biology Flashcards
what is the formula for cardiac output
heart rate X stroke volume
what are the 4 chambers of the heart
right atrium
left atrium
right ventricle
left ventricle
what is the name of the valve on the right side of the heart
tricuspid valve
what is the name of the valve of the left side of the heart
bicuspid valve
what is the function of the SAN node
hearts pacemaker, responsible for the regular contraction of the heart muscle
what is the function of the vena cava
carries deoxygenated blood from the upper and lower parts of the body.
what is the function of the right pulmonary artery
carries deoxygenated blood to right lung
what is the function of the aorta
carries oxygenated blood to the body
what is the function of the left pulmonary artery
carries deoxygenated blood to left lung
what is the function of the semilunar valve
prevent backward flow of blood
what is the function of the bundle of his
transmits impulses from the AV node to the ventricles
what is the structure of the arteries
- relatively thick wall
- smooth muscle
- elastic fibres
- lined with a smooth layer of endothelial cells
- narrow lumen
what is the structure of the capillaries
- very thin wall (one cell thick)
- small lumen
what is the structure of the veins
- relatively thin wall
- very little smooth muscle and elastic fibres
- wide lumen
- valves
what is the function of the arteries
- withstand high blood pressure
- allow walls to stretch and recoil to smooth blood flow
- low friction surface to ease blood flow
what is the function of the veins
- blood under low pressure
- no stretching and recoiling
- acts as a blood reservoir due to the large volume
- valves stop backflow, ensuring a one-way flow of blood toward the heart
what is the function of the capillaries
- allows rapid exchange between blood and tissues
- links arteries and veins
what is an antigen
protein on the surface of every cell membrane
what is an antibody
attaches itself to the antigen to make the bacteria inactive
what antibody can group A have
antibody b
what antigen can group A have
antigen A
what antibody can group B have
antibody A
what antigen can group B have
antigen B
what antibody can group AB have
none, its a universal recipient
what antigen does group AB have
antigen A and B
what antibody can group O have
antibody A and B
what antigen can group O have
none, its a universal donor
what is the cardiac cycle
- blood fills the atrium via gravity
- right and left atria contract together
- blood leaves the atrium
- atrial kick happens to push blood into the ventricle
- blood moves into the ventricles
- AV valves close
- ventricular pressure rises
- volume rises
- pockets fill with blood
- as the ventricles finish contracting the ventricular rises above the pressure in the aorta and pulmonary artery
- apex contracts and semi lumar valve opens
- blood passes from ventricles into the semi lumar valve
what is systole
period of ventricular/ atrial contraction
what is diastole
period of ventricular/ atrial relaxation
what is a P wave
activation of the atria
what is the QRS complex
activation of ventricle
what happens between the P-R waves
delay in excitation from the SA node to the AV node
what is a T wave
shows diastole
what is tachycardia
fast heartbeat
what is brochycardia
slow heartbeat
what is sinus arrhythmia
irregular heartbeat
what happens in the contraction of the heart
- Contraction is initiated by the SAN, which sends out a wave of contraction around the walls of the atria. this causes the atria to contract together, pushing blood into the ventricles
- Waves of contraction cant pass into the ventricles because there is a barrier of insulating tissue separating the atria and the ventricles; instead, the AV node passes the wave of contraction into the ventricles. The AV node is a slow conducting bridge through the insulating tissue. it carries the contraction into the ventricles but does it slowly, so there is time for the ventricles to fill before it contracts
- The AV node is connected to the Purkinje fibres (through the bundle of his), the fibres are fast conducting and lead the contraction to the bottom of the ventricles. This means that the ventricles contract bottom-upwards, ensuring that all the blood is forced out into the circulation.
