9: Nervous I Flashcards
What is the technical name for a nerve fibre?
Axon
What material insulates the axon?
Myelin sheath
Axons are insulated by __ sheaths.
myelin
What is the bulky centre of a nerve cell called?
The body
What name is given to the projections coming off the body of a nerve cell?
Dendrites
Which organs make up the central nervous system?
Brain
Spinal cord
Which type of nerves connect with the spinal cord?
Spinal nerves
Which nerves, of which there are 12, travel in the cranial cavity?
Cranial nerves
well done
What is the autonomic nervous system?
The nervous system responsible for unconscious control of the body, e.g breathing, heartbeat, digestion…
What are the two divisions of the autonomic nervous system?
Sympathetic
Parasympathetic
What are the two main types of neuron?
Afferent neurons
Efferent neurons
Afferent neurons are (sensory / motor).
sensory
Where do afferent neurons carry signals?
Towards the CNS
Efferent neurons are (sensory / motor).
motor
Where do efferent neurons carry signals?
Away from the CNS
What is a site of chemical communication between 2+ neurons?
Synapse
What kind of communication occurs at a synapse?
Chemical communication
What molecules carry chemical signals across synapses?
Neurotransmitters
___ signals travel along axons. ___ signals are carried across synapses.
Electrical , Chemical
Neurotransmitters can be blocked by certain ___.
drugs
What is the somatic nervous system concerned with?
The body wall and external environment - sensation and movement
What is the autonomic nervous system concerned with?
The organs and internal environment - i.e breathing, heartbeat, digestion, glands
Each bone of the skull corresponds to a ___ of the brain.
lobe
Each brain lobe is named according to the ___ bone covering it.
cranial
What is a gyrus?
A ridge on the brain
What is a sulcus?
A smaller depression or groove on the brain
usually surrounds a gyrus.
What is the outermost surface of the brain called?
The cerebral cortex
Generally, what is the superior part of the brain called?
Cerebrum
What is the posteroinferior portion of the brain called?
Cerebellum
What is found just anterior to the spinal cord?
The brainstem
What are the three depressions which make up the floor of the cranial cavity?
Anterior, middle and posterior fossae (fossa)
The floor of the cranial cavity runs along the ___ of the skull.
base
What is the name of the hole found in the posterior cranial fossa?
Foramen magnum
The ___ becomes the ___ ___ once it has passed through the foramen magnum.
brainstem
spinal cord
What is the spinal cord called superior to the foramen magnum?
Brainstem
What is the brainstem called inferior to the foramen magnum?
Spinal cord
Name the three sections of the brainstem in descending order.
Midbrain
Pons
Medulla oblongata
What is the end of the spinal cord called?
Conus medullaris
At what vertebral level is the conus medullaris found?
L1/2
The spinal cord is (longer / shorter) than the vertebral column.
shorter
What makes up the cerebral cortex of the brain?
Grey matter
What kind of matter makes up the inner part of the brain?
White matter
Why is the inner part of the brain white?
Lots of myelinated axons - myelin is white
What are the three components of the peripheral nervous system?
Somatic cranial nerves
Somatic spinal nerves
Autonomic nerves (sympathetic and parasympathetic)
Learn the spinal nerves!!!
!!!
Are spinal nerves sensory or motor?
Mixed - can be both
Where in the vertebral column do spinal nerves emerge from?
Intervertebral foramen
How many vertebrae are there in each section of spine?
7 cervical vertebrae
12 thoracic vertebrae
5 lumbar vertebrae
5 fused sacral vertebrae
4 fused coccygeal vertebrae
How many vertebrae are there in total?
33 vertebrae
(7C + 12T + 5L + 5S + 5CG)
How many cervical spinal nerves are there?
8 cervical spinal nerves
(Confusing as there are only 7 cervical vertebrae!)
How many coccygeal spinal nerves are there?
Just one
How many spinal nerves are there in total?
31
(8C + 12T + 5L + 5S + 1CG)
Each spinal nerve supplies one ___ of the body wall.
strip
Each spinal nerve has two projections - what are they called?
Anterior ramus
Posterior ramus
supply different strips of the body wall.
The body wall is divided into segments, each supplied by a single pair of spinal nerves. What are these segments called?
Dermatomes
come back when more knowledgable for some work on dermatomes and nerve plexuses
Where do sympathetic nerves exit the spinal cord?
T1 to L2
i.e not the whole spinal cord!
Once sympathetic nerves have passed down and out of the spinal nerves, where do they go?
Sympathetic chain
Sympathetic nerves emerge from the sympathetic chain into ___ nerves which eventually supply the organs.
splanchnic
Splanchnic nerves
Spinal cord
Sympathetic chain
Autonomic centres in brain
Arrange these to describe the route taken by sympathetic nerves originating from the brain.
Autonomic centres in brain
Spinal cord
Sympathetic chain
Splanchnic nerves
How do parasympathetic axons leave the CNS?
Via cranial nerves
Which cranial nerves allow parasympathetic nerves to leave the CNS?
III (oculomotor), VII (facial), IX (glossopharyngeal), X (vagus)
