PSYBIOP Nervous System and Neuroanatomy

CNS

located within skull and spine (brain& spinal cord)

PNS

outside skull and spine, somatic & autonomic

Somatic Nervous System

part of the PNS that interacts with external environment

Afferent Nerves

carrying sensory signals to the CNS

Efferent Nerves

carrying motor signals from CNS to skeletal muscles

Autonomic Nervous System

part of the PNS that regulates the body's internat environment

Sympathetic (Autonomic)

motor nerves from lumbar (small nerves of the back) and Thoracic (chest area) regions of spinal cord

Sympathetic

fight or flight

Parasympathetic (autonomic)

rest and digest

Parasympathetic

motor nerves that project from the brain and sacral (lower back) regions of spinal cord

Sympathetic

stimulate, organize and mobilize energy resources in threatening situations, psychological aroual

Parasympathetic

conserve energy, psychological relaxation

Vagus, Glossopharyngeal, Facial, Trigeminal (1975)

Both motor and sensory

Dura matter

outer meninx

Arachnoid membrane

spider-web-like membrane

Subarachnoid space

contains many large blood vessels and cerebrospinal fluid

Pia matter

delicate, innermost meninx, adheres to the surface of the CNS

Cerebrospinal fluid

protects CNS, supports and cushions the brain

Subarachnoid space

Cerebrospinal fluid is found in

Hydrocephalus

build up of fluid from ventricles and removal of obstruction

draining if excess fluid from ventricles and removal of obstruction

Treatment of hydrocephalus

rapid increase in head size, bulge on the fontanel, vomiting, irritability, seizures, sun setting eyes (downwards), sleepiness

symptoms of hydrocephalus

Choroid plexus, Lateral Ventricle, Foramen if Monroe, Third Ventrice, Sylvian Acqueduct, Fourth Ventricle, Foramen of Magendie & Luschka, Subarachnoid Space, Arachnoid Villi

CEREBROSPINAL FLUID FLOW

Blood Brain Barrier

impedes the passage of many toxic substances from the blood into the brain

Glucose

critical for brain function

therapeutic or recreational drugs can influence brain activity

Application of Blood Brain Barrier

Neurons

cells that are specialized for the reception, conduction, and transmission of electrochemical signals

Neuron cell membrane

lipid bilayer or 2 layers of fat molecules

Channel proteins

where certain molecules can pass

signal protein

transfer a signal to the inside of the neuron

Cell membrane

semi-permeable membrane that encloses neuron

Dendrites

short processes emanating from the cell body, receives most if the synaptic contacts from other neurons

Axon hillock

cone-shaped region atvthe junction between the axon and the cell body

Axon

long, narrow process that projects from the cell body

Myelin

fatty insulation around many axons

Cell body

metabolic center of neuron

Soma

other term of cell body

Nodes of Ranvier

gaps between sections of myelin

Buttons

gaps between adjacent neurons across which chemical signals are transmitted

Multipolar neuron

more than 2 processes extending from its cell body

Unipolar neuron

neuron with one process extending from its cell body

Bipolar neuron

neuron w/ 2 processes extending from its cell body

Interneurons

function is to integrate neural activity within a single brain structure NOT conduct signals from 1 to another

Endoplasmic Reticulum

system of folded membranes in the cell body

cytoplasm

the clear internal fluid of the cell

ribosomes

internal cellular structures on which proteins are synthesized

Endoplasmic reticulum

where ribosomes are located

Golgi complex

connected system of membranes that packages molecules in vesicles

Nucleus

spherical DNA-containing structure of the cell body

mitochondria

sites of aerobic (oxygen-consuming) energy release

Microtubules

tubules responsible for the rapid transport of material throughout neurons

synaptic vesicles

spherical membrane packages that stores neurotransmitter

Neurotransmitter

molecules that are released from active neurons and influence the activity of other cells

nuclei or nucleus

clusters of cell bodies (CNS)

tracts

bundles of axons (CNS)

ganglia

nerves (PNS)

Oligodendrocytes

glial cells with extensions that wrap around the axons of CNS neurons

myelin sheaths

increases speed and efficiency of axonal conduction

Schwann cells

glial cell, found in PNS. Only constitue 1 myelin segment

regrowth

other term of axonal regeneration

microglia

smaller than other glial cells, respond to injury or disease by multiplying, engulfing cellular debris, triggering inflammatory respinses

microglia

regulation if cell death, synapse formation and elimination

Astrocytes

largest glial cells, named because they are star shaped.

Astrocytes

glial cells that have an affinity for blood vessels, make contact w neurons

Golgi stain

visualize shape of neurons, through its silhouette

Nissl stain

can give an estimate of number of neurons in an area

Electron microscopy

provides details of the neuronal structure

Anterior

toward nose end

rostral

anterior

caudal

posterior

posterior

toward tail end

dorsal

toward the surface of the back or top of the head

ventral

towards surface of the chest or the bottom of the head

medial

midline of the body

lateral

away from the midline

Proximal

close or near

Distal

far

midsaggital section

cut down the center of the brain, between 2 hemispheres

cross section

cut at a right angle to any long, narrow structure, such as spinal cord or nerve

Gray matter

cell bodies and unmyelinated interneurons

white matter

myelinated axons (glossy white sheen)

Telencephalon, Dien, Mesen,Meten, Myelen

divisions of the brain

myelencephalon

where the medulla is

myelencephalon

most posterior division of the brain, contains reticular formation (little net)

myelencephalon

arousal, sleep, attention, movement, the maintenance, of muscle tone and various cardiac, curculatory and respiratory reflexes

Metencephalon

houses many ascending and descending tracts and part of the reticular formation

pons and cerebellum

Metencephalon contains

pons

(metencephalon) buldge on the brainstem's ventral surface

cerebellum

large, convoluted structure on the brain stem's dorsal surface

cerebellum

(metencephalon) important sensorimotor structure

tectum and tegmentum

2 divisions of mesencephalon

tectum

(roof) dorsal surface of the midbrain

tegmentum

divisions if mesencephalon ventral to the tectum

inferior colliculi

(posterior pair) auditory function

superior colliculi

(anterior pair) visual-motor function specifically in the direction of the body's orientation

periaqueductal gray

gray matter situated around the cerebral aqueduct

Analgestic (gray matter)

pain reducing effects of opioid drugs

Substantia nigra and red nucleus

both important components of sensorimotor system

thalamus and hypothalamus

2 structures of diencephalon

thalamus

2 lobed structure that constitutes the too if the brain stem