Week 6 + Workshop 4: NS > CNS Flashcards
Central Nervous System (CNS) structures
Brain + Spinal cord
Nervous System is split into
CNS (Central Nervous System)
PNS (Peripheral Nervous System)
Peripheral Nervous System (PNS) contains
All nerves outside the brain and spinal cord
brain nerves
spinal nerves
Central nervous System (CNS) Function
primary command centre for the body processing:
-higher order cognitive functions
-Integrative and control centres/ - signals
Peripheral Nervous System (PNS) Function
Connects the CNS to the Peripheral organs and muscles
- somatic
- automatic
Nervous System Function
Communication!
- collect: external
- process (logic+planning)
- respond
CNS tissue is divided into
White + grey matter
CNS grey matters comprises of
Neuron cell bodies and their dendrites, glial cells and capillaries
Brain grey matter is found
in the outer layers
White matter refers to the areas of the CNS which host the majority of
Axons
Axons are
long cords that extend from the neurons
A neuron has 3 main parts
dendrites, cell body or soma and axon
Label the features of a typical neuron
Soma (cell body)
Dendrites
Axons are wrapped in
Myelin sheath
The primary functional unit of the nervous system is a
Neuron/ nerve cell
Divisions of the central nervous system
Most axons are coated in myelin a white fatty insulating cover that helps nerve signals
travel quickly and reliably
In the spinal cord white matter is the
external layer surrounding the grey core
The CNS is the
Processing centre of the brain and the brain is its headquarters
The brain is broadly organised into 3 main regions
Forebrain
Midbrain
Hind braind
The Forebrain aka Cerebrum is the
Outer most layer cerbral cortex
and smaller structures towards the centre:
thalamus
hypothalamus
pineal gland
Encephalon from embriology means
The Brain
The lobes of the brain are divided into
Gyri (bumps - increase surface area)
Sulcus (grooves or fissures)
The frontal lobe is seperated from parietal lobe by the
Central Sulcus
The frontal lobe is seperated by the temporal lobe by the
Lateral Sulcus
3 main fibre traits of white matter in the telencephalon “the brain” are grouped by the direction of fibres/tracts
Projection fibres
Association fibres
commissural fibres
Encelephalon “The Brain” is divided into specific parts =
Telencephalon > Cerebrum + Basal Nuclei
Diencephalon > Thalamus + Hypothalamus
Cerebellum
Brain Stem > Mid brain, Pons, Medulla
+spinal cord
White matter in the brain =
Myelintated axons
The cerebrum consits of two hemispheres
Right and Left
Telencephalon is latin for
Cerebrum
White matter can be Association fibres connect
structures in the same hemisphere
Projection fibres
Inferior and superior movements
Commissural fibres
travel left to right hemisphere
The left and right hemisphere is seperated by the
Longitudinal fissure
What forms the Basal Nuclei (3 smaller structures) deep inside “The Brain”
Hippocampus
Amygdala
Striatrum
Hippocampus (pair-one in each hemisphere ) location + function
Brains temporal lobe + where new memories are formed, spatial orientation
Amygdala location + function
Almond shaped mass responsible for emotional responses - pleasure, fear, anxiety, rage.
Striatum function
Motor movement, pattern, more complex movement
Function of the Thalamus
Prime processing centre for information - prevents or enhances the passage of information
All sensory information except olfactory passes through the thalamus before reaching the cortex
Relays information from basal nuclei & cerebullum
Also controls sleep
What is the function of the limbic system?
Interconnected brain structures that help regulate emotions and behaviour, motivators and memory & automatic nervous systems
- produces natural instincts e.g. hunger, thrist, care, fight or flight
What are the four components of the limbic system
Hippocampus
Amygdala
Thalamus
Hypothalamus
Where is the limbic system located?
deep in the brain
above brainstem and underneath cerebal cortex
Location of Thalamus
Two lobes of grey matter under the cerebal cortex Birds head
Location of Hypothalamus
Quite small (size of an almond)
Under the Thalamus = Birds beak
Function of Hypothalamus
Major control centre of the ANS (Autonomic Nervous System)
Cardiac function, respiration and reflexes such as vomitting, coughing and sneezing
Autonmic Nervous System (ANS) is divided into
Sympathetic - fight or flight
Parasympathetic - rest and relax
The brainstem comprises of
Midbrain
Pons
Medulla
The brainstem is the origin of most
Cranial nerves (PNS)
The forth ventricle is located between
Pons and the Cerebellum
Brainstem function
Most important parts of the entire central nervous system because it connects the brain and the spinal cord
The midbrains function
vital connection between the forebrain and hindbrain
it is the top most part of the brainstem
connection between the brain and spinal cord
Connects the thalamus
The hindbrain includes most of the brainstem and comprimes of the
Pons
Medulla
Cerebellum
The midbrain (mesencephalon) coronal view looks like
Mickey Mouse
Identify the surface features of the midbrain
Superior colliculi (double chin) - vision
Inferior colliculi (above double chin area) - auditory
Cerebral Peduncles (ear area white matter) - motor control, sensory information relay.
Identify the internal features of the midbrain
Red nucleus (eyes) - motor control and muscle tone
Substantial nigra (black lines - ears) - motor pattern
Cerebral aqueduct (hole - nose) - connects third and fourth ventricle - allows CFS to drain from third to fourth ventricle
Pons Function ‘bridge’ ‘bulbous in shape’
Sits underneath the midbrain
‘Bridge’ Relays sensory information to the Cerebellum
coordination centre for signals
connects forebrain motor and hindbrain sensory
regulates breathing, swallowing, hearing, facial expressions and sleep
Pons Features
Cerebellar pundcles
4 th ventricle
Function of Medulla Oblongata
nerve tract for control centres for autonomic (can’t control) vital functions - heart rate, blood pressure, breathing and involuntary reflexes e.g. swallowing, hiccuping, coughing, sneezing
connects spinal cord to rest of brain
sensory tracts pit stop
Medualla key features
open medulla
closed medulla
pyramids - top
olives
4th ventricle - where the open medualla would be
Reticular Formation
Network of nuerons in the brainstem that works togehter and integrates different system functions - movement, pain, breathing and heartrate, consciousness and attention
Cerebullum function
The coordinator and predictor of movement - feedforward and feedback
predicts consequences & adjusts the movement commands
The human brain is highly convoluted with
gyri (grey matter - cell bodies ) and sulci (white matter - axons)
Identify the brain landmarks
Longitudinal fissure - seperates left and right
Central Sulcus
Precentral gyrus
Postcentral gyrus
Cortical parcellations
assigning a neuroanatomical label to a region
Function of the Frontal cortical lobe
Motor control
High cognitive (critical) thinking, decision making
Executive Functions: emotional regualtion, planning, reasoning, problem solving
Personality
Function of the Parietal cortical lobe
Tactile sensation
Sensory information: touch, tempreature, pleasure, pain
Function of the Occipital cortical lobe
Vision - visual processing
Function of the Temporal cortical lobe
Hearing, language & Learning
Function of the Limbic cortical lobe
Emotions, memory & body functions
The limbic system is buried deep within the brain & includes
- Thalamus
- Hypothalamus
- Basal ganglia -
- Amygdala & Hippocampus
The Insular cortex is covered by the ______
It sits inside the ________________
Frontal, parietal and temporal lobes
Inside the later sulcus
Under the Insula is
A thin nucleus called claustrum & is hyperconnected with most cortical areas (hub)
Brocas’s area is located in the
Frontal lobe
The precentral gyrus is located in the
Frontal lobe
The precentral gyrus is the site of the
primary motor cortex
Dominant hemisphere is usually
The left hemisphere
Primary motor cortex functions
regulates pattern of breathing
vocalisation for speech
coordinates activity of respitatory, larrngeal and paharyngeal muscles
muscles of tongue, soft palate, lips, cheeks, mandible
Broca’s area function is
production of speech
The postcentral gyrus is in the
Parietal lobe
The postcentral gyrus contains
Primary sensory cortex
The Wernicke’s area is located in the
Parietal, temporal and occiptal lobes
Interpretation centre
Sits at the end of the lateral sulcus
needs information from all areas
Wernicke area function is
Language comprehension
Recieves information about all sensory association areas
Integrates sensory information
corrdinates complex visual & auditory memories
interprets what is seen and heard
Decussation of pyramids movement
Crosses to the other side - right hemisphere controls left
Temporal lobe is the site of the
Primary auditory cortex
Occipital Lobe is divided by the
Calcarine sulcus
Occipial lobe processess visual information for what area
Wernicke - to interpret what we see
The primary auditory cortex is located in the
temporal lobe
The Limbic system is nvolved in
behvioural and emotional responses - especially when it comes to survival: feeding, caring, fight or flight
learning, motivation and memory
White matter tracts connects different _______________
made from ___________________
parts of the brain
myelinated axons
Commissural fibres connect the _______________
this is called the _________________
two cerebal hemispheres
corpus callosum
The corpus callosum connects what lobes
frontal, parietal and occipital lobes
The anterior commissure connects what lobes
temporal
The projection fibres consist of
efferent (exiting)
afferent (arriving) fibres
The connection fibres connect the
cereberal cortex with the thalamus, basil ganglia (deep cerebral nuclei) , brain stem and spinal cord
Association fibres connect
different parts of the same cerebral hemisphere
e.g. Broca’s area to Wernike
What are Meninges
3 layers of membrane that cover and protect your brain and spinal cord (CNS)
What are the functions of Meninges
Support, protect and hold the brain
What do meninges look like?
What are the 3 layers of Meninges known as
Dura mater - outermost tough layer
Arachnoid mater - web-like structure with blood vessels and fluid
Pia mater - delicate thin layer “skin”
The Falx Cerebri dural fold function
Keeps brain suspended
The superior and inferior sagitall sinus drain down into the
Internal Jugular vein
What are the functions of the Brains ventricualr system
Physical support/ cushioning
Excretory function (removes excess waste)
Chemical communication
What is homeostasis
Tendancy towards a relatively stable equilibrum
What is the function of the Node of Ranvier
Regenerate and recharge the action potential that travels along the axon - Salatory conduction that allows for fast and efficienct communication within the nervous system
What is the function on the myelin sheath covering the axon
insulate and protect the axon enabling electrical impulses
What is the function of the schwann cell
they produce the myelin sheath that insulates the axon and help propagate the electrical signals
What is the function of the Dendrite
Recieves inforamtion from other neurons and transmits electrical signal to the cell body
What is the function of the cell body (soma)
Organises and keeps the cell functional - cells life support centre
The nucleus contains the cells
DNA-RNA
The function of the Axon
Sends the electrical signals away from the cell body
The function of the Axon Termina
button like structure. It conducts action potentials and releases neurotransmitters into the synapse to communicate with other neurons or cells
The third ventricle in the brain is located between the
Hypothalamus
Thalamus
The function of the subclavian arteries is to
supply oxygenated blood from the heart to the brain, neck, and arms
The left subcalvian artery branches off from the
It supplies
Arch of Aorta (last one)
upper body, head, neck and left arm
The right subcalvian artery originates from the
It supplies
brachiocephalic trunck from the aortic arch
upper body, head, neck and right arm
The anterior cerebral artery (antlers on circle of willis head) supply
mainly the medial surface of the fronal and parietal lobe
The posterior cerebral artery (arms of willis) supply
mainly the meidal surface of the occcipital lobe and basal surface of occipital and temporal lobes
The middle cerebral artery (ears of willis)
mainly supplies the lateral surface of all lobes
What are the 2 types of stroke
Ischemic stroke
Hemorrhagic stroke
What is the feature of a ischemic stroke
Blood flow obstructed
What is the feature of a Hemorrhagic stroke
Ruptured blood vessel leaks blood into the brain
Where is CSF produced
lateral ventricle
Describe the flow of CSF
Produced in the lateral ventricle > to the third ventricle > cerebral aqueduct >to the fourth ventricle
what is the function of the Choroid plexus
Production and circulation of the CSF
Review image of the flow of CSF:
Fourth ventricle
Choroid plexus
Third Ventricle
Name the 4 types of glial cells that support a neuron
A.M.O.E
Astrocytes
Microglia
Oligodenrocytes
Ependymal
Explain what a Astrocyte glial cell does
Star shapes cell that maintains the neurons working environment by controlling the neurotransmitter around the synapses
Explain what a Microglia glial cell does
These are the brains immune cells that serves to protect it aginst injury and disease - they identify when something has gone wrong and initates a response - removes toxic agent /clears away the dead cells
Explain what a Oligodendrocyte glial cell does
provide support to axons particularly those that travel long distances within the brain. They produce a fatty substance called myelin.
Explain what a Ependymal cell
line the spinal cord and ventricles of the brain. They are involved in creating cerebrospinal fluid (CSF).
Function of Wernikes area
spaital awareness/ orientation
Speech comprehension
Function of Broca area
Production of speech
Herch’s area
Primary auditory
