Get premium membership and access questions with answers, video lessons as well as revision papers.
The central nervous system consists of the brain; and the spinal cord; and nerve fibres; that serve the sensory organs ; and the effector organs and glands; the brain is a collection of millions/billions/109 neurones; that form the biggest ganglion; it is highly convoluted; to provide a large surface area for impulse reception, processing and transmission; the brain and the spinal cord are protected by the meninges; the brain and the spinal cord have spaces/canals and ventricles; filled with a cerebrospinal fluid; which acts as a bridge/supply medium for oxygen and nutrients; and the removal of metabolic waste; the brain has centres for the storage; retrieval and processing of impulses; the cerebrum processes and stores information; the cerebellum; sends impulses to joints and muscles; to correct balance; the medulla oblongata sends impulses to the cardiovascular; and breathing/ventilation systems; to regulate them; the brain has the hypothalamus that secretes a neurosecretion to influence a pituitary gland that secretes hormones; involved in reproduction; and homeostatic functions; the hypothalamus; detects changes in temperature; and osmotic pressure; and sends impulses to relevant effector organs for their regulation; the thalamus; receives majority of the impulses and channels them to the relevant areas of the brain; both the brain and the spinal cord have regions of the grey matter; that enable very rapid processing/transmission of impulses; the nervous system has neurones (relay/intermediate, motor and sensory); that transmit impulses at a very rapid note/speed (100 ms-1) to and from the central nervous system to effect suitable responses; there exists in the central nervous system an electrochemical gradient/concentration gradient; that allows for the generation of electrical impulses; they have numerous mitochondria; for generating energy for the function of the sodium pump; which enables polarization and repolarisation; during impulse transmission and refractory/recovery periods; the spinal cord has no integration/association functions and is therefore suited for reflex actions; needed in emergencies; the spinal cord is long; and connects nerve fibres of the peripheral nerves with the brain for storage of information; the spinal cord has a dorsal root for sensory fibres/neurones; and a ventral root; for motor neurones/fibres; Accept any other correct.
Edwinnyongesa8 answered the question on December 6, 2018 at 03:39
- State the economic importance of members of Monera and Fungi and for each economic importance name a suitable or appropriate organism(Solved)
State the economic importance of members of Monera and Fungi and for each economic importance name a suitable or appropriate organism
Date posted: December 6, 2018. Answers (1)
- Describe the process of mitosis(Solved)
Describe the process of mitosis
Date posted: December 4, 2018. Answers (1)
- Describe how the various supportive tissues in plants adapt them to their habitats(Solved)
Describe how the various supportive tissues in plants adapt them to their habitats
Date posted: December 4, 2018. Answers (1)
- Discuss Lamarck’s and Darwin’s theories of evolution(Solved)
Discuss Lamarck’s and Darwin’s theories of evolution
Date posted: December 4, 2018. Answers (1)
- Describe the process of secondary thickening in a woody stem
(Solved)
Describe the process of secondary thickening in a woody stem
Date posted: December 4, 2018. Answers (1)
- What is secondary growth(Solved)
What is secondary growth?
Date posted: December 4, 2018. Answers (1)
- Which organelle is most abundant in white blood cell?(Solved)
Which organelle is most abundant in white blood cell?
Date posted: November 13, 2018. Answers (1)
- Explain how altitude affects the rate of breathing(Solved)
Explain how altitude affects the rate of breathing.
Date posted: November 8, 2018. Answers (1)
- Explain how mammals regulate their body temperature and relate this to their body size(Solved)
Explain how mammals regulate their body temperature and relate this to their body size
Date posted: November 7, 2018. Answers (1)
- Name 5 characteristics of phylum platyhelminthes?(Solved)
Name 5 characteristics of phylum platyhelminthes?
Date posted: November 7, 2018. Answers (1)
- Giving specific examples; explain the forms of aneuploidy in animals.(Solved)
Giving specific examples; explain the forms of Aneuploidy in animals.
Date posted: November 5, 2018. Answers (1)
- What is the difference between glycosuria and hyperglycemia?(Solved)
What is the difference between glycosuria and hyperglycemia?
Date posted: October 31, 2018. Answers (1)
- Describe the events that take place from the time when a mature pollen grain lands on stigma until formation of fruits and seeds(Solved)
Describe the events that take place from the time when a mature pollen grain lands on stigma until formation of fruits and seeds.
Date posted: October 30, 2018. Answers (1)
- Define the following in relation to reception, response and coordination in plants and animals (a) Irritability (b) response (c) Stimulus (Solved)
Define the following in relation to reception, response and coordination in plants and animals
(a) Irritability
(b) Response
(c) Stimulus
Date posted: October 28, 2018. Answers (1)
- State two reasons why accumulation of lactic acid acid [in animal cells, produced from pyruvic acid through anaerobic respiration, in “power” exercises e.g. sprinting]...(Solved)
State two reasons why accumulation of lactic acid acid [in animal cells, produced from pyruvic acid through anaerobic respiration, in “power” exercises e.g. sprinting] leads to an increase in the rate of the heart beat.
Date posted: October 27, 2018. Answers (1)
- State and explain four chromosome structure and variation.(Solved)
State and explain four chromosome structure and variation.
Date posted: October 24, 2018. Answers (1)
- Discuss the double helix structure of DNA(Solved)
Discuss the double helix structure of DNA.
Date posted: October 23, 2018. Answers (1)
- State and explain characteristics of genetics material(Solved)
State and explain characteristics of genetics material.
Date posted: October 23, 2018. Answers (1)
- Define gene regulation and state five reasons why gene activity is regulated in a cell(Solved)
Define gene regulation and state five reasons why gene activity is regulated in a cell.
Date posted: October 21, 2018. Answers (1)
- What are the functions of centrosomes?(Solved)
What are the functions of centrosomes?
Date posted: October 21, 2018. Answers (1)