Life And Death

Question 1

What is homeostasis?

Answer 1

The tendency of the body to establish and maintain a relatively stable equilibrium
Autonomic nervous system

Question 2

What receptors detect changes in blood pressure?

Answer 2

Baroreceptors

Question 3

What receptors detect changes in carbon dioxide levels?

Answer 3

Chemoreceptors

Question 4

What is a negative feedback loop?

Answer 4

Responds to an abnormal change and acts to restore homeostasis
Opposes the change

E.g. temperature, blood pressure

Question 5

What is a positive feedback loop?

Answer 5

Acts to amplify the change. Has built in termination mechanisms

E.g. uterine contractions, blood clotting

Question 6

What is energy?

Answer 6

The ability to do ‘work’
Cannot be created or destroyed

Question 7

What are the two main types of energy?

Answer 7

Potential which is stored (e.g. gravitational potential energy, elastic energy)
Kinetic which is moving (e.g. thermal energy is the movement of particles)

Question 8

What is chemical energy and an example in the body?

Answer 8

Energy stored (PE) in bonds of molecules

Released when glucose is metabolised

Question 9

What is mechanical energy and an example in the body?

Answer 9

Associated with movement (KE)

Muscles contracting from ATP

Question 10

What is thermal energy and an example in the body?

Answer 10

The movement (KE) of particles due to temperature

Body produces heat from metabolism

Question 11

What is an example of electrical energy in the body?

Answer 11

Transmission of electrical signals along neurons

Question 12

What is an example of light energy in the body?

Answer 12

Cells in the retina receive light energy and convert into electrical signals for the brain

Question 13

What is an anabolic reaction?

Answer 13

Energy consuming reaction to create molecules

Question 14

What is a catabolic reaction?

Answer 14

Energy generating reaction by breaking down molecules
(Glucose broken down to produce ATP)

Question 15

What is diffusion?

Answer 15

Movement of particles from area of high concentration to area of low concentration
A passive process

Question 16

What is osmosis?

Answer 16

The movement of water through a semi-permeable membrane to balance the concentration on each side.
A passive process

Question 17

What is a cell membrane channel protein?

Answer 17

A ‘pore’ in the membrane which allows movement of specific molecules/ions
A passive transport process that relies on a gradient
5 types of channel proteins that respond to various triggers

Question 18

What is a cell membrane carrier protein?

Answer 18

A protein which changes shape to then allow entry of specific molecules/ions
A process which requires energy and can move against the gradient
These proteins can perform passive transport also

Question 19

What is a non-gated channel protein?

Answer 19

Always open

Question 20

What is a voltage-gated channel protein?

Answer 20

Responds to a change in the voltage across the membrane

Question 21

What is a ligand-gated channel protein?

Answer 21

Responds to a chemical messenger binding to it first

Question 22

What is a signal-gated channel protein?

Answer 22

Responds to a signal from within the cell

Question 23

What is a mechanically-gated channel protein?

Answer 23

Responds to a change in pressure

Question 24

What are the 6 causes of disease?

Answer 24

Pathogens
Iatrogenic
Toxins
Cellular adaptation/cancer
Genetic inheritance
Mental/emotional

Question 25

How do pathogens cause disease?

Answer 25

Infectious microbes colonises the body Bacteria, virus, fungi, parasite

Question 26

How can bacteria cause disease?

Answer 26

Growth creates a mass that interferes with normal function Produce/excrete toxin Invade and damage tissues/cells

Question 27

How do viruses cause disease?

Answer 27

They destroy host cells

Question 28

How do fungi cause disease?

Answer 28

Toxic ingestion Allergic reaction Parasitic infection

Question 29

What is iatrogenic disease?

Answer 29

Disease caused by medical intervention

Question 30

How do toxins cause disease?

Answer 30

There is a dose at which any substance is harmful LD50 is the median lethal dose of a substance (the minimum concentration to cause death in 50% of patients)

Question 31

What is the difference between a poison and a toxin?

Answer 31

A poison is a chemical substance that can cause harm A toxin is a chemical substance produced by a living organism

Question 32

What is cellular adaptation?

Answer 32

A normal physiological response where cells change in response to stimulus like environmental changes

Question 33

What is cancer?

Answer 33

Cancer occurs when cellular adaptation becomes unregulated and so the cells proliferate uncontrollably damaging nearby tissue and metastasising. Cancer is a result of genetic mutation

Question 34

What are neoplastic and non-neoplastic cells?

Answer 34

Neoplastic: new cells grow Non-neoplastic: existing cells change via hypertrophy, dysplasia, hyperplasia, atrophy or metaplasia

Question 35

What is cell hypertrophy?

Answer 35

Increase in cell size due to increased load/stress

Question 36

What is cell atrophy?

Answer 36

Reduced cell size or number due to reduced load, stimulus to grow or reduced blood supply

Question 37

What is cell hyperplasia?

Answer 37

Increased cell number in response to increased demand or stimulus

Question 38

What is cell dysplasia?

Answer 38

Changed shape, size or organisation of cells (precancer)

Question 39

What is cell metaplasia?

Answer 39

A reversible change where the usual cell type is replaced by another, better suited cell type. Usually from irritation

Question 40

What happens with genetic inheritance?

Answer 40

Genetic mutation: Parent has a gene mutation that is passed down Altered protein production: Gene mutation = code for protein = abnormal protein produced Cellular dysfunction: Abnormal protein leads to abnormal cell processes Tissue/organ dysfunction: Abnormal protein may have been essential to tissue/organ function Disease manifestation

Question 41

How does emotional stress cause disease?

Answer 41

It doesn’t cause disease but significantly influences it Prolonged stress increases cortisol which causes inflammation, lowers immunity and increases susceptibility

Question 42

What are the 5 dimensions of development?

Answer 42

Physical Social Emotional Cognitive Language

Question 43

What is the definition of death?

Answer 43

The irreversible cessation of circulatory and respiratory function

Question 44

What is senescence?

Answer 44

The natural aging death Factors include cell damage, telomere shortening, reduced organ function, reduced immunity, hormonal change etc

Question 45

What is a telomere?

Answer 45

The protective caps on chromosomes which shorten with each cell division