Nervous System!!! Flashcards
What are the two systems that the brain are controlled by?
Autonomic nervous system (ANS) - involuntary
Somatic Nervous system (SNS) - voluntary
What are the 3 protections of brain?
the skull
meninges
cerebrospinal fluid (CSF)
What are the meninges?
3 continuous connective tissue membranes covering the brain and spinal cord
What is dura mater?
- outer layer tough, fibrous, double layered membrane
- forms the dural sinuses which collect venous blood and CSF for return to the general circulation
What is the subdural space?
lies beneath the dura
potential space
(normally, empty can fill with blood after an injury)
What is arachnoid mater?
middle layer, loose web like covering
What is subarachnoid mater?
contains CSF and cerebral arteries and veins
lies below the arachnoid
What is pia mater?
- inner layer
- delicate, connective tissue that adheres closely to all convolutions on the surface of the brain
- contains many small blood vessels
What is the order of the meninges from the brain outwards?
PAD- Pia Arachnoid Dura
What is CSF? And what does it do?
Cerebral Spinal fluid
Provides a cushion for the brain and spinal cord
What is CSF important to maintain in the brain?
normal ICP (inter cranial pressure) it is important that equal amounts of CSF are produced and reabsorbed
What is arachnoid villi?
- small protrusions
- they protrude in the venous sinuses of the brain and allow CSF to exit the sub arachnoid space and enter the blood stream
- once in the blood stream, it is carried away and filtered by the kidneys and liver the same way other fluids are
What is the blood brain barrier??
- protective mechanism provided by relatively impermeable capillaries in the brain
- this barrier limits the passage of potentially damaging materials into the brain and controls the delicate balance of electrolytes, glucose and proteins in the brain
What are the cerebral hemispheres?
2 hemispheres seperated by a fissure (opening)
make up the largest portion of the brain
What is a fissure?
an opening that separates both hemispheres
What are the four major lobes of each hemisphere?
frontal, parietal, occipital, temporal
Each hemisphere is concerned with voluntary movement and sensory function to the _________ side of the body! What kind of pt is this important to know for?
OPPOSITE side
stroke patients- which area of brain is affected
What is the primary cortex repsonsible for?
primary cortex= responsible for recognizing and interpreting the received data
Your dominant hemisphere is the one that controls the ___________
language
What does broca’s area control?
controls the output of words- the ability to talk
located base of the let frontal lobe
What does WERNICKE’S area control?
comprehends language received both written spoken- understanding what you are saying
located posterior temporal lobe
What is the limbic system?
controls emotional reactions and feelings
What is the diencephalon?
central portion of the brain
contains the thalamus and hypothalamus
What does the thalamus?
main nerve bodies that serve as a sorting and relay station for incoming sensory impulses
What is the hypothalamus key role?
in maintaining homeostasis in the body
regulation of body temp, intake of food, and fluid and the regulation of sleep cycles
What is the brainstem?
connects the brain to the spinal cord
What does the brainstem contain?
Pons
medulla oblongata
RAS- Reticular Activating System
What is the first thing to be affected when your brain starts swelling down?
Medulla oblongata
What does pons contain/do in the body?
It controls sleep cycle and breathing (inspiration/expiration)
What does the medulla oblongata do?
vital control center that regulate respiratory and cardiovascular function
What does the RAS stand for?
Reticular Activating System
What does the RAS system determine?
the degree or arousal or awareness of the cerebral cortex
decides which of the incoming sensory impulses the brain ignores and which it notices
What is the first part to be affected when your brain starts swelling downwards?
medulla oblongata
What is your cerebellum??
coordinates movement and maintain posture and equilibrium
What are the main arteries that are the blood supply to the brain?
internal carotid arteries
vertebral arteries
What are the main arteries that are the blood supply to the brain?
internal carotid arteries
vertebral arteries
The vertebral arteries branch off the _______ arteries!!!!
subclavian
Where does the deoxygenated blood drain into to be returned into the heart?
right and left juglar veins
What structure is located inside the head that supplied blood to the brain?
circle of willis
What does the circle of willis ensure??
that blood flow remains UNIMPEDED in case any of the principle supplies are damaged
Where are the cranial nerves located?
from the brainstem and pass into the skull to serve structures in the head and neck
What are the two fibers that the cranial nerves consist of?
motor and sensory OR both
What are the 12 cranial nerves (pneumonic- Oh Oh OH to touch and feel A girls vagina so hot)
olfactory
optical
oculomotor
trochlear
trigeminal
abducens
facial
auditory/vestibulocohlear
glossopharyngeal
vagus
spinal accessory
hypoglossal
What are the functions of the cranial nerves?
“some say marry money but my big brother says big booties matter most”
Sensory
Sensory
Motor
motor
both
motor
Both
Sensory
Both
Both
Motor
Motor
What does the olfactory nerve control?
smell- sensory
What does the optic nerve control?
vision- sensory
What does the oculomotor nerve control?
eye movements including eyelids- motor
What does the trochlear nerve control?
eye movements- motor
What does the trigeminal nerve control?
general sensory- eye nose face or oral cavity teeth
speech muscles- motor
What does the abducens nerve control?
eye movements- motor
What does the facial nerve control?
taste, muscles of facial expression, scalp muscles
sensory and motor
What does the auditory/vestibulocochlear nerve control?
hearing and balance - sensory
What does the glossopharyngeal nerve control?
taste, gag reflux- sensory/motor
What does the vagus nerve control?
external ear, parts of taste, heart and lungs smooth muscle, glands of GI system, diaphragm- sensory/motor
What does the spinal accessory nerve control?
voluntary muscles of pharynx, head movements- motor
What does the hypoglossal nerve control?
muscles of the tongue- motor
Where does the spinal cord start?
the medulla oblongata
Where does the spinal cord end?
at the level of the 1st lumbar vertebra
What is the cauda equina?
nerves that innervate the skeletal muscles
Where do ascending tracts relay info from and to??
the skeletal muscles to the brain
Where do descending tracts relay info from and to??
from the brain to the muscles for movement
How many pairs of spinal nerves are there?
31 pairs
What is an example of an acquired reflex?
salivation with smell of food!!
What do neurons require for metabolism/function? (2)
glucose and O2
What are the main parts of a neuron in the brain?
dendrite
cell body
axon
myelin sheath
nodes of ranvier
How are impulse transmissions transmitted from cell to cell??
chemical neurotransmitters
What are the types of chemical neurotransmitters? and what do they control??
acetylcholine- PNS
norepi/epi- SNS
dopamine- expecting a reward, motivation, reinforcement
serotonin- mood, sexual desire, apetite, sleep, memory and learning, temperature regulation, some social behaviour
What does the central nervous system contain?
brain and spinal cord
What does the peripheral nervous system contain?
autonomic nervous system & somatic nervous system
What 2 systems does the autonomic nervous system contain?
SNS & PNS
What 2 types of nerves does the somatic nervous system contain?
sensory and motor
What is the role (type of control) of the autonomic nervous system??
acts as the involuntary control!!!
What are the two chemicals associated with the SNS response? Explain what the SNS does!!
norepi and epi
FIGHT or FLIGHT!!!!, acts on stress, increases the level of activity including cardio, respiratory and neurologic functions!!
What is the chemical associated with PNS?? Explain what the PNS does! What nerve is it inneverated by?
acetylcholine
dominated the digestive system and aids in recovery after SNS stimulation, slows HR, RR and constricts pupils
innervated by VAGUS nerve
What is intercranial pressure? (define it)
the constant relative pressures of the brain tissue, blood and CSF !!!
Because the brain is encased in the hard skull….. ANY increase in fluid (blood or fluid) or mass (tumour) causes an _______ of pressure on the BRAIN!!!!
INCREEEEEEEEEEASE.
What does ICP result in in terms of the brain tissue?? (one word answer- hint: what happens physically to the brain after build up of pressure?)
COMPRESSION.
BRAIN= COMPRESSED
