Chapter 19- The heart Flashcards Preview

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Flashcards in Chapter 19- The heart Deck (54)
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0
Q

Pulmonary circulation

A

Right side pumps deoxygenated blood to the lungs for gas exchange as part of

1
Q

Heart location

A

In the thoracic cavity, between the lungs in the mediastinum

2
Q

Systematic circulation

A

Left side pumps accident oxygenated blood to the rest of the body for gas, nutrients and waste exchange is a part of

3
Q

Atrium

A

Superior chamber that receives blood

4
Q

Ventricle

A

Inferior chamber that pumps blood away

5
Q

Veins

A

Superior Vena cava
Pulmonary veins
Inferior vena cava

6
Q

Superior & inferior vena cava

A

Deliver deoxygenated blood into right atrium

7
Q

Pulmonary veins

A

Deliver oxygenated blood into the left atrium

8
Q

Arteries

A

Aorta

pulmonary trunk

9
Q

Aorta

A

Receives oxygenated blood from the left ventricle

10
Q

Pulmonary trunk

A

Receives the deoxygenated blood from right ventricle

11
Q

Contains valves-

A

Connected tissue (cusps) that ensure one-way flow

12
Q

Pulmonary semilunar valve

A

No Chordae tendinae

13
Q

Aortic semilunar valve

A

No Chordae tendinae

14
Q

Right atrioventricular valve

A

Tricuspid

with Chordae tendinae

15
Q

Left atrioventricular valve

A

Bicuspid (or mitral)

With Chordae tendinae

16
Q

Cardiomyocytes

A

Short branched
with 1 to 2 nuclei
striated

17
Q

Intercalated disc

A

Cells have extensively folded sarcolemma at the cell to cell junctions

  • Desmosomes
  • gap junctions
18
Q

Desmosomes

A

Junctions that bind adjacent cells

19
Q

Gap junctions

A

Channels that allow direct communication between cells

20
Q

Internal structure of cardio myocytes

A
Sarcolemma
T tubules
Sarcoplasmic reticulum
Myofibrils
Mitochondria
21
Q

And aerobic metabolism

A

Able to use different types of fuel molecules (fatty acids, glucose, lactic acid) but, requires constant supply of oxygen

22
Q

Coronary circulation

A

Circulatory system of the heart

23
Q

Branch off the ascending aorta

A

Left coronary artery

Right coronary artery

24
Q

Drain into the right atrium

A

Great cardiac vein
Middle cardiac vein
Small cardiac vein

25
Q

Atherosclerosis

A

Formation of Plaques

26
Q

Coronary spasm

A

Sudden construction of a coronary artery

27
Q

Angina pectoris

A

Pain caused by the reduced supply of oxygen

28
Q

Myocardial infarction

A

(heart attack)

Blockage of a coronary artery leading to possible death tissue

29
Q

Fibrous skeleton of the heart

A

(Dense irregular connective tissue)

  • provide structural support for walls and valves
  • place of attachment of cardiac muscle
  • an electrical insulator that prevents simultaneous contraction of atria & ventricles
30
Q

conduction system

A

Includes specialized party at muscle cells that initiate and transmit an action potential (electrical signal) to the cardiac muscle cells

31
Q

Contractile cardiac muscle cells

A

Contract in response to the action potential transmitted along their sarcolemma

32
Q

Sinoatrial (SA) node

A

Located in the posterior wall of the right atrium

F: initiates heartbeat (pacemaker)

33
Q

Atriventricular (AV) node

A

Located in the floor of the right atrium

34
Q

Atrioventricular (AV) bundle

A

Extends through interventricular septum, divides into left and right branches

35
Q

Purkinje fibers

A

Extend from left and right bundles through the walls of ventricles

36
Q

Initiation of the AP

A

Nodal cells in SA node initiate heartbeat by generating AP due to:

  • Na+/K+ pumps, K+ & Na+ leak channels (establish RMP at -60 mV)
  • Ca2+ pumps that create calcium Gradient with more outside the cell
  • slow V-gated Na+ channels, fast v-gated Ca2+ channels, & v-gated K+ channels (Carry out AP)
37
Q

Skeletal muscle cell RMP

neuron RMP

A
  • 95mV

- 70mV

38
Q

Reaching threshold

A

Slow voltage gated Na+ channels open Membrane potential (MP) changes:

-60 to -40

39
Q

Depolarization

A

Fast voltage gated Ca2+ channels open
MP changes: -40 to above 0
Fast voltage gated Ca2+ close

40
Q

Repolarization

A

Voted gated K+ channels open

MP returns to -60 mV

K+ channels close

41
Q

Comparison of Nodal cells and neurons

A

-do not have a stable resting membrane potential (RMP) gradually decreasing to the threshold without stimulation termed pacemaker potential

42
Q

Depolarization occurs with entrance of…

A

Ca2+ into cells (unlike neurons)

43
Q

Autorythmicity

A

Ability to depolarize and fire action potential spontaneously

44
Q

Transmission of the AP

A

spreading, passing, or conduction of AP) in a highly organized manner

45
Q

1 Generated in the SA node AP spreads and causes

A

simultaneous contraction of the atrial myocardium

46
Q

2 AV node causes a 0.1 second delay before…

A

Transmitting AP to the AV bundle

47
Q

3 The AV bundle transmits the AP

A

Left and right bundle branches

-> purkinje fibers

48
Q

4 The AP spreads throughout ventricular myocardium leading to the…

A

simultaneous contraction of the ventricles
(Bottom -> up)
Hand pray squeeze

49
Q

Innervation of the heart

A

-While the heartbeat is initiated by the SA node (hearts own conduction system) the heart rate and the strength of contraction are regulated by the autonomic nervous system (sympathetic increased, parasympathetic decrease)

50
Q

Cardiac center

A
(In medulla)
-Receives and reflexively response of the info from 
chemo receptors (with CO2 and H+ levels)
baroreceptors (blood pressure changes)
-To maintain homeostasis
51
Q

Heartbeats very ____ sec = HR ___ beats/min

A

0.8

75

52
Q

Inherent rhythm

A

(set by the SA nodal cells) is faster - 100 beats/min

53
Q

Slow rate is due to _________ simulation by vagus nerve, ________

A

Parasympathetic

Vagal tone