Cardiovascular system Flashcards
(54 cards)
What are the 5 functions of the cardiovascular system?
- delivery of O2 and nutrients to each cell
- removal of CO2 and waste products from each cell
- communication between organs through transport of hormones and other extracellular mediators
- temperature regulation
- crucial hydrodynamic device in sexual reproduction
What is the compositition of plasma?
water, ions, proteins, nutrients, hormones, metabolic wastes, gases
What are arteries formed of?
a large lumen
thick layer of smooth muscle
What are arterioles formed of?
small lumen
thin muscular wall
What are capillaries formed of?
single layer of epithelial cells which allow exchange of nutrients, oxygen and wastes
What are veins and venules formed of?
thin walls
large lumen
valves
How is venous blood moved?
assisted by skeletal muscle?
What are the types and locations of valves in the heart?
Pulmonary semilunar
Aortic semilunar
Right AV tricuspid
Left AV bicuspid
What is coronary arterial disease?
- insufficient blood flow (ischemia) is associated with chest pains (angina) often radiating down left arm
- severe blockage leads to damage (death) of the heart region and myocardial infarction or heart attack
- ventricular fibrillation and death (heart attack)
What causes coronary arterial disease?
- Atherosclerosis (thickening of the coronary arteries)
- Blood clot (coronary thrombosis)
- Drugs
- Surgery
What is meningitis?
An infection in the CSF, increaed pressure in the brain and can causes seizures and loss of consciousness)
What is the Cerebral spinal fluid?
- CSF cushions the brain against damage (brain is floating in CSF)
- CSF produced in specialised epithelial cell called choroid plexus (500ml/day)
- Circulation around brain and spinal cord driven by changes in circulation, respiratory and posture
- Passes into vein via valves at the top of the skull (arachnoid villus)
What is an osmole?
One osmole (osm) = 1 mole (6.02 x 1023 ) of solute particles in 1L
Osmolarity is independent of molecular weight
What is osmotic pressure?
pressure required to prevent osmosis
What is colloid osmotic pressure ?
pressure exerted by the higher levels of protein in the plasma compared with the interstitial fluid
draws water back into plasma by osmosis (absorption)
What is hydrostatic pressure?
The force exerted by the blood on capillary walls, drives blood from plasma into interstitial space
What is capillary net filtration pressure
(Pc + πif) – (Pif + πc)
P - hydrostatic pressure
π - Osmotic pressure
c - capillary
if - intertitial fluid
What is the difference in pressure between the arterial and venous end?
Arterial - net outward filtration, hydrostatic pressure dominates
Venous - net inward filtratio , colloid osmotic pressure dominates
What are the functions of the lymphatic system?
- Draining fluid from the tissues and returning to the cardiovascular system
- Maintenance of the immune response
How does the lymphatic system drain fluid?
Fluid (plasma) passes (8l/day) from blood into the interstitial area (surrounds cells in the tissues)
Collects fats from the intestines/liver and deposits into veins
Excess fluid passes into lymph capillaries, through lymph nodes (detection of infection) before passing back to blood stream at the neck (largest is thoracic duct that drains into subclavian vein)
Lymph vessels contain valves and fluid is forced along by action of muscles and breathing (respiration). Larger lymph vessels are surrounded by smooth muscle that contract spontaneously and driven by pacemaker cells (~ heart)
How does the lyphatic system aid immunity?
Lymph fluid contains white immune blood cells (lymphocytes, macrophages, dendritic cells)
Collects antigens (proteins produced by pathogens)
Antigens recognised by B-lymphocytes in lymph nodes leading to activation of immunity.
B-cell proliferate to produce antibodies. Lymph nodes also contain multiple other immune cells (swelling can occur)
Increased capillary pressure caused by
heart failure
Decrease in colloid osmotic pressure caused by
Reduction in plasma proteins
Blockage of lymph nodes caused by
cancer, infections, surgery
