[HCS] human circulatory system Flashcards
(30 cards)
what are the four primary functions of blood?
- transport medium for oxygen, carbon dioxide, nutrients and waste products
- provides protection against pathogens through white blood cells
- provides protection against blood loss through blood clotting
- regulates pH
what are the major components of blood, and their respective percentages?
plasma (55%)
red blood cells (45%)
white blood cells and platelets
what is the composition of plasma?
- approximately 90% water
- about 10% proteins (including antibodies, enzymes, dissolved substances such as salts, glucose, amino acids and waste products like carbon dioxide and urea)
what is the primary role of red blood cells?
red blood cells transport oxygen to other body cells
how does oxygenated blood differ from deoxygenated blood in terms of colour?
oxygenated blood: bright red
deoxygenated blood: dark red
what is the red colour of blood due to?
heme, a component of haemoglobin
what adaptations do red blood cells have for their function?
- biconcanve shape increases surface area to volume ratio, enhancing the rate of diffusion of oxygen
- absence of nucleus allows more space for haemoglobin
- haemoglobin combines reversible with oxygen
what are white blood cells?
white blood cells are immune cells
what are the key characteristics of white blood cells?
- they contain a nucleus
- the are capable of moving, changing shape and squeezing through narrow capillaries
what are the two types of white blood cells?
lymphocytes and phagocytes
what are the functions of lymphocytes and phagocytes?
lymphocytes - identify and neutralise pathogens
phagocytes - engulf pathogens
what are platelets?
they are membrane-bound fragments of cytoplasm from the bone marrow
what is the role of platelets?
they contain clotting factors and enzymes needed for blood clotting and are highly adhesive, sticking to damaged cell surfaces
describe the process of blood clotting
- platelets form a platelet plug at the wound site
- enzymatic reactions triggered by damaged tissue and platelets form a mesh, trapping blood cells and bacteria
- the clot solidifies into a scab, protecting underlying layers during cell regeneration
what are the four human blood groups?
A,B,AB,O
what are blood group O and AB considered as?
O- universal donor
AB- universal recipient
what are the main blood vessels?
artery, vein and capillary
what is the function of the artery?
it transports blood away from to heart
what is the function of the vein?
it transports blood towards the heart
what is the function of the capillary?`
it allows for the exchange of oxygen,carbon dioxide, nutrients and waste products between tissue fluid and blood by diffusion
what is the purpose of the thick, elastic and muscular wall of arteries?
to withstand the high pressure of blood flow
what is the role of valves in veins?
they prevent back flow of blood, helping push blood back to the heart, aided by the contraction of surrounding skeletal muscles
what is tissue fluid?
it is an intermediary between blood and body cells
what is the role of tissue fluid in nutrient exchange?
it allows material to diffuse from capillaries to cells and vice versa
- the materials include oxygen, nutrients, carbon dioxide and waste products
