non infectious disease

Question 1

homeostasis

Answer 1

Hom-eo-stay-sis- is the process of keeping conditions inside the organism relatively constant, or stable. Homeostasis involves the systems of control and coordination such as the nervous system and the endocrine system (the glands in your body that produces hormones).
Homeostasis consists of two stages:
• Detecting changes from the stable state
• Counteracting changes from the stable state.

Question 2

How does a neuron conduct electrical signals?

Answer 2

Electrochemical signals are conducted by neurons by a change in the electrical potential of the cell membrane. On either side of the cell membrane in a neuron there are charged ions of K+, Na+ and CI (potassium, sodium, chloride). A change in concentration of ions across the cell membrane generates an electrical impulse. This temporary change is known as an action potential.

Question 3

Repolarisation

Answer 3

During repolarisation of the neurone the Na gates close. The potassium gates open ( K+). All K+ go outside the membrane. The membrane becomes more negative on the inside and is repolarised.

Question 4

What is a synapse?

Answer 4

It is a gap between the axon terminal of the next neuron and the dendrites of the next neuron along which signals are transmitted by neurotransmitters (chemicals).
When the electrical signal/action potential reaches the axon terminal chemicals called neurotransmitters are releases which pass on the message to the next neurone.

Question 5

What is the threshold of a neurone at which an action potential will be

Answer 5

-55 mv (milli volts) = difference in charge

Question 6

1. What is the resting potential of a neurone

Answer 6

-70 mv

Question 7

PNS

Peripheral nervous system

Answer 7

• All the nerves in the body except brain and spinal cord

* Carry electrical impulses (massages) to and from the CNS

Question 8

CNS

Central nervous system

Answer 8

• The brain and the spinal cord

* Processes signals transmitted by peripheral nerves

Question 9

loops

Answer 9

Positive loop – release of oxytocin in child birth

Negative feedback – controlling temperature and blood glucose level

Question 10

genetic disease

Answer 10

Example - Phenylketonuria
Mutation in gene coding for enzyme phenylalanine hydroxylase.
Body cannot convert phenylalanine to tyrosine without enzyme → increase in concentration of phenylalanine.

RESULTS IN:
– MENTAL RETARDATION
FADED SKIN/HAIR COLOUR.
SMALLER HEAD SIZE.
SEIZURES.

Question 11

Nutritional diseases

Answer 11

Scurvy
Deficiency of vitamin C
Swelling of body parts and fatigue..