The Circulatory System Flashcards
What are the components of the circulatory system
Cardiovascular system
Lymphatic system
What are the primary functions of the circulatory system
Distribution of gases and other molecules for nutrition, growth and repair
Hormones
Mediate inflammation
Defence responses
What are the 3 main components of the cardiovascular system
Arterial system
Heart
Veinous system
What are the stages of pulmonary circulation
Blood from the body enters into the RA then RV, into the lungs where blood is oxygenated
What are the stages of the systemic circulation system
Oxygenated blood from the lungs enters into the LA then LV and is pushed throughout the body
When does the heart contract
Systole
When does the heart relax
Diastole
What are the 2 components of the pulmonary trunk
2 pulmonary arteries
What is the function of the pulmonary arteries
Carry deoxygenated blood to the lungs
How many pulmonary veins are there
4
What is the function of the pulmonary veins
Carry oxygenated blood to the heart (LA)
What is the function of the aorta
Carries oxygenated blood from the LV to the body (capillary bed)
How does deoxygenated blood enter the heart
Through the superior and inferior vena vaca
What are the 3 layers of the hearts wall
Epicardium(external)
Myocardium (middle)
Endocardium (internal
Which layer of the heart is responsible for the cardiac muscle
Myocardium
What is the name of the right atrioventricular valve
Tricuspid
What is the name of the left atrioventricular valve
Mitral
Where is blood leaving when it passes through the aortic semilunar valve
Left ventricle
Which ventricle is blood leaving when it passes through the pulmonary semilunar valve
Right ventricle (pulmonary trunk)
Which node is responsible for causing both atria to contract
Sinoatrial node
Which node does the impulse travel to after leaving the sinoatrial node
Atrioventricular node at septum
Where does the impulse travel down after leaving the atrioventricular node
Right and left in interventricular septum
What causes both ventricles to contract
Impulse spreads out to myocardium through conducting fibres
Why does the lumen of the vein flatten
Due to thick layer of tunica adventitia (not elastic)
Which blood vessel has the most pressure
Arteries, >120/80
What terminology lets you know an artery will divide again
Common or trunk
What is the splitting of arteries known as
Branching, bifurcate or trifurcate
Which part of the arterioles wall allows it to contract or dilate
Smooth muscle
What happens to the smooth muscle during vasodilation
Relaxes, lumen widens which increases blood flow
What happens to the smooth muscle during vasoconstriction
Contraction, narrow lumen reduces blood flow
What term describes the low level of contraction of smooth muscle
Sympathetic tone due to tonic (continuous) conduction of action potentials
What is anastomosis
Arteries connect with each other without intervening capillary networks
What is the function of anastomosis
Provides alternative routes for blood flow to supply the cells distal to an arterial occlusion (block)
What is an arterial anastomosis of the brain
Circle of willis - prevents cerebrovascular accident
What are alternative routes of blood flow known as
Collateral arteries/collateral circulation
What is an end artery
The only arterial blood supply to a given area
What can an untreated occlusion to an end artery lead to
Infarction
What is an infarction
Irreversible cell death due to hypoxia caused by loss of arterial blood supply
Which arterial blood supply enters the aorta first
Systemic
When does the aorta receive blood
At high pressure during a systole
How is peripheral flow maintained in an aorta during diastole
Elastic recoil
What are the 4 components of the aorta
Ascending aorta
Arch of the aorta
Thoracic aorta
Abdominal aorta
What are the 2 branches of the ascending aorta
Left coronary artery
Right coronary artery
What are the branches of the arch of the aorta
Brachiocephalic trunk
Left common carotid artery (head)
Left subclavian artery
Right common carotid
Right subclavian
Where does the left subclavian artery lead to
Axillary artery
Brachial artery - bifurcates:
Left radial artery
Left ulnar artery
What does the abdominal aorta bifurcate into
External iliac
Internal iliac
What is a continuation of the external iliac artery
Femoral artery
What artery supplies the foot
Dorsalis pedis artery
What are the components of a neurovascular bundle
Nerve
Artery
Vein
What is the function of a vein
Drain blood away from a territory
What is a collection of veins that merge called
Tributaries
How is venous blood returned to the heart
Venous valves - unidirectional against gravity
Skeletal muscle pump
Venae comitantes
What is the function of accompanying veins (venae comitantes)
Small veins in pairs or more wrapped over an artery
Artery pulsation pushes venous blood along
Where do superficial veins drain into
Run into superficial fascia which drain into deep veins running into deep fascia and cavities
Which organs is the hepatic portal venous system responsible for
GI tract and associated organs to liver for cleaning
What organs is the systemic venous system responsible for
Drains venous blood from all other organs and tissues into the superior or inferior vena cava
How is lymph returned to central veins
Lymphatic capillaries collect tissue fluid
Becomes lymph
Carried through lymph nodes
Returned to central veins in root of neck
Which angle does the right lymphatic duct drain into
Right venous duct
Which angle does the thoracic duct drain into (responsible for left upper and bottom quadrants)
Left venous angle
When are lymph nodes enlarged
When fighting infection or when taken over
