The Heart Flashcards
What are the main components of the cardiovascular system?
Arterial system
Heart
Pump system/venous system
What is the arterial system?
Arteries carry blood away from the heart
What is the heart?
The pump of the system
What is repurpose system?
Veins carry blood towards the heart
What direction does blood flow in the system?
Body-RA-RV-Lungs-LA-LV-Body
Does oxygenated or deoxygenated blood flow through the right side of heart?
Deoxygenated
Does oxygenated or deoxygenated blood flow through the left side of heart?
Oxygenated
What is systole and diastole?
Systole - contraction
Diastole -relaxation
What is the average pulse rate of the heart?
70 bpm
Can change due to exercise
Speed up inhale
Slow down exhale
What component takes deoxygenated blood away from heart to lungs?
Pulmonary trunk
Then 2 pulmonary arteries
What component takes oxygenated blood away from heart to body?
Aorta
What component brings deoxygenated blood from body to heart?
Vene cavae x2
What component brings oxygenated blood from lungs to heart?
Pulmonary veins x4
What are the 3 layers of the heart wall?
Epicardium - external visceral serous pericardium
Myocardium - middle cardiac muscle layer
Endocardium - internal continuous with endothelium of blood vessels connecting with heart
What are the two types of valves in the heart?
Atrioventricular- mitral (left) and tricuspid (right)
Semilunar - aortic and pulmonary (blood leaving)
What is one normal route of conduction in the heart?
Electrical impulse starts spontaneously at sinoatrial node causing both atria to contract
Travels to atrioventricular node at atrioventricular septum
Travels down right and left bundles in interventricular septum
Spreads out to myocardium through conducting fibres causing both ventricles to contract
What are the 3 layers of the blood vessels?
Tunica intima - internal, endothelium
Tunica media - middle, smooth muscle and elastic fibres
Tunica adventitia - external, connective tissue
What do arteries give rise to?
Branches
What is bifurcate and trifurcate?
Artery splits into 2 branches
Artery splits into 3 branches
What do the terms common and trunk mean in reference to arteries?
That the artery will divide again
What is vasodilation?
Relaxation of the smooth muscle and widening of the lumen to INCREASE blood flow to organ/tissue
What is vasoconstriction?
Contraction of the smooth muscle to REDUCE blood flow to the organ/tissue
What can arteriolar smooth muscle contraction help to do?
Reduce blood loss following an injury
What is sympathetic tone?
Low level of contraction of smooth muscle in arteriole
Due to tonic conduction of action potentials to arterioles by sympathetic nerves
What is anastomoses?
Arteries connect with each other without an intervening capillary network
Provides alternative routes for blood flow to supply the cells distal to an arterial occlusion (blockage)
What is the circle of Willis?
An arterial anastomoses of the brain
May help to prevent a cerebrovascular accident (CVA/stroke)
What are alternative routes to anastomoses?
Collateral arteries or collateral circulation
However they bleed from both sides of a cut, so haemorrhage can be worse
What is an end artery?
The only arterial blood supply to a given area (no collateral vessels)
What can untreated occlusion of an end artery lead to?
Infraction of its territory
Infraction means irreversible cell death due to hypoxia (lack of oxygen) caused by loss of arterial blood supply
What is occlusion of a coronary artery?
Heart attack
What is occlusion of a central artery of the retina?
Monocular blindness
Is blood that is entering the aorta during systole at a high or low pressure?
High pressure
What type of walls does the aorta have?
Elastic
What does elastic recall do?
Maintains peripheral flow during diastole
What are the 4 parts of the aorta?
Ascending aorta - branches, left and right coronary arteries
Arch of the aorta - 3 branches,
Thoracic aorta - numerous branches
Abdominal aorta - 3 unpaired midline branches and several parred, bilateral
What are the branches of the aorta?
Brachiocephalic trunk - upper limbs and head
Left comman carotid artery - head
Left subclavian artery - inferior to clavicle
What is the basic upper limb blood supply?
Left subclavian artery which becomes the left axillary artery which then becomes the left brachial artery
The brachial artery is anterior to the elbow joint and bifurcates to give 2 branches, left radial artery and left ulnar artery
What do the branches at the aorta supply blood to?
Abdominal organs
What do the common iliac arteries supply blood to?
Pelvis/perineum and lower limbs
What/where are the peripheral pulses?
Carotid - bifurcation of common carotid artery (neck)
Radial artery - radial side of palmer aspect of wrist
Brachial artery - anterior to elbow joint
Femoral artery - continuation of external iliac artery
Popliteal artery - posterior to knee
Dorsalis pedis artery - dorsum of foot
What is a neurovascular bundle?
Bundle of nerve, artery and vein
What are the 6 principles of veins?
1- carry deoxygenated blood
2- low pressure and non- pulsatile
3- draw blood away from a territory
4- have tributaries: venues and veins which merge like a river
5- thin walled which collapse when empty
6- they have valves!
What are the venous valves?
In limb veins, values are present to ensure unidirectional how back to the heart against gravity
What are the skeletal muscle pumps?
Contraction at skeletal muscles in lower limbs helps assist blood flow back towards the heart
What are the venue comitantes?
Small reins run in pairs or more with an artery in a sheath and arterial pulsation pushes venous blood back towards heart
What is the difference between superficial and deep veins?
Superficial veins are smaller and run in superficial fascia then drain into deep veins
Deep veins are larger and run deep in deep fascia and in cavities
Deep veins are often found in neurovascular bundles
What are capillaries lined with?
Single layer of endothelium
What travels through the lumen of the capillaries?
One red blood cell (erythrocyte) at a time
What do the capillaries allow?
Exchange of gases
What do lymphatic capillaries do?
Collect tissue fluid
(fluid that normally leaks outwhen blood flows through capillary bed)
Once in the lymphatic capillaries the fluid is called lymph
What do lymphatics do?
Carry lymph through lymph nodes
(carry white blood cells to filter foreign particles and fight infection/cancer)
Where does lymph eventually end up?
Central veins in root of neck
What does the right lymphatic duct do?
Drains lymph into right venous angle
What does the thoracic duct do?
Drams lymph into left venous angle
Only lymphatic vessel large enough to be found in dissection
