Chapter 8: Neuromuscular System and Myocytes

Question 1

Types of Muscle

Answer 1

1. ) Skeletal: Striated, voluntary
2. ) Cardiac: Striated, uninucleated, Involuntary
3. ) Smooth: Non-striated, involuntary, found in organs

Question 2

Muscle Fiber (cell)

Answer 2

AKA Myocyte
1.) Organelles store Ca+2
2.) Triad: One transverse tubule (t-tubule)
Two endoplasmic reticulum cisternea (folds) on each side
3.) Contains Sarcoplasmic Reticulum
4.) Myofilaments: THICK AND THIN

Question 3

Sarcomere

Answer 3

1. ) When myosin (thick filament) binds actin (thin filament) they from cross-bridges
2. ) A- Bands: dark are on top of H band, Thick and Thin
3. ) H- Bands: Thick, dark
4. ) I- Bands: Light, Thin
5. ) Z- Line: within the I-band, darker area, formed by the Z-disks to which thin myofilaments attach.

Question 4

Thick Myofilaments

Answer 4

Myosin

Question 5

Thin Myofilaments

Answer 5

Actin

1.) Contains G-actin, Tropomyosin, Troponin

Question 6

Globular (G) actin

Answer 6

Enzyme that binds to myosin

Question 7

Tropomyosin

Answer 7

long protein, fits in the groves of the thin filament and blocks ‘open’ sites on G actin

Question 8

Troponin

Answer 8

binds to tropomyosin and binds Ca++

Question 9

Resting Membrane Potential (RMP)

Answer 9

-90 mV RMP

Question 10

Cell Polarity

Answer 10

1. ) Negative inside and positive outside
2. ) Due to Na+/K+-ATPase pump (pumps 3 Na+ out and only 2 K+ into the cell)
3. ) Most intracellular proteins are anionic

Question 11

Polarized Cells

Answer 11

1. ) A cation entering the cell results in depolarization (less separation of charge),
2. ) A cation leaving the cell results in repolarization (back to resting membrane potential or hyperpolarization,
3. ) An anion entering the cell results hyperpolarization

Question 12

Pre-syanptic Cell

Answer 12

Contain acetylcholine (ACh) a neurotransmitter released into synaptic cleft when electrical signal arrives to neuron.

Question 13

Post-syanptic Cell

Answer 13

1. ) Acetylcholine receptors are transmembrane proteins on junctional folds (muscle) that bind Acetylcholine,
2. ) Acetylcholine receptors allow Na+ to move into muscle cell.

Question 14

Synaptic Cleft

Answer 14

Acetylcholinesterase (AchE) is an enzyme found in the basement membrane of synaptic cleft, breaks down ACh into an Acetyl group and a Choline group to be reabsorbed by presynaptic neuron.

Question 15

Acetylcholine (ACh) Receptors on Muscle

Answer 15

1. ) Are Transmembrane proteins, ligand-gated receptors

2. ) Ion receptors: Na+ enters, depolarizing cell, Ca+2 released

Question 16

Relaxation of Skeletal Muscle

Answer 16

Acetylcholinestarase – in synaptic cleft breaks down Acetylcholine into acetyl and choline

Question 17

Aerobic cellular respiration

Answer 17

provides large amounts of ATP per fuel molecule by using O2, byproduct is water
1.) Contains 36 ATP per Glucose

Question 18

Anaerobic Fermentation

Answer 18

produces less ATP per fuel molecule than aerobic respiration, byproduct – lactic acid, which can cause pain and increase blood H+ (decreases pH – blood acidosis)
1.) 4 ATP per Glucose

Question 19

Substrate phosphorylation (Phosphagen)

Answer 19

produces even less ATP per fuel molecule can be depleted if fuel molecules not replentished
1.) Phosphate is taken and added to an ADP

Question 20

Creatine and ATP

Answer 20

Products

Question 21

Creatine Phosphate and ADP

Answer 21

Reactants

Question 22

Phosphagen System

Answer 22

Creatine P and ADP —-> ATP and Creatine

ADP + ADP —> ATP + AMP (cAMP)