Download Chapter 16

Chapter 16
General plan of the nervous system: CNS and PNS
Functions of main parts of the brain: cerebrum, cerebellum and medulla oblongata
Functions of spinal cord
Neurone: sensory neurone, interneurone and motor neurone
Synapse
Reflex arc, reflex action and voluntary actions
Nature of hormonal coordination
General plan of the endocrine system
1.
What are the two coordination systems in our body?
Nervous system and endocrine system
2.
What are the two parts of our nervous system?
Central nervous system and peripheral nervous system
3.
What are the two parts of central nervous system?
Brain and spinal cord
4.
What are the two parts of peripheral nervous system?
Cranial nerves (nerves connected to the brain) and spinal nerves (nerves connected to the spinal cord)
5.
What are the uses of nerves?
Transmit nerve impulses. If the dendron and axon are long, the cell can transmit nerve impulse over a long distance.
6.
How are our CNS protected?
It is protected by bone, 3 layers of membranes and cerebrospinal fluid.
7.
What are the functions of cerebrospinal fluid?
It provides nutrients and oxygen to the nerve cells. It helps to remove wastes from the nerve cells. It absorbs shock to protect
the nerve cells. It supports the brain and spinal cord.
8.
Describe the structure of a neurone.
It has a cell body. The cytoplasm branches out from the cell body. The long cytoplasm extension is called nerve fibre.
9.
What is the use of myelin sheath?
It is a fatty material surrounding the nerve fibres. It protects the nerve fibres. It insulates the nerve fibres. It speeds up the
transmission of nerve impulse.
Page 1
10. What is the use of dendrons?
It carries nerve impulses towards the cell body.
11. What is the use of axons?
It carries nerve impulses away from the cell body.
12. What are the functions of sensory neurone and motor neurone?
Sensory neurone connects the receptor. It carries impulse from receptor to CNS. Motor neurone connects the effector. It
carries impulse from CNS to effector (muscles or glands)
13. What kinds of cell body can be found in the CNS?
Cell body of interneurone and cell body of motor neurone
14. What is synapse?
The gap between two neurones
15. How can a nerve impulse be transmitted across a synapse?
When a nerve impulse reaches the ending of the axon of one neurone, the ending releases a chemical called neurotransmitter.
The neurotransmitter diffuses across the synapse. The neurotransmitter touches the cell membrane of the dendron of another
neurone. It stimulates the dendron to generate a nerve impulse.
16. What is the use of a synapse?
To allow the nerve impulse to be transmitted in one direction only (from axon of one neurone to the dendron of next neurone)
To allow one neurone to communicate with many neurones.
17. What are the three parts of brain?
Cerebrum, cerebellum and medulla oblongata
18. How can the brain be protected?
It is protected by cranium, 3 membranes and cerebrospinal fluid in central cavity
19. Why are the surface of the cerebrum and cerebellum folded?
To increase surface area for packing more neurons, so that coordination can be more efficient.
20. What is the location of grey matter in the cerebrum?
Grey matter is located in the outer region. White matter is located in the inner region.
21. What are found in the grey matter?
Cell bodies of interneurones and motor neurones.
Page 2
22. What are found in the white matter?
Nerve fibres of sensory and motro neurones
23. What are the uses of association area of cerebrum?
Integrate information from receptors or sensory areas. It is for thinking and memory.
24. What is the use of sensory area of cerebrum?
It receives nerve impulse from receptors and gives sensations.
25. What is the use of cerebellum?
It sends out nerve impulse to effectors to carry out a response or a voluntary action.
26. What are the uses of medulla oblongata?
It regulates cranial reflex and controls involuntary action such as breathing and heart beat.
27. What is the location of grey matter in medulla oblongata and spinal cord?
Grey matter is located at the inner layer and white matter is located at the outer layer.
28. Why is reflex important?
It regulates many important processes in body like breathing and heartbeat. It protects us from danger.
29. How can the spinal cord be protected?
It is protected by vertebral column (backbone), 3 layers of membranes and cerebrospinal fluid in central canal.
30. Explain why there is a dorsal root ganglion but not a ventral root ganglion.
The cell bodies of sensory neurons are located in the dorsal root ganglion. Cell bodies of motor neurons are located in the
grey matter of the spinal cord.
31. What can be found in the dorsal root and ventral root?
Dorsal root: sensory neurone; ventral root: motor neurone
32. Which part of body regulate cranial reflex? Which part of body regulate spinal reflex?
Cranial reflex: medulla oblongata; spinal reflex: spinal cord
33. Name two cranial reflexes and two spinal reflexes.
Cranial reflex: swallowing and blinking; spinal reflex: withdrawal reflex and knee-jerk reflex
34. What are the functions of spinal cord?
It acts as a bridge between the brain and the body parts. It allows nerve impulses to pass into and out of the brain. It is for
spinal reflex.
Page 3
35. What is a reflex action?
It is an inborn, rapid and automatic response to a stimulus. It is stereotyped and involuntary. It does not involve the cerebrum.
36. How can a withdrawal reflex and knee jerk reflex initiated?
Withdrawal reflex: pain receptors on hand or leg; Knee-jerk reflex: Stretch receptor in thigh muscle (tapping the tendon
below the knee cap)
37. What are the differences between reflex action and voluntary action?
Reflex action
Voluntary action
Does not involve the cerebrum
Must involve the cerebrum
Inborn response
Learning is required
A receptor must be required
Receptor may not be required (It can be a response or not.)
Stereotyped
Not stereotyped
38. What is the difference between exocrine gland and endocrine gland?
Exocrine gland
Endocrine gland
Secrete juice via a duct to outside
Secrete hormone into blood directly without via a duct
39. What is hormone? Is it an enzyme?
It is a chemical. It works as a messenger. It is secreted by cells in endocrine gland. It is transported in blood. It stimulates
target cells to work. It is not an enzyme. It may be protein (insulin) or may not be protein (sex hormone). It does not speed up
a chemical reaction.
40. What hormones are secreted by pancreas? What juice is secreted by pancreas?
Insulin from beta cells in pancreas. Glucagon from alpha cells in pancreas. Pancreatic juice (contains amylase, protease and
lipase) is secreted into duodenum.
41. Compare hormonal coordination and nervous coordination.
Hormonal coordination
Nervous coordination
Endocrine system: endocrine gland, blood
Nervous system: brain, spinal cord, nerves
Chemical messenger
Electrical messenger and chemical messenger
Messenger moves in blood
Messenger moves along nerve and across synapse
Slow transmission
Fast transmission
Area of response: widespread
Area of response: localized
Duration of effect: long lasting
Duration of effect: short-term
Body processes: reproduction, growth, regulation
Body processes: reflex action, involuntary and voluntary action
Page 4