neuro test 2

DNA is inside

Nucleus

RNA is inside

Nucleolus

Nucleolus function

Produces ribosomes

Microtubules

Contribute to cell framework and movement of cell parts

ER does what

Produces proteins, fatty acids, enzymes, etc

Ribsomes do what

Produce proteins

Golgi apparatus

Packs and sends sugar and protein out of cell

Lysosomes

Garbage collectors; break down and recycle used molecules

Centrosome/centioles

Directs growth of cell thru division

Astrocytes

Maintain neural environment, repair/feed neurons, etc. In CNS

Oligodendrocytes

Produce myelin in cns

Microglia

Scavenge debris and defend against invaders

Schwann cells

Produce myelin in pns

Satellite cells

Astrocytes in pns

Acetylcholine

Excitatory: skeletal muscle contraction, memory and learning

Inhibitory: cardiac tissue

PNS

Glutamate

Excitatory: memory, learning, movement

Ach of CNS

GABA

Inhibitory: blocks excitatory NTs; sleep-wake cycle

Main inhibitory NT of CNS

Dopamine

Inhibitory: indirect motor pathway

Excitatory: direct motor pathway, heart rate, blood pressure, reward/pleasure

Epinephrine

Excitatory: fight or flight

Norepinephrine

Excitatory: fight or flight

Serotonin

Regulatory: mood, sleep, appetite

Substance P

Excitatory: pain, inflammation in response to injury

Wallerian degeneration

Part of alone after injury degenerates and alone pulls away from synapse IN CNS

Do axons in the pns regenerate?

Yes

2 phases of communication

1. Electrical (dendrites and axons)

2. Chemical (NTs and synaptic cleft)

Active transport

Energy used

Passive transport

No energy used

Gradient

Imbalance; some ions in and others out

3 steps of neuron function

1. Polarization/loaded gun

2. a. Chemical transmission/firing

3. 2b. Depolarization/ electrical firing

4. 3. Reploarization/reloading

Steps 1: why polarized?

1. Concentration gradient of Na and K

2. Charge gradient of -70mv

Step 2a. Chemical transmission

NTs released into synapse and attavh to post-synaptic receptors like a lock and key

Step 2b. Depolarization/electrical firing

Ion channel’s open, Na gradients equalized, electrical charge (action potential) goes down axon

Step 3. Repolarization/reloading

Reestablishing both gradients thru Na/K pump (Na close and K open; active transport), inside of alone negative again

Absolute refractory period

New stimulation has no effect

Relative refractory period

Neuron will respond to very strong stimulation

ID def

Sub average intelligence in minors

Limitations on functioning like school

Dendritic spines long and thin

ID dx

Psych testing to determine (IQ test)

ID tx

If needed, lang., social, and verbal communication (maybe AAC)

Brain tumor def

Abnormal growth of brain tissue

Neoplasm

Brain tumor

Neuroma

Neuron tumor

Are most tumors benign ir malignant?

Slightly more malignant

Neoplasm cause

Tumor suppressor off

Neoplasm dx

First indicator clinical signs, imaging confirms, tumor grading

Neoplasm tx

Depends on type and grade- surgery is common

ALS def

Motor neuron disease - withering of UMN and LMN

Cause mostly unknown

Types of ALS

Spinal (limbs) and bulbar (mouth)

ALS dx

Speech and swallowing (esp w/ bulbar)

Dx by clinical presentation and ruling out other MNDs

ALS tx

Dysphagia management, AAC, communication support

MS def

Autoimmune disorders of the myelin

Unknown cause (maybe mono), no cure, but meds suppress symptoms

4 types of MS

1. Relapsing remitting- most common

2. Primary progressive - worst, like ALS

3. Secondary progressive - RR then P

4. Progressive relapsing

MS dx

Young women most common

Neuro signs appear, imaging and bloodwork confirm

MS tx

Management of comm cognitive and swallowing problems (maybe hearing)

MG def

Neuromuscular junction disease

Main symptoms- weakness and fatigue

Cause -maybe thymus gland

MS dx

Ptosis, muscles of eyes and face, can have attacks

Function gets worse, then better with rest

MS tx

Management of speech and swallowing problems

Guillain-Barre

Rapid progressive demyelinating PNS disease

Starts in lower limbs

Most common form autoimmune

GB dx

Progressive paralysis over a month, then pt recovers

GB tx

May need ventilator

Management of comm and swallowing

Where do SNs emerge?

From between vertebrae

4 SC fiber types

1. GSE - skeletal muscles

2. GVE - smooth muscles and glands

3. GSA - Skin

4. GVA - lungs and digestive tract

____ + ______ = SC

Dorsal Ramus and ventral ramus

Plexus

Network of SNs which branches out and innervates part of the body

Dorsal ramus (branch)

Carries GSA and GSE to/from dorsal part of body; outside vertebral column

Ventral ramus

Carries GSA and GSE to/from ventral part of body; outside vertebral column

Dorsal root

GVA and GSA; inside vertebral column

Dorsal root ganglion bulges out

Ventral root

Motor- GVE and GSE; inside vertebral column

Sensory first order neurons

Carry info from SRs to CNS

Synapse in dorsal root ganglion

Sensory second order neurons

Synapse in dorsal root ganglion

Decussate and arrive at thalamus

Sensory third order neurons

Route info to reception area in cortex

Sensory fourth order neurons

From sensory reception area to processing area

Dorsal columns

Sensory tract - touch, pressure, proprioception

Spinothalamic tract

Sensory; pain, temp, crude and light touch

Spinocerebellar tract

Proprioceptive info from peripheral sense receptors to cerebellum (only 2 neurons in sequence)

Dorsal horns

Sensory gray matter

Ventral horns

Motor function via LMNs

Most common cause of SC injury

Car accidents

Paralysis vs paresis

Complete vs incomplete loss of movement/sensation

Hemiparalysis

Arm/leg on one side

Paraplegia

Legs

Quadriplegia

Arms and legs

SCI tx

Surgery, steroids, rehab

Myelitis def

Inflammation of SC

Myelitis types

Polio - grey matter (motor loss)

Leuko- white matter (sensory loss)

Transverse- both

Spina bifida

Can result in damage to lower SC

Possible paresis and bowel/bladder issues

Peripheral neuropathy

Inflammation of PNS → degeneration of SNs esp in feet

PN causes

Diabetes, toxins, alcohol, infections, nutritional deficiencies

PN leads to

Paresthesia (partial numbness) or anesthesia (complete numbness)

Wounds heal poorly

Can PN be reversed?

Sometimes depending on underlying cause

Bumper sticker

SO4LR6AO3

Brainstem in charge of

Vital functions - respiration, heart rate, wakefulness, blood pressure, digestion

6 structures of medulla

1. Cerebellar peduncles - connect to cerebellum

2. Pyramids

3. Olive - motor coordination

4. Nuclei for CN IX-XII

5. Nucleus solitarus- sens for swallowing

6. Nucleus ambiguus- motor for swallowing

Pons

Bridge of info

Middle cerebellar peduncles

Respiration, swallowing, hearing

CN nuclei V-VIII (motor for eye, sense and motor for face)

6 structures of Midbrain

Cerebral peduncle - link pons and cerebrum

Substantia nigra

Superior colliculi - track visually

Inferior colliculi - localize sound

Pineal gland

CN III and IV

Brainstem functions

Vital functions

Head and neck reflexes

Alertness/wakefulness

Medullary damage

Wallenburg syndrome -stroke in medulla; dysphagia, dysarthria, dysphonia, violent hiccups, contra pain and temp loss in body, ipsi loss of pain and temp in face

Some recover some don’t

Pontine damage

Coma and/or locked in syndrome (cognition and eyes intact, complete paralysis)

Most die in 4 mos

Midbrain damage

Weber syndrome- caused by stroke; contra hemiplegia, lower facial paralysis, and tongue paresis; ipsi CN III paralysis with ptosis

Additional 3 CN fiber types

1. SSA - visual and auditory info

2. SVA - smell and taste

3. SVE - motor control for glands in head/neck

Anopsia

Loss of vision; blindness