CVS and anatomy of heart Flashcards
1
Q
2 vascular system of the cardiovascular system
A
Blood vascular system
Lymphatic vascular system
2
Q
Blood vascular system (2)
A
A closed supply and drainage system
A continuous loop - starting at the heart and out to the tissues for exchange and then back tot he heart
3
Q
Lymphatic vascular system (2)
A
An open-entry drainage system (towards the blood vascular space)
A one-way system
4
Q
What is the only supply path
A
arteries
5
Q
Where are the major arteries situated and why
A
They are situated to avoid damage
eg. deep in the trunk, on flexor aspects of limbs
6
Q
Important structures often receive supply from __ sources? And how many arteries does brain have?
A
2,4
7
Q
What makes up the exchange network
A
Capillaries of varying degree of permeability
8
Q
3 types of capillaries
A
Continuous - tight control over what enters and leaves (most common)
Fenestrated - leaky
Sinusoidal - very leaky
9
Q
3 pathways for drainage
A
Deep veins (deep to fascia) - situated next to supply arteries carrying blood opposite to them
Superficial veins - can be quite large
Lymphatics - hard to see even in live tissues as there are no RBC (fluid comes out is clear)
10
Q
Drainage channels/veins vs. supply network/arteries (pressure, velocity, CSA)
A
Drainage channels are carrying blood at low pressure and low velocity whereas the supply network arteries carries blood at high pressure and high velocity
Cross sectional area of veins is at least twice that of arteries in order to shift the same volume of blood per second
11
Q
Cardiovascular diseases cause at least ___% of deaths?
A
50
12
Q
Orientation of heart in the thorax
A
In the mediastinum (middle region of thorax), behind the body of sternum between the points of attachment of the second through to the sixth ribs
13
Q
Location of apex of heart
A
Lies on the diaphragm on the mid-clavicular line on the left in the space between the 5th intercostal space
14
Q
PMI - Point of maximal impulse
A
Where the apex beat is observed
15
Q
How is the apex affected by the rotation and tilt position of the heart
A
It’s pushed against the anterior wall on the left of the mid-clavicular line
16
Q
__ of the heart sits to the left of the midline
__ of the heart sits to the right of the midline
A
2/3
1/3
17
Q
left pleural cavity vs. right pleural cavity (volume/size)
A
The left pleural cavity has less volume than the right
18
Q
Shape of the heart (3)
A
Blunt, cone shaped
pointed end - apex
Broad end - base
19
Q
Why is the rotation and tilt of the heart important
A
Because it shifts the position of the 4 chambers of the heart in relation to surrounding structures
20
Q
After rotation and tilt: Right atrium becomes \_\_\_\_ Right ventricle becomes \_\_\_ Left atrium becomes \_\_\_ Left ventricle becomes \_\_\_
A
right lateral margin
quite anterior
most posterior structure
left lateral margin
21
Q
Septum
A
Extension of the heart that separates the chambers of the heart
22
Q
2 types of septums
A
Interventricular septum
Interatrial septum
23
Q
Role of ventricles
A
Receives blood from the atria and pump blood out of the heart to arteries
24
Q
Ventricle myocardium vs. atrium myocardium
A
As more force is needed to pump blood, the myocardium of each ventricle is thicker than any of the myocardium of the atria
25
Left ventricle myocardium vs. right ventricle myocardium
Left > right
As the left pushes blood through most vessels of the body (systemic circuit) whereas the right side pushes only through the nearby pulmonary vessels that serves as gas exchange tissues of the lungs
26
systemic circuit + route
Is the circuit through the rest of the body to provide oxygenated blood and bringing deoxygenated blood back to the heart
Left ventricle pumps blood -> peripheral organs -> right atrium
27
Pulmonary circuit + route
The circuit to the lungs where the blood is oxygenated and then back to the heart again
Right ventricle -> lungs -> left atrium
28
Atrium
Thin walled (receiving) chambers - receives blood from veins
29
What does the right atrium receive
Deoxygenated blood from the periphery which drains into the right ventricle and pumps through the pulmonary circuit to oxygenate blood by passing through the pulmonary semilunar valve
30
Right atrium receives via (3)
Superior vena cava
Inferior vena cava
Coronary sinus
31
Superior vena cava
brings all the deoxygenated blood from head, neck, chest and upper libs which all drains through the large vein
32
Inferior vena cava
drains everything below the diaphragm
33
Coronary sinus (3)
- Blood that has supplied the heart muscles itself returns and enters through the right atrium
- Last part of venous drainage of the heart muscle
- Space where all the veins from the heart muscle has accumulated which has brought the deoxygenated blood from the heart into the sinus space which in turn drains to the right atrium
34
Left atrium receives
Oxygenated blood from the lungs which drains into the left ventricle and pushed out to the aorta
35
Left atrium receives via
4 pulmonary veins
36
Layers of the heart wall (3)
Endocardium
Myocardium
Epicardium
37
What does the endocardium line
all the chambers of the heart including all the veins, arteries and valves
38
Boundary between the chamber and the wall - refers to what?
The endocardium
39
What is the endocardium made up of (4)
Squamous epithelium
Loose irregular fibrous connective tissue
(small) blood vessels
Purkinje fibres/cells
40
Squamous epithelium
Part of the endocardium
Single non-stick layer of flat/endothelium cells
Stops blood from coagulating inside the blood vessels against the blood wall
41
Myocardium (2)
Layer of the heart with muscle
| Seen most in the heart wall
42
Epicardium
Continuous layer that covers the heart surface
| Upon the myocardium
43
What is the epicardium surrounded by (2)
Loose irregular Fibrous connective tissue, adipose
44
Components of the epicardium
Visceral pericardium
Blood vessels (large)
Surrounded by loose irregular fibrous connective tissue and adipose
45
Visceral serous pericardium (3)
Part of the epicardium
Thin layer, part of the membrane that sits over the heart that forms a visceral layer of the pericardium
Serous membrane
46
Serous membrane
Membrane that forms a closed space
47
```
Blood vessels (large)
Coronary artery vs. coronary vein
```
What the epicardium is adherent to
Thicker wall + higher pressure = coronary artery
Thinner collapsed all + lower pressure = cardiac vein
48
Pericardial space
Potential space where the heart sits
49
Pericardium (3)
Protective outer covering
2 layers
Described as a serous membrane
The visceral serous pericardium part of it is fused to the epicardium
50
Pericardial cavity
The space between the 2 layers of serous pericardium which is filled with serous fluid, produced by cells that form the serous membrane which protects the heart from any kind of external shock
51
2 layers of the percardium
Fibrous pericardium
| Serous pericardium
52
Fibrous pericardium
Tough, loose fit, inelastic sac around the heart
53
Serous pericardium - 2 layers
Inner layer = fuse and become visceral layer of the membrane
| Outer layer that faces the air = parietal pericardium
54
Visceral and parietal layer switching
The single serous layer changes from being visceral to the parietal layer at the base of the heart and anchors the base, whereas the apex of the heart runs free
55
Wall thickness - Right ventricle
0. 5cm
- muscle is 1/3 thickness of the left side
- less muscle because it only needs to push the blood from the right hand side of heart to the capillaries of the lungs so is a short journey
- same volume of blood as left side but less pressure needed
56
Wall thickness - left ventricle
1. 5cm
- 3 times more muscle thickness than right side because the same volume of blood is pushed to the aorta and goes to everywhere else in the body through the systemic circuit
- Therefore more pressure so more force
57
Heart valve function
Allow the heart to act as a pump that forces continuous flow of blood up in one direction - prevents back flow of blood
58
2 heart valves
Atrioventricular (AV) valves aka. cupsid valves
| Semilunar valves
59
Atrioventricular valves - location and function
Valves between the atria an ventricles
Control flow between atrial chambers and ventricular chamber and prevent back flow of blood from the ventricle back up to the atrium during ventricular contraction
60
AV valves - right vs.left
Right: 3 leaflets - tricuspid valves (cusps)
Left: 2 leaflets - bicuspid valves (mitral valves)
61
What is mitral valves anther name for?
The left AV valves/bicuspid valves
62
Operation of AV valves (ie. when are they open or closed)
Diastole (filling phase of ventricles) - AV open
| Systole (during ventricular contraction) - AV closed
63
Semilunar valves - location and function
Where the pulmonary artery joins the right ventricle (pulmonary valve) and where the aorta joins the left ventricle (aortic valve)
Prevents blood returning to ventricles during diastole (filling phase)
64
Semilunar valves - left vs. right
Left: aortic semilunar valve - 3 cusps
Right: pulmonary semilunar valve - 3 cusps
65
Operation of semilunar valves (ie. opening and closing)
Ventricular systole - open, as blood flows out of heart
| Ventricular diastole - closed, as blood starts to back flow
66
Papillary muscles in left ventricle - where it is and relationship to AV valves
Muscle coming off the ventricular wall
| 1 muscle per AV valve eg. tricuspid valves = 2 papillary muscles and bicuspid valves = 2 papillary muscles
67
Why does the semilunar valves not require papillary muscle or chordae tendinae
Because it is small in size
68
Diastole - describe, valves open/close
Atrial contraction/blood filling phase where blood is forced through the ventricles
AV open
semilunar valves shut
69
Systole - describe, valves open/closed
Ventricular contraction where blood is forced out of ventricles through the semilunar valves and into arteries
semilunar valves open
AV shut
70
Role of cardiac circulation
It's the way myocardial cells receive blood via coronary arteries
71
Role of coronary arteries
supply blood to the heart muscle
72
What are the coronary arteries
First branch coming off the aorta that goes into the coronary circulation to the heart (encircles the myocardium)
73
Where do the opening to the coronary arteries lie
Behind the leaflets of the aortic semilunar valve
74
What happens to the coronary arteries during ventricular relaxation
The aortic valves are closed and the back flow of blood closes the valves and fills the coronary artery
75
Where do the opening to the coronary arteries lie
Behind the leaflets of the aortic semilunar valve
76
What happens to the coronary arteries during ventricular relaxation
The aortic valves are closed and the back flow of blood closes the valves and fills the coronary artery
77
Location of the coronary arteries
They run through the epicardium above the myocardium and dives down into the muscle (along the surface of the heart is a lot of adipose and hidden beneath would be the coronary vessels)
78
How many main branches does the left and right coronary arteries have
2
79
2 branches of the left coronary artery
Circumflex artery
| Anterior interventricular artery
80
Left circumflex artery
Circumflexes between the left atria and the left ventricles to supply left marginal and posterior heart
81
Anterior interventricular artery
runs along the interventricular septum and then branches out a lot especially to the left ventricle
82
Location of the right coronary artery
between the atria and ventricle and branches
83
Drainage route
blood - capillary networks in the myocardium - cardiac veins - coronary sinus - right atrium
84
Coronary veins (2)
Great cardiac vein
| Small cardiac vein
85
Great cardiac vein - drainage route
Drains anterior interventricular artery and circumflex artery and back to the posterior of the heart via coronary sinus
86
Small cardiac vein - drainage route
Drains the right side of the heart and back to the posterior of the heart via coronary sinus
87
Any domination between right or left coronary arteries?
No
88
Both ventricles receive their blood supply from where?
The branches of the right and left coronary arteries
89
Each atrium receives blood only from ...?
a small branch of the corresponding coronary artery
90
Part of heart that receives the most abundant blood supply and why
Myocardium of the left ventricle as it does the most work hence needs most oxygen and nutrients
91
What is the capillary network
long thin structures between the myocardial cells
92
What are capillaries formed by
endothelial cell walls that form a thin tube, joined together by tight junction
93
25% mitochondria correspond to what type of muscle
cardiac muscle
94
Where are intercalated disks located
between 2 neighbouring cardiac cells
95
3 types of intercellular junction
Adhesion belts
Desmosomes
Gap junctions
96
Adhesion belts (3)
Links actin to actin
Sit in vertical portion (perpendicular to the ventricle contraction)
Physical propagation of contraction - during contraction, actin of neighbouring cell stimulate the next cell to contract
97
Desmosomes (4)
Link cytokeratin to cytokeratin
Not a contractile protein
Flexible skeleton in a cell between the neighbouring cells
During contraction, they keep the cells together so they do not come apart
98
Gap junctions (3)
Horizontal portion parallel to contraction plane
Allow electrical coupling/electrical propagation
Electrochemical communication through neighbouring cells
99
Vagus (parasympathetic autonomic nerves) ___ heart rate
Decrease
100
T1-4 spinal nerves (sympathetic) ____ heart rate
Increase
101
Where is the Sinoatrial node (SA) located
At the junction of superior vena cava and the right atrium
102
Where does the interatrial bundles conduct the AP from and to?
From the right atrium to the anterior part of the left atrium
103
Where does the internodal bundles conduct the AP from and to?
From the SA node to the AV node
104
How does the AP reach the purkinje fibres from the AV node
Right and left branches of AV bundles (bundle of His) conducts the AP from the AV node to the right and left ventricles down the interventricular septum and to the purkinje fibres
105
Another name for purkinje fibres
Subendocardial fibres
106
Role of purkinje fibres
Conduct AP to all parts of the ventricles, stimulating them to contract almost simultaneously
107
What are purkinje cells
Originally cardiac muscle cells but have become modified for conduction role and not contractile anymore
108
Characteristics of purkinje cells (5)
(some) peripheral myofibrils which are redundant and put to the side
Central nucleus
Mitochondria, glycogen (for conduction use)
ICD's - lots of gap junctions, not a lot of adhesion belts and desmosomes
1% cardiac cells
