B3.2 Heart and Circulation

#1

right Atrium

#3

Left Atrium

#2

Right Ventricle

#4

Left Ventricle

E

septum

#5

pulmonary artery

#9

pulmonary veins

#6

aorta

A

AV tricuspid valve

D

AV Bicuspid/mitral valve

B

SL pulmonary valve

C

SL aortic valve

What is this?

Artery

What is this?

vein

What is this?

capillary

Artery Structure + Function

carry blood AWAY from the heart to organs and tissues, can with stand high blood pressure.

thick wall, thick muscle, narrow lumen (helps keep high bp)

vein structure + Function

carry blood TO the heart from organs and tissues, lower blood pressure.

thin wall, less muscle, wider lumen (allows for blood flow). (needs compression)

capillaries structure + function

connects arteries to veins, to exchange materials between blood and cells (through diffusion) (extra: Microscopic blood vessels that permit nutrient and gas exchange)

large surface area, narrow branches, narrow/thin lumen

Systemic circulation

(The part of the circulatory system that carries oxygenated blood away from the heart to the body and returns deoxygenated blood back to the heart.) It begins at the left ventricle to the body and ends at the right atrium, starts oxygen rich to oxygen poor.

pulmonary circulation

(The part of the circulatory system that carries deoxygenated blood from the heart to the lungs and returns oxygenated blood back to the heart.) It begins at the right ventricle and ends at the left atrium. starts oxygen poor (goes to lungs) to oxygen rich

What does blood contain/carry?

Blood contains red blood cells, white blood cells, platelets, and plasma. It carries oxygen, nutrients, hormones, carbon dioxide, and waste products throughout the body.

myogenic

does not depend on central nervous system or brain to stimulate activity

systolic

contraction of heart muscle

diastolic

relaxation of heart muscle

SA node

initiates stimulus to cause contraction. Action Potential from ( ) causes ventricle to enter systole

Pulse

caused by beating of heart. can feel beat because of contraction pushing blood out

fenestration

small pores in capillaries that allow fluid to pass

lymph fluid/vessel

tissue fluid that does not directly re-enter blood, is taken up by lymph ducts

What is a important component of the cardiac cycle?

pressure

Cardiac cycle order? (4)

1. atrial diastole

2. atrial systole

3. ventricle systole

4. ventricular diastole

atrial diastole

(The phase of the cardiac cycle where the atria relax and fill with blood from the veins, allowing pressure to decrease in the atria before contraction.)

• atria relaxed AV valve opens

• blood enters atrium from (vena cava or pul. veins)

• (SA node fires (Action Potential causes atrium to enter systole) )

atrial systole

(The phase of the cardiac cycle where the atria contract to push blood into the ventricles, increasing atrial pressure and closing the AV valves.)

• atria contract

• blood enters ventricle (from atrium)

• (AV node fires

• impulse travels through AV bundle and into purkinje fibers

• receives impulse to contract from purkinje fibers)

ventricle systole

(The phase of the cardiac cycle where the ventricles contract to pump blood out of the heart, increasing ventricular pressure and closing the AV valves.)

• ventricles contract = pressure increase

• AV valves close (1st sound)

• higher pressure in ventricle than atrium = SL valves open

• blood moves in aorta or pulmonary artery

ventricular diastole

(The phase of the cardiac cycle where the ventricles relax and fill with blood from the atria, decreasing pressure in the ventricles before the next contraction.)

• ventricle enters diastole

• pressure decreases

• higher pressure in aorta/ pul. artery than ventricle

• SL valves open (2nd sound)

• when pressure decreases in atrium AV valves open

Atherosclerosis

hardening and narrowing of arteries due to build up of cholesterol, triglycerides, and other substances on artery walls

• coronary arteries occluded (blocked) = death of heart tissue/ heart attack

• inner lining of artery damaged because of increase blood pressure

• macrophages= fibrous tissue growth- consume cholesterol = form plaque = block = clot

Atherosclerosis uncontrollable risk factors

• genetics

• age (older)

• gender (males more likely)

Atherosclerosis controllable risk factors

• obesity

• physical inactivity

• smoking

• diet

Explain release of tissue fluid in capillaries

blood leaves artery (high pressure) and enters capillary. increase blood pressure filters blood plasma through the gaps in capillaries forming tissue fluid

Explain reuptake of tissue fluid in capillaries

blood pressure decrease as blood moves along capillary plasma proteins decrease the osmotic potential of blood. most tissue fluid returns to the blood by osmosis due to oncotic pressure (is higher than hydrostatic pressure)

contrast circulation of Bony fish to mammals

Bony Fish:

• single circulatory system (2 chambers)

• ventricle pumps blood to gills

• oxygen and carbon dioxide exchanged as blood passes through capillaries in the gills

• oxygenated blood leaves gills and transports to tissues

• deoxygenated blood returns to heart

Mammals:

• double circulatory system (4 chambers)

• right side of heart pumping blood to lungs

• oxygen and carbon dioxide exchanged as blood passes through capillaries in the lungs

• oxygenated blood returns to left side of heart and pumped to body

• deoxygenated blood returns to right side of heart