we live in a society Flashcards
revise
What is the function of the kidney?
The kidneys remove urea from the bloodstream by ultrafiltration.
what is the function of the arteries?
Withstand high blood pressure. Alter diameter of lumen to vary blood flow. Allow walls to stretch when blood is pumped into the artery and then recoil, smoothing blood flow. low friction surface to ease blood flow,
what is the function of capillaries?
allow rapid exchange between blood and tissues. link arteries and veins.
what is the function of the veins?
blood under low pressure. no pulse of blood so no stretching and recoiling. large volume acts as blood reservoir. valves stop backflow, ensuring a one-way flow of blood toward the heart.
What is the structure of the arteries?
relatively thick wall. smooth muscles. elastic fibres. lined with smooth layer of endothelial cells. narrow lumen.
what is the structure of capillaries?
very thin wall (one cell thick). small lumen.
what is the structure of the veins?
relatively thin wall. very little smooth muscle or elastic fibres. wide lumen. valves
What happens in the process of inhalation?
Intercostal muscles contract. ribs are raised up and out. diaphragm contracts. volume of thorax increases. pleural membrane hold lungs to wall. volume of thoracic cavity and therefore lungs increase. pressure in lungs decreases.compared to outside. Air moves in.
What is surfactant?
It lowers surface tension, keeps alveoli ‘open’ and prevents collapse.
What is ultrafiltration?
Ultrafiltration is the process when fluid from the blood filtrates through the glomerulus.
What is needed for an efficient exchange surface?
Large surface area of alveoli, numerous capillaries around the alveoli, thin walls of alveoli and capillaries, moist surface, surfactant and a concentration gradient.
State 2 ways in which the cell in the pct is adapted to reabsorb glucose.
Has mitochondria to provide energy using ATP. They have villi for increased surface area.
When breathing in what happens to the diaphragm and the external intercostal muscles?
The diaphragm and external intercostal muscle both contract.
What is the function of the atrioventricular node?
Slow down the electrical impulse.
What is the function of the sinoatrial node?
Generate electrical impulses
Which valves prevent blood from travelling back into the atria from the ventricles?
atrioventricular.
Which antibodies are present in a person with A blood?
B
Which individuals can receive O+ blood?
A+ blood type
B+ blood type
AB+ blood type
O+ blood type
At what stage in the cardiac cycle are the ventricles passively filling?
cardiac diastole
what are the steps involved in inhalation?
Ribs move up and out.
Diaphragm moves down.
Thoracic cavity volume increases.
describe how mechanical ventilators work
Positive pressure from the ventilator forces air into the lungs.
what is the definition of tidal volume?
normal breathing volume
what is Residual volume?
Air that is in the lungs after you have fully breathed out