Topic 6 - Muscular System

Question 1

Some functions of ______ tissue include body movement, substance movement, control of substance movement and thermogenesis.

Answer 1

Muscle

Question 2

Some characteristics of all types of ______ tissue include:
- Electrical excitability
- Contractility
- Extensibility
- Elasticity

Answer 2

Muscle

Question 3

The ability to respond to certain stimuli by producing electrical signals called action potentials.

Answer 3

Electrical Excitability

Question 4

The ability of muscle tissue to generate tension/force when stimulated by an AP.

Answer 4

Contractility

Question 5

The ability of muscle to stretch/lengthen without being damaged. The muscle can still contract when stretched.

Answer 5

Extensibility

Question 6

The ability of muscle tissue to return to its original shape after contraction or stretch.

Answer 6

Elasticity

Question 7

Alternating light and dark bands that are characteristic of skeletal muscle.

Answer 7

Striations

Question 8

T/F - Skeletal muscle is under voluntary/conscious control, but is also subject to involuntary control.

Answer 8

True

Question 9

Order the following components of skeletal muscle in the correct hierarchy:
- Fascicle
- Myofibril
- Muscle
- Muscle Fibre (aka. Muscle Cell)

Answer 9

1) Muscle
2) Fascicle
3) Muscle Fibre (aka. Muscle Cell)
4) Myofibril

Question 10

A component of skeletal muscle that is named, measured in cm and can be subdivided into bundles of fasciles.

Answer 10

Muscle

Question 11

A component of skeletal muscle that is measured in mm and made up of many muscle fibres.

Answer 11

Fascicle

Question 12

A cylindrical-shaped component of skeletal muscle containing a lot of mitochondria, is multi-nucleated, measured in µm and filled with myofibrils.

Answer 12

Muscle Fibre (aka. Muscle Cell)

Question 13

The cell (plasma) membrane of the muscle cell.

Answer 13

Sarcolemma

Question 14

Tiny invaginations that tunnel in from the sarcolemma towards the centre of the muscle fibre.

Answer 14

Transverse Tubules (T-Tubules)

Question 15

The cytoplasm of the muscle fibres that contains a lot of glycogen.

Answer 15

Sarcoplasm

Question 16

A protein that binds oxygen that has diffused into the muscle fibre and delivers it to the mitochondria.

Answer 16

Myoglobin

Question 17

Specialized contractile organelles measured in µm that extend the length of the muscle fibre/cell. They are held in place by cytoskeletal proteins.

Answer 17

Myofibrils

Question 18

Fluid filled tubes and sacs running along and surrounding each myofibril. They store and release calcium into the cell when it’s needed.

Answer 18

Sarcoplasmic Reticulum

Question 19

Myofibrils are composed of a number of __________ arranged in series (end to end).

Answer 19

Sarcomeres

Question 20

The functional unit of a myofibril containing myofilaments that overlap and this interaction is what generates force/contraction. It also creates light and dark strips, which give skeletal muscle its striated appearance.

Answer 20

Sarcomere

Question 21

What are the 2 contractile proteins (aka. myofilaments) contained in the sarcomere?

Answer 21

1) Actin
2) Myosin

Question 22

A contractile protein that makes up the thin filaments of the sarcomere.

Answer 22

Actin

Question 23

A contractile protein that makes up the the thick filaments of the sarcomere.

Answer 23

Myosin

Question 24

To generate tension, skeletal muscle cells must be stimulated by a nerve signal from a _____ neuron.

Answer 24

Motor

Question 25

A neuron/nerve cell that conducts APs to muscle cells.

Answer 25

Motor Neuron

Question 26

The axon of the _____ neuron connects with the muscle. When it reaches the muscle, it branches out into a number of axon _________.

Answer 26

Motor
Terminals

Question 27

Each axon terminal of the motor neuron forms a junction called the _____________ junction with the sarcolemma of a number of different muscle cells.

Answer 27

Neuromuscular

Question 28

T/F - The axon terminal of a motor neuron and the sarcolemma touch to form the synaptic cleft.

Answer 28

False - The axon terminal of a motor neuron and the sarcolemma NEVER ACTUALLY touch. THERE IS A GAP BETWEEN THEM called the synaptic cleft.

Question 29

The the signal arrives at the neuromuscular junction, it releases a ________________ (e.g. acetylcholine) which cross the synaptic cleft.

Answer 29

Neurotransmitter

Question 30

When a nerve signal crosses the synaptic cleft, it stimulates the __________ as it is then continued by the muscle fibres and spreads out across this cell membrane.

Answer 30

Sarcolemma

Question 31

After spreading out across the sarcolemma, the signal then travels down the __________ _______ and stimulates the sarcoplasmic reticulum to release _______. This in turn allows the myosin to connect with the actin.

Answer 31

Transverse Tubules
Calcium

Question 32

T/F - Actin pulls the myosin together, then it disengages and starts the cycle again.

Answer 32

False - MYOSIN pulls the ACTIN together, then it disengages and starts the cycle again.

Question 33

T/F - The “ratcheting” of actin and myosin uses ATP and will shorten the muscle with repetition.

Answer 33

True

Question 34

When APs stop, the ____________ _________ pumps calcium back inside (this uses ATP). Without sufficient calcium, the _____ filaments cannot continue their ratcheting of the ____ filaments. Tension generation stops.

Answer 34

Sarcoplasmic Reticulum
Thick
Thin

Question 35

The motor neuron and all the skeletal muscle fibres it innervates.

Answer 35

Motor Unit

Question 36

T/F - Axon terminals of one motor unit will overlap with the axon terminals of another motor unit.

Answer 36

False - Axon terminals of one motor unit WILL NOT overlap with the axon terminals of another motor unit.