Circulatory system

Question 1

Cells require what?

Answer 1

A continuous supply of nutrients, oxygen, and removal of waste products

Question 2

In very small animals, how are materials exchanged?

Answer 2

By diffusion

Question 3

What provides a medium for diffusion of oxygen, nutrients, and wastes?

Answer 3

Fluid between the cells

Question 4

What does fluid between the cells do?

Answer 4

Provides a medium for diffusion of oxygen, nutrients, and wastes

Question 5

What does the evolution of specialized circulatory systems allow?

Answer 5

Animals to increase in size because it reduced the distance needed for diffusion

Question 6

What animals lack a separate circulatory system?

Answer 6

Sponges, cnidarians, and nematodes

Question 7

What makes cnidarians unique in regards to the circulatory system?

Answer 7

Their central gastrovascular cavity is a circulatory and digestive organ

Question 8

What are the three parts of the circulatory system of larger animals?

Answer 8

Blood, a pumping organ (generally a heart), and blood vessels through which blood circulates

Question 9

What is blood?

Answer 9

A connective tissue consisting of cells and cell fragments dispersed in plasma

Question 10

What are the two types of circulatory systems?

Answer 10

Open and closed

Question 11

What defines an open circulatory system? What is the name for its fluid(s)?

Answer 11

No distinction between circulating and extracellular fluid, and this fluid is called hemolymph

Question 12

What defines a closed circulatory system?

Answer 12

Distinct circulatory fluid enclosed in blood vessels and transported away from and back to the heart

Question 13

What are the 8 things vertebrate circulatory systems do?

Answer 13

Transports nutrients from digestive system or storage to cells, transports oxygen from respiratory structures to cells, transports metabolic wastes from cells to excretory organs, transports hormones from endocrine glands to target tissues, helps maintain fluid balance, helps distribute metabolic heat and maintain body temperature, helps maintain appropriate pH, and defends the body against invading microorganisms

Question 14

Describe capillaries

Answer 14

The smallest blood vessels, have very thin walls that permit exchange of materials between blood and interstitial fluid

Question 15

What makes up the vertebrate circulatory system?

Answer 15

Blood vessels, blood, lymph, lymph vessels, and associated organs such as the thymus, spleen, and liver

Question 16

What did the vertebrate cardiovascular system become modified for and why?

Answer 16

Vertebrate cardiovascular system became modified as the site of gas exchange shifted from gills to lungs, and as metabolic rates increased

Question 17

Briefly describe the vertebrate heart

Answer 17

One or two chambers receive blood returning from the tissues and one or two ventricles that pump blood into arteries

Question 18

Most nonavian reptiles have what?

Answer 18

A double circuit of blood flow; a wall partly divides the ventricles (except crocodilians)

Question 19

What’s the pattern of blood circulation in birds and mammals?

Answer 19

Veins (from organs) → right atrium → right ventricle → pulmonary arteries → capillaries in the lungs → pulmonary veins → left atrium → left ventricle → aorta → arteries (to organs) → arterioles→ capillaries → veins

Question 20

What is the extracellular matrix of blood called?

Answer 20

Plasma

Question 21

What are the 3 types of cells in blood?

Answer 21

RBCs, WBCs, platelets

Question 22

What makes up plasma?

Answer 22

~92% water, 7% proteins, salts, and transported materials

Question 23

What are the plasma proteins?

Answer 23

Fibrinogen (involved in clotting), globulins (alpha, beta, gamma), and albumins

Question 24

What do plasma proteins do?

Answer 24

Plasma proteins help regulate distribution of fluid between plasma and interstitial fluid

Question 25

If fibrinogen is removed, what is plasma called?

Answer 25

Serum

Question 26

What are the ions present in plasma?

Answer 26

Na+, Cl–, HCO3, and trace Ca2+, Mg2+, Cu2+, K+, Zn2+

Question 27

What makes RBCs in mammals unique?

Answer 27

The RBC nucleus is ejected – each RBC is a flexible, biconcave disc with an elastic internal framework

Question 28

What's another name for RBCs?

Answer 28

Erythrocyctes

Question 29

What are erythrocytes?

Answer 29

RBCs

Question 30

How many RBCs are there per microliter of blood?

Answer 30

About 5 million

Question 31

What is the fraction of the total blood volume occupied by red blood cells?

Answer 31

Hematocrit

Question 32

How long do RBCs live?

Answer 32

About 120 days

Question 33

What is hemoglobin?

Answer 33

The pigment that binds and transports oxygen

Question 34

How are old RBCs removed?

Answer 34

They're removed from circulation by phagocytic cells in the liver and spleen

Question 35

How are new RBCs made?

Answer 35

They're produced in bone marrow, regulated by the erythropoietin hormone

Question 36

What are leukocytes?

Answer 36

WBCs

Question 37

What is another name for WBCs?

Answer 37

Leukocytes

Question 38

Where are leukocytes made?

Answer 38

Red bone marrow

Question 39

What are the two main types of WBCs?

Answer 39

Granular and agranular

Question 40

What are the types of granular WBCs?

Answer 40

Neutrophils. eosinophils, and basophils

Question 41

What are neutrophils?

Answer 41

Phagocytic granular WBCs that ingest bacteria and dead cells; granules contain digestive enzymes

Question 42

What are eosinophils?

Answer 42

Granular WBCs that contain lysosomes with enzymes that degrade cell membranes of parasitic worms and protozoa

Question 43

What are basophils?

Answer 43

Granular WBCs that release histamine and heparin

Question 44

Describe agranular leukocytes

Answer 44

They lack granules and their nuclei are rounded or kidney-shaped

Question 45

What are the two types of agranular leukocytes?

Answer 45

Monocytes and lymphocytes

Question 46

What are lymphocytes?

Answer 46

Agranular WBCs that fight infections: some produce antibodies; others directly attack invaders such as bacteria or viruses

Question 47

What are monocytes?

Answer 47

Agranular WBC phagocytes that migrate from blood into tissues during an infection; they differentiate into macrophages and dendritic cells

Question 48

What are the four steps of blood clotting?

Answer 48

Injury to blood vessel, wall of vessel contracts, platelets adhere to collagen fibers of damaged vessel wall, and a more permanent clot forms.

Question 49

What is important in blood clotting in mammals?

Answer 49

Platelets and a variety of clotting factors are important in blood clotting

Question 50

What do most non-mammal vertebrates have to help with blood clotting?

Answer 50

Thrombocytes

Question 51

What do mammals have for blood clotting and what are they?

Answer 51

Platelets: tiny spherical or disc-shaped fragments of cytoplasm pinched off from large bone marrow cell

Question 52

What are the three main types of blood vessels?

Answer 52

Arteries, capillaries, and veins

Question 53

What are the three layers of the walls of arteries/veins?

Answer 53

Endothelium, connective tissue & smooth muscle cells, and connective tissue rich in elastic and collagen fibers

Question 54

Where are materials exchanged with blood?

Answer 54

Materials are exchanged between blood and interstitial fluid through capillary walls

Question 55

Describe arteries

Answer 55

They carry blood away from the heart, and divide into many smaller branches (arterioles) which lead to capillaries

Question 56

Capillaries are ____ ____

Answer 56

microscopic vessels

Question 57

What are arterioles?

Answer 57

The finest, microscopic branches of the arterial tree

Question 58

Describe the structure of capillaries

Answer 58

They branch off from metarterioles and rejoin them, and also interconnect with one another

Question 59

Describe what happens when a tissue is inactive

Answer 59

Sphincters are closed, only its metarterioles are open.

Question 60

Describe what happens when a tissue is active

Answer 60

Sphincters are open, decreased oxygen tension in the tissue relaxes the precapillary sphincters, and the capillaries open.

Question 61

What does the opening of capillaries in active tissue do?

Answer 61

It increases the blood supply and thus the delivery of nutrients and oxygen to the active tissue.

Question 62

What happens to fluid that doesn't return to capillaries?

Answer 62

Fluid that does not return to capillaries is returned to circulation by the lymphatic system

Question 63

Where does lymph return to circulation?

Answer 63

The subclavian vein

Question 64

What do semilunar valves do?

Answer 64

Control exits from the heart

Question 65

What do atrioventricular valves do?

Answer 65

Prevent blood from flowing backward from ventricles into atria

Question 66

How are atrioventricular valves attached?

Answer 66

They're held in place by chordae tendineae attached to papillary muscles

Question 67

What do purkinje fibers do?

Answer 67

They form and conduct impulses to the muscle fibers of both ventricles, causing ventricles to contract

Question 68

What is the period of contraction of the heart called?

Answer 68

Systole

Question 69

What is the period of relaxation of the heart called?

Answer 69

Diastole

Question 70

What is Starling's law of the heart?

Answer 70

If veins deliver more blood to the heart, the heart pumps more blood into the arteries. Increased venous return stretches the cardiac muscle fibers more and they contract with greater force, increasing stroke volume

Question 71

The volume of blood one ventricle pumps during one beat depends on mainly what?

Answer 71

The amount of blood veins deliver to the heart

Question 72

Define blood pressure

Answer 72

The force exerted by the blood against the inner walls of the blood vessels

Question 73

What factors determine blood pressure?

Answer 73

CO2, blood volume, and resistance to blood flow

Question 74

When does blood pressure decrease?

Answer 74

As blood flows away from the heart – by the time blood enters the veins, its pressure is very low

Question 75

What is the aorta?

Answer 75

The largest artery

Question 76

What 3 things make up the lymphatic system?

Answer 76

Lymph, an extensive network of lymphatic vessels, and lymph tissue

Question 77

What is lymph?

Answer 77

Fluid formed from interstitial fluid

Question 78

What is lymph tissue?

Answer 78

Connective tissue with large numbers of lymphocytes

Question 79

What is lymph tissue organized into?

Answer 79

Lymph nodes and lymph nodules

Question 80

What organs consist mainly of lymph tissue?

Answer 80

Tonsils, thymus gland, and spleen

Question 81

What is net filtration pressure in regards to the lymphatic system?

Answer 81

The tendency for plasma to leave blood at the arterial end of a capillary and enter interstitial fluid

Question 82

What is interstitial fluid regarding the lymphatic system?

Answer 82

Contains no red blood cells, platelets, or large proteins, only a few white blood cells and smaller molecules dissolved in the plasma (glucose, amino acids, and other nutrients; a variety of salts; and oxygen needed by the cells)

Question 83

What is the main force of net filtration pressure?

Answer 83

Hydrostatic pressure, augmented by the osmotic pressure of interstitial fluid