Slide Set 5

Question 1

3 types of muscles

Answer 1

• skeletal
• cardiac
• smooth

Question 2

Which muscles do we have voluntary control over?

Answer 2

Skeletal

Question 3

Structure of skeletal muscle

Answer 3

multinucleated
striations
large muscle fibers

Question 4

a flexor-extensor pair of muscle is called:

Answer 4

antagonist muscle group

Question 5

Which tissue is present in skeletal muscles

Answer 5

connective tissue

Question 6

Connective tissue components

Answer 6

• epimysium : covers the muscle as a whole
• perimysium : binds fascicles together and is wrapped around it
• endomysium : covers skeletal muscle fibers

Question 7

Unique structure of skeletal muscle cell is due to :

Answer 7

• T tubules : allow electrical signals traveling along sarcolemma to move deeper in cell
• The triad : formed from a triplet of tubules, made of the sarcoplasmic reticulum, allows signal traveling along T tubule

Question 8

What is the contractile unit of muscle fibres

Answer 8

the sarcomere

= segment of myofibril between 2 successive Z lines

Question 9

what gives skeletal muscle its striations?

Answer 9

The A and Z bands of the sarcomere

Question 10

Muscle fibers -> __ -> myofilaments

Answer 10

myofibrils

Question 11

Myofilaments are made up of 4 different proteins

Answer 11

Myosin : thick filaments
Actin
Tropomyosin
Troponin

Question 12

Thin filaments attach to

Answer 12

both Z lines of a sarcomere

Question 13

What are the regulatory proteins

Answer 13

• nebulin : helps align actin

- titin : provide elasticity, stabilise mysosin

Question 14

Globular protein that forms 2 fibrous strands that twist around each other to form bulk of thin filament is

Answer 14

actin

Question 15

What are 2 phases leading to muscle fibre contraction

Answer 15

Phase 1 : motor neuron stimulates muscle fiber

Phase 2 : excitation-contraction coupling occurs

Question 16

In neuromuscular junctions, motor neurons connect to sarcolemma at __

Answer 16

motor endplate

Question 17

Neuromuscular junction

Answer 17

= synapse where neurotransmitter molecules transmits signals, motor neuron is in contact with muscle fiber

Question 18

Which neurotransmitter is released by a motor neuron when it binds with receptors of muscle fiber

Answer 18

acetylcholine

Question 19

Mechanism of contraction

Answer 19

• fiber stimulated by motor neuron releasing ACH
• electrical impulse travels from sarcolemma down the T tubule where voltage change triggers opening of the voltage gated calcium channels
• allows passive diffusion of calcium out of the SR -> triggers contraction process

Question 20

What initiates a muscle action potential?

Answer 20

The net entry of SODIUM through ACH receptor-channel

Question 21

Can muscles store ATP?

Answer 21

very little

Question 22

Muscles store __ used to make ATP on __

Answer 22

phosphate

creatine

Question 23

A sprinter would have which kind of fibres?

Answer 23

Fast-twitch glycolytic fibres (work anaerobically)

Question 24

what are the types of skeletal muscle fibres?

Answer 24

Slow-twitch

Fast twitch : oxidative-glycolytic fibres and glycolytic fibres

Question 25

Why are slow twitch fibres darker?

Answer 25

due to myoglobin

Question 26

Cardiac muscle fibers are different to skeletal muscle fibres in that :

Answer 26

- they have intercalated disks - branched fibres - retain calcium in the SR longer, longer contraction

Question 27

Smooth muscle

Answer 27

- small, tapered cells, single nuclei - no T tubules - loosely organized SR - calcium finds to CALMODULIN - no stations (still has thick & thin filaments)

Question 28

Types of smooth muscle tissue

Answer 28

- single unit | - multiunit

Question 29

Difference between the types of smooth muscle

Answer 29

single unit : have gap junctions, many cells contract as a unit multi unit : doesn't act as a single unit, each fiber responds to 1 nervous input

Question 30

Each cell is individually enervated

Answer 30

= multi unit smooth muscle tissue

Question 31

Smooth muscle contraction is

Answer 31

slower and longer

Question 32

6 groups with smooth muscle

Answer 32

``` vascular gastrointestinal urinary respiratory reproductive eye ```

Question 33

What controls smooth muscle

Answer 33

- hormones - paracrines - neurotransmitters

Question 34

Where is the heart found?

Answer 34

in mediastinum

Question 35

2 circuits in heart

Answer 35

pulmonary (low pressure, low resistance) | systemic (high pressure, high resistance)

Question 36

Veins

Answer 36

carry blood to heart

Question 37

Arteries

Answer 37

carry blood away

Question 38

Heart is composed mostly of

Answer 38

myocardium

Question 39

Which 2 factors influence arterial blood pressure by peripheral resistance ?

Answer 39

- blood viscosity | - diameter of arterioles

Question 40

What are the 4 different valves

Answer 40

- 2 AV valves= atrioventricular valves (R&L) | - pulmonary and artery semilunar valves

Question 41

Which valves prevent back flow from left and right atria

Answer 41

AV valves | thanks to chord tendinae

Question 42

Which valves prevents back flow of blood

Answer 42

semilunar valves

Question 43

__ cells receive signal from __ cells in the hear

Answer 43

Contractile; autorhythmic

Question 44

5 major structures compose the conduction system of the heart

Answer 44

- Sinoatrial node - Atrioventricular node - AV bundle (bundle of HIs) - Right & Left bundle branches - Purkinje system

Question 45

What is the heart's pacemaker?

Answer 45

the SA node

Question 46

what can be overexcited due to lack of sleep, caffeine, excess nicotine? This causes a higher depolarisation

Answer 46

Purkinje fibers | -> ectopic focus

Question 47

What is an indicator of heart damage

Answer 47

cardiac troponins