Neuro Flashcards
3 Layers of the brain
Dua Mater- tough outer covering lining skull separated from the arachnoid mater by the subdural space
Arachnoid mater- delicate impermeable membrane separated from the Pia mater by the subarachnoid space
Pia Mater- innermost layer of membrane, adheres to the brain and spinal chord
Cerebral spinal fluid
In the subarachnoid space CSF 500ml/day or 20ml/hr clear/straw coloured made within ventricles flows down the brain stem into venous return
Venous return in the arachnoid villi in the dura mater
Cerebral Compliance
Monroe Kellie hypothesis
Tissue, blood, csf= filled capacity
skull is closed box
The deep groove dividing hemispheres
Corpus Callosium
Central nervous system: 6 regions
Cerebrum Thalamus and Hypothalamus Midbrain Pona and Cerebellum Medulla Spinal Chord
FRONTAL LOBE
Voluntary movement
expressive language
Prefrontal cortex (motor activities)
PARIETAL LOBE
Somatosensory information
sensations
creative thought/memories
TEMPORAL LOBE
processing auditory info
encoding memory
olfactory
smell and taste sensations
OCCIPITAL LOBE
Visual cortex
distance and depth perception
colour, object, face recognition, memory formation
Sulci
Fissuers between gyri
Gyri
Raised surfaces of the convolutions
Folds (Gyri/Sulca)
Increase surface area
Billions of neurons
Cerebrum
Grey matter
contains 4 lobes
White matter
Consists of mylinated nerve tracts
Allows straight quick communication of electrical impulses
Association fibers- links different parts within hemisphere
Commissural fibers- links similar parts between hemispheres
Projection Fibers- sensory and motor cortex down or up chords
Thalamus
Emotional expressions, sensory fibres
Contains pineal gland
Melatonin produced for sleep cycles
Hypothalamus
Control of sympathetic and parasympathetic system
Body temperature Food intake (appestat detects blood glucose) and Satiety centre (determines if you've eaten enough)
Nervous and Endocrine control
Autonomous nervous system
10/12 cranial nerves pass through
Hippocampus
Learning and memory
part of limbic system
short and long term
mapping behaviours
Cerebellum
Primitive area of brain Fight or flight fine motor movement, dexterity motor coordination sensory inpits motor areas
Brain stem: Midbrain, pons and medulla oblongata
Control of organs
Locked in syndrome
cos reg, cardiovascular centre, cranial nerve,
reticular formation- human consciousness
Intracranial Pressure
ICP 10 Normal
Increased through coughing, intrathoracic pressure, bleeds, swelling etc.
Circle of Willis
located at base of skull
blood supply to brain
No of Spinal Nerves
31 pairs
Composition of Neuron
Dendrites Nucleus Cell body Myelin Axon Node of Ranvier Axon terminals synapses
Cushings Triad
Increased intracranial pressure
similar to arterial pressure
so no flow
Hypertensive
Bradycardia
Irregular pressure
Blood Brain Barrier
Slightly permeable to Na+, K+ and Cl-
Very permeable to oxygen, Co2, water, alcohol, and anaesthetics
Not permeable to blood proteins and non-lipids organic molecules
Peripheral nervous system
Sensory-somatic- cranial and spinal nerves
Autonomic system- parasympathetic and sympathetic
Sensory-somatic system
Sensation: light, touch, pain, temperature, muscle position sense
Autonomic Nervous system
Sensory and motor neurns
Acts through sympathetic and parasympathetic nervous system
CRANIAL NERVES
Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharayngeal Vagus Spinal Accessroy Hypoglossal
Motor, sensory or both for cranial nerves
S - olfactory S- optic M- ocular motor M- trochlear B-trigeminal M-abducens B-facial S-vestibulocochlear B-glossopharangeal B-vagus M- accessory M-hypoglossal
Signs of herniation
Pupillary changes confusion motor weakness nausea/vomitting headache
Brain Stem Death
Tests:
Brainstem reflexes (pupil reaction, dolls head, corneal reflex, motor reflex, motor response, cochlear response, no gag on suction)
Irreversible apnoea (increase co2>5.3 for over 5 minutes)
Re-test by another physician
Spinal Nerves
Cervical C1-8
Thoracic T1-12
Lumbar L1-5
Sacrum S1-5
Spinal Nerve anatomy
Contains:
Dorsal Root: carry signals to CNS from receptors
Ventral Root: contain axons of motor neurones that carry information to muscles/gland effectors
Pain Definition
Unpleasant sensory and emotional experience associated with actual or potential tissue damage
Acute, Chronic, Cancer
Types of Pain
Nociceptive pain (stimuli from Somatic and visceral structures)
Neuropathic pain (stimuli abnormally processed)
Transduction
Noxious stimuli tissues release inflammatory and pain mediators stimulates neuron Neuron becomes permeable to sodium creates a positive charge which hen depolarises causing an impulse to be generated moves across the neutron
Transmission
Impulse spinal cord brain stem thalamus central structures of brain pain is processed
neurotransmitters are needed to continue the impulse from the Spinal cord to brain
Process- perception of pain
occurs in cortical structures of brain
Modulation of pain
changing or inhibiting pain impulses in descending tract (ie brain to spinal cord)
Descending fibres release substances such as norepinephrine and seratonin= inhibits noxious pain stimuli
Substance P
Bodys main pain neurotransmitter
Pain, inflammation, anxiety, depression and nausea
Gate Theory
In dorsal horn
small nerve fibers (pain receptors)
Larger nerve fibers (normal receptors)
