O Level Biology

Compare nervous and hormonal control, limited to speed of action and duration of effect

Explain accommodation to view near and distant objects in terms of the contraction and relaxation of the ciliary muscles, tension in the suspensory ligaments, shape of the lens and refraction of light

Explain the pupil reflex in terms of light intensity and antagonistic action of circular and radial muscles in the iris

Identify, on a diagram, the structures of the eye, limited to: cornea, iris, pupil, lens, ciliary muscles, suspensory ligaments, retina, fovea, optic nerve and blind spot

Describe that synapses ensure that impulses travel in one direction only

Describe the events at a synapse: (a) an impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap (b) the neurotransmitter molecules diffuse across the gap and bind with receptor proteins (c) an impulse is stimulated in the next neurone

Describe simple reflex arcs in terms of receptor, sensory neurone, relay neurone, motor neurone and effector (muscles and glands)

State that electrical impulses travel along neurones

Identify, on diagrams, sensory, relay and motor neurones

Describe that the nervous system (brain, spinal cord and nerves) coordinates and regulates body functions