Central nervous system Flashcards
The central nervous system is the body’s _____ _____ and is made up of the _____ and _____ ___
- processing centre
- brain and spinal cord
what are the two systems the human nervous system consists of?
central and peripheral systems
what is the role of the brain
The brain is the organ of behaviour,
what is the role of the spinal cord
the spinal cord is the pathway for messages sent from the brain to the body, and messages from the body to the brain.
the central nervous system is the _____ force behind all of our _____
- driving force
- behaviours
what is the peripheral nervous system and its role
it radiates throughout the whole body and is responsible for connecting all organs and systems to the central nervous system.
where is the peripheral nervous system located
The division located outside of the skull and spine
what are the three main nerve systems in the peripheral nervous system
cranial nerves, spinal nerves, and the autonomic nervous system.
where do cranial nerves have a direct connection to?
the brain
where do cranial nerves not join?
spinal cord
how many pairs of cranial nerves are there?
12
- one of the pair serves the right side and the other serves the left side,
what are the 3 categories the cranial nerves fit into?
sensory information
motor information
or sensory and motor information.
what 3 cranial nerves carry sensory info
the olfactory nerve carries information about smell
the optic nerve carries visual information
vestibulocochlear nerve carries information about hearing and balance.
5 cranial nerves that provide motor function to structures in the head
the oculomotor nerves, the trochlear nerves and the abducens nerves provide motor function that allows the eyes to move.
The spinal accessory nerves control neck muscles and the hypoglossal nerves provide motor function to the tongue.
the cranial nerves that provide sensory AND motor functions
The trigeminal nerve has a role to play in both facial sensation and chewing.
The facial nerves control facial muscles and also receive information about taste.
The glossopharyngeal nerves control the muscles in the throat and receive sensory feedback from the throat.
The vagus nerve is an extremely long nerve and runs from the head to the heart, liver and intestines
where are spinal nerves connected to
Spinal cord
where does the spinal column run from
base of the brain to the tailbone
how many pairs of spinal nerves are there
thirty one pairs of nerves emerge through openings in the bony spine.
one of the pair of spinal nerves will serve the right side of the body, and the other will serve the left side of the body.
what are the different sections of the spinal cord named after
named after the corresponding area of the body, and has a different appearance at different levels.
how many pairs of cervical spinal nerves are there?
where are these located?
The eight pairs of cervical spinal nerves emerge above each of the bony cervical vertebrae, in the neck region.
what do cervical spinal nerves do
They stimulate muscle movement in your neck, shoulder, arm and hand, and provide sensation.
At all other areas of the spinal cord, the spinal nerves emerge ______ the ______
- below
- vertebre
how many pairs of thoracic spinal nerves are there?
where are these located?
- 12
-T1 through to T12;
emerge below the corresponding thoracic vertebrae, in the chest area.
function of thoracic spinal nerves
The thoracic spinal nerves (T1–T12) have three main functions:
Motor: They control the intercostal muscles (involved in breathing) and some abdominal muscles.
Sensory: They provide sensation to the skin of the chest and abdomen and transmit signals from internal organs (e.g., heart, lungs, stomach).
Autonomic: They are part of the sympathetic nervous system, helping regulate functions like heart rate and blood pressure.
how many pairs of lumbar spinal nerves are there?
where are they located
- 5
L1-L5
emerge below the corresponding lumbar vertebrae, found towards the lower part of the back
function of lumbar spinal nerves
Motor functions: Controlling muscles in the lower back, hips, thighs, and legs, including those involved in walking and bending.
Sensory functions: Providing sensation from the skin of the lower back, hips, thighs, and groin.
Autonomic functions: Contributing to bladder and bowel control.
Reflexes: Involved in reflexes like the knee-jerk (patellar reflex).
how many pairs of sacral spinal nerves are there?
where are these located?
- 5 pairs
S1- S5
emerge below the corresponding sacral vertebrae.
function of sacral nerves
Motor: They control muscles of the lower legs, feet, and pelvic floor, aiding in walking, standing, and bowel/bladder control.
Sensory: They provide sensation to the skin of the groin, buttocks, genitals, and parts of the legs and feet.
Autonomic: They play a significant role in controlling bladder, bowel, and sexual functions.
what are coccygeal spinal nerves?
where are these located
is located at the end of the spinal cord, emerging from the coccyx (the tailbone) region.
Motor Functions: They provide motor control to the small muscles of the pelvic floor, assisting with functions like support for the pelvis and bowel/bladder control.
Sensory Functions: They carry sensory information from the skin around the coccyx (tailbone) and the lower part of the anus.
each spinal nerve consists of the _____ of two functionally distinct branches called _____
- fusion
- roots
what are the two roots called
- ventral
- dorsal
where does the spinal nerve receive sensory input from?
how does this work
the dorsal root
The body sends sensory information to the spinal nerves via this dorsal root.
what does the ventral root allow spinal nerves to do
allows the spinal nerves to send motor projections to muscles.
what is the role of the autonomic nervous system
The autonomic nervous system regulates internal function, and we do not have conscious, voluntary control over this system.
what are the 2 divisions of the autonomic nervous system?
parasympathetic
sympathetic
describe the sympathetic nervous system
The sympathetic nervous system prepares the organism for action.
Sympathetic nerves are responsible for what is known as the `fight or flight’ response: the heart rate quickens, the pupils in the eye dilate, and blood pressure increases.
what neurotransmitter does the sympathetic nervous system use?
The sympathetic nervous system uses noradrenaline, sometimes known as norepinephrine, which is known to accelerate activity.
describe the parasympathetic nervous system
The parasympathetic system, on the other hand, is responsible for the body’s ability to relax and to prevent the body from overworking.
This is sometimes referred to as the `rest and digest’ response.
Parasympathetic nerves slow down the heart rate and constrict the pupil.
differences between sympathetic and parasympathetic nervous system?
The sympathetic nervous system speeds up heart rate during exercise, but the parasympathetic nervous system slows down heart rate during rest.
The activity of sympathetic nerves constricts blood vessels, raising blood pressure, whereas the activity of parasympathetic nerves dilates blood vessels by relaxing blood vessel walls and in turn lowering blood pressure.
what neurotransmitter does the parasympathetic nervous system use
The parasympathetic nervous system uses acetylcholine which slows down activity.
in embryonic development which 3 swellings does the brain develop from
the brain develops from three separate swellings at the top of what is known as the `neural tube’.
These swellings become the forebrain, midbrain and hindbrain.
The hindbrain, midbrain and diencephalon form the upper end of a cylinder continuous with the spinal cord.
what does the embryonic hindbrain develop into?
the cerebellum, the pons and the medulla
role of the cerebellum
The cerebellum has an important role in motor function.
role of the medulla
The medulla is responsible for autonomic, involuntary actions such as breathing, vomiting, sneezing and swallowing, egulating the function of the heart.
role of the pons
The pons contains cranial nerve nuclei for cranial nerves V to VIII. These cranial nerves have both motor and sensory roles in vision, hearing and taste.
what makes up the brain stem?
The medulla and the pons, along with the midbrain, make up the brainstem.
what is the midbrain and what does it consist of?
The midbrain, is the third part of the brainstem, along with the medulla and the pons.
The midbrain contains groups of neurons with many functions. In adults, the midbrain consists of the tectum, the cerebral aqueduct, and the tegmentum.
what is the tectums role?
The tectum has an important role in visual and auditory responses.
what is on the surface of the tectum
On the surface of the tectum is a pair of superior colliculi.
what does the superior colliculi process
process visual information to guide saccadic eye movements.
They also have connections with the lateral geniculate nucleus, which is a very important area in the visual system.
An additional pair of ____ colliculi present on the surface of the tectum receive _____ input.
- inferior
- auditory
what is the cerebral aqueduct?
The cerebral aqueduct is a channel for the flow of cerebrospinal fluid from one ventricle of the brain to another.
what is a ventricle
what processes is the tegmentum involved in
The tegmentum is involved in regulating motor functions, maintaining alertness, regulating autonomic processes such as heart rate and respiration, and pain perception.
what does the embryonic diencephalon develop into?
The embryonic diencephalon develops into two important structures: the thalamus and the hypothalamus.
what does the thalamus do
The thalamus relays sensory and motor impulses between the spinal cord, the medulla oblongata, and the cerebrum.
where is the thalamus and hypothalamus located
The thalamus sits at the top of the brainstem, with the hypothalamus below.
what does the hypothalamus do
has a role in regulating body temperature, sleep, and hunger.
The hypothalamus forms part of the limbic system.
what is the limbic system
The limbic system is thought to be the brain system responsible for emotions, behaviour, and memory formation.
where do the cerebral hemispheres lie over
the thalamus and midbrain. With the exception of midline structures like the corpus callosum, the pineal gland and the pituitary gland, the brain, like the rest of the body, is bilaterally symmetrical.
Each hemisphere controls the opposite side of the bod
which matter do the cerebral hemispheres consist of
white and grey matter
what makes up grey matter
neutron cell bodies
what makes up white matter
myelinated axons of neurons.
what is the cerebral cortex made up of
a thick sheet of neurons and their axons which is folded together to give the wrinkled appearance of the brain.
This folding substantially increases the surface area of the brain.
The raised ridges of tissue are known as ____ and the furrows that separate the ____are known as ____
- Gyri
-Gyri
-Sulci
Approximately ___ of the brain is contained, out of sight, within the folds of the cerebral cortex.
2/3rds
what is the surface of the cerebral hemispheres divided into?
lobes
where are the frontal lobes located
found at the front of the brain, beneath the forehead.
what are the frontal lobes responsible for
higher order cognitive functions like impulse control, problem solving and social interaction.
where are the parietal lobes located
sit behind the frontal lobes, at the top of the head.
what are the parietal lobes responsible for
They process sensory information such as touch and taste. The parietal lobes are also an important area for integrating visual motion.
where are the temporal lobes located?
side of the head
what are the temporal lobe responsible for
for processing hearing and smell.
They also play an important role in the visual perception of objects.
where are the occipital lobes located
found at the back of the head, beneath the occipital bone.
what’s the occipital lobes responsible for
responsible for the early stages of visual information processing.
what does the corpus collosum do
he left and right hemispheres of the cerebral cortex are connected by the corpus callosum.
This allows the two hemispheres to communicate with each other. The corpus callosum is made up of nerve fibres
what is the largest collection of white matter tissue in the brain
The corpus callosum
what is cerebral sulcus
The central sulcus is an important landmark in the brain because it precisely separates the somatic sensory cortex of the parietal lobe from the motor cortex of the frontal lobe.
The central sulcus indicates the separation of motor and sensory units in the _____ _____
cerebral cortex
the lateral sulcus is a deep fissure that marks the edges of the ____ ____
temporal lobe
what is subcortical nuclei
The cerebral hemispheres contain many subcortical nuclei.
Subcortical simply means that the structures are not visible when looking at the surface of the brain.
Instead, these subcortical structures and networks are buried deep inside the cerebral cortex.
what is basil ganglia important for
The basal ganglia are one network of subcortical nuclei, and they are very important for motor control.
why is CSF important
Cerebrospinal fluid cushions the brain and spinal cord to protect them from injury, and also delivers nutrients and removes waste.
which spinal nerves emerge above the bony spinal vertebrae
cervical
ventral roots provide …..
motor output
dorsal roots provide
sensory output
what is the brain stem made up of
the pons, medulla and mid brain
the thalamus and hypothalamus develop from the embryonic ….
diencephalon
superior colliculi can be found …..
surface of the tectum
