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Bio 121 > Circulation > Flashcards

Flashcards in Circulation Deck (41):
1

Gastrovascular cavities

Digestion and distribution of substances throughout the body
Simple animals such as cnidarians

2

Circulatory system components

Circulatory fluid (blood)
Tubes (blood vessels)
Muscular pump (heart)

3

Open circulatory system

Insects, arthropods, most molluscs
Blood bathes organs directly
Valves keep hemolymph going in right direction
Advantage: all cells are directly exposed to hemolymph

4

Hemolymph

Exchange fluid in open circulatory system

5

Closed circulatory system

Blood is confined to vessels and is distinct from interstitial fluid
More efficient at transporting circulatory fluids to tissues and cells
Advantage: concentrate blood in specific areas- move particles more efficiently

6

Interstitial fluid

Completes exchange between blood and cells

7

Cardiovascular system

Vertebrate closed circulatory system
Blood vessels and 2-4 chambered heart

8

Arteries

Carry blood to capillaries away from heart

9

Veins

Return blood from capillaries to heart

10

Capillaries

Most direct contact with cells
Exchange of substances between blood and interstitial fluid

11

Double circulation

2 trips to heart before going to rest of body
Pulmonary circuit and systemic circuit (rest of body)

12

Ventricle

Pumps blood out of heart

13

Atrium

Pumps blood into heart

14

Fish circulatory system

2 chambered heart: 1 ventricle and 1 atrium
Single circulation
Ventricle -> artery -> gill capillaries -> systemic capillaries -> vein -> atrium

15

Amphibian circulatory system

3 chambered heart: 2 atria and 1 ventricle
Double circulation
Pulmocutaneous: breathe through skin
Ventricle pumps blood into forked artery- splits ventricle's output into pulmocutaneous circuit (oxygen-poor blood) and systemic circuit (oxygen-rich blood)

16

Reptile circulatory system

Double circulation
Turtles, snakes, and lizards: 3 chambered heart
Extra vessel from ventricle: bypass lungs, allowing animal to swim for prolonged periods of time

17

Mammalian and avian circulatory system

Ventricle is completely divided into separate right and left chambers
Left side of heart pumps and receives only oxygen-rich blood
Right side of heart pumps and receives only oxygen-poor blood

18

4-chambered heart and endothermic lifestyle

Increased oxygen input- needed for oxidative phosphorylation (O2 is final electron receptor in electron chain)

19

Mammalian circulatory pathway

Right ventricle -> pulmonary artery -> lung capillaries (diffusion of oxygen) -> pulmonary vein -> left atrium -> left ventricle -> aorta -> systemic capillaries -> vena cava -> right atrium

20

Atrioventricular valves

Separate atria from ventricles

21

Semilunar valves

Separate ventricles from arteries

22

Systole

Pumping or contraction phase of cardiac cycle

23

Diastole

Relaxation or filling phase of cardiac cycle

24

Cardiac cycle

1. Atrial and ventricular diastole: AV valves open, semilunar valves closed
2. Atrial systole and ventricular diastole
3. Atrial diastole and ventricular systole: AV valves closed, semilunar valves open

25

Self-excitable

Some cardiac muscle cells
Contract without any signal from the nervous system

26

Sinoatrial (SA) node

Pacemaker: sets rate and timing for cardiac muscle cell contraction
Influenced by nerves, hormones, body temperature, and exercise

27

Heartbeat

1. SA node generates wave of signals to contract
2. Signals are delayed at AV node
3. Signals pass to heart apex and then Purkinje fibers
4. Ventricles contract

28

Heart sounds

AV valve recoil: "lub"
Semilunar valve recoil: "dub"

29

Electrocardiogram (EKG)

Displays electric impulses that travel through the cardiac cycle

30

Blood vessels

Infrastructure of circulatory system
Cavity: central lumen
Valve in veinous lumen: prevent backflow
3 layers (inside to outside): Epithelium (endothelium), smooth muscle, connective tissue

31

Skeletal muscle

Aids in veinous blood flow

32

Velocity of blood flow

Varies in the circulatory system
Slowest in capillaries: high resistance and large cross-sectional area to allow diffusion

33

Blood pressure

Hydrostatic pressure that blood exerts against the wall of a vessel

34

Systolic pressure

Pressure in arteries during ventricular systole
Highest pressure in arteries

35

Diastolic pressure

Pressure in arteries during diastole
Lower than systolic pressure

36

Measuring blood pressure

Cuff puts pressure against an artery (almost cutting off blood flow): measure systolic
Slowly release pressure: measure diastolic

37

Distribution of blood in capillary beds

Contraction of smooth muscle layer in wall of arteriole (small branch of artery) constricts vessel
Precapillary sphincters control the flow of blood between arterioles and venules: open- blood flow into capillaries, closed- blood flow only between arterioles and venules

38

Atherosclerosis

Buildup of cholesterol within arteries

39

Hypertension

High blood pressure
Promotes atherosclerosis and increases risk of heart attack or stroke

40

Heart attack

Death of cardiac muscle resulting from blockage of one or more coronary arteries

41

Stroke

Death of nervous tissue in the brain
Usually results from rupture or blockage of arteries in head