Cardiovascular system Flashcards
Components of the circulatory system
Cardiovascular system and lymphatic system
Cardiovascular system. Its function and why it is important?
Distributes blood in a series of parallel circuits.
- various circuits ensures an adequate supply of oxygen, nutrients and signalling molecules to all bodily tissues and prevent toxic build-up.
Limbic system. Its components and function.
Comprises of lymph nodes, lymphoid tissues (storage and colonial sites of immune cells - lymphocytes and macrophages), lymphatic vessels, valves, ducts and capillaries and lymph (filtered blood plasma).
FUNCTION
- returns excess filtered blood plasma from interstitial fluid.
- Maintain pressure and volume of interstitial fluid and blood.
- Lymph nodes and lymphoid tissues are main sides for immune cell production
Components of the cardiovascular system
Heart - as a pump
Blood
Blood vessels
Cardiovascular system function
Functions:
• Brings blood containing oxygen, nutrients, and hormones
to cells
• Transports CO2 and other wastes away
from cells – for biotransformation/excretion (liver and
kidney)
• Fights infection (contains immune system components)
• Regulates body temperature ( links to the hypothalamus)
• Helps stabilize pH and ionic concentration of body fluids
Describe upper body circulation
- Deoxygenated blood from the RIGHT VENTRICLE travels to the lungs through PULMONARY ARTERY.
- Blood gets oxygenated and travels to the LEFT ATRIUM through PULMONARY VEIN.
- From the left atrium blood travels to LEFT VENTRICLE through MITRAL VALVE.
- From the left ventricle oxygenated blood travels to AORTA and into BRANCHIAL ARTERIES.
- From branchial arteries blood travels to the upper limbs and also reach the head and brain through CAROTID ARTERIES.
- Blood gets deoxygenated in those regions and travels to SUPERIOR VENA CAVA. From the head through JUGULAR VEINS and from upper limbs through CEPHALIC veins.
- From the superior vena cava blood drains back to the heart into the RIGHT ATRIUM and into the RIGHT VENTRICLE through TRICUSPID VALVE.
Describe lower body circulation
- From the LEFT VENTRICLE, oxygenated blood travels to AORTA and into the LIVER through HEPATIC ARTERY.
- In the liver blood gets deoxygenated and drains back into the RIGHT ATRIUM of the HEART through HEPATIC VEINS AND THEN INFERIOR VENA CAVA.
- From the aorta, oxygenated blood also travels to GASTROINTESTINAL TRACT through MESENTERIC ARTERY, there it gets deoxygenated and also mixed will nutrients and molecules from the intestine and drain to the LIVER through HEPATIC PORTAL VEIN where it gets filtered from any pathogens before returning to INFERIOR VENA CAVA and HEART through HEPATIC VEIN.
- From AORTA blood also travels to KIDNEYS through RENAL ARTERIES where it gets deoxygenated and travels back to the HEART through RENAL VEINS and INFERIOR VENA CAVA.
- Lastly, blood also reach lower limbs through AORTA and FEMORAL ARTERIES where it gets deoxygenated and travels back to the RIGHT ATRIUM of the heart through FEMORAL VEINS and inferior vena cava.
Myocardial ischemia
Partial or complete obstruction of the blood flow in coronary arteries.
Coronary circulation. Definition, components and their functions
DEFINITION - blood circulation in the blood vessels of the heart muscle (myocardium)
Coronary arteries - bring oxygenated blood to the myocardium. The right and left coronary arteries branch from the Aorta.
Coronary veins - remove deoxygenated blood from the myocardium. Deliver blood to the Coronary sinus and back to the Right Atrium of the heart.
Systemic and pulmonary circulation meaning
Systemic describes blood circulation from the heart and around the body and pulmonary circulation describes deoxygenated blood circulation between the heart and the lungs.
Vascular system. Definition and its components
Network of blood vessels which transport blood around the body.
comprises of:
- Arteries - bring oxygenated blood to the tissues (except pulmonary arteries)
- Arterioles
- Veins - take deoxygenated blood back to the heart and lungs (except pulmonary vein)
- Venules
- Capillaries - small vessels connecting arteries and veins
Structure and function of arteries and arterioles
- Have elastic fibres allowing withstand high pressures
- Have abundant smooth muscle cells allowing a change in diameter and thus altering blood flow
- Sympathetic neurones innervate muscle cells - heightened SNS activity generally cause vasoconstriction
- Arterioles play a key role in blood flow regulation from arteries to capillary beds. Vasoconstriction increase vascular resistance - increase BP. Vasodilation decrease vascular resistance - decrease BP. Pre-capillary spinners monitor blood flow into capillary beds.
Structure and function of veins and venules
- Relatively low smooth muscle and elastic fibres
- many veins have valves (especially lower limbs) to prevent backflow
- contain pleated collagen fibres in the vessel walls what allow for expansion thus great capacity of storing blood
Structure and function of capillaries
Are the site of the exchange of materials between blood and tissue fluids.
- have one layer of endothelial cells - perfectly suited to be exchange vessels.
- contain no smooth muscle fibres
- capillary beds are under the control of arterioles and precapillary sphincters.
Capillary exchange - what forces cause movement of the substances between blood and tissue fluids?
simple diffusion is the mechanism of exchange
Two forces govern the flow of the fluids:
- blood hydrostatic pressure pushes fluid out of capillaries
- blood Colloid Osmotic pressure (caused by plasma protein) - tend to pull fluid from interstitial spaces into capillaries.
