Flashcards in The Cardio-Vascular (CV) System Deck (37)
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1
CV system Functions
Transport: essential food, oxygen, water, enzymes, hormones to cells of the body.
Remove: waste products to excretory organs
2
Components of CV system
1. Heart
2. Blood Vessels
3. Blood
3
Location of the Heart
Situated in the thoracic cavity.
it lies behind the STERNUM in front of the SPINE, between the LUNGS & above the DIAPHRAGM
4
Structure of the Heart
Hollow
Cone Shaped
Muscular Organ
5
Walls of the Heart
3 main layers:
1. pericardium (outer layer)
2. Myocardium (middle layer)
3. Endocardium (inner layer)
6
Name the Four Chambers of the heart
Left and right Atria.
Left and right ventricles
7
Describe the Atria
Two thinner walled upper chambers of the heart
Separated by the inter-atrial septum in an adult of normal health
8
Describe the Ventricles
Two thicker walled muscular lower chambers that receive blood form their respective atria.
They pump the blood either around the body (left) or through the lungs (right)
9
describe the Inter-ventricular Septum
A dividing wall of tissue which partitions the heart into left and right sides
10
describe the Atrio-ventricular septum
separates the atria from the ventricles
11
name the valves of the heart
Tricuspid valve
Pulmonary Semi-lunar valve
Bicuspid valve
Aortic Semi-lunar valve
12
Electrical Conduction System - name the components
specialised cardiac cells that produce electrical impulses to cause the heart to contract
-sino-atrial node
-atrio-ventricular node
-left & right bundle branches
-Conduction pathways (Purkinje fibres)
13
What Is the Cardiac Cycle
0.1 sec - Atrial Systole - contraction of atria
0.3 sec - Ventricular Systole - contraction of ventricles
0.4 sec - Cardiac Diastole - Relaxation phase
14
What is Cardiac Output (CO) and how is it calculated?
the amount of blood expelled form the ventricles in 1 minute.
SV x HR = CO
15
What is Stroke Volume (SV)
the amount of blood expelled from the ventricles in each contraction.
16
Nervous control
The heart is controlled primarily by the rate of self-excitation of its own tissue. HOWEVER, the Autonomic Nervous System does play a role.
17
Cardiovascular Centre
Located in the Medulla Oblongata. Sympathetic and Parasympathetic control regulates heart rate.
18
five types of Blood Vessels
Arteries
Arterioles
Capillaries
Venules
Veins
19
Blood Vessel composition
An outer fibrous sheath
A middle layer of muscle and elastic fibre
A smooth inner lining of Endothelium
20
Arteries
Carry blood away from the heart
Have a thick outer coat
Have a thick muscle layer
21
Arterioles
Smaller then arteries
Arterioles (and Venules) dilate or contact to control blood flow into and out of the capillary bed.
22
Capillaries
Have one cell thick walls
Allow the interchange of gasses
Transfer nutrients and waste products
23
Venules
Smaller then Veins.
Can dilate or contract to control blood flow into and out of the capillary bed.
24
Veins
Return blood to the heart
Have thinner walls then arteries
Some veins have valves to prevent the back flow of blood.
25
Blood
Carries oxygen and carbon dioxide
Carries nutrients and water
Carry waste products
Protect the body from infection
Sealing of wounds
Distributes secretions from glands
Distributes heat
26
Blood composition
Plasma 55%
Erythrocytes - red cells
leucocytes - white cells
Thrombocytes - platelets
27
Circulatory Systems four sub-systems
Systemic
Coronary
Pulmonary
Hepatic Portal
plus an additional network call the Lymphatic system
28
Systemic circulation
deals with the passage of blood around the body
29
Coronary circulation
deals with the supply of blood to the heart muscle itself
30
Pulmonary circulation
deals with the passage of blood through the lungs
31
Hepatic Portal circulation
deals with the supply of blood to and from the Liver.
It is a branch of the Systemic circulation
32
Lymphatic system
is a system of vessels similar to capillaries and works in conjunction with the main circulatory system.
33
Lymphatic system assists in:
the removal of waste from body tissues
the transportation of nutrients
fighting infection
34
The pulse is:
the rhythmic pulsation of an artery
35
The pulse can be felt at:
Radial Pulse - in the wrist
Brachial Pulse - above the elbow
Femoral Pulse - in the groin
Carotid Pulse - felt in the neck
36
Blood pressure is:
the pressure exerted by the blood on arterial walls. expressed in mmhg (millimetres of mercury).
37
