Neuroanatomy and Neurons

what are the 4 main lobes of the brain

frontal lobe

pariental lobe 

occipital lobe 

temoral lobe

where is the occipital lobe located 

at the posterior (back) end of the cortex

what is the occipital lobe important for

vision

what occurs if the occipital lobe is damaged 

loss of vision

what are some disorders of the occipital lobe

• visual hallucinations (visual images with no external stimuli)

• visual illusions (disorted perceptions)

what are visual hallucinations 

visual images with no external stimuli

what are visual illusions 

distorted perceptions, can take the form of objects appearing larger or smaller than they actually are, objects lacking color or objects having abnormal coloring.

how can visual hallucinations occur 

can be caused by lesions to the occipital region or temporal lobe seizures.

what can occur if there was a lesion in the pariental temoral association area

can cause word blindness with writing impairments (alexia and agraphia)

whare is the pariental lobe located

infront of the occipital lobe, behind the central fissure/sulcus

function of the pariental lobe 

• spatial awareness 

• locationg the body in space (somatosensation)

• interpretaing visual information/visual recognition

• taste temperature and touch

what occurs if the pariental lobe is damaged unilaterally 

hemispatial neglect can result

what happens If the pariental lobe is damaged by a stroke

Attention and experience heavy spacious neglect

what happens if the pariental lobe is damaged at the right 

wont be able to pay attention at the left side

what is hemispatial neglect

the inability of a person to process and perceive stimuli on one side of the body or environment, where that inability is not due to a lack of sensation

where is the temporal lobe located 

underneath the other lobes under teh sylvian/lateral fissure 

function of the temporal lobe 

1. language

2. hearing and selective listening

3. receives sensory info such as sounds & speech from the ears 

4. comprehension of meaningful speech 

5. plays a role in emotion & memory

who identified the eight pricipale symptoms of tempral damage 

Kolb & Wishaw (1990)

Kolb & Wishaw (1990) have identified eight principle symptoms of temporal lobe damage:

1) disturbance of auditory sensation and perception

2) disturbance of selective attention of auditory and visual input

3) disorders of visual perception

4) impaired organization and categorization of verbal material

5) disturbance of language comprehension

6) impaired long-term memory 

7) altered personality and affective behavior

8) altered sexual behavior.

where is the frontal lobe located 

at the front of the brain, anterior to the pariental loce and dorsal to the temporal lobe 

 

what does the frontal lobe deal with

Deals with complex processes like language, planning, coordinating, carrying out plans, controlling behaviour

where is the primary motor cortex located 

in the frontal lobe (precentral gyrus)

what are ventricles used for in the brain 

cushioning

what are the ventrickes of the brain called 

ventricles

where do the ventricles extend to

extend through the brainstem to the central canal of the spinal cord

what are ventricles filled with 

CEREBROSPINAL FLUID (CSF)

where is the cerebrospinal fluid (cfs) produced

CHLORIDE PLEXUS in the interventricular foramen

what are the 4 ventricles in the brain

–Right Lateral Ventricle

–Left Lateral Ventricle

–Third Ventricle

–Fourth Ventricle

function of the CSF (cerebrospinal fluid)

• cushions the brain on impact

• keeps the brain buoyant in the skull

• regulates cerebral blood flow 

• clearing waste from the brain

what does the cns in the spinal cord carry 

carries nerve fibres to/from the rest of the body

what does the CNS do in the spinal cord

• continues from the medulla oblangata in the hindbrain

• travels down the vertebral column

• terminates at the lower boundary of the fisrt LUMBAR VERTEBRAE

how many individual vertebrae is there in the spinal cord

24 (protect the spinal cord)

name the components of the spine 

 

cervical 

thoracic

lumbar 

sacral 

coccygeal

where do nerve fibres emerge from the spinal cord

between the verebrae to form 31 sets of dorsal and ventral roots

is dorsal, motor or sensory 

sensory

is ventral motor or sensory 

motor

what does the peripheral nervous system consists of 

• motor neurons

• sensory neurons

• somatic nervous system 

• autonomic nervous system 

• sympathetic division

• parasympathetic division

what does the somatic nervous system control

controls voluntary movement 

what does the autonomic nervous system control

contols the involuntary responses

what is the sympathetic divasion also now as 

fight or flight

what is the central nervous system composed of 

brain and spinal cord 

where does the peripheral nervous system lie

lies outside of the brain and spinal cord/skull and spine 

what does the peripheral nervous system allows the brain to do 

■communicate with muscles and organs via nerve fibres

what carries information from the sensory receptors towards the CNS 

sensory/afferent nerves

what do motor/efferent nerves carry 

carry info from the CNS to muscle glands via vntral roots

what are reflexes 

A mechanism whereby the spinal cord can step in and make a decision, bypassing the brain!

what is the blood brain barrier

a selectively permeable wall between the CNS and the rest of the body 

what does the blood brain barrier protect the brain from 

from toxic substances from the blood

peripheral VS CNS 

PNS

• not encased

• not protected 

• can be exposed to toxins, injuries

• regeneration occurs here 

• two divisions: somatic and autonomic nervous systems

CNS

• Encased in bone (skull, spine)

• protected by the BLOOD BRAIN BARRIER

• less likely to be exposed

• less regenaration occurs here 

• no divisions 

 

what does the somantic nervous systme controls

voluntary muscular movement in the body 

what is the somantic nervous system made up of 

cranial nerves, spinal nerves and many smaller association nerves 

where is the cranial nerves in the somantic nervous system exit 

from underneath of the brain 

where do the spinal nerves exit in the somantic nervous system 

from the spinal cord 

how many cranial nerves are there 

12 pairs

what are cranial nerves responsible for 

both sensory and motor information transmission

what do the cranial nerves attach to 

connect directly into the brain or into the very beginnings of the spinal cord (at the brain stem), by-passing the spinal column.

name all the cranial nerves 

1. OLFACTORY

2. OPTIC

3. OCULOMOTOR

4. TROCHLEAR

5. ABDUCENS

6. TRIGEMINAL

7. FACIAL

8. VESTIBULOCOCHLEAR

9. GLOSSOPHARYNGEAL

10. HYPOGLOSSAL

11. VAGUS

12. ACCESSORY

optic

visual info (belongs to the CNS)

olfactory

sense of smell

1.OCULOMOTOR

2.TROCHLEAR

3.ABDUCENS

Coordinate eye movements

TRIGEMINAL

information from the teeth, gums, face, anterior tongue

FACIAL

facial expressions

VESTIBULOCOCHLEAR

hearing & balance

GLOSSOPHARYNGEAL

taste, salivation

HYPOGLOSSAL

tongue movement

VAGUS

parasympathetic innervation – blood pressure, heart rate

ACCESSORY

shoulder and head movement

how many spinal nerves are there

31 pairs 

C1-8

pairs of cervical nerves

T1-12

12 pairs of thoracic nerves

L1-5

5 pairs of lumbar nerves

S1-5

5 pairs of sacral nerves 

1 pair of…

1 pair of coccygeal nerves 

whay does the autonomic nervous system controls

■Controls involuntary or SMOOTH MUSCLE activity (i.e.organs)

–Heart Rate, Blood Pressure, Perspiration, Digestion

what does the autonomic nervous system works with

works independently of the SNS and the CNS 

what are the other 2 subdivision sog the autonomic nervous system

sympathetic and parasympathetic nervous system 

what are sympathetic nerves 

autonomic nerves that prepare your internal system for emergency action

what is the parasympathetic nerves

autonomic nerves that prepare your internal systems for calm

characteristics of sympathetic nervous system (ANS)

■“FIGHT OR FLIGHT”

■Originates from the THORACIC and LUMBAR regions of the spinal cord

■Form the sympathetic ganglion chain

what are actions associated woth the sympathetic ANS 

–Dilating bronchia (air towards lungs)

–Accelerating heart

–Increasing secretion of sweat

–Inhibiting digestion

–Inhibiting bladder contraction

charactersitics of the parasympathetic ANS 

■“REST AND DIGEST”

■Returns the body to a normal state after sympathetic activation

■Effectively does the opposite of the sANS

what are the 2 nervous system cells 

• neurons

• glia 

what do neurons do 

transmits info 

what does the glia do

support functions 

who put the idea that neurons are the basicbuilding blocks of the nervous system 

Santiago Ramon y Cajal in the late 19th century

what are nerves made up of 

made up of the tail ends (AXONS/NERVE FIBRES) of neurons

what do axons do 

Axons extrude from the neuron body, carrying information in the form of ELECTRICAL IMPULSES

Neurons are....

specialised communication cells

how do neurons communicate 

communicate using electrochemical signals

Glia are support cells with a wide range of functions:

–Attacking invading organisms

–Promoting neuron repair

–Providing insulation for the electrochemical communications between neurons

what are the 2 diff glial cells 

Microglia

Macroglia

what is cytoarchitecture

is the study of the cellular composition of the central nervous system's tissues under the microscope.

structure of teh neuron image 

SOMA

The cell body, metabolic centre

DENDRITES

bring information to the soma from other cells/neurons

axon 

Project from the soma to other cells, carry information away

 

AXON HILLOCK

■Junction between soma and axon

 

MYELIN SHEATH:

Layer of fat surrounding most axons

 

NODES of RANVIER

gaps between myelin sections