Neural Control and Coordination quiz

The structural and functional unit of the neural system is the:

The resting membrane is more permeable to:

Myelin sheath around the axons in the PNS is formed by:

The gaps between adjacent myelin sheaths are called:

The part of the brain that controls respiration and cardiovascular reflexes is the:

Bipolar neurons are found in the:

The cranial meninges in order from outside to inside are:

Neurotransmitters are released from:

The corpora quadrigemina are found in the:

The brain stem consists of the:

Distinguish between the central and peripheral neural systems. (2 marks)

What are the functions of the autonomic neural system? (2 marks)

Distinguish between sensory (afferent) and motor (efferent) nerve fibres. (2 marks)

What happens during depolarisation of the axon membrane? (2 marks)

What is saltatory conduction? (2 marks)

What is the role of the synaptic cleft? (2 marks)

Why is the cerebral cortex called grey matter? (2 marks)

What is the limbic system? State its function. (2 marks)

What is the function of the cerebellum? (2 marks)

How does Hydra's neural system differ from that of humans? (2 marks)

An impulse travels 1.2 m along a motor neuron in 15 ms. Calculate the speed of conduction in m/s. (3 marks)

An axon has a resting potential of -70 mV. During an action potential it rises to +40 mV. Calculate the change in potential and express it as a percentage of the magnitude of the resting potential. (3 marks)

A message passes through 4 neurons, each with an axon 0.3 m long and a speed of 60 m/s, with a synaptic delay of 0.5 ms at each of the 3 synapses. Calculate the total time taken. (3 marks)

A sodium-potassium pump uses 30% of a neuron's ATP. If a neuron uses 5 x 10^9 ATP molecules per second, how many are used by the pump? (3 marks)

A non-myelinated fibre 0.5 m long conducts at 1 m/s and a myelinated fibre of the same length at 50 m/s. Calculate the difference in conduction time. (3 marks)

Read the passage and answer the questions. A neuron is a microscopic structure composed of three major parts, namely the cell body, dendrites and axon. The cell body contains cytoplasm with typical cell organelles and certain granular bodies called Nissl's granules. Short fibres which branch repeatedly and project out of the cell body also contain Nissl's granules and are called dendrites. The axon is a long fibre, the distal end of which is branched. (i) What are Nissl's granules? (ii) What is the function of dendrites? (iii) Where do synaptic knobs lie, and what do they contain? (5 marks)

Read the passage and answer the questions. When a stimulus is applied at a site on the polarised membrane, the membrane at that site becomes freely permeable to sodium ions. This leads to a rapid influx of sodium ions followed by the reversal of the polarity at that site. The electrical potential difference across the membrane at that site is called the action potential. (i) What is a polarised membrane? (ii) What happens to the polarity during the action potential? (iii) How is the resting potential restored? (5 marks)

Read the passage and answer the questions. At a chemical synapse, the membranes of the pre- and post-synaptic neurons are separated by a fluid-filled space called the synaptic cleft. Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses. The axon terminals contain vesicles filled with these neurotransmitters. (i) What makes the vesicles release neurotransmitters? (ii) How do neurotransmitters affect the post-synaptic membrane? (iii) Why is transmission across chemical synapses slower than across electrical synapses? (5 marks)

Read the passage and answer the questions. The brain is the central information processing organ of our body and acts as the command and control system. It controls voluntary movements, the balance of the body, the functioning of vital involuntary organs, thermoregulation, hunger and thirst, circadian rhythms, the activities of several endocrine glands and human behaviour. (i) Which part of the brain controls hunger and thirst? (ii) What is the role of the thalamus? (iii) Which part of the brain is responsible for balance? (5 marks)

Read the passage and answer the questions. The cerebrum forms the major part of the human brain. A deep cleft divides the cerebrum longitudinally into two halves, which are termed the left and right cerebral hemispheres. The hemispheres are connected by a tract of nerve fibres called the corpus callosum. The layer of cells which covers the cerebral hemisphere is called the cerebral cortex and is thrown into prominent folds. (i) What is the role of the association areas? (ii) Why is the cerebral cortex folded? (iii) What is white matter made of? (5 marks)

Describe the human neural system and its divisions. Draw a flowchart showing the CNS, PNS and their subdivisions. (6 marks)

Describe the structure of a neuron with a labelled diagram. Explain the types of neurons based on the number of axons and dendrites. (6 marks)

Explain how a nerve impulse is generated and conducted, with diagrams showing the resting and action potentials. (6 marks)

Explain the transmission of impulses across a synapse with a labelled diagram of a chemical synapse. (6 marks)

Describe the structure and functions of the forebrain, midbrain and hindbrain with a labelled diagram of the human brain. (6 marks)