chapter 7

Question 1

components of circulatory system

Answer 1

heart, blood vessels, blood❤️

Question 2

functions of blood (8)

Answer 2

1. transport nutrients and oxygen to cell
2. transport co2 and wastes away from cell
3. transport hormones to cells
4. regulate pH
5. thermoregulation
6. protect against disease (WBC)🦠
7. clotting to prevent blood loss
8. maintain water and ion content in bodily fluids 💦

Question 3

components of blood

Answer 3

liquid: palms 55%

non-liquid: formed elements 45% (cells and cell fragments)

Question 4

erythrocytes

Answer 4

RBC
suited for o2 and co2 transport
have HGB (protein) and has no nucleus to make room for it ( when combine with o2, HGB is red)
large SA to V to speed up gas exchange
made in bone marrow, destroyed in liver/spleen by macrophages (120 days)😩
small, 8um and flexible to go through narrow capillaries

Question 5

leucocytes

Answer 5

fight infections/provide immune responses
granulocytes: granular cytoplasm, lobed nucleus
agranular: lymphocytes and monocytes
macrophage is type of monocyte- phagocytic
few minutes to YEARS!!
get rid of dead or injured cells 😭(RIP) and invading microorganisms 🦠

Question 6

thrombocytes

Answer 6

small cell fragments with no nucleus😔
1/3 of RBC🖕👌
made in bone marrow life span of a week
important in coagulation

Question 7

plasma

Answer 7

91% water
rest is dissolved substances
glucose, AA, ions, wastes (urea: waste of protein metabolism), gases

Question 8

oxygen transport x2

Answer 8

3% dissolved in plasma
97% carried in HGB to make oxyhemoglobin
this bond is v loose to breaks down easily to release oxygen
when o2 conc is high (capillaries in lungs), o2 combines with HGB easily
when o2 conc is low (cells) oxyhemoglobin breaks down

Question 9

Oxygenated

Answer 9

lots of oxyhemoglobin

Question 10

Deoxygenated

Answer 10

only haemoglobin

Question 11

co2 transport x3

Answer 11

8% dissolved in blood plasma
22% combines with HGB to form carbaminohaemoglobin
70% carried in plasma as bicarbonate ions (HCO3-) (H+)
co2 diffuse into plasma because of con grad, most of it reacts with water to from carbonic acid. this then dissociates into hydrogen ions and bicarbonate ions
in lungs:
8% diffuses out
22% breakdown then diffuse
70% ions recombine to carbonic acid then breaks down by enzymes to water and co2, then diffusion

Question 12

how are nutrients and waste transported

Answer 12

all dissolved in blood plasm

inorganic: ions

Question 13

low thrombocytes=
low erythrocytes=
high leucocytes=

Answer 13

Haemophilia
Anaemia
Infection

Question 14

arteries

Answer 14

carry blood away from the heart
carry oxygenated blood
have thick, smooth, muscular walls with elastic fibres
no valves
high pressure blood because it is closer the heart, increase as ventricles contact
further down in skin because it contains high pressure blood

Question 15

veins

Answer 15

carry blood toward the heart
carry deoxygenated blood
thin, relatively inelastic (pressure is constant) walls with little muscle
have valves
blood is under low pressure because most of the pressure is lost as it flows through the tiny capillaries

Question 16

Capillaries

Answer 16

Microscopic
connects veins and arteries
network
1 cell thick: thin for easy diffusion of nutrients and wastes

Question 17

arterioles (vaso)

Answer 17

smooth muscle and elastic fibres (stretch and recoil)
Vasoconstriction: contraction to reduce the lume (inside space) size/diameter of artery to reduce blood flow to an area. reduce loss of body heat in cold temperatures, arteries constrict to let less blood go to the skin and more in the core region.
vasodilation: relaxing to increase lumen size, increase blood flow to an organ.In the heat, blood vessels close to the surface of the skin enlarge. This process is called vasodilation . This allows more heat to be lost from the blood.

adrenaline causes vasoconstriction in most arterioles, but vasodilation in skeletal/cardiac muscle

Question 18

cardiac cycle

Answer 18

sequence of events that occur in one heart beat

Question 19

systole and diastole

Answer 19

systole: when heart muscles contract, pumping
diastole: when heart muscles relax, filling

artrial systole/ventricular diastole: atria contracts forcing blood into ventricles

ventricular systole/ atrial dyastole: atria relax and refill while ventricles contact which forces blood into arteries

Question 20

cardiac output

Answer 20

=stroke volume x heart beat

stoke volume= volume of blood forced from a ventricle each contraction
cardiac output= amount of blood leaving leaving a ventricle every minute

Question 21

sinoatrial node

Answer 21

collection of nerve cells in the wall of the right atrium
pacemaker
starts each cardiac cycle by sending nervous impulses which cause the atria walls to contracts, nerve impulses reach the atrioventricular node causing ventricles to contract-> frequency of this is called heart rate

Question 22

Vasodilation and exercise

Answer 22

when you exercise, large increase in blood flow Is needed to supply oxygen and nutrients and remove carbon dioxide and heat
vasodilation of blood vessels in muscles and contraction to blood vessels
started by anticipatory response from nervous system
continued because wastes (CO2, lactic acid, heat) all act as vasodilators

Question 23

pulmonary circulation

systematic circulation

Answer 23

blood going to lungs and back to heart
blood going to there parts of the body and back
as blood asses through heart twice ->double circulation

Question 24

antigen

Answer 24

protein molecules of the surface of erythrocytes that determine blood type
capable of stimulating formation of antibodies

Question 25

antibodies

Answer 25

molecules in plasm that remove foreign bodies (pathogens)
leucocytes then engulf and destroy inactivated pathogens
specific to each pathogen

Question 26

Rhesus factor

Answer 26

a further antigen on erythrocyte surface
rh- doesn’t have antigen and makes antibodies that destroy the Rhesus factor
rh+ person has the antigen that makes no antibodies that destroy the Rhesus factor

Question 27

if the wrong blood type is given…

Answer 27

antibodies in plasma combine with antigens on the surface of foreign blood
Agglutination occurs (clumping of cells)

Question 28

types of blood transfusions x7

Answer 28

whole blood: blood taken with anti-clotting agent added (eliminates disease risk)

Autologous: patienst own blood used that was collected before surgery

red cell concentrate: blood centrifuged and only erythrocytes taken (anaemic/heart disease)

plamsa: used to provide extra clotting factors in severe bleeding and liver disease
platelets: when platelets are too low

Cryoprecipitate: plasma frozen and slowly thawed. contains many clotting factors and used for haemophiliacs

Immunoglobulins: group of proteins acting as antibodies extracted from blood of people that are immune to a particular disease.

Question 29

blood clotting and defence

Answer 29

1. injury to lining of a blood vessels expose collagen fibres to the blood. platelets stick to the collagen fibres.
2. platelets releases chemicals that make the surrounding platelets sticky
3. platelets clump together. they form an emergency protection against blood loss
4. a fibrin cloth reinforces the seal. the clot traps blood cells and eventually dries to form a scab, acts as a mechanical barrier to the entry of pathogens.

after clot is formed, clot retraction occurs(threads contract, pulling damaged blood vessel edges together,) as this occurs a fluid called serum is squeezed out. then scab formed

blood coagulates to prevent blood loss from injured tissue.

clotting factors catalyse the conversion of plasma protein to an active enzyme