Lecture 27

Question 1

The function of skeletal muscle:

Answer 1

• Posture, movement, heat

- On-demand individual-specific

Question 2

The function of cardiac muscle:

Answer 2

• Pumping bloof
• Continuous
• All at once
• Build pressure

Question 3

At the connection of two myocytes in cardiac muscle you’ll find….

Answer 3

• An intercalated disc

- Inside the intercalated disc you’ll find z discs

Question 4

How do myocytes in the cardiac muscle connect?

Answer 4

• Gap junction (electrical)

- Desmosome (mechanical)

Question 5

In the right atrium ______ cells are located. The depolarisation wave is initiated in the ______ node and travels to the _____ node.

Answer 5

• Pacemaker
• Sinoatrial (SA) node
• Atrioventricular (AV) node

Question 6

What is the order of depolarisation in the heart?

Answer 6

• Atria
• Septum
• Apex
• Ventricles (via purkinje fibres)
• FURTHER DEPOLARISATION up ^^^
• Fully depolarised, contraction!

Question 7

The smooth muscle cell has no ____ cells which means it’s not ____. There are ____ length changes. Single-unit smooth muscle cells also have ____ ____ like cardiac muscle. Which means that action potentials can reach other cells through them.

Answer 7

• Sarcomeres
• Striated
• Large
• Gap junctions

Question 8

Smooth muscle cells can be found in the ____ _____.

Answer 8

• Digestive tract

Question 9

In a multi-unit smooth muscle cell they are ______ innervated by neurons.

Answer 9

• Individually

Question 10

Relaxation of the smooth muscle cells = ______. The opposite of this is ______.

Answer 10

• Vasodilation
• More blood flow
• Decrease resistance
• Vasoconstriction

Question 11

Smooth Muscle: Excitation-Contraction

Answer 11

• Action potential / hormones make Calcium ride
• C2+ binds to calmodulin
• Ca-calmoduo\lin complext activates MLCK
• MLCK activates MLC which activates cross bridge
• Myosin filament regulated

Question 12

Skeletal cells have …… cells

Answer 12

• Long, cylindrical, multinucleate

Question 13

Cardiac muscle cells have….cells

Answer 13

• Mononucleate

- Branching

Question 14

Smooth muscle tissues has …….cells

Answer 14

• Mononucleate

- Spindle-shaped

Question 15

In skeletal and cardiac muscle, ____ and myosin organised along an _____ therefore stronger _____ along the axis. ____ filament regulated. Needs calcium to bind to ____.

Answer 15

• Actin
• Axon
• Force
• Thin
• Troponin

Question 16

In smooth muscle, actin and _____ arranged in various directions so are ____. ___ filament regulated. ____ needed for calmodulin.

Answer 16

• Myosin
• Weak
• Thick
• Calcium

Question 17

In which types of muscle can action potentials be spread from cell to cell?

Answer 17

• Cardiac

- Smooth (only in single-unit)

Question 18

Which types of muscles do we have control over?

Answer 18

• Skeletal

Question 19

What type of muscle do we not have control over? (Involuntary)

Answer 19

• Cardiac

- Smooth

Question 20

Speed of contraction for muscle types…

Answer 20

• Skeletal (fast)
• Cardiac (slow)
• Smooth muscle (very slow)

Question 21

Important info to remember:

Answer 21

• Why do we need muscle?
• Structure
• Mechanism of contraction
• Energy source for contraction of skeletal muscle
• Twitch and tetanus
• Skeletal muscle fibre types
• Structural/functional differences of all muscle types