glucose

type 2a fast twitch fibre(intermediate) s, rich capillary supply, aerobic with high myoglobin levels they have many to intermediate mitochondrial numbers. many cytochrome and they are red to pink. they use fatty acids and glycogen
brown- intermediate - a mixture of fast and slow twitch fibres. initially there is a lot of CO2 present and then lots of lactate =.

type 2b sfast twitch fibres have a poor capillary supply, they are anaerobic with low myoglobin levels and have low mitochondrial numbers, there are few cyt

Question 4

define ptosis

Answer 4

dropping( left) ey;eod

Question 5

what is myasthenia graves

Answer 5

it is an autoimmune disease caused by antibodies blocking the Ach receptor

30% reduction in receptor number causes the symptoms

the endplate invaginations are reduced so there are less synaptic transmutation and this intermittent muscle weakness

Question 6

what is the origin and the insertion point

Answer 6

bone, typically proximal which has greater mass and is more stable during contraction than the muscles insertion

Question 7

agonists

Answer 7

agonists are prime movers
antagonists ( oppose prime movers)
synergists assist prime movers , they cannot complete the movement alone but their angle of pul assists the movement

neutralisers, prevent the unwanted actions that an agonist can perform

fixations act to hold a body part immobile whilst

Question 8

first class lever

Answer 8

see saw : semispinalis capital muscle in neck extensions ,

Question 9

wheelbarrow ( second class)

Answer 9

effort at one end , fulcrum at the other
plantar flexion of food

Question 10

third class level

Question 11

compartment syndrome

Answer 11

limbs divided into compartments delineated by fascia
trauma in one compartment could cause internal bleeding which exerts pressure on blood vessels and nerves

symptoms
deep constant poorly located pain,
aggravated by passive stretch of muscle group
parasthesia