lecture 2 - neurons, glial, and the nervous system

central nervous system

brain and spinal cord

peripheral nervous system

neurons outside brain and spinal cord

can a single cell span both CNS and PNS?

yes (sensory neurons for example)

soma

somatic nervous system

(PNS) sensation and control of skeletal muscles

autonomic nervous systme

(PNS) “automatically” controls state of being

sympathetic division

(PNS - ANS) ACTIVATED - Arousal, fight or flight, energy expenditure, increased heart rate

parasympathetic nervous system

(PNS - ANS) - DEACTIVATED - relaxation, digestion, slow heart rate (rest and digest)

meninges

a series of protective layers that surround the brain and spinal cord

cerebrospinal fluid

a fluid that is found within the meninges layers, cushioning the brain inside the skull

dura mater

DURABLE - tough outer layer of the meninges

arachnoid mater

SPIDERWEBS - middle layer of the meninges containing cerebrospinal fluid and vasculature (blood vessels)

pia mater

tight and thin lower layer of the meninges that hug the brain and spinal cord

what word describes the presence of the cerebral blood supply?

redundant

how is blood supplied to the brain?

through internal carotid arteries and vertebral arteries

blood brain barriers

a special type of capillary, a layer of cells that surround the blood vessels in the brain - protects the brain from changing the content of the blood and from foreign substances while permitting other substances to enter.

what part of the blood brain barrier cells actually make the BBB to be important barriers?

the lipid bilayer that makes up the cell membrane, determining solubility and the entrance of specific substances

gray matter

neurons (the cell bodies)

white matter

the axons of neurons

nucleus (in CNS) and ganglion (in PNS)

a dense cluster of neurons

ventricles

fluid filled cavities where metabolic byproducts accumulate and drain into venous circulation

tracts

axon bundles in the CNS

nerves

axon bundles in PNS

cerebral cortex

most “evolved” portion of human brain

sensory, movement execution, planning, cognition, learning functions

cortex folds, increaisng nervous area (more neurons)

gyrus (p. gyri)

ridges in surface of cerebral cortex

sulcus (p. sulci)

valleys in surface of cerebral cortex

brainstem

continuous with the spinal cord, evolutionary “oldest” parts of brain, controls automaic and vital functions (respiration and heartrate)

Top to bottom parts = midbrain, pons, medulla oblongata

hindbrain/cerebellum

critical in regulation of fine movement, coordination, timing of movements, and postural control.

has its own cortex (cerebellum cortex) containing Purkinje cells, whose activity changes when we learn how to time and make movements

corpus callosum

connects the left and right hemispheres of the brain

thalamus

RELAY - interacts with the cortex, relaying/gating input and output signals/dynamics

hypothalamus

(below thalamus) - SURVIVAL - controls survival functions, like eating, drinking, body temperature, and fear

anatomical refrencing (medial, lateral, dorsal, ventral, anterior, posterior)

glial cells

support cells of nervous system, do not span great distances, not as much dynamic activity as neurons

nutrient transporting, neurotransmitter trafficking, myelination, responding to injury

myelination

insulation on actions, increasing speed of signal conduction

mac

macroglia

larger glial cells

astrocytes

macroglia involved with nutritive function, metabolism, neurotransmission, removes dead neurons

oligodenrocytes

macroglia that create myelin sheath on CNS axons

schwann cells

myelinate PNS axons

microglia

smaller glial cells that mobilized after injury, infection, or disease, helping to clean up

neurons

a polarized cell (voltage difference between extracellular fluid and intracellular fluid) that translate input signals, whether chemical, mechanical, radiant, etc. into electrical signals, processing the information

soma

neuron cell body, contains the cellular machinery/organelles

dendrites

the receiving end of the neuron, often many in number

axon

the sending end of the neuron, typically only one, but can be short or long in length

efferent neuron

carries information out

afferent neuron

brings information in

multipolar neuron

many dendrites (at least 2 major branches) and one axon, common in cortex

unipolar/monopolar neuron

axon branching in two directions, acts as dendrite + axon, common in peripheral sensory neurons

bipolar neuron

one dendrite and one axon, also common in sensory systems