Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOL 1190 COPY M.L > Ch. 20 - The Heart > Flashcards

Ch. 20 - The Heart Flashcards

1
Q

Where is the heart located?

A

mediastinum; mostly left of midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Pericardium: fibrous and serous pericardium

A

F - Dense irregular connective tissue. protects and anchors heart; prevents overstretching. Near the apex, anchored to the diaphragm. The diaphragm facilitates movement of blood by the heart

S - parietal layer fuses with F____ percardium; visceral layer in direct contact with the heart.

Layers are separated by the pericardial cavity. this contain serous fluid that reduces friction btwn layers of the serous pericardium as the heart moves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the layers of the heart wall?

A

Epicardium: outside (contains visceral layer of the serous pericardium and mesothelium)
Myocardium: thickest and has the most muscle, responsible for the pumping action of the heart
endocardium: smooth lining for the chambers of the heart, covers heart valves, minimizes friction as blood passes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are sulci?

A

grooves on outside of heart that separate chambers; contain BV and fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an auricle?

A

pouch-like structure on anterior surface of each atrium; helps atria hold greater vol of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which chambers receive?

A

atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which chambers pump?

A

ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where does the R atrium receive blood from? Where does it pump blood to?

A

superior/inferior vena cava, coronary sinus; right ventricle via tricuspid valve (right AV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where does the R ventricle receive blood from? Where does it pump blood to?

A

right atrium; into pulmonary trunk via right semilunar valve (pulmonary valve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does the L atrium receive blood from? Where does it pump blood to?

A

oxygenated blood from lungs; left ventricle via bicuspid valve (left AV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where does the L ventricle receive blood from? Where does it pump blood to?

A

left atrium; aorta via left semilunar valve (aortic valve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

AV valves prevent back flow from…

A

…ventricles into atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Semilunar valves prevent back flow from…

A

….arteries into ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What triggers the opening and closing of heart valves?

A

pressure changes; not neurons/AP!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are valves composed of?

A

dense irregular CT covered with endocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do AV valves prevent back flow?

A

papillary muscles attached to valve cusps by chordae tendinae; chordae prevent valve cusps from opening into atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are semilunar valves composed of?

A

3 moon-shaped cusps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When do semilunar valves open?

A

when pressure in ventricles exceed pressure in arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of coronary arteries?

A

supply myocardium cells with fresh nutrients and O2; branch off aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of coronary veins?

A

collect waste from cardiac muscle and drain into coronary sinus, which then empties into R atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is systole and diastole?

A

S - contraction

D - relaxation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does the cardiac cycle consist of?

A

systole + diastole of both atria followed by systole + diastole of both ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are characteristics of cardiac muscle?

A

branched, intercalated discs connected by gap junctions and desmosomes, involuntary, striated, single central nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do cardiac muscle sarcomeres differ form skeletal muscle?

A
  • more mitochondria (25% of cell vol)
  • T-tubules wider but less abundaent
  • SR less prominent; need Ca2+ from outside cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How do cardiac muscles produce ATP?

A
  • aerobic cellular resp
    a. at rest: use FA, glucose
    b. during exercise; use lactic acid
  • creatine phosphate when something is wrong!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the role of autorhythmic fibers?

A
  • generate spontaneous action potentials that trigger heart contractions
  1. act as pacemaker, setting baseline rhythm of electrical excitation that causes contraction
  2. form conduction system; propagates AP through heart muscle
  3. allows heart to continue beating even when disconnected from the brain since they are self-excitable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the sinoatrial (SA) node?

A
  • cluster of cells in wall of R atrium
  • repeated spontaneous depolarization; no stable resting potential
  • triggers contraction of both atria
    -Hearts natural pace maker
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the atrioventricular (AV) node?

A
  • located in b/t 2 atria (atrial septum)

- signal is slightly delayed at AV node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why is the delay of the signal at AV node important?

A

atria have to contract then relax; ventricles have to contract then relax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is AV bundle?

A
  • where signal can be transmitted from atria and ventricles
  • send signal down ventricular septum to apex
  • Purkinje fibers conduct signal up ventricle wall
  • triggers contraction of ventricles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the 3 phases of an AP in a ventricular contractile fiber?

A
  1. rapid depolarization
  2. plateau
  3. repolarization: closure of Ca2+ channels and K+ outflow when additional K+ channels open

**prolonged refractory period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What occurs during depolarization phase?

A

Na+ inflow as Na+ channels open; resting membrane potential is -90mv

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What occurs during plateau phase?

A
  • Ca2+ inflow from outside cell/SR as Ca2+ channels open –> Ca2+ binds to troponin
  • K+ outflow as K+ channels open
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What occurs during repolarization phase?

A
  • Ca2+ channels close
  • K+ channels open to let K+ out of cell
  • muscle contraction ceases –> relaxation!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Is tetanus possible in cardiac muscle cells?

A

no because potential is maintained

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What occurs at atrial and ventricular diastole?

A

4 chambers are relaxed; passive filling of blood into heart

37
Q

What occurs at atrial systole, ventricular diastole?

A

atria contract; blood pushes into ventricles

38
Q

What occurs at atrial diastole, ventricular systole?

A

atria relaxes; ventricles contract; blood pushes out of heart

39
Q

What does an electrocardiogram record?

A

spread of AP through heart

40
Q

What are the recognizable waves in an EKG that appear with each heartbeat?

A
  1. P wave - atrial depol ( ATRIA contraction!)
  2. QRS complex - rapid ventricular depol (contraction!)
  3. T wave - ventricular repol (relaxes)`

Explain the graph

41
Q

Describe the AP propagation through the heart

A
  1. electrical impulse from SA node to walls of atria; atria contract=
  2. impulses reaches AV node; delay
  3. bundle branches carry signal from AV node to apex
  4. signal spreads through ventricle walls; ventricles contract
42
Q

What causes the sound of a heartbeat?

A

turbulence of blood flow caused by closure of valves

43
Q

What is the first heart sound?

A
  • AV valves close soon after V systole begins
44
Q

What is the second heart sound?

A
  • SL valves close near beginning of V diastole
45
Q

What does the R-R interval tell you?

A

length of time a heartbeat takes

46
Q

What kinds of information can you get from an ECG?

A

how muscles are conducting AP; can detect valve malfunction

47
Q

What is cardiac output? (CO)

A

vol of blood ejected from a ventricle each minute

48
Q

What is stroke volume? (SV)

A

vol of blood ejected by the ventricle with each contraction

49
Q

What is heart rate? (HR)

A

number of beats per minute

50
Q

What is the formula for cardiac output?

A

CO = SV x HR

51
Q

How many times can the average person increase their CO resting value? How about a top endurance athlete?

A

4-5 times; 7-8 times

52
Q

What is a cardiac reserve?

A

difference between person’s max cardiac output & cardiac output at rest

53
Q

What hormones influence heart rate?

A

epinephrine, norepinephrine

54
Q

How are specific ion concentrations crucial to heart rate?

A
  1. increased K+ blocks AP generation
  2. increased Na+ blocks Ca2+
  3. increased Ca2+ speeds heart rate and force of contraction
55
Q

What other factors influence heart rate?

A

age, gender, physical fitness (athletes have lower rate), body temp (increased temp leads to increased heart rate)

56
Q

What are the 3 factors of regulation of stroke volume?

A

preload, contractility, afterload

57
Q

What is preload?

A

degree of stretching

more blood filling chamber –> more stretching –> greater force of contraction

58
Q

What is the amount of blood in chamber dependent on?

A

venous return and duration of diastole (relaxation)

59
Q

What is contractility?

A

force of contraction of myocardium

60
Q

C/C positive and negative inotropic agents

A

+ : increase contractility by increasing Ca2+ inflow

  • : decrease contractility by decreasing Ca2+ inflow/increasing K+ outflow
61
Q

What does inotropic mean?

A

drugs acting on contractility fibres

62
Q

What is afterload?

A

amount of pressure required to open semilunar valves

63
Q

What causes high afterload?

A

high BP

64
Q

What leads to increased stroke volume?

A

increased preload + contractility, decreased afterload
-th lower the after load, the higher the stroke volume

65
Q

Pericarditis

A

inflamation of the pericardium

66
Q

myocarditis

A

inflamation of the myocardium

67
Q

endocarditis

A

inflamation of the endocardium

68
Q

Fibrous Skeleton of the Heart

A

-Dense connective tissue
-4 rings surround the valves of the heart and fuses w one another. merge w the interventricular septum
-prevent overstretching as blood flows
-acts as an electrical insulator : This allows for the atri to contract first

69
Q

coronary circulation

A

Coronary arteries and veins that transports blood to and away the myocardium

70
Q

myocardial ischemia

A

reduced blood flow to the myocardium
- can cause hypoxia (reduced oxygen supply)
-angina pectoris (pain)M

71
Q

Myocardial infarction

A

Heart attack
-interrupted blood supply

72
Q

The Conduction System

A
  1. SA Node sends an action potential to the atria. They contract
  2. Then the action potential goes through the AV node
  3. then into the AV bundle
  4. Purkinje fibres conduct the action potential to the remainder of the ventricular myocardium. Ventricles contract
73
Q

Artificial Pacemaker

A

Sends out small electrical current to stimulate the SA node for the heart to contract

74
Q

The Cardiac Cycle

A
75
Q

Regulation of Heart Rate

A

-Autonomic nervous system
-Hormones
-ions
-gender
-age
-physical fitness
-temo

76
Q

-Autonomic nervous system

A

Involuntary contractions

77
Q

Hormones

A

Epinephrine and norepinephrine inhance the hearts pumping effectiveness. Both increase the heart rate and contractility

78
Q

Cations

A

three cations—K+, Ca2+, and Na+—have a large effect on cardiac function. Elevated blood levels of K+ or Na+ decrease heart rate and contractility. Excess Na+ blocks Ca2+ inflow during cardiac action potentials, thereby decreasing the force of contraction, whereas excess K+ blocks generation of action potentials. A moderate increase in interstitial (and thus intracellular) Ca2+ level speeds heart rate and strengthens the heartbeat.

79
Q

Gender

A

male and female slighty diff heart rate

80
Q

physical fitness

A

a lot - higher stroke volume, contracts harder

81
Q

temp

A

high temp increases heart rate

82
Q

Factors that increase cardiac output

A
83
Q

Excercise and the heart

A

-increase cardiac output
-increase high density proteins, good cholesterol
-decrease fat
-improve lung function
-assist in weight control

84
Q

.

Explain the Cardiac Cycle

A
85
Q

Help for Failing Hearts: Intra-aortic balloon pump (IABP)

A

Help weak heart to pump blood more affectively. Inserted into the aorta. When heart relaxes, the balloon inflates to push more blood towards the body. The balloon is inflated btwn heartbeats, this pushes blood both backwards and towards the heart.

During ventrical contraction, the balloon shrinks to allow the left ventricle to eject blood easier

86
Q

VAD

A

Helps the ventricles to contract to send blood to the body. This can be used more longterm, usually used as a person waits for a heart transplant

87
Q

Cardiomyoplasty

A

Heart wrapped in back muscle. An implanted pacemaker stimulates the muscle motor neurons to help the heart beat

88
Q

Skeletal Muscle assist device

A

A piece of the patient’s own skeletal muscle is surgically removed
This muscle is shaped into a pouch
The pouch is placed between the heart and aorta
A pacemaker is connected to the muscle’s motor neurons
The pacemaker triggers the muscle to contract, creating a “booster” effect for the heart’s pumping action

89
Q

Disorders: Homeostatic Imbalances

A
  • Coronary artery disease. -reduced blood flow to the heart
  • Atherosclerotic plaques. -cellular debris that accumulates in arterial walls reducing blood flow
  • Congenital heart defects. - structural abnormalities present at birth
  • Arrhythmia. - irregular heart rhythm
  • Congestive heart failure. -heart unable to pump blood effectively

BIOL 1190 COPY M.L (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions