physio exam 2 part dose

cluster of neurons cell bodies within the PNS

Group of CNS neuron cell bodies with a common function

Center that displays discrete anatomic boundaries

Axon bundle extending through the PSN

Network of nerves

CNS axon bundle in with the axons have a similar function and share a common origin and destination

Group of tracts in a specific area of the spinal cord

Centers and tracts that connect the CNS with body organs and systems

Gray matter

-Neuron cell bodies

-Dendrites

-Unmyelinated axons

-Brain (gray outside, white inside)

brain stem

-Spinal cord (white outside, gray inside)

White matter

-Myelinated axons

made of nervous & connective tissue, and blood vessel

Dorsal root

- sensory neuron axons ONLY

Unipolar neuron cell bodies located in posterior root ganglion

dorsal root ganglian- soma is outside CNS (Afferent)

Ventral root

-motor neuron axons ONLY

- anterior horn of gray matter in cord

-Efferent fibers - soma is inside CNS (nucleus

Dura mater- tough outside layer

Arachnoid Mater- filled with intricate “web” of collagen (barrier for CNS)

subarachnoid- cerebral spinal fluid 

Pia Mater- Innermost layer; lines every sulci and gyri of the hemispheres, contours brainstem, and all folds of cerebellum (produces cerebral spinal fluid)

Endothelial- bodyguard for top people

Pericytes-

Regulate cerebral blood flow and BBB permeability by cell signaling to astrocyte, endothelial and neurons

Astrocyte- communication with endothelial and pericytes

-influence express of pump, receptors, mechanisms

-support energy supply

-liquid surrounding brain and spinal cord formed in choroid plexus by ependymal cell and flows in subarachnoid area

-physical support

-controlled chemical environment -> nutrient and waste removal

Produced in choroid plexus

-flow through ventricles and into subarachnoid space

-absorbed into dural venous sinuses via arachnoid villi

-thin gray outermost portion of cerebrum, 75% of all neurons in nervous system

-Ultimate control/information processing center

Master endocrine gland

motor movement (eye, auditory, visual)

Breathing, Hearing Taste, balance

Pathway to neural fibers traveling to/from brain. Simple reflexes

Regulate breathing, heart and blood vessel

voluntary movement. Balance and memory

emotions ( reward, fear, social functions)

memory, cognition (long term memory, map navigation, spatial memory)

Carries signal from hippocampus to mammillary bodies and septal nuclei

relay motor and sensory messages (except smell) between lower brain and cerebral cortex

-large group of nuclei in diencephalon

-left/left lobe connected by interthalamic adhesion/intermediate mass (travel through third ventricle

Axon fibers connecting 2 cerebral hemisphere

Cerebrum

prominent, anterior part of vertebrate brain (2 hemisphere)

-Both gray and white mater

-cell body and nerve fiber

-control voluntary muscle movement

Cerebral cortex

-outer layer of cerebrum

-folded grey matter

-cell bodies and dendrites

-4 lobes

-consciousness

longitudinal fissure

white tract: corpus callosum

Gyri- increase surface area

Sulci- some divide into 5 lobes (frontal, central, parietal, occipital)

cerebral lateralization

left hemisphere: language production

right hemisphere: visuospatial

Frontal lobe

Reasoning, planning, speech, movement, emotions, problem solving

Parietal

Movement, orientation, recognition, perception of stimuli

Occipital

Visual

Temporal

Perception, Hearing

homunculus- amount of brain tissue devoted to each sonsory/motor functions

Primary somatosensory area -site where sensation originate

Primary motor area - generate action potential for movement, receive info from lobes of brain from d

•Primary Motor Cortex (somatic motor area)—voluntary skeletal muscle activity; located within the precentral gyrus

•Motor Speech Area (Broca’s Area)— movements for vocalization;  located within the inferolateral portion of the left frontal lobe

•Frontal Eye Field—regulates eye movements and binocular vision; located immediately anterior to the premotor cortex 

•Primary somatosensory cortex—receives general   somatic sensory information from touch, pressure, pain,   and temperature receptors; located within the postcentral   gyrus

•  Primary visual cortex—receives and processes incoming   visual information; located in occipital lobe

•  Primary auditory cortex—receives and processes   auditory information; located in temporal lobe

•  Primary gustatory cortex—processes taste information;   located in insula

•  Primary olfactory cortex—provides conscious awareness   of smell; located in medial temporal lobe

-under cerebrum

Master control of the Autonomic Nervous System

and Endocrine System (emotion and reward)

-body temperature

-certain emotions and sex drive

-thirst and hunger

-hormones, growth

-metabolism

-water and electrolyte balance

blood pressure,

sleep,

homeostasis

coordinating skeletal muscle contraction

Comprised of nuclei:

-Caudate nucleus

-Lentiform nucleus

-Putamen

-Globus pallidus

parkison disease

muscle tone, coordination of movement, posture/balance, eye movement, motor learning, cognitive function (language, riding bike)

-influence ipsilateral(same) side of body

-compare motor plan (intent) in cortex with motor performance (from periphery) and smooth them

-synaptic contact with brain stem "motor" and cerebral hemisphere

Control info from brain and body, breathing, swallowing heart rate, blood pressure, conscious

Diencephalon of thalamus (relay/process sensory info) and hypothalamus(emotions, autonomic, hormone)

Midbrain-connects pons and medulla oblongata

-process auditory and visual. create reflexive somatic motor response. maintain consciousness

Pons-relay sensory into to cerebellum and thalamus

Medulla oblongata- relay sensory info thalamus and other brainstem. regulation of visceral function (cardiovascular, respiratory, digestive)

Short term- hold 7-12 info for hours, disappears

Long term- hold large amount of info for days/years.

Converted from short by consolidation

need break and repetition

Sensory (afferent) transmit action potential from receptor to CNS

Motor (efferent) transmit action potential from CNS to effectors (muscle, glands)

Sensory reception (detect stimuli inside and outside body), transduction, transmission, integration

Simple- neurons with free nerve ending (pain, tickle, itch, temp)

Complex- have nerve endings enclosed in connective tissue capsules (touch, pressure, vibration)

Special sensory receptors- cells that release neurotransmitters onto sensory neurons initating action potential (vision, hearing, taste, smell)

conversion of stimulus energy (light, heat, touch, sound, etc into nerve signal by

EX transducers: sense organ, gasoline engine

subjective awareness of stimulus

most sensory signals delivered to the CNS produce no conscious sensation

-filtered out in the brainstem

-some do not require conscious awareness like pH and body temperature

transduce

Modality, Location, Intensity, Duration

Modality- which type of environmental stimuli do our neurons sense?

Mechanoreceptors-pressure, touch vibration, stretch, itch, proprioception and equilibrium

Thermoreceptors- temperature

Photoreceptors-electromagnetic radiation

Chemoreceptors-chemicals; taste, smell , changes in body fluid chemistry

Nociceptors-tissue damage

Osmoreceptors– detect changes in concentration of solutes

Interoceptor- monitor internal systems of organ and blood vessel

(chemoreceptor for O2, baroreceptor for blood pressure, mechanical receptor stretch in organ)

Exteroceptor- external senses (touch, temp, pressure)

-distance sense (seeing, hearing, smelling)

Proprioceptor- monitor position and movement (skeletal muscle and joints)

location

fingers have smaller more # touch receptor than forearm

fine tuning of signal

excited neuron reduce activity of neighbor, depends on location

frequency of action potential

Tonic receptor- slowly adapting receptors that respond for the duration of a stimulus (constant firing)

Ex- stretch receptor, pain receptor, photoreceptor, mechanoreceptor

Phasic receptors- rapidly adapt to a constant stimulus and turn off

Ex-smell, pressure, touch, temp

Sensation- awareness of changes

-stimulation of receptor

Perception

conscious awareness & interpretation of sensation

generate action potential then to brain

First order neuron- soma in dorsal root ganglion or cranial ganglion (environment to spinal cord/brain stem)

Second order neuron- soma in brain stem, dorsal root and medulla it travels to thalamus

Thirds order neuron- thalamus to sensory area of cerebral cortex

Upper motor neuron- Carry motor output from cerebral cortex and brain stem to lower motor neuron in spinal cord/brain stem

Lower motor neuron- in anterior gray horn of spinal cord that innervate muscle

nervous, skeletal, and muscular

sensory neuron, upper motor neuron, lower motor neuron

Sympathetic- preganglion release ACH and post  release norepinephrine

Parasympathetic- preganglion release Ach- Post release ACH/norepinephrine

Most visceral organs innervated by both

postganglionic

Varicosities

Single unit- cells connected by gap junction that act as group. Walls of hallow organs (viscera)

Multi-unit- contract individual cells. iris of eye, walls of blood vessel

-adrenal medulla

-arrector pilli- goose bump/hair stands up

-blood vessel

-sweat glands

regulation through increase/decrease firing rate by sympathetic neurons

through balance of sympathetic "fight or flight"

parasympathetic "rest and digest"

Hypothalamus- water balance, temp, hunger

Pons- respiration, cardiac, vasoconstriction

Medulla- respiration

Preganglionic neurons- in CNS, release ACH(excitatory)

Post ganglionic neuron- ganglia outside CNS

increase

heart rate, blood pressure, vasodilation in blood vessel, diameter of respiratory airway(max air), glycogen, sweat,

decrease digestion, urine production

preganglionic neuron- short, branched, cholinergic neuron

Postganglionic neuron- long, adrenergic neuron

Preganglionic neuron –cholinergic -> release ?

->binds nicotinic Ach receptors on postganglionic neurons

excitatory!

Postganglionic neuron – adrenergic neurons

usually release ?

excitatory or inhibitory depending on type of adrenergic receptor it binds on target

↑ age -> ↑ levels of sympathetic activity

may increase hypertension & cardiovascular disease

Preganglionic neurons:-origin:  brain or spinal cord. long, cholinergic

Postganglionic neurons:-origin:  outside CNS near/in effector organ. -short, usually cholinergeric

Vagus nerve –major nerve carrying preganglionic axons of parasympathetic

Preganglionic neuron -> releases ?

-binds nicotinic receptors on postganglionic cell -excitatory

Postganglionic neuron ->releases ? (some release NO)

-ACh binds muscarinic receptors

-inhibition (IPSPs) in heart

-excitation (EPSPs) in digestive tract

•Body movement/skeletal muscle

•Appendages

•Locomotion

•Single neuron

-CNS origin

-Myelinated

•Terminus

-Branches

-Neuromuscular junction

skeletal, smooth, cardiac

chemical energy into mechanical energy

repeating sarcomeres (striated)

myosin and actin

attach to bones through tendons

line walls of hallow organs and blood vessel

Nonstriated and under involunatry control

striated,

intercalated disc

involuntary, autorhythmic

one contract and another return to position

contraction = shortens

moves tendons and bones

voluntary control

contract rapidly but tired easily

overall body motility

T tubules bring action poetntial into muscle fibers

Depolarization cause sarcoplasmic reticulum to release calcium

Muscle fiber contains many myofibril (A band, I band, Z line)

myofibril contain many sarcomere

myofilament (action and myosin)

Basic contractile of muscle unit, between 2 Z line

M line, central myosin filament anchor

H zone- only myosin

I band-only actin filament

A band -myosin and actin

Thick filament (myosin) 2 gobular head and tail

Thin tilament- actin with tropomyosin and troponin

muscle contract- chemical to mechanical

-Nervous system changes in pulmary potential

-myosin head of thick bind to actin of thin propel toward M line

- H zone, sarcomere, muscle cell, whole muscle shortens

by causing change in membrane potential

Motor cortex- generate motor action potential

cerebellum= smooth action

down to spinal cord then muscle

muscle made of many motor units

Motor unit: made up of motor neuron and muscle fibers(either fast or slow twitch) within the muscle it innervates

-Groups of motor unit often work together

-All motor units that subserve single muscle are considered a motor unit pool

-Action potential gets picked up by voltage gated Ca+ channels.

-Ca+ flows in and it releases Ach. Ach bind to motor end plate and flow of Na+ inside.

-Na+ polarize muscle fibers. Action potential travel to T tubules (bring in action potential.

-DHP activated and linked to RyR that release calcium into cytoplasm

-calcium bind to troponin cause tropomyosin to move and expose myosin. Myosin and actin bind (z disc move closer to m line with calcium and ATP)

1. muscle contractions begin and continues if ATP available and Ca++ in sarcoplasm is high

2. Ca++ released and bind to troponin which cause tropomyosin to release and expose actin

3. Myosin head and actin form cross bridge with help from Ca+

4. ADP and P release, Powerstroke slide thin filament. Sarcomere & Z line shorten (muscle contract)

5. ATP bind to myosin cause detachment

6. Hydrolysis of ATP "cock" myosin head

-acetylcholinesterase decomposes acetylcholine

-calcium pump back in SR

-tropomyosin cover myosin binding site

-sarcomere relax and back to normal length

involuntary motor response without conscious control.

-short neuronal circuits =quick reaction

-involve spinal cord or brain stem

-fast, higher brain center not involved (few synapses)

•Protect from tissue damage

•homeostasis

•optimal muscle length for strong contraction

All have similar properties

-stimulus required

-few neurons involved

-preprogrammed response is the same way every time

-involuntary response requires no intent or pre-awareness

-Stimulus activates receptor

-Nerve impulse travel through sensory neuron to spinal cord

-Nerve impulse processed in by interneurons

-Motor neuron transmits nerve impulse to effector

-Effector responds to impulse from motor neuron

Monosynaptic- direct communication between sensory and motor neuron (knee flex)

Polysynaptic reflex-interneuron faciliates sensory motor communication (hot stove)

Polysynaptic with 1 synapse in CNS and another in Autonomic ganglion

- protect from mechanical injury

-provide blood supply to skull

-provide space for cerebrospinal fluid

pressure, touch vibration, stretch, itch, proprioception and equilibrium

temperature

electromagnetic radiation