Study Quide Lecture Exam #2

Question 1

1. Describe detailed structure of skeletal muscle: connective tissue components, fibers, myofibrils, sarcomeres, thick and thin filaments components.

Answer 1

Sarcomere -> Myofibrils -> Muscle fibers (surrounded by endomysium) -> Fascicles (surrounded by perimysium) -> Skeletal Muscle (surrounded by epimysium)
Thick filaments: myosin, longtail with globular heads. Release energy for contraction
Thin filaments: four proteins Actin (G actin), tropomyosin, troponin, nebulin

Question 2

Sarcoplasmic reticulum

Answer 2

Storage and release site for calcium ions

Question 3

Sarcomere

Answer 3

Repeating unit of a skeletal muscle fiber

Question 4

Thin filaments

Answer 4

Consist of G actin, troponin, tropomyosin, nebulin

Question 5

Thick filaments

Answer 5

Acts as ATPase during contraction cycle

Question 6

Myosin head

Answer 6

Consist of myosin molecules

Question 7

Troponin

Answer 7

Binds to calcium and moves tropomyosin

Question 8

Epimysium

Answer 8

Dense layer of CT that surrounds entire skeletal muscle.

Question 9

Skeletal muscle triad

Answer 9

Transverse tubule and two terminal cisternae

Question 10

Myoglobin

Answer 10

Oxygen-binding protein found in the muscle tissue

Question 11

Tropomyosin

Answer 11

Preventing interactions between actin and myosin

Question 12

Role of ATP in muscle contraction and relaxation

Answer 12

a. ATP in muscle contraction and relaxation disconnects myosin cross bridge from actin; responsible for cocking (pulling back) the myosin head, ready for another cycle; provides energy for active transport of Ca2+ back into SR; Maintains RMP of the skeletal muscle cells.

Question 13

What is role of Calcium in muscle contraction?

Answer 13

Binds to troponin, which activates troponin-tropomyosin complex.

Question 14

Rigor mortis: explain why stiffness of the body occurs shortly after death.

Answer 14

This occurs because skeletal muscles partially contract and are unable to relax. (The joints are fixed, and the body stiff)

Question 15

How energy is supplied for contraction.

Answer 15

The energy is provided through energy (cellular) metabolism.

Question 16

Events in order of a muscle contraction

Answer 16

Calcium ion is released from the sarcoplasmic reticulum

Calcium ion binds to troponin

Myosin cross-bridges bind to the actin

The myosin head pivots toward the center of the sarcomere

The myosin head binds an ATP molecule and detaches from the actin

The free myosin head splits ATP

Question 17

Somatic vs autonomic nervous systems

Answer 17

Somatic- voluntary and involuntary, effects skeletal muscles, one lower motor neuron. No stops only to one location.

Autonomic- only involuntary/visceral reflexes autonomic reflexes, effects smooth muscle, cardiac muscle, and glands, 2 lower motor neurons

Question 18

Parasympathetic

Answer 18

increase digestion, decrease Heart rate/ blood pressure, bronchonstriction, pupil contr. Sacralarea of s2-s4 spinal cord. Ganglia close to targe organ. Paraganglia- long, postganglionic- short.

Question 19

Sympathetic

Answer 19

inhibit digestion, increase heart rate/ blood pressure, vasoconstriction/vasodilation, bronchodilation, pupil dilation. Lateral horn of SC T1-L2. Ganglia- close to CNS. Preganglionic- short. Postganglionic- long.

Question 20

Nicotinic receptor

Answer 20

found on all ganglionic neurons and adrenal medulla. Always excitatory.

Question 21

Muscarinic

Answer 21

all target membranes in parasympathetic division. Could be excitatory or inhibitory

Question 22

Cholinergic

Answer 22

nicotinic (excitatory)/ muscarinic (excitatory or inhibitory) (parasympathetic)

Question 23

Adrenergic

Answer 23

Alpha- 1 & 2: vasoconstriction (excitatory/inhibitory), Beta- 1 (always excitatory, heart, increase heart rate), 2 (always inhibitor, bronchioles, vasodilation of skeletal muscle), 3 (adipose tissue)

Question 24

Beta 1

Answer 24

always excitatory, heart, increase heart rate

Question 25

Beta 2

Answer 25

always inhibitor, bronchioles, vasodilation of skeletal muscle

Question 26

Beta 3

Answer 26

adipose tissue

Question 27

Describe possible effects of beta blockers (medication that blocks beta receptors), medication that is used to decrease blood pressure

Answer 27

Decrease heart rate, bronchoconstriction, vasoconstriction of skeletal muscle.

Question 28

Explain why atropine (medication that blocks muscarinic receptors) will cause tachycardia, dry mouth, constipation, increased blood pressure, and dilated pupils.

Answer 28

Atropine will cause tachycardia, dry mouth, constipation, increased blood pressure, and dilated pupils (sympathetic nervous system effects), because by blocking the muscarinic receptors it will decrease the parasympathetic nervous system causing an increase in the sympathetic nervous system.

Question 29

Nervous system

Answer 29

wired, neurotransmitters, limited distance, rapid response, short duration, rapid onset.

Question 30

Endocrine system

Answer 30

wireless, hormones, long distance, regulation, prolonged duration, delayed onset.

Question 31

Describe how production of hormones is regulated in our body

Answer 31

a. Negative feedback process.
b. A stimulus elicits the release of a substance (hormone) -> once the substance (hormone) reaches a certain level, it sends a signal that stops further release of substance -> in this way, the concentration of hormones in blood is maintained within a narrow range.

Question 32

List functions of endocrine system

Answer 32

a. Maintain homeostasis of blood composition and volume
b. Controlling reproductive activities
c. Regulating development, growth, and metabolism
d. Controlling digestive processes

Question 33

Thyroid and calcium

Answer 33

Thyroid (c-cells)- calcitonin decreases calcium level builds bones by activating osteoblasts and inhibiting osteoclasts.

Question 34

Parathyroid gland and calcium

Answer 34

Parathyroid gland- Parathyroid hormone- calcium increases- destroy bones- activates calcitriol.

Question 35

Kidney and calcium

Answer 35

Kidney- calcitriol- enhances PTH- enhances Ca2+, PO43- absorption by digestive system.

Question 36

Lipid-soluble: steroid hormone

Answer 36

lipid-soluble, formed from cholesterol, produced by gonads and adrenal cortex. Cortisol, estrogen, and testosterone.

Question 37

Water-soluble (except thyroid hormone): protein hormone

Answer 37

water soluble, amino acid chain, 3 sub groups- polypeptides, oligopeptides, glycoproteins. Parathyroid hormone, insulin

Question 38

Water-soluble (except thyroid hormone): biogenic amine

Answer 38

water-soluble (excluding thyroid hormone), derived from amino acid that is modified (e.g. tyrosine). Norepinephrine, melatonin, T3 and T4.

Question 39

Glucose is decreased by

Answer 39

insulin which is produced by the pancreas, it is regulated by blood glucose level.

Question 40

Glucose is increased by

Answer 40

glucagon (pancreases), cortisol (zona fasciculata of adrenal gland), growth hormone (released by hypothalamus), and epinephrine (adrenal medulla of adrenal gland)

Question 41

Describe how water balance is regulated by endocrine system.

Answer 41

Antidiuretic Hormone (vasopressin) plays an important part in regulating water, it does so by reduced urine volume and cause water retention.

Question 42

Describe how nervous and endocrine systems maintain arterial blood pressure.

Answer 42

a. ADH increases blood pressure.
b. Atrial Natriuretic Peptide reduces blood pressure.
c. Blood pressure is increased during sympathetic autonomic nervous system.
d. Blood pressure is decreased during parasympathetic autonomic nervous system.