6 Human Health And Physiology

Front 1

Where does absorption happen?

Back 1

small intestine

Front 2

assimilated

Back 2

becoming tissue of the body

Front 3

Why do we need Absorption? (2)

Back 3

1. molecules does not suit the human tissue and need to be broken down and reassembled in a vom that is suitable
2. many molecules too large to be absorbed

Front 4

Amylase: Example of this Enzyme, Source, Substrate, products, optimum pH

Back 4

Salivary amylase, salivary glands, starch, maltose, pH 7

Front 5

Protease: Example of this Enzyme, Source, Substrate, products, optimum pH

Back 5

Pepsin, Wall of stomach, proteins, small polypeptides, pH 1.5

Front 6

Lipase: Example of this Enzyme, Source, Substrate, products, optimum pH

Back 6

Pancreatic lipase, Pancreas, Triglycerides (fats or oils), Fatty acids and glycerol, pH 7

Front 7

Draw the human digestive system!

Back 7

p.47

Front 8

Function of a villi?

Back 8

increase the surface area over which the food is absorbed

Front 9

Function of the epithelium?

Back 9

all food have to pass through to be absorbed

Front 10

Function of protusions?

Back 10

increase the surface area

Front 11

Function of protein channels?

Back 11

rapid absorption of food by facilitated diffusion

Front 12

Function of pumps?

Back 12

rapid absorption by active transport

Front 13

Function of mitochondria?

Back 13

ATP

Front 14

Function of blood capillaries?

Back 14

close to epithelium, so distance fo diffusion of food is very small

Front 15

Function of a lacteal?

Back 15

carries away fats after Absorption

Front 16

Functions of the stomach and intestines?

Back 16

- digestion of proteins begins in stomach, Pepsin
- acid conditions in stomach kill bacteria
- acidity provides optimum pH for Pepsin
- enzymes secreted by the small intestine end Digestion
- end products absorbed by the villi
- indigestible parts and water pass through the large intestine
- water absorbed in large intestine, leaving solid feces which are eventually egested

Front 17

myogenic?

Back 17

being able to contract on its own without being stimulated (heart)

Front 18

walls of the heart are composed of ... muscle

Back 18

cardiac

Front 19

What does the blood brought by the coronary arteries to the heart contain?

Back 19

- nutrients
- Oxygen for aerobic cell respiration which provides the energy for the cardiac muscle to contract

Front 20

What types of blood vessels are there? (3)

Back 20

1. arteries
2. veins
3. capillaries

Front 21

Draw the structure of arteries and explain the function

Back 21

- tick outer layer of longitudinal collagen and elastic fibres to avoid bulges and leaks
- thick wall to withstand high pressure
- thick layers of circulare elastic and muscle fibres to help pump the blood on after each heart beat
- narrow Lumen to help maintain the high pressures

Front 22

Draw the structure of veins and explain the function

Back 22

- thin layers with a few circular Elastik and muscle fibres because blood does not flow in pulses so the veins wall cannot help pump it
- wide lumen is needed to accomodate the slow-flowing blood
- thin wall allows the vein to be presset flat by adjacent muscles, helping to move the blood
- thin outer layer of longitudinal collagen and elastic fibres because there is little danger of bursting

Front 23

Draw the structure of capillaries and explain the function

Back 23

- wall consists of a single layer of thin cells so the distance for diffusion in or out is small
- pores between cells in the wall allow some of the plasma to leas out and form tissue fluid. Phagocytes can also squeeze out
- very narrow Lumen - only about 10micrometers across so that capillaries fit into small spaces. Many small capillaries have a large surface area than fewer wider ones

Front 24

Describe the sequence of actions in a heart beat (3)

Back 24

1.
- walls of atria contract
- blood pushed from atria into ventricles
- ventricles fill with blood
2.
- walls of the ventricles contract
- blood pressure rises
- blood pumped into arteries
- atria refill with blood from the veins
3.
- blood refills ventricles

Front 25

What is the peacemaker?

Back 25

a region in the wall of the right atrium which is responsible for initiating each contraction

Front 26

How is the heart bet Controlled? (3)

Back 26

1. one nerve carries a message from the brain to the peacemaker that tells the peace maker to speed up the beating of the heart
2. another nerve carries messages from the brain to the peacemaker that tell the peacemaker to slow down the beating
3. adrenalin, carried to the peacemaker by the blood stream, tells the peacemaker to speed up the beating of the heart

Front 27

Outline the composition of blood and the functions of the components

Back 27

1. leukocytes (lymphocytes and phagocytes) white blood cells
2. erythrocytes transpoting Oxygen
3. platelets
4. plasma transporting nutrients, acrbon dioxide, hormones, antibodies and urea

Front 28

pathogen

Back 28

an organism or virus that causes disease

Front 29

phagocytes

Back 29

- white blood cells
- identify pathogens and ingest them by endocytosis
- killed and digested inside the cell
- can ingest them in blood, but can also squeeze through the walls of capillaries

Front 30

large numbers of phagocytes at a site of Infektion form ...

Back 30

pus

Front 31

Blood plasma transports ... (5)

Back 31

- nutrients
- carbon Dioxide
- hormones
- antibodies
- urea

Front 32

the two main functions of blood are

Back 32

transport and defence against infectious disease

Front 33

antibodies

Back 33

proteins that recognize and bing to specific antigens, defend the body against pathogens by binding to antigens on surface of a pathogen and stimulating its destruction

Front 34

antigens

Back 34

foreign substances that stimulate the production of antibodies

Front 35

antibiotics

Back 35

chemicals produced by microorganisms, to kill or control the growth of other microorganisms

Front 36

Why can virus disease not be treated with antibiotics?

Back 36

Viruses rely on a host cell, not possible to block these processes with an antibiotic without harming the human cell

Front 37

Barriers to infection (2)

Back 37

1. outer layer of the skin
2. micous membranes

Front 38

(production of antibodies) Antibodies are made by ...

Back 38

lymphocytes, one of the two main types of leukocytes

Front 39

(production of antibodies) each lymphocyte puts some of the antibody that it can make ...

Back 39

into its plasma membranewith the antiken-combining site projecting outwards

Front 40

(production of antibodies) When a pathogen enters the body, its antigens ...

Back 40

bind to the antibodies in the Plasma membrane of one type of lymphocyte

Front 41

(production of antibodies) When antigens bind to the antibodies on the surface of a lymphocyte, this lymphocyte ...

Back 41

becomes active and divides by mitriss to produce a clone of many identical cells

Front 42

(production of antibodies) The clone of cells starts to ...

Back 42

produce large quantities of the same antibody

Front 43

Cause of AIDS

Back 43

- HIV
- virus infects a type of lymphocyte that plays a vital role in the antibody production
- lymphocytes are destroyed and cannot produce anymore antibodies
- body now vulnerable to pathogens

Front 44

Transmission of HIV

Back 44

- transfer of body fluids
1. through small cuts or tears in the genitals
2. in traces of blood on needles used by drug addicts
3. across the placenta from a mother to a baby
4. transfused blood

Front 45

Social implications of HIV

Back 45

- family and friends suffer grief
- families may become poorer if the HIV patient was the wage earner
- infected individuals may not find a partner, job etc
- sexual activity may be reduced in fear of HIV

Front 46

gas exchange

Back 46

the process of swapping one gas with another

Front 47

Where does gas exchange hapen?

Back 47

in the alveoli of human lungs

Front 48

ventilation

Back 48

the process of bringing fresh air to the alveoli and removing stale air

Front 49

Draw the ventilation system!

Back 49

p.51

Front 50

Process of inhaling

Back 50

- the external intercostal muscles contract, moving the ribcage up and out
- the diaphragm contracts, becoming flatter and moving down
- these muscle movements increase the volume of the Thorax
- the pressure inside the Thorax therefore drops below atmospheric pressure
- air flows into the lungs from outside the body until the pressure inside the lungs rises to atmospheric pressure

Front 51

process of exhaling

Back 51

- the internal intercostal muscles contract, moving the ribcage down and in
- the abdominal muscles contract, pushing the diaphragm up into a dome shape
- these muscle movements decrease the volume of the Thorax
- the pressure inside the thorax therefore rises above atmospheric pressure
- air flows out from the lungs to outside the body until the pressure inside the lungs falls to atmospheric pressure

Front 52

adaptations of the alveolus to gas exchange

Back 52

1. huge number of alveoli
2. thin layers of cells so that gases only have to diffuse a very short distance
3. dense network of capillaries with concentration gradients for diffusion
4. fluid which keeps the inner surface moist, allowing gases to dissolve

Front 53

the nervous system is composed of cells called ...

Back 53

neurons

Front 54

two parts of the nervous system

Back 54

1. the central nervous system (CNS), consisting of the brain and the spinal cord
2. peripheral nerves that connect all parts of the body to the central nervous system

Front 55

Functions of sensory and motor neurons

Back 55

- sensory neurons can carry electrical impulses from receptors (sensory cells) to the CNS
- motor neurons carry Impulses from the CNS to effectors (muscles)
- relay neurons carry Impulses within the CNS, from one neuron to another

Front 56

Draw the structure of a motor neuron!

Back 56

p.52

Front 57

a synapse ...

Back 57

is a junction between two neurons

Front 58

synaptic cleft

Back 58

the plasma membranes of the neurons are seperated by a narrow fluid-filled gap

Front 59

Many synapses function in the following way (7)

Back 59

1. a nerve impulse reaches the end of the pre-synaptic neuron
2. depolarization of the pre-synpatic membrane causes voltage-gated calcium channels to open. Calcium ions diffuse into the pre-synaptic neuron
3. vesicles of neurotransmitter move to the membrane and release their contents
4. Neuro- transmitter diffuse across the synaptic cleft and binds to reseptors
5. sodium ions enter the post-synaptic neuron and cause depolarization
6. nerve impulses setting off the post-synaptic neuron
7. calcium is pumped out. neurotransmitter is broken down in the cleft and reabsorbed into the vesicles

Front 60

Resting potential

Back 60

is the electical potential across the plasma membrane of a cell that is not conducting an impulse.

Front 61

action potential

Back 61

is the reversal and restoration of the electrical potential across the plasma membrane of a cell, as an electrical impulse passes along it (depolarization and repolarization).

Front 62

Stages in the passage of a nerve impulse (4)

Back 62

1.
- an action potential in one part of the neuron causes and action potential in the next section
- sodium ions diffuse between areas of action and resting potential
- ion movements reduce resting potential
- if potential rises above threshold, Vortage-gated channels open
2. entry of positively chrged sodium ions causes the indise of the neuron to develop a net positive charge compared to the outside
- depolarization
3. potassium channels open after a short delay
- exit of positively charged potassium ions cause the inside of the neuron to develop a net negative charge
- repolarization
4. concentration gradients of potassium and sodium restored by active transport

Front 63

Homeostasis

Back 63

is maintaing the internal environment of the body between limits

Front 64

the parameters controlled include .. (5)

Back 64

1. body temperature
2. blood pH
3. carbon Dioxide concentration
4. blood glucose concentration
5. water balance

Front 65

The endocrine system consists of ...

Back 65

glands which release hormones that are transported in the blood

Front 66

Feedback

Back 66

in feedback systems, the level of a product feeds back to control the rate of its own production

Front 67

negative feedback

Back 67

- stabilizing effect because a change in level always causes the opposite change
- a rise in levels feeds back to decrease production and reduce the level
- a decrease in levels feeds back to increase production

Front 68

the hypothalamus of the brain monitors ...

Back 68

the temperature of the blood and compares it with a set point

Front 69

responses to over heating

Back 69

- skin arterioles become wider, more heat is lost to the environment as more blood is transported to the skin
- skeletal muscles remain relaxed
- sweat

Front 70

responses to chilling

Back 70

1. skin arterioles become narrower, less heat is lost to the environment
2. skeletal muscles do many smal parid contractions to generate heat, shivering
3. skin remains dry, no sweat

Front 71

cells in the pacreas monitor ...

Back 71

the concentration of blood glucose and send hormone message sto target organs

Front 72

Responses to high blood glucose levels

Back 72

- beta cells in the pancreatic islets produce Insulin
- stimulates the liver and muscle cells to absorb glucose from the blood and convert it to glycogen

Front 73

Responses to low blood glucose levels

Back 73

- alpha cells in the pancreatic islets produce glucagon
- stimulates the liver cells to break glycogen down into glucose and release the glucose into the blood

Front 74

type I diabetes

Back 74

- onset usually during childhood
- beta cells produce insufficient Insulin
- insulin injections are used to control glucose levels
- diet by itself canot control this condition

Front 75

Type II diabetes

Back 75

- onset is usually after childhood
- target cells become insensitive to Insulin
- insulin injections are not usually needed
- low carbohydrate diets usually control the condition

Front 76

Draw the female reproductive system!

Back 76

p. 56

Front 77

Draw the male reproductive system!

Back 77

p. 56

Front 78

The pituitary gland produces ...

Back 78

LH and FSH

Front 79

FSH stimulates ...

Back 79

the development of follicles

Front 80

follicles

Back 80

fluid filled sacs that contain an egg cell

Front 81

LH stimulates ...

Back 81

follicles to grow and become nature, release their egg and then develop in a structure called corpus luteum

Front 82

ovulation

Back 82

process when the egg is released

Front 83

ovary produces ...

Back 83

estrogen and progesterone

Front 84

estrogen and progesterone stimulate ...

Back 84

- the development of secondary sexual characteristics
- development of the uterus lining

Front 85

Cells in the testes of the male produce ...

Back 85

testosterone

Front 86

Testosterone has several roles

Back 86

1. the developing testes of a male fetus secrete testosterone, which causes male gentalia to develop in the fetus
2. development of male seconday sexual characteristics in puberty
3. sex drive
4. sperm production

Front 87

outline the menstrual cycle

Back 87

p.57

Front 88

Timetable for IVF

Back 88

week 1-3: a drug is injected once a day for three weeks, to stop the woman's normal menstrual cycle
week 4: large doses of FSH are injected once a day for 10-12 days to stimulate the ovaries to develop many follicles
week 5: HCG is injected 36 hours befor egg collection, to losen the egg in the follicles and to make them mature
week 5: the man provides semen by ejaculating into a jar. The sperm are processed to concentrate the healthiest ones.
week 5: The egg are extracted from the follicles using a device Inserate through the wall of the vagina
week 5: each egg us mixed with sperm in a shallow dish. The dishes are kept overnight in an Incubator.
week 6: the dishes are checked to see if fertilisation has worked
week 6: two or three Embryos are selected and placed, via a long plastic Tube, into the uterus
week 7: a pregancy test is done to see if any embryos have implanted.
week 9: a scan is done to see if the pregnancy is continuing normally. the heart should be visible beating.

Front 89

Ethical arguments against IVF (5)

Back 89

1. inherited forms of infertility might be passd to children
2. spare embryos are killed
3. humans are deciding whether new individuals die or survive
4. unnatural process
5. infertility should be accepted as the will of god

Front 90

Ethical arguments for IVF (5)

Back 90

1. infertility due to environmental factors so offspring will not inherit that
2. embryos that are killed are unable to feel pain bexause their nervous syste has not yet developed
3. suffering due to genetic disease can be reduced by Scanning
4. parents who do IVF will be lovely parents
5. infertility brings great unhappiness to parents