14. Coordination and response

Nota:

• as an electrical signal that passes along nerve cells called neurones

Nota:

• in terms of: - the central nervous system consisting of brain and spinal cord - the peripheral nervous system - coordination and regulation of body functions

1. distinguish between voluntary and involuntary actions

1. motor (effector)
2. relay (connector)
3. sensory

Nota:

• in terms of receptor, sensory neurone, relay neurone, motor neurones and effector

1. describe a simple reflex action

   Nota:

   • as a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors (muscles and glands)

Nota:

• as a junction between two neurones

1. describe the structure of a synapse

   Nota:

   • including the presence of neurotransmitter vesicles, the synaptic cleft and neurotransmitter receptor molecules

Nota:

• from vesicles into the synaptic gap and how the neurotransmitter diffuses across to bind with receptor molecules, in the membrane of the neurone after the synaptic gap, causing the impulse to continue

1. state that in a reflex arc the synapses ensure that impulses travel in one direction only
2. state that many drugs, e.g. heroin, act upon synapses

Nota:

• as groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals

Nota:

• limited to cornea, iris, pupil, lens, retina, optic nerve and blind spot

1. describe the function of each part of the eye
   1. cornea

      Nota:

      • refracts light
   2. iris

      Nota:

      • controls how much light enters pupil
      1. explain the pupil reflex

         Nota:

         • in terms of light intensity and pupil diameter, and antagonistic action of circular and radial muscles in the iris
   3. lens

      Nota:

      • focuses light onto retina
      1. explain accommodation to view near and distant objects

         Nota:

         • in terms of the contraction and relaxation of the ciliary muscles, tension in the suspensory ligaments, shape of the lens and refraction of light
   4. retina

      Nota:

      • contains light receptors, some sensitive to light of different colours
      1. state the distribution of rods and cones

         Nota:

         • in the retina of a human
         1. outline the function of rods and cones

            Nota:

            • limited to greater sensitivity of rods for night vision and three different kinds of cones absorbing light of different colours for colour vision
   5. optic nerve

      Nota:

      • carries impulses to the brain
2. identify the position of the fovea

Nota:

• as a chemical substance produced by a gland and carried by the blood, which alters the activity of one or more specific target organs

Nota:

• limited to: -adrenal glands and adrenaline -pancreas and insulin -testes and testosterone -ovaries and oestrogen

Nota:

• limited to increased breathing and pulse rate and widened pupils

1. discuss the role of the hormone adrenaline

   Nota:

   • in the chemical control of metabolic activity, including increasing the blood glucose concentration and pulse rate
2. give examples of situations in which adrenaline secretion increases

Nota:

• in terms of speed and longevity of action

1. insulin
2. oestrogen
3. testosterone

Nota:

• as the maintenance of a constant internal environment

1. explain that homeostasis is the control of internal conditions within set limits

Nota:

• by the liver and the roles of insulin and glucagon from the pancreas

1. outline the symptoms and treatment of Type 1 diabetes

   Nota:

   • details of B cells is NOT required

1. hairs
2. hair erector muscles
3. sweat glands
4. receptors
5. sensory neurones
6. blood vessels
7. fatty tissue

Nota:

• in terms of insulation, seating, shivering, vasodilation and vasoconstriction of arterioles supplying skin surface capillaries and the role of the brain (limited to blood temperature receptors and coordination)

Nota:

• as a response in which parts of a plant grow towards or away from gravity

Nota:

• as a response in which parts of a plant grow towards or away from the direction from which light is coming

Nota:

• as examples of the chemical control of plant growth

Nota:

• limited to: - auxin made in shoot tip (only) - auxin spreads through the plant from the shoot tip - auxin is unequally distributed in response to light and gravity - auxin stimulates cell elongation

1. brain
2. spinal cord

1. cranial nerves
2. spinal nerves