The Circulatory System Flashcards
Revision
1
Q
What systems do the circulatory system consist of?
A
The cardiovascular system and lymphatic system.
2
Q
What are the functions of the circulatory system?
A
Distribution of gases and other molecules for nutrition, growth and repair.
Chemical signalling (hormones)
Thermoregulation
Mediate inflammation and host defense responses.
(The lymph system also get rid of some of the body’s waste).
3
Q
What are the three components that the cardiovascular system is comprised of?
A
Arterial System
Heart
Venous system
4
Q
What is the role of the Arterial system?
A
All the arteries of the body carry blood away from the heart.
5
Q
What is the role of the heart?
A
The heart’s role is to act as the pump of the cardiovascular system.
6
Q
What is the role of the venous system?
A
All the veins of the body carry blood towards the heart.
7
Q
What are the 2 main circulations that the cardiovascular system is divided into?
A
Pulmonary circulation
Systemic circulation
8
Q
What is the role of the Pulmonary circulation?
A
this pumps oxygen depleted blood from the right side of the heart to the lungs and back to the left side of the heart.
9
Q
What is the role of the systemic system?
A
It pumps oxygenated blood from the left side of the heart to capillary beds of organs and tissues back to the right side of the heart.
10
Q
The heart is a muscular double pump. what are the two actions that the heart carries out?
A
Systole (contraction) and Diastole (relaxation)
Diastole is where the contraction dies and so the heart relaxes
11
Q
What is the average pulse rate of a person?
A
70 beats per minute
12
Q
What is the plural of atrium?
A
Atria
13
Q
What is the biggest, chunkiest artery in the body?
A
Aorta
14
Q
How many pulmonary veins are there?
A
4
15
Q
How many vena cava’s are there?
A
There is a superior vena cava and an inferior vena cava.
16
Q
How many layers does the heart have?
A
3
17
Q
What are the names and types of tissues in each layer?
A
the external layer is the epicardium. Visceral serous pericardium
The middle layer is the Myocardium. Cardiac muscle layer.
The internal layer is the endocardium. Continuous with endothelium of blood vessels connecting with the heart.
18
Q
What structure forms the right border of the heart?
A
Right atrium
19
Q
What structure forms most of the anterior surface of the heart?
A
Right ventricle
20
Q
What structure forms the posterior surface of the heart?
A
Left atrium
21
Q
What structure form the left border of the heart?
A
Left ventricle
22
Q
Is the myocardium the same all the way around the heart?
A
No it is thicker on the left than the right.
23
Q
What is the role of cardiac valves?
A
They ensure uni-directional flow
24
Q
Where is the pulmonary valve located?
A
between the right ventricle and pulmonary trunk
25
Where is the tricuspid valve located?
between the right atrium and right ventricle
| The tricuspid valve slams shut and stops a back flow of blood into the right atrium.
26
Where is the aortic valve located?
between left ventricle and the aorta
27
Where is the mitral (bicuspid) valve located?
```
between right ventricle and pulmonary trunk
The mitral (bicuspid) valve has to deal with large pressure of a strong flow of blood.
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28
What is the name of the veins and arteries that exit and enter the heart?
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Superior vena cava (SVC)
Inferior vena cava (IVC)
Aorta
Pulmonary trunk
Pulmonary veins (x4)
```
29
What are the four steps that talk you through the conduction system of the heart?
There is one normal route for electrical conduction in the heart:
1. Electrical impulses starts spontaneously at SA node. Causing both atria to contract.
2. Travels to AV node at atrioventricular septum. The AV node sandwiched between the atrium and the ventricle.
3. Travels down right and left bundles in the interventricular septum.
4. Spreads out to myocardium through conducting fibres. Causing both ventricles to contract.
30
What are the three layers that most blood vessels are comprised of?
```
Tunica Intima (internal) - endothelium
Tunica media (middle) - smooth muscle and elastic fibres
Tunica adventitia (external) - connective tissue
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The bigger the artery the more elastic muscles and less muscle. The smaller the arteries, the more muscles, the less elastic fibres.
31
What the 7 key principles about arteries?
Often part of a neurovascular bundle (nerve, artery, vein)
High pressure (>120/80 mmHg)
Often named by anatomical location - (e.g. brachial artery, intercostal artery)
Round lumen
Pulsatile - you can see/take a pulse
Typically located deeper than veins
Carry oxygenated blood
32
What does proximal and distal mean?
Proximal means closer to the heart
| Distal means away from the heart
33
What do arteries give rise to
branches
34
What do arteries supply?
Arteries supply a territory (region of the body supplied by a single artery and its branches).
35
What does Bifurcation and Trifurcation mean?
Bifurcation means that the artery divides in 2.
| Trifurcation means that the artery divides in 3.
36
What does the terms common and trunk indicate?
They indicate that the named artery will definitely divide again
37
Why are arteries typically round?
They are typically round becuase of the elasticity of the arteries. they have a large numbers of elastic fibres.
38
How can the smooth muscle in the walls of arterioles ( and some arteries called muscular arteries) affect the vessels?
The smooth muscle in the walls of arterioles (and some arteries caled muscular arteries) can contract to narrow the vessel's lumen: They can cause vasodilation or vasoconstriction.
39
What is vasodilation?
Its the relaxation of the smooth muscle and widening of the lumen to increase blood flow to the organ/tissue supplied.
40
What is vasoconstriction?
Its the contraction of smooth muscle to reduce blood flow to the organ/tissue supplied.
41
What is sympathetic tone?
It occurs in the background and is a low level of contraction of smooth muscle in arterioles.
Due to tonic (continuous) conduction of action potentials to arterioles by sympathetic nerves.
Decrease tone to further dilate.
Increase tone to further contract.
42
How can arteriolar smooth contraction help to reduce blood loss?
The arteriolar smooth muscle contracts following an injury to help to reduce blood loss (the vessel is said to b in spasm).
43
What is an anastomosis and what is it's role?
An anastomosis is where arteries connect with each other without an intervening capillary network.
It provides alternative routes for blood to flow to supply the cells distal to an arterial occlusion (blockage).
44
What is Circle of Willis?
It is an arterial anastomosis of the brain.
| In the case of the brain, this can help to prevent a cerebrovascular accident (CVA/Stroke)
45
What is an anastomosis?
A connection made between adjacent blood vessels.
46
What is a collateral?
A collateral is eah alternative route in any given anastomosis.
47
What is a disadvantage 0f a collateral?
Collaterals bleed from both sides of a cut so the haemorrhage can be worse.
48
What is an end artery?
An end artery is the only arterial blood supply to a given area of the boy (there are no collaterals).
49
What can an untreated occlusion of an end artery result in?
This can result in an infarction of the artery's territory.
E.g. A myocardial infarction is an occlusion of a coronary artery (heart attack or death). The anastomosis in the heart isn't good enough to get enough blood to that area of the heart that's why if there is a blood clot in the coronary artery you can have a heart attack.
A retinal infarction is an occlusion of the central artery of the retina (monocular blindness). If the single artery of the retina is disrupted the retina will start to die out.
A fingertip infarction is an occlusion of a digital artery branch (amputation).
50
What does infarction mean?
It means irreversible cell death due to hypoxia (lack of oxygen) caused by loss of arterial blood supply.
51
What is the role of the aorta?
All the systemic arterial blood enters the aorta first
It receives blood at high pressure during systole (when he heart contracts).
Its elastic walls expand under this pressure.
Elastic recoil maintains peripheral flow when the heart relaxes (during diastole).
The Aorta has 4 parts and many branches which supplies the whole body.
A nerve is not needed when the aorta is highly elastic. It is needed of the aorta had a lot of muscle. Elastic recoil is really important.
52
What are the 4 parts of the aorta?
1. Ascending aorta
2. Arch of the aorta
3. Thoracic aorta
4. Abdominal Aorta
The thoracic and abdominal aorta can be grouped into the descending aorta
53
What is the ascending aorta composed of?
2 Branches
| left coronary artery and right coronary artery
54
What is the arch of the aorta?
3 branches
55
What is the Thoracic aorta composed of?
numerous branches
56
What is the abdominal Aorta composed of?
3 unpaired midline branches & 3 paired, bilateral branches
57
What are the three branches of the arch of the aorta?
1. Brachiocephalic trunk (brachio=arm cephalic=head)
2. LEFT common carotid artery. this artery is named common because it splits into the internal and external carotid artery.
3. LEFT subclavian artery (runs below the clavicle)
58
What is the basic upper limb blood supply?
The left subclavian artery (passes under the clavicle) then becomes the Left axillary artery then becomes Left brachial artery. Anterior to the elbow joint the brachial artery bifurcates to give 2 branches:
Left radial artery
Left ulnar artery
ARTERIES CAN CHANGE THEIR NAME
59
Wht is the role of the common iliac arteries?
They supply the pelvis/perineum & the lower limbs. The external iliac goes to the lower limbs and the internal iliac goes to the pelvis and the perineum
60
What are the peripheral pulses?
```
Carotid ulse
Brachial artery pulse
Radial artery pulse
Femoral artery pulse
Popliteal artery pulse
Dorsalis pedis artery pulse
```
61
What is the location of the carotid pulse?
At the bifurcation of the common carotid artery
62
What is the location of the brachial artery pulse?
Anterior to the elbow joint
63
What is the radial artery pulse?
Radial side of the palmer aspect of the wrist
64
What is the location of the femoral artery pulse?
the continuation of the external iliac artery in the midpoint of the groin.
65
What is the location of the popliteal artery pulse?
Posterior to the knee joint
66
What is the location of the Dorsalis pedis artery pulse?
On the dorsum of the foot.
| If you can find the dorsalis pedis then the blood is okay!
67
How is venous blood pumped back towards the heart?
Venous valves
Skeletal muscle pump
Accompanying veins
68
What is the role of Venous valves?
They are in limb veins, valves are present to ensure unidirectional flow back to the heart against gravity.
69
What is the role of the skeletal muscle pump?
Contraction of skeletal muscles in the lower limb.
70
What is the role of the accompanying veins?
Small veins run in pairs or more with an artery in a sheath. Artery pulsation pushes venous blood along. Some veins run really deep between muscles. As the muscles contract it squeezes the vein and aids the movement of blood.
71
What are the 2 sets of veins the body has?
Superficial veins and deep veins.
Superficial veins are smaller and run within superficial fascia then drain into deep veins that are larger and run deep to the deep fascia and in cavities often in NVB.
The deep venous system follows the arterial supply.
72
How do doctors take a sample of venous blood?
Clinicians often access the superficial veins of the upper limb.
73
What are the 2 main venous systems in the body?
Hepatic portal venous system and systemic venous system
74
What is the role of the venous portal venous system?
Drains venous blood from absorptive parts of the GI tract and associated organs to the liver for "cleaning".
All the nutrient rich blood has to reach the liver first. The hepatic portal vein system collects nutrient rich blood from the GI tract and takes it to the liver.
75
What is the role of the systemic venous system?
It drains venous blood from all other organs and tissues into the superior or inferior vena cava.
76
What is the role of capillaries?
Capillaries form extensive vascular networks approx. 50000 miles.
They are lined with single layer of endothelium
Narrow lumen only allowing one red blood cell (erythrocyte) through at a time.
Allow for exchange of gases, metabolites and waste products.
These allow all gas exchange to happen at a cellular level.
77
What is the role of the lymphatic circulation?
Lymphatic capillaries collect tissue fluid (the fluid that normally leaks out when blood flows through capillary beds).
Once in the lymphatic capillaries the fluid is called lymph.
Lymphatics carry lymph through lymph nodes (contain white blood cells to filter out foreign particles and fight infection/cancer).
Eventually lymph is returned into the central veins in the root of the neck.
78
Where does the right lymphatic duct drain into?
The right lymhatic duct drains lymph into the right venous angle.
79
Where does the thoracic duct drain into?
The thoracic duct drains lymph into the let venous angle.
80
What is the only thoracic duct large enough to be found in dissection?
The thoracic duct
81
Where do superficial lymphatics drain into?
Superficial lymphatics drain into deep and lymphatics
82
Why is the lymphatic system known as the recycling system?
Lymph eventually drains back into the venous system at the venous angles n the root of the neck (where the central veins returning from the head/neck and upper limbs meet).
83
Can normal lymph nodes be palpated?
Normal lymph nodes cannot usually be palpated (felt beneath the examining doctors fingertips). Lymph nodes fighting infection or being taken over by a spreading cancer usually enlarge and can be palpated or seen on a CT scan.
It is important to know about the lymph system because the unwanted cells such as cancer or metastatic cells can join the lymph system and move around the body.
