Muscle Part II

Question 1

Motor unit is consists of:

Answer 1

neuron
muscle cell it innervates

Question 2

A muscle may contract with varying degrees of strength because only some of the muscle cell contracts.

Answer 2

MOTOR UNIT

Question 3

Individual muscle cell – “all or none law”

Answer 3

MOTOR UNIT

Question 4

Finer muscle movements require fewer muscles per motor unit (eye movement)

Answer 4

MOTOR UNIT

Question 5

Motor nerve endings (MNJ) and sensory nerve endings (muscle spindles and Golgi tendon organs for proprioception)

Answer 5

INNERVATION OF SKELETAL MUSCLE

Question 6

synapse between a branch of a motor nerve axon and a skeletal muscle cell

Answer 6

Myoneural junction

Question 7

Depol presynaptic memb 🡪 Ca channels open 🡪 inc cytosolic Ca 🡪 Ach released 🡪 bind to Ach receptors in sarcolemma 🡪 depol

Answer 7

INNERVATION OF SKELETAL MUSCLE

Question 8

Postmortem rigidity appearing as hardening of skeletal muscles

Answer 8

RIGOR MORTIS

Question 9

Unable to synthesize ATP 🡪 myosin remains bound to actin 🡪 muscles remain contracted

Answer 9

RIGOR MORTIS

Question 10

Sensory receptors that monitor contraction:

Answer 10

Muscle spindles
Golgi tendon organs

Question 11

provides feedback about changes in muscle length and its rate of alteration

Answer 11

Muscle spindles

Question 12

monitor the tension and its rate produced during movement

Answer 12

Golgi tendon organs

Question 13

autoimmune disease in which antibodies block Ach receptors

Answer 13

Myasthenia gravis

Question 14

food poisoning in which Clostridium botulinum toxin inhibits Ach release at MNJ

Answer 14

Botulism

Question 15

Example of this is Botox cosmetic procedure

Answer 15

Botulism

Question 16

Shape and size of cells of skeletal muscle:

Answer 16

Long, cylindrical

Question 17

How many number and location of nucleus are there in a skeletal muscle?

Answer 17

Many, peripheral

Question 18

Is there a striations in a skeletal muscle?

Answer 18

Yes

Question 19

Property of skeletal muscle: T-tubules, sarcoplasmic reticulum

Answer 19

Triads at A-I junctions

Question 20

Is there a gap junctions in a skeletal muscle?

Answer 20

No

Question 21

Is there a sarcomere in a skeletal muscle?

Answer 21

Yes

Question 22

Does the skeletal muscle do regenerations?

Answer 22

Restricted

Question 23

Does the skeletal muscle do voluntary contraction?

Answer 23

Yes

Question 24

What is the distinctive characteristics of a skeletal muscle

Answer 24

Peripheral nuclei

Question 25

Contract spontaneously and display a rhythmic beat modified by hormonal and neural (parasympathetic and sympathetic) stimuli

Answer 25

CARDIAC MUSCLE

Question 26

Poorly defined myofibrils (thick and thin filaments)

Answer 26

CARDIAC MUSCLE

Question 27

Calcium source is more extracellular

Answer 27

CARDIAC MUSCLE

Question 28

Has more mitochondria

Answer 28

CARDIAC MUSCLE

Question 29

complex steplike junctions forming end to end attachments between adjacent cardiac muscle cells 🡪 functional syncytium

Answer 29

Intercalated disks

Question 30

modified cardiac fibers in the bundle of His; for conduction

Answer 30

Purkinje fibers

Question 31

Shape and size of cells of Cardiac Muscle

Answer 31

Blunt-ended, branched

Question 32

Number and location of nucleus of cardiac muscle

Answer 32

One or two, central

Question 33

Is there a striations in cardiac muscle?

Answer 33

Yes

Question 34

T tubules, sarcoplasmic reticulum of cardiac muscle

Answer 34

Dyads at Z disks

Question 35

Is there a gap junctions in cardiac muscle?

Answer 35

Yes (in intercalated disks)

Question 36

Is there a sarcomere in cardiac muscle?

Answer 36

Yes

Question 37

Is there a Regeneration in cardiac muscle?

Answer 37

None

Question 38

Does cardiac muscle do voluntary contraction?

Answer 38

No

Question 39

Distinctive characteristics of cardiac muscle

Answer 39

Intercalated disks

Question 40

Nonstriated, fusiform

Answer 40

SMOOTH MUSCLE

Question 41

20 um in small blood vessels to 500 um in a pregnant uterus

Answer 41

SMOOTH MUSCLE

Question 42

Nucleus has a corkscrew shape during contraction

Answer 42

SMOOTH MUSCLE

Question 43

Sarcolemmal vesicles (caveolae)

Answer 43

SMOOTH MUSCLE

Question 44

Contractile filaments (actin, myosin) are not arranged in myofibrils (Non-striated)

Answer 44

SMOOTH MUSCLE

Question 45

Contraction is Slower and longer (slower ATP hydrolysis)

Answer 45

SMOOTH MUSCLE

Question 46

types of smooth muscle:

Answer 46

Multi-unit smooth muscle Unitary (Single unit) smooth muscle

Question 47

types of smooth muscle: Contracts independently of one another

Answer 47

Multi-unit smooth muscle

Question 48

types of smooth muscle: Individual muscle cells cannot contract independently

Answer 48

Unitary (Single unit) smooth muscle