Bio - 9.1, 9.2, 9.3, 9.4 Flashcards
circulatory system - definition
a system of blood vessels with a pump & valves to ensure one way flow in blood
valves - definition
structures that the blood to flow in 1 direction
oxygenated blood
- blood in the left-handed side of the heart
- come from the lungs
- contains oxygen (picked up from capillaries)
- red
deoxygenated blood
- oxygen is taken up by cells that need it for RESPIRATION
- blood brought back to right-hand side of the heart
- travels to the lungs to get oxygen
double circulatory - definition
a system in which blood passes through the heart TWICE in one complete circuit of the body
(eg.) mammals / birds / reptiles
single circulatory - definition
a system in which where blood passes through the heart only once in a complete circuit
(e.g) fish - heart => gills => body => heart
double circulatory system - advantages
- higher pressure (faster delivery of oxygen & nutrients to body cells)
- efficient oxygenation (passes through twice)
process of blood
body => vena cava => right atrium => R.A contract => atrioventricular valve opens => right ventricle => RV contract => semilunar valve opens => LUNGS => left atrium => L.A contract => atrioventricular valve opens => left ventricle => L.V contracts => semilunar valve opens => aorta => body
difference in muscle wall thickness - ventricles
- right is thinner than left ventricle
- right.V pumps to lung
- left.V pumps to body
- left has thicker
septum - definition
- to separate the left and right side of the heart
atrioventricular valve
- between atria and ventricular
- ensures blood flows in correct direction
- flaps
- inside the heart
(eg.) tricuspid valve => between R.A and R.V
(eg.) biscuspid = >between L.A and L.V
semiventricular valves
- between ventricles & arteries
- prevent backflow from arteries to ventricle after blood is pumped out
- pocket-like cusps
- to outside the heart
(eg.) pulmonary valve => R.V to pulmonary artery
(eg.) aortic valve => L.V to aorta
coronary arteries
- vessels that supplies heart with nutrients and oxygen
coronary artery disease (CHD) - causes
- smoking
- high cholesterol
- lack of exercise
coronary artery disease (CHD)- prevention
- exercise
- avoid saturated fats
coronary artery disease (CHD) - treatment (medication / surgery)
medication
- statin (lower blood pressure)
- aspirin (reduces blood clot)
surgery
- coronary bypass
- angioplasty
- stent
coronary heart disease (CHD) - process
cholesterol deposits from plaque => makes artery narrower & walls stiffer => increases blood pressure => blood clot forms (thrombosis) => some breaks away and blocks smaller blood vessels
heart beats per min
60 - 75 beats
how to measure pulse - surface of skin
- big tendons in neck
- inside wrist
how to measure pulse - hospital
- ECG (electrocardiograph)
- little electrodes are stuck onto the person’s body
- recorded in a graph
pulse - definition
relaxation and expansion of an artery
artery - purpose
- heart to rest of body
- carries oxygenated blood
- flows AWAY from the heart
- pulses thru doesn’t flow smoothly
artery - features
- small lumen
- thick elastic walls (pulses)
- thick muscles walls
- no valves (pressure produced pushes it forward)
veins - purpose
- low pressure
- rest of body to heart
- carries deoxygenated blood
- carries blood TOWARDS heart
veins - features
- large lumen
- thin walls
- thin, elastic muscle wall
- valves (prevent backflow)
3 types of blood vessels
- artery
- vein
- capillary
capillary - purpose
- connects arteries and veins
- carries both oxygenated and deoxygenated blood
- reaches every cell
capillaries - features
- one cell thick (diffision)
- large surface area
- no valves
- small lumen
sizes - artery, veins
- arteriole => artery => aorta
- venule => vein => vena cava
why arteries need to be thicker than veins
- stretch and recoil = maintains smooth blood flow
- withstand high pressure
- helps blood push forward
2 blood vessels in liver
- hepatic artery
- hepatic vein
hepatic artery
- carries oxygenated blood to the liver from the aorta
- from heart
- heart (aorta) => liver
hepatic vein
- carries deoxygenated blood away from the liver to the vena cava
- from digestive system (liver can process food)
- liver => heart (vena cava)
how liver differs from other organs - blood supply
- dual blood supply (hepatic artery and hepatic vein)
- liver processes nutrients & detoxifies blood before it goes to the rest of the body.
3 types of blood
- red blood cell (RBC) = erythrocyte
- white blood cell = leucocyte
- platelet = thrombocyte
red blood cell (RBC)
- contains haemoglobin (oxygen)
- is a protein and contains iron
- no nucleus (carry more haemoglobin)
- circular biconcave shape (more S.A)
- tiny enough for capillaries
white blood cells (WBC)
- fights pathogens & clears dead body cells
- has nucleus
- 2 types = phagocytes & lymphocytes
platelets
- small fragments of cells
- no nucleus
- made in red bone marrow
- blood clotting : provides a barrier against the entry of bacteria and viruses
lobed nucleus - WBC
- multi-lobed (2-5 lobes)
- high flexible = can squeeze through capillaries
- phagocytosis = engulfs & digests pathogens
non-lobed nucleus - WBC
- round or slightly oval
- produce antibodies & coordinated immune response
plasma
- pale yellow liquid
- liquid part of blood
- ## transport hormones (eg. adrenaline)
