0428 Muscle tissue

Question 1

List the 3 types of muscle tissue

Answer 1

Skeletal, cardiac and smooth

Question 2

Which of the 3 muscle tissues is striated

Answer 2

Striated = skeletal and cardiac

Non striated = smooth

Question 3

Which of the 3 muscle is volutnary

Answer 3

Voluntary = skeletal
Involuntary = smooth and cardiac

Question 4

Define sacrolemma, sarcoplasm, sarcoplasmic reticulum?

Answer 4

Sacrolemma = plasma membrane
Sarcoplasm = cytoplasm
Sarcoplasmic reticulum = endoplasmic reticulum

Question 5

Briefly describe the structure skeletal muscle (think E.M.P.F.E.M.)

Answer 5

Epimysium srrounds muscle belly, made of perimysium surrounding fascicles, made of endomysium surrounding muscle fibres

Question 6

Describe the cells of skeletal muscle (structural form and nucleus)

Answer 6

Skeletal muscle cells are extremely elongated, has a 5 sided structure and multi-nucleated at the periphery

Question 7

What are the 2 types of skeletal muscle? Describe their differences?

Answer 7

Type 1: Slow contraction, aerobic, high mitochondria and myoglobin, red colour

Type 2: fast contraction, anaerobic, rich in glycogen, white colour

Question 8

Describe the myofibril structure (list the 3 bands). What is a sarcomere?

Answer 8

I band (light, myosin), A band (dark, actin) and Z band (black, site of actin attachment)

A sarcomere is a contractile unit and is the distance from 1 Z band to an adjacent Z band

Question 9

Describe the 3 types of skeletal muscle innervation input

Answer 9

Motor innervation, sensory innervation and sympathetic innervation

Question 10

What is a motor unit

Answer 10

A motor unit is a motor nueron and the muscle fibres it supplies

Question 11

What is the primary excitatory neurotransmitter at the neuromuscular junction

Answer 11

Acetylcholine

Question 12

List a disease relating to skeletal muscle

Answer 12

Duchenne muscular dystrophy

Question 13

What is the function of smooth muscle

Answer 13

Rhythmic or continuous autonomic contraction

Question 14

Give some locations of smooth muscle

Answer 14

The GI tract, bladder, vessels

Question 15

Describe the organisation of smooth muscle cells

Answer 15

Smooth muscle cells are spindle-shaped and form irregular branching fasciculi

Question 16

What do smooth muscle cells have instead of Z lines

Answer 16

Dense bodies (focal densities and attachment junctions)

Question 17

True or false - myosin predominates in smooth muscle

Answer 17

False, Actin predominates

Question 18

What are the 2 types smooth muscle (by unit and contraction)

Answer 18

Single unit and multiunit type. Phasic and tonic

Question 19

What is an example of smooth muscle pathophysiology

Answer 19

Familial visceral myopathy

Question 20

How do cardiac myocytes communicate with one another

Answer 20

through intercallating discs

Question 21

How do smooth muscle cells communicate with one another

Answer 21

Gap junctions

Question 22

Describe the structure of a cardiomyocyte (shape and nuceli)

Answer 22

Cardiomyocytes are elognated and contain central nuclei

Question 23

What are intercalated discs? what is their function in the heart

Answer 23

Intercalated discs are specialised cellular junctions that permit rapid spread of contractile stimuli and thus allow simultaneous contraction

Question 24

What 3 types of membrane contacts make up intercalating discs

Answer 24

fascia adherens, desmosomes and gap junctions

Question 25

What is the effect of the sympathetic and parasympathetic nervous system on the heart rate

Answer 25

Sympathetic nervous system increase bpm. Parasympathetic nervous system decreases bpm

Question 26

List one example of a disease that affects cardiomyocytes

Answer 26

hypertrophied cardiomyopathy