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Flashcards in biology chapter 5 Deck (60)
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1

protozoans

movement of gases and nutrients is accomplished by simple diffusion within the cell

2

cnidarians

have body walls that are two cells thick. All cells are in direct contact with either the internal or external environments so there is no need for a specialized circulatory system

3

arthropods

have open circulatory sytems in which their blood-like fluid (interstitial fluid) is in direct contact with the body tissues. The fluid is circulated primarily by body movements. Fluid flows through a dorsal vessel and into spaces called sinuses where exchange occurs

4

annelids

use a closed circulatory system to deliver materials to cells that are not in direct contact with the external environment

5

aorta

which branches into a series of arteries

6

capillaries

converge into venules, and eventually into veins, leading deoxygenated blood back toward the heart

7

right side of heart

pumps deoxygenated blood into pulmonary circulation (toward the lungs)

8

left side of heart

pumps oxygenated blood into systemic circulation (throughout the body)

9

atria

two upper chambers. Thin walled

10

ventricles

two lower chambers. Are extremely muscular

11

left ventricle

more muscular than the right ventricle because it is responsible for generating the force that propels systemic circulation and because it pumps against a higher resistance

12

atrioventricular valves

located between the atria and ventricles on both sides of the heart, prevent backflow of blood into the atria

13

tricuspid valve

the valve on the right side of the heart that has three cusps

14

mitral valve

valve on the left side of the heart that has two cusps

15

semilunar valves

have three cusps and are located between the left ventricle and the aorta (the aortic valve) and between the right ventricle and the pulmonary artery (the pulmonic valve)

16

heartbeat

made up by the systole and diastole

17

systole

is the period during which the ventricles contract

18

diastole

is the period of cardiac muscle relaxation during which blood drains into all four chambers

19

cardiac output

is defined as the total volume of blood the left ventricle pumps out per minute. = heart rate x stroke volume

20

heart rate

number of heartbeats per minute

21

stroke volume

volume of blood pumped out of the left ventricle per contraction

22

sinoatrial (SA) node

a small mass of specialized tissue located in the wall of the right atrium. It spreads impulses through both atria, stimulating them to contract simultaneously

23

autonomic nervous system

modifies the rate of heart contraction

24

arteries

are thick walled, muscular, elastic vessels that transport oxygenated blood away from the heart-- except for the pulmonary arteries, which transport deoxygenated blood from the heart to the lungs

25

veins

are relatively thinly walled, inelastic vessels that conduct deoxygenated blood towards the heart-- except for the pulmonary veins, which carry oxygenated blood from the lungs to the heart

26

capillaries

have very thin walls composed of a single layer of endothelial cells across which respiratory gases, nutrients, enzymes, hormones, and wastes can easily defuse. They have the smallest diameter of all three types of vessels; red blood cells must often travel through them single file

27

lymph nodes

are swellings along lymph vessels containing phagocytic cells (leukocytes) that filter the lymph, removing and destroying foreign particles and pathogens

28

plasma

is the liquid portion of the blood

29

erythrocytes (red blood cells)

are the oxygen carrying components of blood

30

oxyhemoglobin

when hemoglobin binds oxygen