Anatomy & Physiology Ii -- Lecture Exam 1

Front 1

the adrenal medulla releases which hormones

Back 1

epinephrine & norepinephrine

Front 2

the adrenal cortex releases which hormone

Back 2

corticosteroids

Front 3

what is the effect of epinephrine and norepinephrine on heart rate, blood vessels, etc.?

Back 3

increases heart rate

vasoconstriction

converts glycogen into glucose for transport in blood

Front 4

the _____ is the master switch for the pituitary gland & regulates the pituitary gland

Back 4

hypothalamus

Front 5

what is bifurcation?

Back 5

the splitting of blood vessels into smaller vessels

Front 6

what does hydrocortisone (cortisol) do?

Back 6

it regulates the conversion of fats, proteins, & carbohydrates to energy for muscles

it enhances blood pressure, inhibits basophils

Front 7

what does histamine do?

Back 7

increases capillary permeability so WBCs can leave blood vessel into infected tissues

Front 8

what does corticosterone do?

Back 8

works with cortisol to regulate immune response to stress

Front 9

What hormone does the hypothalamus release?

Back 9

Corticotrophin-releasing hormone [goes to pituitary gland]

Front 10

What hormone does the anterior pituitary gland release?

Back 10

Adrenal coticotrophic hormone [into blood, goes to adrenal glands]

Front 11

Corticosteroid hormones=

Back 11

Glucocorticoids + mineralcorticoids

Front 12

Stress leads to production of epinephrine which leads to....

Back 12

Platelet production & aggregation

Front 13

What are coronary arteries?

Back 13

Arteries from aorta to heart

Front 14

What is myocardial ischemia?

Back 14

Coronary arteries become clogged and the supply of oxygen and glucose to the myocardium are limited.

Symptom: angina pectoris

Front 15

Prolonged stress leads to long term high blood pressure which leads to...

Back 15

Left ventricular hypertrophy, irregular heartbeat, and then sudden cardiac arrest

Front 16

What is smooth muscle?

Back 16

It is muscle located in the wall of internal structures, such as blood vessels, stomach & intestines; not striated, often regulated by neurotransmitters & hormones; mostly involuntary

Front 17

Why the left ventricle?

Back 17

Because it has the most work to do! Blood leaves the LV and is pumped throughout the body (systemic circulation)

Front 18

What is an axon?

Back 18

A single, long process of a nerve cell that propagates a nerve impulse toward axon terminals

Front 19

What is repolarization?

Back 19

Membrane potential of a cell becomes negative again, returning to resting membrane potential, usually by an efflux of cations leaving the cell

Front 20

What is hyperpolarization?

Back 20

Membrane potential of a cell becomes more negative than resting membrane potential, often caused by an efflux of cations or an influx of anions

Front 21

What is a motor unit?

Back 21

Motor neuron + all skeletal muscle cells that the neuron stimulates

Front 22

What is an axon terminal?

Back 22

Where synaptic vesicles perform exocytosis and release neurotransmitter molecules

Front 23

What is the sarcolemma?

Back 23

The cell membrane of a skeletal or cardiac muscle fiber (cell), along which AP is propagated

Front 24

What is the sarcoplasm?

Back 24

The cytoplasm of a muscle cell that contains myofibrils

Front 25

What is a synapse?

Back 25

Junction between 2 neurons or a neuron and a muscle or gland; communication between cells; electrical or chemical (i.e. Neurotransmitters)

Front 26

What is a synaptic cleft?

Back 26

A gap that separates 2 cells at a synapse

Front 27

Why is the Resting Membrane Potential negative?

Back 27

1. There are more proteins on the inside of the cell than the outside of the cell (tend to be negatively charged)

2. Intercellular ions are bound in the cytoplasm (and tend to accumulate on the inside of the cell)

3. The Sodium-Potassium Pump (pumps out 3 Na for every 2 K it brings back into the cell)

Front 28

What is a graded potential?

Back 28

A small deviation from resting membrane potential that increases or decreases polarization

Front 29

What is depolarization?

Back 29

Membrane potential of a cell becomes less negative, usually by an influx of cations into the cell, resulting in an action potential

Front 30

what is action potential?

Back 30

an electrochemical signal that spreads along the membrane of a muscle fiber to stimulate contraction; briefly reverses the membrane potential and then restores it to the resting state (carried by a motor neuron)

Front 31

what is a motor neuron?

Back 31

neurons in the brain or spinal cord that extend axons to stimulate muscle contraction via action potential

Front 32

what is a neuromuscular junction (NMJ)

Back 32

a synapse between an axon terminal of a motor neuron and sarcolemma of a skeletal muscle cell; AP is an electrical signal in axon, becomes chemical across synapse, then electric again in muscle [region where motor neuron & skeletal muscle interaction]

Front 33

why is the resting membrane potential maintained?

Back 33

1. intracellular anions are bound in the cytoplasm

2. there are more proteins on the inside of the cell than the outside (proteins tend to be negatively charged)

3. sodium-potassium pump: keeps negative charge inside of cell

Front 34

the sodium-potassium pump pumps out 3 _____ for every 2 ____ it brings back in

Back 34

sodium, potassium

Front 35

the sodium potassium pump goes _____________

Back 35

against the concentration gradient (against diffusion!)

Front 36

what is graded potential?

Back 36

a small deviation from resting membrane potential that increases or decreases polarization

it varies in amplitude, can summate (possibly to AP if past the threshold) or can cancel each other out (if opposite charges)

Front 37

what is the magic number for AP and depolarizaion?

Back 37

the threshold is -55 mV!

Front 38

what are myofibrils?

Back 38

threadlike structure of a muscle cell consisting of thick filaments and thin filaments (proteins)

Front 39

what are the thick filaments?

Back 39

myosin

Front 40

what are the thin filaments?

Back 40

actin, troponin, tropomyosin

Front 41

what is a sarcomere?

Back 41

a contractile unit of a striated muscle cell extending from one Z disc to the next (what physically contracts)

Front 42

what is a synaptic vesicle?

Back 42

membrane-bound sac that stores neurotransmitters for release into the synaptic clet

Front 43

what is acetylcholine (Ach)?

Back 43

an excitatory neurotransmitter at NMJ that transfers AP from neuron to muscle cell

Front 44

what is Acetylcholinesterase (AchE)?

Back 44

an enzyme in synaptic cleft to stop synaptic transmission of acetylcholine by breaking it up into choline + acetic acid

Front 45

what is a transverse (T) tubule?

Back 45

infolding of sarcolemma to allow membrane depolarization, and AP, to quickly reach the interior of the cell

Front 46

what is the sarcoplasmic reticulum

Back 46

smooth endoplasmic reticulum of muscle cells that store calcium during muscle relaxation and release calcium ions when muscle is stimulated by an action potential

Front 47

what is an A band?

Back 47

region within sarcomere, relatively dark, that has both thick filaments and portions of thin filaments; dark area

Front 48

what is an I band?

Back 48

less dense area of only thin filaments; light area

Front 49

in a relaxed muscle:

Back 49

tropomyosin (attached to troponin) covers the myosin-binding sites of actin & prevents their attachment to myosin

the release of calcium ions from the sarcoplasmic reticulum into the sarcoplasm initiates muscle contraction, dislodging troponin-tropomyosin complex from actin

Front 50

what is tetanus?

Back 50

condition by infection of Clostridium tetani with prolonged contraction of skeletal muscle fibers resulting in muscle tears.

the toxin blocks release of inhibitory neurotransmitters across the synaptic cleft by inactivation of a synaptic vesicle protein

similar for botulism, shellfish, and some spider or snake bite toxins

Front 51

what are symptoms and treatments of muscular dystrophy?

Back 51

symptoms: defect in muscle proteins, death of muscle cells and tissue, and progressive skeletal muscle weakness

treatments: limited to speech, respiratory, and physical therapy, orthopedic devices and surgeries, coticosteroids to slow muscle degeneration

Front 52

in muscular dystrophy: absence of what leads to what

Back 52

the protein dystrophin:

1. links actin of muscular cell to support proteins of sarcolemma, which is linked do endomysium, a fibrous sheath outside the sarcolemma

2. regulates concentration of calcium ions in muscle cell (sarcoplasm)

Front 53

what is a lever?

Back 53

a rod (BONES) that moves about a fixed point, the fulcrum (JOINTS)

Front 54

what is resistance?

Back 54

a force (LOAD) that opposes movement; the weight of a body part that is to be moved

Front 55

what is effort?

Back 55

a force exerted to achieve an action

Front 56

what is an example of a first class lever?

Back 56

seesaw; head resting on vertebral column

the fulcrum is between the effort and the resistance

Front 57

what is an example of a second class lever?

Back 57

wheelbarrow; body on toes

the fulcrum is at one end with the effort on the opposite side

Front 58

what is an example of a third class lever?

Back 58

flexing of the forearm at the elbow -- most common levers of the body

consist of a fulcrum at one end, load at opposite end, and effort between them

Front 59

what is an intercalated disc?

Back 59

fiber ends connected by thick sarcolemma

Front 60

what are desmosomes?

Back 60

they clam the fibers together

Front 61

what are gap junctions?

Back 61

they allow the AP to spread from one fiber to the next

Front 62

what are autorhythmic fibers?

Back 62

self-excitable cells that repeatedly generate AP that trigger heart contractions; it has 2 functions, the pacemaker and the cardiac conduction system

the initiation of contraction doesn't come from the brain or spinal cord!

Front 63

what is the pacemaker?

Back 63

it sets the rhythm of electrical activity that leads to heart contraction-- the SA node

Front 64

what is the cardiac conduction system?

Back 64

it ensures that cardiac chambers contract in a coordinated manner so that the heart provides an efficient pump; so the beat is regular and it beats exactly the same way every time

Front 65

why the SA node?

Back 65

the cells of the SA node become depolarized much faster than other cells of the heart, it's 100x faster than the other autorhythmic cells

Front 66

what is the final goal of the cardiac conduction system?

Back 66

ventricles contract, pump blood toward the semilunar (aortic and pulmonary) valves

electrochemical impulses from ANS modify timing and strength of heartbeats, but DO NOT ESTABLISH FUNDAMENTAL RHYTHM!

Front 67

what does an EKG do?

Back 67

it records cardiac action potential

Front 68

what is the P wave?

Back 68

atrial depolarzation as AP spreads form SA node to fibers in both atria, leading to their contraction

Front 69

what is the QRS complex?

Back 69

ventricular depolarization and contraction

Front 70

what is the T wave?

Back 70

ventricular repolarization as ventricles relax

Front 71

what could a flattened T wave mean?

Back 71

insufficient oxygen, possibly coronary heart disease

Front 72

what could an enlarged P wave mean?

Back 72

atrial enlargement, as with hypertension

Front 73

what could an enlarged Q wave mean?

Back 73

myocardial infarction (heart attack)

Front 74

what could an enlarged R wave mean?

Back 74

enlarged ventricles, as with hypertension

Front 75

what happens with the SA node and AP?

Back 75

AP propagates along atrial muscle cells to AV node

AP enters AV bundle (bundle of His), so AP travels from atria to ventricles