CHAPTER 34 CIRCULATORY AND GAS EXCHANGE

Question 1

diffusion

Answer 1

small nonpolar molecules such as O2 and CO2 move between cells and their immediate surroundings, only efficient over small distances

Question 2

gastrovascular cavity

Answer 2

functions in both digestion and distribution of substances throughout the body

Question 3

what are the three components of a circulatory system

Answer 3

circulatory fluid, interconnecting vessels, heart

Question 4

open circulatory system

Answer 4

circulatory fluid bathes the organs directly

Question 5

hemolympth

Answer 5

no distinction between circulatory fluid and interstitial fluid, and this general body fluid is called this

Question 6

closed circulatory system

Answer 6

circulatory fluid called blood is confined to vessels and distinct from interstitial fluid

Question 7

what are the three types of blood vessels

Answer 7

arteries, capillary beds, venules

Question 8

arteries

Answer 8

branch into arterioles (which are called this the further away from the heart they are) and carry blood away from the heart to the capillaries

Question 9

capillary beds

Answer 9

are the sites of chemical exchange between blood and interstitial fluid

Question 10

venules

Answer 10

converge into veins and return blood from capillaries to the heart
- veins return blood to the heart

Question 11

two chambers of the heart

Answer 11

atrium and ventricle

Question 12

atrium

Answer 12

blood enters here, receives incoming blood

Question 13

ventricle

Answer 13

pumps out the blood from the atrium

Question 14

single circulation

Answer 14

blood leaving the heart passes through two capillary beds (chemical exchange between blood and fluid)

Question 15

double circulation

Answer 15

oxygen poor blood flows through the pulmonary circuit to pick up oxygen through the lungs
- oxygen rich blood delivers through the systemic circuit, maintains higher blood pressure in the organs than single circulation

Question 16

cardiac cycle

Answer 16

one complete sequence of pumping and filling is called this

Question 17

what are the two valves in the heart

Answer 17

• atrioventricular valve separate each atrium and ventricle
• semilunar valves control blood flow to the aorta and the pulmonary artery

Question 18

systole

Answer 18

contraction phase of the cycle, pushes blood out, big # for the blood pressure

Question 19

diastole

Answer 19

relaxation phase of the heart, receives incoming blood, small number for blood pressure

Question 20

lymphatic system

Answer 20

returns fluid called lymph that leaks out from the capillary beds, has a similar composition to interstitial fluid

Question 21

lymph nodes

Answer 21

organs that filter lymph and play an important role in body’s defense, immune system

Question 22

plasma

Answer 22

blood is a connective tissue consisting of cells suspended in a liquid matrix called plasma

Question 23

what are the two classes of cells in the blood

Answer 23

RBC (erythrocytes) transport O2 with hemoglobin
WBC (leukocytes) function in immune defense

Question 24

platelets

Answer 24

are involved in clotting

Question 25

atherosclerosis

Answer 25

build up fatty acid deposits within arteries, artery walls become thick, stiff and obstructed

Question 26

heart attack

Answer 26

death of muscle tissue resulting from blockage of coronary arteries

Question 27

stroke

Answer 27

death of nervous tissue in the brain resulting from a blockage of arteries in the head

Question 28

gas exchange

Answer 28

uptake of O2 and the discharge of CO2 from or to the environment by diffusion

Question 29

countercurrent exchange

Answer 29

blood flows in the opposite direction to water passing over the gills, in fish

Question 30

tracheal system in insects

Answer 30

insects consisting of a network of air tubes that branch through the body, can transport O2 and CO2 without the participation of the animals open circulatory system

Question 31

lungs

Answer 31

in folding of the body surface, divided into numerous pockets, the circulatory system transports gasses between the lungs and the rest of the body

Question 32

pharynx

Answer 32

directs air to the lungs, back of the mouth going down the trachea,

Question 33

air flow

Answer 33

pharynx, larynx, trachea, bronchi, bronchioles, alveoli

Question 34

breathing

Answer 34

process that ventilates the lungs, inhalation and exhalation of air

Question 35

negative pressure breathing

Answer 35

air is pulled into the lungs

Question 36

diaphragm

Answer 36

lung volume increases as the diaphragm contracts creating lower pressure in the lung allowing air to flow in
- lung volume decreases as the diaphragm relaxes, creates higher pressure in the lung air flows out