Circulatory

Question 1

Diffusion

Answer 1

Passive movement of molecules (like gases or nutrients) from high to low concentration; efficient only over short distances.

Question 2

Heart

Answer 2

Muscular organ that contracts to pump blood through the body.

Question 3

Open Circulatory

Answer 3

Blood (called hemolymph) is not confined entirely to vessels; it bathes organs directly in body cavities (e.g., insects, arthropods)

Question 4

Closed Circulatory

Answer 4

Blood is confined within vessels and seperated from interstitial fluid; more efficient transport (e.g. humans, vertebrates).

Question 5

Hemolymph

Answer 5

The fluid that acts as blood and intersitual fluid in intervertes with open circulation.

Question 6

Cardiovascular system

Answer 6

The organ system composed of the heart, blood, and blood vessels that transport substances throughout the body.

Question 7

Arteries

Answer 7

Thick, elastic blood vessels that carry blood away from the heart (usually oxygen-rich)

Question 8

Veins

Answer 8

Thinner-walled vessels that carry blood toward the heart (usually oxygen-poor)

Question 9

Capillary

Answer 9

Microscopic vessels that allow the exchanges gases, nutrients, and wastes between blood and tissues.

Question 10

Arterioles

Answer 10

Small branches of arteries that blood flow into capillary beds through smooth muscle contraction.

Question 11

Capillary beds

Answer 11

Networks of capillaries within tissues where exchange of materials occurs.

Question 12

Venules

Answer 12

Small veins that collect blood from capillary beds and lead to larger veins.

Question 13

Atria

Answer 13

the upper chambers of the beart that receive blood.

Question 14

Ventricles

Answer 14

the lower chambers that pump blood out of the heart

Question 15

Single Circulation

Answer 15

Blood passes through the heart once per full circuit (fish)

Question 16

Double Circulation

Answer 16

Blood passes through the heart twince per circuit, once for oxygenation, and another for systemic flow (mammals)

Question 17

Pulmocutaneous circuit

Answer 17

In amphibians - blood goes to the lungs and skin for gas exchange.

Question 18

Partially divided

Answer 18

seein in amphibians and reptiles; incomplete separation between oxygen-rich and oxygen-poor blood.

Question 19

Cardiac cycle

Answer 19

One complete heartbeat — includes contraction (systole) and relaxation (diastole).

Question 20

Systole

Answer 20

Contraction phase of the heart; blood is pumped out of the chambers.

Question 21

Diastole

Answer 21

Relaxation phase; heart fills with blood.

Question 22

Cardiac output

Answer 22

The total volume of blood pumped by each ventricle per minute (CO = Heart Rate × Stroke Volume).

Question 23

Heart rate

Answer 23

Number of beats per minute (bpm).

Question 24

Stroke volume

Answer 24

Amount of blood pumped by one ventricle in a single contraction.

Question 25

Atrioventricular valve

Answer 25

Between atria and ventricles; prevent backflow into the atria (right = tricuspid, left = bicuspid/mitral).

Question 26

Semilunar valve

Answer 26

Between ventricles and major arteries; prevent backflow into the ventricles (pulmonary and aortic valves).

Question 27

Heart murmur

Answer 27

Abnormal heart sound due to valve malfunction or turbulent blood flow.

Question 28

Auto rhythmic

Answer 28

Specialized cardiac muscle cells that generate and conduct their own electrical impulses.

Question 29

Sinoatrial node

Answer 29

The heart’s natural pacemaker; initiates each heartbeat and sets the rate.

Question 30

Electrocardiogram (EKG)

Answer 30

a recording of the heart's electrical activity through repeated cardiac cycles

Question 31

Endothelium

Answer 31

The thin inner lining of blood vessels that reduces friction and allows smooth blood flow.

Question 32

Blood Pressure

Answer 32

The force exerted by blood on vessel walls; determined by cardiac output and resistance.

Question 33

Systolic Pressure

Answer 33

Pressure in arteries during ventricular contraction.

Question 34

Diastolic Pressure

Answer 34

Pressure in arteries during ventricular relaxation.

Question 35

Lymphatic system

Answer 35

Network of vessels that returns excess interstitial fluid to the blood, helps in immune defense, and absorbs fats from the digestive system.

Question 36

Lymph nodes

Answer 36

Small structures that filter lymph and house immune cells (lymphocytes, macrophages).

Question 37

Edema

Answer 37

welling caused by excess fluid accumulation in tissues (often due to poor lymph drainage).

Question 38

Plasma

Answer 38

Liquid component of blood; mostly water, also contains nutrients, hormones, ions, and proteins.

Question 39

Blood composition

Answer 39

~55% plasma, ~45% cells (RBCs, WBCs, and platelets).

Question 40

WB cells

Answer 40

Defend the body against infection.

Question 41

RB cells

Answer 41

Carry oxygen using hemoglobin.

Question 42

Plaletes

Answer 42

Cell fragments that help in blood clotting.

Question 43

Hemoglobin

Answer 43

Iron-containing protein that binds oxygen in red blood cells.

Question 44

Sickle cell

Answer 44

Genetic disorder where RBCs become misshapen, reducing oxygen transport and causing blockages.

Question 45

Stem cells

Answer 45

Undifferentiated cells in bone marrow that produce all blood cell types.

Question 46

Hormone EPO

Answer 46

Produced by the kidneys; stimulates red blood cell production when oxygen levels are low.

Question 47

Atheroscloersis

Answer 47

Buildup of fatty plaques inside arteries, reducing blood flow.

Question 48

Heart-attack

Answer 48

Blockage of coronary arteries cutting off blood supply to heart muscle, causing tissue death.

Question 49

Stroke

Answer 49

Blockage or rupture of blood vessels in the brain, leading to brain cell damage.

Question 50

LDL

Answer 50

(low-density lipoprotein - “Bad” cholesterol — contributes to plaque buildup in arteries.)

Question 51

HDL

Answer 51

high-density) lipoprotein - “Good” cholesterol — removes cholesterol from blood vessels and carries it to the liver.

Question 52

Hypertension

Answer 52

Chronically high blood pressure; increases risk of heart attack, stroke, and kidney disease.