Chapter 17: The Heart Flashcards
1
Q
Parts of the cardiovascular system
A
- Heart
- Blood vessels
- Blood
2
Q
Function of cardiovascular system
A
- Pump blood into blood vessels and distribute oxygen throughout the body
3
Q
Heart
A
A pump that contracts rhythmically to deliver blood to the body
4
Q
Mediastinum
A
Subdivision of the thoracic cavity which houses the heart, great blood vessels, trachea, and esophagus
5
Q
Pericardial cavity
A
Subcavity of the mediastinum
6
Q
Orientation of the heart
A
- Apex points toward the left hip
- Flattened base on the posterior side
7
Q
Chambers of the heart
A
- Atrium (R & L)
- Ventricle (R & L)
8
Q
Atrioventricular sulcus
A
An external indentation found at the boundary between the atria and ventricles
9
Q
Interventricular sulcus
A
- An external indentation found at the boundary between the ventricles
- AKA interventricular groove
10
Q
Veins
A
Blood vessels that bring blood to the heart
11
Q
Veins that directly feed the heart
A
- Superior/inferior vena cava
- Pulmonary veins
12
Q
Arteries
A
Blood vessels that carry blood away from the heart
13
Q
Arteries that connect directly to the heart
A
- Pulmonary trunk
- Aorta
14
Q
Great vessels
A
The main veins and arteries that transport blood toward and away from the heart
15
Q
Circuits of the cardiovascular system
A
- Pulmonary circuit
- Systemic circuit
16
Q
Pulmonary circuit
A
Series of blood vessels which direct blood from the heart to the lungs to receive oxygen
17
Q
Systemic circuit
A
Series of blood vessels which direct blood from the heart to the body to deliver oxygen
18
Q
Where does gas exchange take place?
A
In the alveoli
19
Q
Alveoli
A
- Tiny air sacs in the lungs
- Smallest vessels of the pulmonary circuit
20
Q
Low-pressure circuit
A
Pulmonary circuit
21
Q
High-pressure circuit
A
Systemic circuit
22
Q
Functions of the heart
A
- Pump blood
- Maintain BP homeostasis
- Atria acts as as an endocrine organ
23
Q
What hormone do the atria produce?
A
Atrial natriuretic peptide (ANP)
24
Q
Function of ANP
A
Lowers BP by decreasing sodium ion retention in the kidneys
25
Pericardium
The membranous structure surrounding the heart
26
Components of the pericardium
- Fibrous pericardium
| - Serous pericardium
27
Fibrous pericardium
A tough outer layer that attaches the heart to surrounding structures
28
Serous pericardium
A thin inner serous membrane that produces serous fluid
29
What result do the collagen bundles in fibrous pericardium have?
- Make it tough
- Anchor the heart to surrounding structures
- Low distensibility (doesn't change shape when forces are applied)
30
Layers of the serous pericardium
- Parietal pericardium
| - Visceral pericardium
31
Parietal pericardium
Encases the heart like a sac
32
What happens when the parietal pericardium reaches the great vessles
Folds under itself and attaches itself directly to the heart
33
Visceral pericardium
- AKA epicardium
| - Considered the most superficial layer of the heart wall
34
Important consideration about pericardium
Parietal and visceral pericardium are actually one continuous structure
35
Pericardial cavity
Space between parietal and visceral pericardia filled with pericardial fluid
36
Pericardial fluid
Serous fluid which fills the space between parietal and visceral pericardia
37
Function of pericardial fluid
Acts as a lubricant, decreasing friction as the heart moves
38
Layers of heart wall
- Epicardium (visceral pericardium)
- Myocardium
- Endocardium
39
Myocardium
Thickest heart wall layer
40
Components of myocardium
- Cardiac muscle tissue
| - Fibrous skeleton
41
Cardiac muscle cells
Myocytes
42
Fibrous skeleton of myocardium composition
- Irregular collagenous connective tissue
| - Located in regions that need additional support
43
Fibrous skeleton of myocardium function
- Giving cardiac myocytes something to pull on when they contract
- Provide structural support
- Act as an insulator for the heart's electric activity
44
Endocardium
Composed of endothelium and several layers of connective tissue with elastic and collagen fibers
45
Endothelium
A special type of simple squamous epithelium
46
Function of endothelium
Regulate the concentration of electrolytes and other chemicals in the extracellular fluid of the myocardium
47
Superior vena cava
Drains deoxygenated blood from most veins superior to the diaphragm
48
Inferior vena cava
Drains deoxygenated blood from most veins inferior to the diaphragm
49
Pulmonary trunk
Receives deoxygenated blood pumped from the right ventricle
50
Pulmonary veins
Returns oxygenated blood from the lungs to the heart
51
Aorta
- Supplies the entire systemic circuit with oxygenated blood
| - Ascending aorta --> aortic arch
52
Structural differences between atria and ventricles
- Ventricles have thicker walls and are larger
| - Thicker walls make them stronger pumps
53
Differences between atria
- Right atrium is large, thin-walled, and anterior
| - Right atrium has a larger auricle
54
Auricle
A muscular pouch found in each atrium
55
Function of auricle
Expand to give the atria more space to hold blood
56
Pectinate muscles
Muscular ridges on the internal surface of the right atrium
57
Interatrial septum
Thin wall which separates the atria
58
Fossa ovalis
- Small indentation in the interatrial septum
| - Remnant of a hold in the fetal heart called the foramen ovale
59
Function of foramen ovale
Direct blood from the right atrium directly to the left atrium
60
Differences between right and left ventricles
```
Right ventricle
- Thin wall
- Crescent-shaped
Left ventricle
- Thick wall
- Circular
```
61
Trabeculae carneae
Ridged surface in each ventricle created by irregular protrusions of cardiac muscle
62
Papillary muscles
Finger-like projections which attach by the chordae tendineae to the atrioventricular valves
63
Chordae tendineae
Tendon-like cords which connect the papillary muscles to the atrioventricular valves
64
Interventricular septum
A thick, muscular wall separating the right and left ventricles
65
Atrioventricular valves
The valves between the atria and ventricles
66
Right AV valve
Tricuspid valve
67
Left AV valve
- Bicuspid valve
| - AKA mitral valve
68
Semilunar valves
- Prevent backflow into the ventricles
- Pulmonary valve
- Aortic valve
69
Coronary Circulation
- Blood vessels that supply oxygen and nutrients to the heart
- Part of systemic circulation
70
Coronary arteries
- Right and left
| - Immediate branches after the ascending aorta
71
Marginal artery
- The largest branch of the right coronary artery
| - On the inferior margin of the heart
72
Posterior interventricular artery
- After marginal artery
- Curls around to the posterior side
- Travels in the posterior interventricular sulcus
73
Anterior interventricular artery
- AKA leeft anterior descending artery (LAD)
| - Travels along the anterior interventricular sulcus
74
Circumflex artery
- Curves along the left AV sulcus and flexes around the heart
- Supplies the left atrium and parts of the left ventricle
75
Coronary sinus
A large venous structure on the posterior heart into which the majority of the heart's veins empty
76
Major veins supplying the coronary sinus
- Great cardiac vein
- Small cardiac vein
- Middle cardiac vein
77
Great cardiac vein
- Ascends along the anterior interventricular sulcus
- Then travels to the posterior side of the heart along the left AV sulcus
- Drains the left atrium and much of both ventricles
78
Small cardiac vein
- Travels along the right AV sulcus
| - Drains the right atrium and parts of the right ventricle
79
Middle cardiac vein
- Travels along the posterior interventricular sulcus
| - Drains mostly the posterior left ventricle
80
Plaques
Buildup of fatty material in the arteries
81
Coronary Artery Disease
- CAD
- Buildup of fatty material in the coronary arteries
- Decreases blood flow to the myocardium, decreasing its oxygenation
82
Myocardial ischemia
Decreased oxygenation due to decreased blood flow
83
Angina pectoris
Chest pain
84
Myocardial infarction
- Heart attack
- Occurs when plaques in the coronary arteries rupture
- Clot forms that obstructs blood flow to the myocardium
85
Coronary angioplasty
- An invasive procedure during which a ballon is inflated in the blocked artery
- A wire-mesh tubing (stent) is inserted to keep it open
86
Action potential
Electrical excitation
87
Pacemaker cells
Modified cardiac muscle cells which rhythmically and spontaneously generate action potentials
88
Autorhthymicity
Sets its own rhythm without need for input from the nervous system
89
Intercalated discs
Join adjacent cardiac muscle cells
90
Selective gated ion channels
- Voltage-gated sodium ion channels
- Calcium ion channels
- Potassium ion channels
- Nonselective cation channels
91
Voltage-gated sodium ion channels
Found in call cardiac muscle cells except certain pacemaker cells
92
Calcium ion channels
- Present in all cardiac muscle cells
- Voltage-gated opening
- Time-gated closing
93
Potassium ion channels
Present in all cardiac muscle cells
94
Nonselective cation channels
- Unique to certain pacemaker cells
- Activated by hyperpolarization
- Allow sodium ions to enter the cell while potassium ions exit
