circulatory system

Question 1

homeostasis

Answer 1

the body’s maintenance of a relatively stable internal physiological environment

Question 2

negative feedback loop

Answer 2

process that reverses deviation from normal body constant

sensory rececptors -> integrator -> effector

Question 3

positive feedback loop

Answer 3

exacerbates/perpetuates small disturbances

Question 4

veins

Answer 4

blood vessels that return blood to the heart
thinner, more elastic walls + larger lumens due to lower blood pressure
valves prevent the backflow of blood

Question 5

arteries

Answer 5

blood vessels that carry blood from the heart to body tissues
thicker, elastic walls due to higher blood pressure
made of connective, smooth muscle and epithelial tissues

Question 6

capillaries

Answer 6

blood vessels that connect arteries and veins

tiny, one cell thick walls to allow for gas exchange and diffusion

Question 7

the heart

Answer 7

driving force and pump of the circulatory system
4 chambers (right + left atrium, right + left ventricle)
septum prevents blood from mixing
aortic + pulmonary semilunar, tricuspid and biscupid valves

Question 8

pathway of blood

Answer 8

body tissues -> superior vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmonary semi-lunar valve -> pulmonary arties -> lungs -> pulmonary arterioles -> capillaries -> pulmonary venuoles -> pulmonary veins -> left atrium -> bicuspid valve -> left ventricle

Question 9

components of the blood

Answer 9

plasma
erythrocyte (rbc)
leukocyte (wbc)
platelets

Question 10

erythrocytes (rbc)

Answer 10

44% of blood volume
produced in bone marrow
life span 120 days
no nucleus
contains hemoglobin

Question 11

leukocytes (wbc)

Answer 11

1% of blood volume
produced in bone marrow (spleen, tonsils)
can double in volume during infection
nucleus

Question 12

macrophages

Answer 12

big eaters
lives a few days
phagocytic, can cross capillary walls
generalized response to infection

Question 13

lymphocytes

Answer 13

unknown life span
non-phagocytic
acquired, specific immune response

Question 14

systemic circulation

Answer 14

carries oxygenated blood to the body tissues and deoxygenated blood back

Question 15

pulmonary circulation

Answer 15

carries deoxygenated blood to the lungs and oxygenated blood back

Question 16

hypertension (high blood pressure)

Answer 16

condition caused by increased volume/rate of blood or reduced elasticity in the artery

symptom: nosebleeds
cause: diet high in salt
tx: diet lower in salt

Question 17

atherosclerosis

Answer 17

narrowing of arteries due to deposits of cholesterol-rich plaque on the innermost layer of the artery

symptom: heart attack
cause: HDL levels too low
tx: diet lower in saturated fats and higher in fruits and vegetables

Question 18

arteriosclerosis

Answer 18

narrowing of arteries due to deposits of cholesterol-rich plaque underneath the inner layer of the artery

symptom: stroke
cause: years of plaque build-up
tx: coronary bypass surgery

Question 19

stroke

Answer 19

an embolism reaches the brain, blocking the brain from receiving oxygenated blood, the brain cannot receive oxygen

symptom: drooping face (FAST)
cause: arteriosclerosis
tx: thrombolytic medication

Question 20

heart attack

Answer 20

the flow of oxygenated blood to the heart becomes blocked, heart cannot receive oxygen

symptom: pressure in arms, neck, jaw and back
cause: atherosclerosis
tx: aspirin

Question 21

how a heart beats

Answer 21

SA node sends signal
->right atrium fills with blood
AV node sends signal
->tri/biscupid valves open 
signal transfers to bundle of His
signal goes to purkinje fibres, to each side of the ventricle
->heart pumps
->bloods is moved out of the heart

Question 22

SA node

Answer 22

bundle of specialized muscle tissue that stimulates the muscle cells to contract and relax rhythmically by generating a signal that spreads across the heart

Question 23

AV node

Answer 23

bundle of specialized muscle tissue that receives the electrical signal and transmits them through the bundle of His

Question 24

bundle of His

Answer 24

bundle of specialized fibres that relays the electrical signal to the Purkinje fibres

Question 25

Purkinje fibres

Answer 25

2 branches of fibre bundles that receive the electrical signal and initiate contractions in ventricles