PSYC 301 Mid 1

Peripheral Nervous System (PNS)
Central Nervous System (CNS)

Somatic nervous system (SNS)
Autonomic nervous system (ANS)

external

afferent nerves carry sensory signals

Skeletal organs (skin, skeletal muscles, joints, eyes, ears, etc)

The CNS (Central nervous system)

Motor signals

from CNS out to skeletal muscles

inteernal environment

sensory signals

Efferent nerves

CNS (central nervous system)

Motor signals

CNS

Sympathetic nerves
Parasympathetic nerves

Regulates internal organs during fight-or-flight and increases physiological arousal?

conserve energy, rest and digest

Brain
Spinal cord (specifically nervous tissue within spine)

Grey matter (inner H-shaped core)
White matter (area surrounding H-shaped core)

cell bodies, unmyelinated axons

myelinated axons

ventral roots face towards stomach, carry motor neural instructions

dorsal roots face towards back, carry sensory info

More info is generated and accumulated (including info from below)

Rostral

Dorsal

Caudal

Ventral

Anterior

Posterior

Going up, to the top (start) of spine

Goung down, towards tail end of spine (bottom)

Towards the front

Towards the back

Further away from midline (left or right)

Closer to midline

On one side

On the same side

On both sides

Mesencephalon

Telencephalon
Diencephalon

(largely) composed of tracts

carry signals between rest of brain and body

can cause serious damage to brainstem

Pons
Cerebellum

houses fibre tracts

The Cortex (wrinkly outer part of brain)

Important in movement and timing

Tectum (roof)
Tegmentum (floor)

contains nuclei that recieve + relay visual and auditory info

contains nuclei related to motor function and pain

Midbrain
Pons
Medulla

Management of breathing, heart, arousal, attention, etc

Disruption is fatal, processes out of our control stopped

Thalamus
Hypothalamus

it is Bilaterally Symnetrical (one on each side)

process and relay info between receptors and cortex

non-specific nuclei of thalamus

Abnormal synchronization

Endocrine/Hormonal functions

hunger/satiation
Sexual
Sleeping
Emotions
Moving body at particular speed/pattern

Pitutary gland

Hypothalamus = instructorrain of endocrine system; signals pitutary gland to release hormones

wide ranging symptoms:
headaches, seizures
changes in hormonally regulated things

2 people can have same tumor and experience differing symptoms

Collection of nuclei highly connected to cortex, thalamus, midbrain
Involved in movement and learning

Hippocampus
Amygdala

Hippocampus – plays role in spatial memory
Amygdala – plays role in emotion

maximize brain area/surface in a constrained area

Isocortex (neocortex)

less than 6 layers

Interupted folding caused by cells not migrating normally during development

not growing at normal rate

They have trouble breathing

few tracts called cerebral commissures

Corpus callosum

Central sulcus

Lateral sulcus

Longitudinal fissure

In cerebrum and spinal cord

Buoyancy (brain submerged in fluid: makes it lighter)
Protection (reduces injury on impact)
Chemical stability (rinses waste through blood-brain barrier)

ventricles become enlarged, pressure builds in skull

called Hydrocephalus

surgical shunt: small straw allowing CSF to flow out to other part of body for removal

Electrical charge changes relating to function of cell

cell body/soma
branch-like structures (dendrites and axons)

processing energy and removing waste

receiving input into cell (dendrites)
interacting/sending data to other parts of body (axons)

axons and dendrites (word for both)

Unipolar

Bipolar

Multipolar

Interneuron

Interneuron in places that recieve info
All others seen in places that send data

Passive diffusion
Facilitated diffusion
Active transport

fat soluble molecules can pass through barrer

Channels that allow molecules in

Pumps use energy to push molecules through

at rest (no action), healthy neuron has potential (voltage) of -60 mV to -80 mV

ions of sodium and potassium move into or out of cell

3 NA+ out: 2 K+ in

negative

if charge across membrane exceeds -55 mV (going towards 0)

1. Sodium channels open, enters the cell
2. Potassium channels open, leaves the cell
3. Positive charge enters cell more and more (much more sodium entering than potassium leaving)

1. Sodium channels close
2. Potassium channels still open, making cell charge go down (negative)
3. Potassium channels finally close as well (after reaching negative mV)

1. voltage-gated channels close
2. Sodium-potassium pumps catch up and restore cells resting potential

sodium coming in charges nearby parts of axons as well

Cannot start big then become smaller, AP either happens or not at all

Unmylinated axons have Nav channels all along surface

Myelinated axons have nav only at nodes of ranview

If myelin present, sodium can enter one node but cannot be sucked out by pump
then moves down axon increasing potential of AP firing

Caused by stimulus in sensory cell
Caused by inputs from other neurons

Sensory neurons sensitive to environment around you, fires based on what stimulus their supposed to sense

terminal button (end of axon) has neurotransmitters

when action potential reaches terminal button, neurotransmitter released into synapse

Neurotransmitter binds to its receptor, pushes charge of postsynaptic cell up or down

small, active gap between two neurons

Sending neuron

Recieving neuron

Molecules that allow neurons to communicate

Excitatory
Inhibitory
Modulatory

Make receiving neuron more likely to fire action potential

Make receiving neuron less likely to fire action potential

trigger other changes

turn on receptors and active its effects

block receptor from turning on

Drug binds with neurotransmitter receptors by coping effect of real thing that binds with receptors

Diffuse (float) away
Broken down by enzymes
Reuptake

block reabsorption of neurotransmitter into cell

lengthens time neurotransmitter is avaliable in synapse

present in CNS (central nervous system)
myelinates neurons (forms many myelin sheaths)

present in PNS (peripheral nervous system)
each wraps around one axon
many schwann cells per cell

Only in CNS (central nervous system)
responds to injury and disease (engulfs debris, triggers immune response)
rapidly responds to area of injury

Largest glial cell
Only in CNS (central nervous system)
Physical anchor between 2 neurons
Regulate activity of synapse
Communicates with neurons and glia

provided by astroglia
protects brain, transport large molecules

locate level and lateralization of lesion

Olfactory: Smell

Identify familiar smells (one nostril at a time)
Compare strength of smell

Loss of smell

Optic

Standard visual acuity tests for each eye
Visual field confrontation (can you see here?)
Popullary light reflexes (do pupils contract, at right speed, for right amount of time)

Looking at back of eye for increased intracranial pressure

3 motor nerves that move/hold eye

Test motion of eye (can you follow object without moving head)

weakness or loss of certain muscle movements

Trigeminia

feeling for activation of muscles when biting down
holding mouth open

(with eyes closed) where on face are you being touched, is that touch sharp/dull, hot/cold

Equally quick to detect touches on different areas innervated by different parts of the nerve

Whether sensations are equally strong across diff areas

Severe chronic pain (severe - disrupts daily life)

feeling of electric shock/intense pain; triggered by light touch or spontaneously

Pressures on trigeminal nerve by blood vessels

anticonvulsant drugs, surgery to move blood vessel

Facial nerve (everything on face not trigeminal)

Face: drooping, sagging, facial creases
Raise eyebrows
Smile
Puff out cheeks
Close eyes hard

Paralysis of facial nerve causing weakness of one side of face

Similar causes:
Multiple Sclerosis
Tumor
Stroke

Verstibular cochlear - hearing and balance

Whisper to see if they can hear equally on both sides

Test hearing with standardized instrument (tuning fork)

Unilateral hearing loss
Bilateral hearing loss

Unilateral hearing loss caused by lesion to nerve (on peripheral) that talks to that unilateral nerve

Bilateral hearing loss more central, lesions on brain structures involved in hearing on both sides

9 = glassopharyngeal (throat)
10 = vagus (involuntary processes?)

Bilateral central lesions

Strained, strangled voice
Emotional lability
Gag normal or increased

Nasally speech
No emotional lability
Gag absent

localize where these things are happening

Accessory (Neck and Shoulders)

Shrug shoulders
Push head against pressure (head resistance)

Hypoglossal (tongue)

direction deviation + strength of tongue

towards

If lesion/problem is more central, tongue will deviate away

Visuospatial
Executive Function
Memory
Language
Attention/Orientation

Line cancellation
Copy geometric designs (MoCA copies cube)
Judge line orientations
Object/face/colour recognition

Verbal fluency
Abstraction (similarity between...)
Trailmaking or drawing patterns
Clock drawing “10 past 11”

Digit span or N-back
Short term memory (remember these 3 words for 2-5 mins)
Long term memory: past public or personal events

Category cue: if word is face, cue = “its a body part”
Multiple Choice cue: if word is face, cue = “face, eyes, leg, torso”

Tasks like naming body parts and reading, writing, and repeating simple phrases

Fluency
Comprehension
Prosody (use of intonation, stress, rhythm - what syllables are you stressing)

observing patients alertnes
spelling word backwards
counting back from 20
current whereabouts, time

Visuospatial

Memory

Left hemisphere language network

Same as normal MoCA, but no visual questions (what is this animal, draw a clock, etc)

Before any mental status exam, need assessment of level of consciousness

MoCA cannot be used on someone who is asleep/in a coma

Gross appearance of muscle (whta do it look like)
Muscle tone, strength

originate in motor cortex or brainstem

spinal cordrainstem

Weakness
Spasticity
Hyperreflexia
Retained primitive reflexes (things babies do)

exaggerated reflexes

muscles contract all at once

Weakness
Hypotonia
Hyporeflexia
Atrophy
Fasciculations

low/decreased muscle tone

absence of expected reflexes, reflexes not as big

smaller muscles

Inability to recognize objects by touch

Inability to recognize letters/numbers by touch

Sensory cortex of parietal lobe

Inability to do quick, alternating movements

Cerebellar tumor in kids (children dont really get MS)

There are 2 points and you have to match it (2 spatial locations need to be brought together)

Dysmetria

taking heel and running it down the other shin

assymetrical across body
weird timing and walking
weird stance
changing pace

cerebellum

balance with eyes open vs closed

If you close your eyes and start to fall (positive romberg test)

rotation and vertical motion of arm (rotate in, move towards each other)

pyramidal tract (efferent)

Upper motor neuron --> lower motor neuron

Cause neurological symptoms

Irreversible damage to brain tissue

Posterior cerebral artery

Temporal lobes

Anterior cerebral artery

death of brain tissue because of injury/dysfunction of blood vessels

region of dead or dying tissue (following stroke)

Dysfunctional area surrounding infarct; tissue may recover or die

3rd leading cause of death in Canada

blood vessels

Memory (amnesia)
Language (aphasia)
Motor function (paralysis)
Consciousness

High blood pressure + cholestrol
Diabetes
Smoking
Cardiovascular conditions
Psychosocial stress (chronic)

Cause problems to blood vessels containing it

Fat accumulate in blood vessels, makes them narrower --> less room for blood to pass through

Poorer control over blood sugar
High levels of glucose damage blood vessels over time

Inflammation → damages blood vessels, accumulation of stuff in vessels

Lack of access to quality food
Inadequate public health education
Discrimination

Ischemic
Hemorrhagic

bleeding from blood vessel

Thrombosis
Embolism
Arteriosclerosis

occlusion due to blood clot or other substance

moving thrombus (small piece from larger thrombus in vessel breaks off and gets lodged in smaller blood vessel)

More common in arteries because blood pressure higher

Thickening, hardening, narrowing of arteries due to fatty plague build up

Tissue behaving dysfunctionally after stroke releases too much glutamate

Triggers dormant behaviour of cell to break down, change metabolism, die

dying/injured cells release molecules into fluid --> signals nearby microglia to clean damaged neurons

overactive microglia can kill cells that have change to recover

Injured cells release molecules (including highly reactive molecules that should be contained in cell)

Causes uneccesary microglia usage, blood vessel dilation, break down of blood brain barrier

(short term) Interruption of blood flow causing neurological symptoms but no lasting brain damage

weakened portion of blood vessel wall

No

If aneurysm bursts, becomes hemorrhagic stroke

Develop at birth
Develop over course of life
Develop from high blood pressure
Develop from accumulated injury

can have it and never know about it

Neck of aneurysm physically closed with clip so it will not burst

Platinum wire threaded into blood vessel (from other part of body) to aneurysm to fill it up

clipping = invasive (need to open skull), lower rate of reoccurence of aneurysm
coiling = lower risk, not invasive, higher risk of reoccuring

Tissue plasminogen activator (tPA) - injection that breaks up blood clots
Therapeutic hypothermia - cooling to slow down/prevent secondary damage

Mass of cells growing independently of rest of body

encapsulated

not self contained; difficult to remove or destroy

surgically removable; little risk of further growth

Malignant

Grow between the meninges

encapsulated, benign

cerebral cortex

Infiltrating, malignant

Meningiomas (Relatively positive prognosis)

infiltrating tumor that grow from tumors in other parts of body

Original tumor somewhere else → break off and move through bloodstream to brain

inflammation (encephalitis)

Formation of cerebral abcesses (pockets of pus)

Through bloodstream (bacteremia)
Direct extension
Direct penetration

infenction in other area, travels to brain from bloodstream

nearby infenction spread directly to brain

opening into brain

the meninges

produces inflammation called meningitis

Treat with antibiotics

Headache
Stiff neck
Sensitive to sound and light

Bacteria spread as STI