GCSE A* REVISION NOTES


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B1.2: Nerves and the nervous system

B1.2.1: Nerves and the nervous system

Sense Organ

 

Receptor Cells

Stimuli

Eyes

Light Receptors

Light

Ears

Sound Receptors

Sound and changes in position

Nose

Smell Receptors

Chemicals

Tongue

Taste Receptors

Chemicals

Skin

………………………….

Touch, Pressure, Pain and Temperature change

Light Receptor

How the Nervous system works

  1. Receptor cells detect a stimuli
  2. Sensory Neurones carry the electrical impulse from the receptor cells to the central nervous system
  3. The central nervous system works out a response
  4. A relay neurone carries the impulse to a motor neurone
  5. The motor neurone carries the signal to an effector (muscle or gland)
  6. The effector creates a response

Reflex

Synapses

B1.2.2: Control in humans

Conditions

Hormone

Endocrine Gland

Blood sugar level

Insulin and glucagon

Pancreas

Metabolism

Adrenalin

Adrenal

Sexual development

Testosterone

Testes

Water levels

ADH

Pituitary

Nerves

Hormones

Very fast action

Slow action

Act for short time

Act for long time

Act on precise area

Act in a more general way

Negative Feedback Loop

The Brain controls this

 

The Menstrual Cycle

Fertility

IVF

B1.2.3: Control in Plants

Tropism

 

Tropism

Stimulus

Response

Diagram

Phototropism

Light

Shoots +ve

Roots -ve

 

Geotropism

Gravity

Shoots -ve

Roots +ve

 

Hydrotropism

Moisture/Water

Roots +ve

 

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