- Write two differences between axon and dendrites.
Two differences between axon and dendrites are shown below in table:
Axon Dendrites It is long and generally unbranched. It is small, numerous and branched. It conducts the nerve impulses away from the cell body. It conducts the nerve impulses towards the cell body.
- Write the functions of Medulla oblongata.
Functions of Medulla oblongata are:
- It receives and integrates signals from spinal cord and sends resulting signals to the cerebellum.
- It controls complex activities such as heart rate, breathing, vomiting, sneezing.
- Why is pancreas called mixed gland?
- The pancreas is called a mixed gland because it has both endocrine and exocrine functions. It produces both digestive enzymes as well as hormones.
- Write any two effects that are seen due to lack of thyroxine hormone.
- Two effects that are seen due to lack of thyroxine hormone are mental weakness and dry skin.
- Why are hormones called chemical messengers? Write with example.
- The hormone is produced in one part of the body and works in different parts of the body. for example, growth hormone is produced by the pituitary gland and helps in the growth of other parts of the body.
State one function each of the parts A, B and C of the human brain of
A = Spinal cord
B = Cerebellum
C = Cerebrum
- Why is pituitary gland called 'Master gland'?
- The pituitary gland is called the 'Master gland' because it produces hormones that control other glands and many body functions including growth.
- What is the difference between afferent nerve and efferent nerve?
The difference between afferent nerve and efferent nerve is shown below in
Afferent nerve (sensory nerves) Efferent (motor nerve) It carry impulses from sensory receptors (body parts) to the brain or spinal cord. It carry impulses from the brain or spinal cord to effectors muscle. It contains long dendrites and short axon. It contains long axon and short dendrite. For example: optic nerve, auditory nerve. For example: facial nerve.
- Write any two differences between Exocrine and Endocrine gland.
Two differences between Exocrine and Endocrine gland is shown below in
Exocrine gland Endocrine gland It is a ducted gland. It is a non-ducted gland. It produces enzymes. It produces hormones.
- Why is the pituitary gland called the master gland? Write any one effect seen in the body due to over and under secretion of the hormone each by this gland.
The pituitary gland is called the 'Master gland' because it produces
hormones that control other glands and many body functions including growth.
Effect seen in the body due to over secretion of the hormone by this gland is gigantism and lack of this results in dwarfism.
- When we touch a hot iron rod, we remove our hands immediately. How does this process occur in our body? Explain.
- When we touch a hot iron rod, we remove our hand immediately, it is a reflex action. Stimulus is received by the receptors (fingers) and an impulse is then set in the spinal cord. In the spinal code, the impulse passes through the association neurons to motor neurons and finally, to the muscles of the arm. The muscles then contract and hands are moved away.
- What happens if there is the lack of hormone produced by adrenal gland?
- Under secretion of hormones produced by the adrenal gland caused the weakness in the body, decreases blood pressure, low level of sugar in the blood and the sensation of vomiting.