NERVOUS SYSTEM Session 4

Question 1

In the brain stem , what are the midbrain , pons and medulla oblongata each responsible for ?

Answer 1

• Midbrain is a relay station between the cerebrum and the spinal cord or cerebellum.
• Pons communicates with the cerebellum and the rest of the CNS
• The Medulla Oblongata consists of reflex centers that help to regulate heartbeat , blood pressure , vomiting , coughing , sneezing and swallowing

Question 2

What is the reticular formation made of and what is it responsible for ?

Answer 2

• It is a network of nuclei ( masses of gray matter ) and fibres that extends through the brain stem
• it helps you stay alert and filter out unnecessary sensory stimuli (like studying with the TV on)

Question 3

What is the Limbic System responsible for ?

Answer 3

• It integrates emotions with higher mental functions (reasoning, memory)

Question 4

In the Limbic System, what are the Cingulate Gyrus , Amygdala and Hippocampus responsible ?

Answer 4

• Cingulate Gyrus : Expressing emotions through gesture (smile) , involved in decision making
• Amygdala : creates the sensation of fear
• Hippocampus : Plays a crucial role in learning and memory

Question 5

What is long term potentiation ?

Answer 5

• After synapses have been used intensively they releases more neurotransmitters than before which may be involved in memory storage

Question 6

What does the Peripheral nervous system consist of ?

Answer 6

• Somatic and Autonomous system

Question 7

In the peripheral nervous system , how many cranial and spinal nerves are there and where do they arise from and what is the ganglia ?

Answer 7

• 12 pairs of Cranial Nerves : arise from the brain
• 31 Paris of Spinal Nerves : arise from the spinal cord
• Ganglia : collections of nerve cell bodies outside the CNS

Question 8

What does the Somatic system control and is it voluntary or involuntary ?

Answer 8

• It serves the skin , skeletal muscles and tendons and it is mostly voluntary.

Question 9

How does a reflex arc work ?

Answer 9

• Sensory neurons enter the cord through the dorsal root and stimulate many interneurons and then nerve signals travel in these motor fibers to an effector to bring about a response to the stimulus

Question 10

What does the Autonomic system regulate ?

Answer 10

• It regulates the cardiac and smooth muscles , organs and glands

Question 11

What are the two different autonomic systems and what do they do ?

Answer 11

• Sympathetic ( fight or flight ) and parasympathetic ( rest and digest )

Question 12

What does the Autonomic motor system use to generate each impulse ?

Answer 12

• Two neurons and one ganglion

Question 13

In the sympathetic division most preganglionic fibers arise from where and terminate where?

Answer 13

Most of them arise from the middle portion of the spinal cord and terminate in ganglia that lie near the cord

Question 14

In the sympathetic division what neurotransmitter is released by the postganglionic axon ?

Answer 14

• Norepinephrine

Question 15

In the parasympathetic division, where do the cranial nerves and fibers arise from ?

Answer 15

• from the bottom portion of the spinal cord

Question 16

What types of responses does the parasympathetic division promote ?

Answer 16

• it promotes response associated with a relaxed state

Question 17

In the parasympathetic division , what neurotransmitter ?

Answer 17

• Acetylcholine