(a) What is a sense organ?
(b) List four sense organs found in mammals.
(c) Describe the processes that will cause a person who has been spinning to feel dizzy
(d) State two functions each of the following structures:
(i) Cerebellum
(ii) Cerebrum
(iii) Medulla Oblongata.
Explanation
(a) Sense organ: A sense organ is an organ made up of a group of specialized cells/tissues/receptors , which is able to receive/collect/perceive/detect stimulus and transmit the information/impulse/message to the nervous system.
(b) Sense organs in mammals: Nose/olfactory organ; eye; ear; tongue; skin.
(c) When a person spins and stops:
Endolymph, in the inner ear/semi circular canals continues to move causing sensory hairs/sensory cells to be stimulated. impulses reaching the brain/cerebellum through the auditory nerve show that the person is still spinning the brain interprets the body as still moving – and confusion is imposed on the receptors – sensitive to position – giving the person an impression of dizziness.
(d) Functions of:
(i) Cerebellum – Receives impulses from the ear; involved in balance and posture; coordinates voluntary muscles.
(ii) Cerebrum – Controls voluntary actions/any other correct example; concerned with memory; intelligence.
(iii) Medulla Oblongata: Controls involuntary/reflex actions; heartbeat; coughing; sneezing; blinking/any other correct involuntary actions.