chapter 32: circulation and cardiovascular systems

Question 1

What are 3 functions of the circulatory system

Answer 1

circulate oxygen, expel waste products, intake nutrients

Question 2

why do some invertebrates lack circulatory systems?

Answer 2

-lack blood
-more simplistic organisms in body composition
-different ways to regulate the functions

Question 3

What are 3 different ways invertebrates regulate functions without a CS?

Answer 3

-gastrovascular cavity takes up most space in the body, use it as method to pull in oxygen and expel waste
-water vascular system, take oxygen from the water and expel waste into the water, pick up nutrients from water
-thin epidermis, exposure of individual cells to both external and internal environment to allow for transportation

Question 4

What is hemolymph

Answer 4

-mixture of blood & interstitial fluid
-Not always contained within blood vessels & heart
-Fills body cavity

Question 5

What is blood?

Answer 5

-Fluid circulated by heart through closed system of vessels
-Always contained in blood vessels

Question 6

What is the cardiovascular system?

Answer 6

organ system in animals that is involved with circulation of blood or hemolymph

Question 7

All vertebrates have what kind of circulatory systems?

Answer 7

closed

Question 8

3 components of blood vessels

Answer 8

arteries, capillaries, veins

Question 9

What is an artery?

Answer 9

carry blood away from heart
typically rich oxygenated blood

Question 10

What are capillaries?

Answer 10

exchange materials with interstitial fluid

Question 11

What are veins?

Answer 11

-return blood to heart
-typically deoxygenated blood
-have valves attached

Question 12

characteristics of a one-circuit pathway

Answer 12

-Single-loop
-Single atrium & ventricle
-Pumping of heart sends blood to gills (gill capillaries); gas exchange occurs
-Oxygen rich blood carried to the capillaries of body (systemic capillaries)
-Veins return oxygen-poor blood back to heart

Question 13

Characteristics of a two-circuit pathway

Answer 13

-Double loop pathway
-Two atria & single ventricle
-Heart pumps blood to tissue through systemic circuit & to lungs through pulmonary circuit
-Both empty into same ventricle (somewhat separate by pumping & contractions)

Question 14

What is the heart?

Answer 14

Heart: muscular organ whose contraction causes blood to circulate in body of an animal

Question 15

What is the myocardium

Answer 15

major portion of the heart

Question 16

Myocardium consists largely of what?

Answer 16

cardiac muscle fibers

Question 17

The heart lies within an outer membranous sac called what?

Answer 17

pericardium

Question 18

Inner surface of the heart is lined with what?

Answer 18

endocardium

Question 19

structure of the heart

Answer 19

-Wall called septum separates heart into right side & left side
-Four chambers: two atria & two ventricles
-Four valves – direct flow of blood; prevent mixing

Question 20

what is the cardiac cycle?

Answer 20

two-part pumping action that takes about a second

Question 21

what is cardiac output?

Answer 21

volume of blood left ventricle pumps per minute into systemic circuit

Question 22

What is a pulse?

Answer 22

vibration in arterial walls due to expansion of aorta following ventricle contraction

Question 23

what is the pulmonary circuit?

Answer 23

Transports blood between heart & lungs

Question 24

what is the systemic circuit?

Answer 24

Transports blood between heart and the remaining tissues & organs of the body

Question 25

what is blood pressure?

Answer 25

-force of blood pushing against inside wall of blood vessels
-As bloods flows from aorta to arteries pressure reduces

Question 26

What happens because blood pressure in the veins in low and insufficient?

Answer 26

-Skeletal muscles apply pressure on collapsible walls of vein when they contract (a good squeeze!)
-Valves prevent backflow of blood

Question 27

what are the two major portions of blood

Answer 27

liquid and formed elements

Question 28

What is plasma

Answer 28

the liquid portion of blood

Question 29

Characteristics of plasma

Answer 29

-Buffer
-pH near 7.4
-regulate Osmotic pressure
osmotic = water
balancing water pressure (fluid matrix)
-Blood clotting
-Transport large organic molecules

Question 30

what are red blood cells?

Answer 30

-Biconcave disks that lack nuclei when mature
-Contain respiratory pigment hemoglobin
-Manufactured by red bone marrow
-Before release synthesize hemoglobin & lose nuclei

Question 31

what is hemoglobin?

Answer 31

-iron component
-good at forming loose bonds with oxygen, helps transport the oxygen

Question 32

where are red blood cells made?

Answer 32

red bone marrow
-before they are released they synthesize hemoglobin and lose nuclei

Question 33

what is an antigen?

Answer 33

molecule that can trigger a specific immune response

Question 34

How does the ABO system work?

Answer 34

-A & B antigens commonly found on microorganisms
-Plasma usually contains antibodies to the A or B antigens NOT present on red blood cells
-When blood types do not match, agglutination cause red blood cells to stop circulating

Question 35

what is agglutination

Answer 35

clumping of blood

Question 36

How does the Rh system work?

Answer 36

-Presence/absence D antigen
-Present: Rh-positive (+)
-Absent: Rh-negative (-)
-85% U.S. population positive
-Rh-negative individuals do not have antibodies to Rh factor
-May make them when exposed!

Question 37

Characteristics of white blood cells

Answer 37

-Also called leukocytes
-Critical in immune response
-Bigger than red blood cells
-Nucleus
-Lack hemoglobin; appear translucent

Question 38

How do platelets work in blood clotting? What are the steps?

Answer 38

-clump and partially seal leak
-release clotting factor called prothrombin activator, causing prothrombin to turn to thrombin
-thrombin severs amino acid chains from fibrinogen (protein in plasma)
-fragments join end to end forming fibrin
-fibrin threads around platelet plug, red blood cells trapped
-as soon as blood vessel is repaired an enzyme destroys fibrin network

Question 39

What does the release of prothrombin activator cause?

Answer 39

-turns prothrombin in plasma to thrombin

Question 40

What is capillary exchange?

Answer 40

Exchange between systemic capillary & intestinal fluid

Question 41

How does blood enter the capillary?

Answer 41

-Blood enters capillary oxygen & nutrient rich
-Oxygen & nutrients diffuse out of capillaries
-Carbon dioxide & wastes diffuse into capillaries

Question 42

Which of the following features are found in invertebrates that enable them to exchange nutrients and gases without the use of a circulatory system?

a.
All of these features enable invertebrates to exchange gases and nutrients without a circulatory system

b.
Fluid within the body cavity

c.
Exposure of the cells to the external or internal environment

d.
Gastrovascular cavity

Answer 42

a.
All of these features enable invertebrates to exchange gases and nutrients without a circulatory system

Question 43

Veins primarily depend upon which of the following forces to return blood to the heart?

a.
Valves to prevent blood back flow

b.
All of the choices apply

c.
Skeletal muscle contraction

d.
Force of blood entering from the arteries

Answer 43

c.
Skeletal muscle contraction

Question 44

The human heart is composed of

a.
Muscle fibers called myocardium

b.
An outer membranous sac called the pericardium

c.
Endocardium

d.
Cardiac muscle fibers

e.
All of the choices are correct

Answer 44

e.
All of the choices are correct

Question 45

The vessels in our circulatory system that allow molecules to diffuse across their walls to tissues are

a.
Veins

b.
Arteries

c.
Capillaries

d.
Lymph vessels

Answer 45

c.
Capillaries

Question 46

What two forces control the movement of fluid through the capillary wall?

a.
The oxygen and nitrogen concentration

b.
Blood pressure and osmotic pressure

c.
The number of veins and arteries

d.
The thickness of the capillary wall and the number of cilia

Answer 46

b.
Blood pressure (water leaves capillaries)
and osmotic pressure (water enters capillaries)