Ib Biology Year 1- Topic 6: Human Physiology

Front 1

What is the catabolism of large food molecules into smaller and smaller molecules?

Back 1

Digestion

Front 2

Polymer --> Dimer --> ?

Back 2

Monomer

Front 3

Which 3 organs secrete enzymes and other fluids into the small intestine to finish digestion?

Back 3

Liver, gallbladder, pancreas

Front 4

What is the order in which food travels through you?

Back 4

Mouth --> Esophagus --> Stomach --> Small intestine --> Large intestine --> Rectum

Front 5

Which polysaccharide is not digested?

Back 5

Cellulose (Beta glucose polymer for structure in plants, this is what fiber is)

Front 6

The mouth contains what enzyme for breaking down starch?

Back 6

Salivary amylase

Front 7

The stomach contains what enzyme for breaking down proteins?

Back 7

Pepsin

Front 8

The mouth, esophagus, and stomach all have what kind of digestion?

Back 8

Mechanical (physically crushing stuff)

Front 9

What is the breakdown of food macromolecules into monomers in the digestive system tube called?

Back 9

Digestion

Front 10

What is the transfer of monomer nutrients from the digestive system tube to the bloodstream called?

Back 10

Absorption

Front 11

Which 2 very important processes happen in the small intestine?

Back 11

1) finish digestion of food into monomers using a variety of enzymes, 2) absorb monomers into bloodstream out of the digestive system

Front 12

What are the 5 layers of the small intestine, from outside to in?

Back 12

Longitudinal muscle, circular muscle, mucosa, epithelium, lumen

Front 13

True or false: The epithelium is a single cell thick.

Back 13

True

Front 14

What does circular muscle contraction do to the small intestine?

Back 14

It makes the small intestine segment thinner.

Front 15

What does longitudinal muscle contraction do the the small intestine?

Back 15

It makes the small intestine segment shorter.

Front 16

What are the three enzymes secreted by the pancreas into the lumen and what do they do?

Back 16

1) pancreatic amylase: breaks down starch into maltose, 2) pancreatic lipase: breaks down lipids into fatty acids and other monomers, 3) pancreatic endopeptidase: breaks down proteins into amino acids

Front 17

What are the finger-like projections of the mucosa layer called?

Back 17

Villi

Front 18

True or false: each villus is super specialized to increase how many nutrients can be absorbed.

Back 18

True

Front 19

How does the form of the small intestine help its function?

Back 19

Many thin villi increase surface area; Epithelium is one cell thick for short distance to blood vessels; Many blood vessels for increased bloodflow; Microvilli on each cell to further increase surface area; Many membrane proteins, channels for diffusion; pumps for active transport; Mitochondria for ATP for active transport; Lacteal in the middle to transport lipids

Front 20

What is the first step in the journey of the starch molecule?

Back 20

Starch is broken down into the disaccharide maltose by pancreatic amylase

Front 21

What is the second step in the journey of the starch molecule?

Back 21

Maltose is broken down into glucose by the brush-border enzyme maltase in the small intestine wall

Front 22

What is the third step in the journey of the starch molecule?

Back 22

Glucose is co-transported into the epithelium cells with sodium

Front 23

What is the fourth step in the journey of the starch molecule?

Back 23

Glucose then diffuses through the mucosa layer out of a channel protein into the surrounding blood vessels and taken to the liver

Front 24

What is the fifth (and final) step in the journey of the starch molecule?

Back 24

The liver can then turn glucose into glycogen for storage if it's not needed

Front 25

Who is "the blood guy"?

Back 25

William Harvey

Front 26

What did Harvey discover about how blood flow works?

Back 26

The same blood travels in a double circulation, it is not made and consumed; one circulation goes from heart to lungs to heart, the other goes from heart to body to heart; Arteries carry blood away from the heart, veins carry blood towards the heart

Front 27

Where does blood go from the heart?

Back 27

To the arteries

Front 28

What is the function of arteries?

Back 28

To carry blood away from the heart

Front 29

What is the structure of arteries?

Back 29

Thick walls of elastic fibers to withstand high pressure of pulses of bloodflow; thick circular muscle to help pump blood through; Thin lumen to maintain high pressure

Front 30

Where does blood go from the lungs or body?

Back 30

To the veins

Front 31

What is the function of veins?

Back 31

To carry blood toward the heart

Front 32

What is the structure of veins?

Back 32

Thin walls because blood is under low pressure; Thin walls can be pressed flat by nearby muscles to help pump blood forward; wide lumen for slow and steady blood flow; have valves to prevent backflow of blood

Front 33

True or false: nutrients and waste products cannot diffuse across veins or arteries.

Back 33

True

Front 34

Arteries branch out into what kind of blood vessel?

Back 34

Capillaries

Front 35

Where do cells exchange nutrients and waste products with the blood stream?

Back 35

Capillaries

Front 36

What is the function of capillaries?

Back 36

Exchange waste and nutrients with body tissues

Front 37

What is the structure of capillaries?

Back 37

Smallest wall possible- one cell thick for smallest diffusion distance; pores and membrane proteins make them permeable for exchange; many small capillaries for large surface area

Front 38

What are the 4 chambers of the heart?

Back 38

Right atrium, left atrium, right ventricle, left ventricle

Front 39

True or false: ventricles recieve blood from veins.

Back 39

False; atria recieve blood from veins

Front 40

True or false: atria pump blood to arteries.

Back 40

False; ventricles pump blood to arteries.

Front 41

The right side of the heart pumps blood to what?

Back 41

the lungs

Front 42

The left side of the heart pumps blood to what?

Back 42

The body

Front 43

How many valves are there in the heart?

Back 43

4 (one for the exit of each chamber)

Front 44

What is between the atria and the ventricles?

Back 44

The atrioventricular valves

Front 45

What is at the exit of the ventricles into the arteries?

Back 45

The semilunar valves

Front 46

All blood from everywhere in the body collects into the biggest veins, which are called what?

Back 46

The vena cava

Front 47

Where does the vena cava dump blood?

Back 47

Into the right atrium

Front 48

From the right ventricle, the blood enters what?

Back 48

The pulmonary artery

Front 49

What is the only artery that carries deoxygenated blood?

Back 49

The pulmonary artery

Front 50

All blood from the lungs enters what?

Back 50

The pulmonary veins

Front 51

What are the only veins that carry oxygenated blood?

Back 51

The pulmonary veins

Front 52

Where do the pulmonary veins dump blood?

Back 52

The left atrium

Front 53

Where does blood travel from the left ventricle?

Back 53

Everywhere in the body

Front 54

What is the biggest artery in the body and where does it come from?

Back 54

The aorta, it comes from the left ventricle

Front 55

True or false: the heart requires external signals to beat.

Back 55

False; the heart does not require external signals to beat

Front 56

What does myogenic mean?

Back 56

It means it can generate its own muscle contraction

Front 57

True or false: cardiac muscle is myogenic.

Back 57

True

Front 58

What is the sinoatrial node?

Back 58

A group of special cardiac muscle cells in the right atrium that sends out an electrical signal, starting contraction of all heart muscle cells

Front 59

Where does the signal of the sinoatrial node go first?

Back 59

To the atria first, then to the ventricles. This causes the left and right atria to contract first, then the left and right ventricles

Front 60

What is the sinoatrial node called and why?

Back 60

It is called the pacemaker because it controls the pace of the heartbeat

Front 61

What are two ways the pace of the heartbeat can be altered?

Back 61

A nerve from the medulla of the brain can speed it up, another nerve from the medulla can slow it down; The hormone epinephrine (aka adrenaline) increases the rate

Front 62

What are coronary arteries?

Back 62

Small arteries on the surface of the heart that provide nutrients to cardiac tissue and take away waste products

Front 63

What is the first step of a heart attack?

Back 63

Cholesterol plaques build up in coronary arteries

Front 64

What is the second step of a heart attack?

Back 64

A plaque ruptures

Front 65

What is the third step of a heart attack?

Back 65

A blood clot forms to contain the rupture. This clot occludes the coronary artery.

Front 66

What is the fourth (and final) step of a heart attack?

Back 66

Heart muscle cells die from lack of nutrients. This is the heart attack.

Front 67

Bloodflow occurs by what type of pressure?

Back 67

Positive pressure

Front 68

True or False: Blood is pushed through by contraction of the heart, increasing pressure on the blood and pushing it through

Back 68

True

Front 69

Which chamber is the strongest and has the thickest walls and why?

Back 69

The left ventricle pumps blood the farthest (all around the body) so it has the thickest walls and is the strongest

Front 70

The _____ recieves blood immediately from the left ventricle so it is the blood vessel that has to withstand the highest pressure

Back 70

aorta

Front 71

What is a pathogen?

Back 71

Something that causes disease (virus, bacteria, etc.)

Front 72

What is your body's first line of defence against pathogens?

Back 72

The skin and mucous membranes

Front 73

Why are mucous membranes good at defending your body against pathogens?

Back 73

Sticky, unfavorable pH, lysozyme, natural organisms

Front 74

Why is skin good at defending your body against pathogens?

Back 74

Continuous, many layers, tough, dry, unfavorable pH, lysozyme, natural organisms

Front 75

How do pathogens gain entry into the body?

Back 75

Cuts, swallowing, breathing in, bodily fluids, blood to blood contact

Front 76

To clot blood and stop bleeding, what must happen?

Back 76

The soluble protein fibrinogen must be activated into insoluble fibrin, which forms a web that physically blocks bleeding

Front 77

What is the first thing that happens after the skin gets cut?

Back 77

Platelets (anucleate red blood cells) release clotting factors

Front 78

What is the second thing that happens after the skin gets cut?

Back 78

Clotting factors turn prothrombin into thrombin

Front 79

What is the third step that happens after the skin gets cut?

Back 79

Thrombin turns fibrinogen into fibrin

Front 80

What are leukocytes?

Back 80

White blood cells that protect the body against disease

Front 81

What are phagocytes?

Back 81

Non-specific leukocytes/white blood cells, form body's 2nd line of defence

Front 82

What are lymphocytes?

Back 82

Specific white blood cells, form 3rd and final line of defence

Front 83

__________ ingest pathogens and destroy with lysosomes

Back 83

Phagocytes

Front 84

True or false: Lymphocytes produce only one type of antibody to fight a specific pathogen

Back 84

True

Front 85

What is an antibody?

Back 85

A protein used to inactivate or destroy a pathogen

Front 86

What is an antigen?

Back 86

Anything that generates an antibody response

Front 87

What is an allergen?

Back 87

A non-pathogenic molecule that is antigenic

Front 88

What happens in the first step of lymphocyte response?

Back 88

Challenge: an antigen penetrates the skin

Front 89

What happens during the second step of lymphocyte response?

Back 89

Clonal selection: The antigen must interact with its specific lymphocyte to begin the antibody response

Front 90

What happens during the third step of lymphocyte response?

Back 90

Proliferation: The lymphocyte divides over and over

Front 91

What happens during the fourth step of lymphocyte response?

Back 91

Anti-body production: The lymphocyte clones, produces many antibodies and destroys the infection

Front 92

What happens during the fifth step of lymphocyte response?

Back 92

Memory cell formation: most of the clones die but many remain as memory cells to allow for a quicker response next infection. You are now immune

Front 93

What are anti-biotics?

Back 93

Man-made molecules that disrupt prokaryotic pathways

Front 94

True or False: Antibiotics work on both bacteria and viruses.

Back 94

False: antibiotics only work on bacteria

Front 95

Why don't antibiotics work on viruses?

Back 95

Antibiotics do not work on viruses because viruses hijack your eukaryotic pathways, they don't have their own metabolism

Front 96

What was the first antibiotic?

Back 96

Penicillin

Front 97

Who were the scientists that discovered how to purify and isolate penicillin from the fungus that makes it?

Back 97

Florey and Chain

Front 98

What was Florey and Chain's experiment?

Back 98

They infect mice with strept and find that those treated with penicillin survive while those without it die

Front 99

What does HIV stand for?

Back 99

Human immunodeficiency virus

Front 100

What does the HIV attack?

Back 100

Lymphocytes (leukocytes, more generally)

Front 101

What happens after you have HIV for a while? (What condition do you acquire?)

Back 101

You don't have enough lymphocytes to make antibodies and fight off other stuff. This condition is called AIDS.

Front 102

What does AIDS stand for?

Back 102

Acquired Immunodeficiency symndrome

Front 103

Can you die of AIDS?

Back 103

No, you die of an opportunistic infection

Front 104

List three ways that HIV can be transmitted.

Back 104

Blood-blood contact; Sexual intercourse; Childbirth

Front 105

What is ventilation?

Back 105

Breathing

Front 106

Where does all gas exchange occur?

Back 106

Between the alveoli and adjacent capillaries

Front 107

What is the path of airflow (starting from the mouth)?

Back 107

Mouth --> trachea --> bronchi --> bronchioles --> alveoli

Front 108

What diffuses into the alveoli and what diffuses into the bloodstream?

Back 108

CO2 diffuses into the alveoli, O2 diffuses into the bloodstream

Front 109

What are alveoli?

Back 109

Little sacs at the end of the bronchioles

Front 110

How are the alveoli specialized for exchange?

Back 110

Many small alveoli for increased surface area; Walls of alveoli are one cell thick for short diffusion pathway; moist to prevent rubbing and adhering; Many capillaries for bloodflow

Front 111

What are alveoli bordered by?

Back 111

Type 1 pneumocytes

Front 112

What are type 1 pneumocytes kept moist by?

Back 112

Type 2 pneumocytes

Front 113

What is a surfactant?

Back 113

A compound that lowers surface tension, preventing rubbing and sticking

Front 114

What are type 2 pneumocytes?

Back 114

Cells of the lungs that secrete a surfactant to keep alveoli moist

Front 115

Muscles work in ____________ pairs.

Back 115

Antagonistic

Front 116

What is antagonistic muscle action?

Back 116

Some muscles cause movement in one direction, other muscles cause movement in the opposite direction

Front 117

What is expiration?

Back 117

Breathing out

Front 118

What does the thorax do when you expire?

Back 118

Moves down and in

Front 119

What happens to the volume and pressure of your lungs when you expire?

Back 119

Volume of lungs decreases --> pressure of lungs increases and pushes air out

Front 120

What is inspiration?

Back 120

Breathing in

Front 121

What does the thorax do when you inspire?

Back 121

It moves up and out

Front 122

What happens to the volume and pressure of your lungs when you inspire?

Back 122

Volume of lungs increases --> Pressure of lungs decreases and sucks air in

Front 123

What are the 4 muscles involved in breathing?

Back 123

Diaphragm, Internal intercostal muscles, external intercostal muscles, abdominal muscles

Front 124

What happens to the 4 muscles involved in breathing when you inspire?

Back 124

Diaphragm contracts, pulling lungs down, internal intercostal muscles relax, external intercostal muscles contract, pulling ribs up and out, abs relax to allow diaphragm to travel down

Front 125

What happens to the 4 muscles involved in breathing when you expire?

Back 125

Diaphragm relaxes, internal intercostal muscles contract pulling ribs in and down, external intercostal muscles relax, abs contract to push diaphragm back up

Front 126

What is lung cancer?

Back 126

Uncontrolled cell division of the cells in the lungs

Front 127

What are the causes of lung cancer?

Back 127

Cigarette smoking, asbestos, radon gas

Front 128

What are the consequences of lung cancer?

Back 128

Coughing, chest pain, infections, metastasis can spread cancer elsewhere

Front 129

What is emphysema?

Back 129

Emphysema occurs when alveoli are destroyed, stretched, and lose elasticity. Alveoli appear damaged and wrinkled, with large spaces between them

Front 130

What are the causes of emphysema?

Back 130

Cigarette smoking, second-hand smoke, airborne toxins

Front 131

What are the consequences of emphysema?

Back 131

Shortness of breath, fatigue