ANAPHY LEC (NERVOUS SYSTEM)

central nervous system and peripheral nervous system

2 divisions of the nervous system

CNS

Key decision maker

receives information from and sends information to the body.

PNS

Messenger detects stimuli in and around the body and sends the information to the CNS and communicates messages from CNS

to the body.

neurons

fundamental unit of the nervous

system that receive and transmit

signals to different parts of the

body.

sensory

motor

interneuron

astrocytes

Ependymal cells

Oligodendrocytes

Microglia

satellite cells

Schwann cells

Leak Ion Channels

Always open, allowing ions to diffuse across the membrane.

Gated Ion Channels

Open or close in response to specific signals, regulating ion

flow.

Ligand-Gated Channels

Open when specific molecules

(e.g., neurotransmitters) bind to receptor sites.

Voltage-Gated Channels

Open in response to changes

in membrane potential.

Mechanically Gated Channels:

Open due to physical

stimuli like pressure or stretch.

Resting Membrane Potential

The result of K+ diffusion through leak channels and the

electrochemical gradient.

Resting membrane potential

Voltage-gated Na+ channels (pink) and most, but not all, voltage-gated K+

channels (purple) are closed. Outside of the plasma membrane is

positively charged compared to the inside.

Depolarization

Voltage-gated Na+ channels open.——results because the

inward movement of Na+ makes the inside of the membrane more

positive

Repolarization

Na+ movement into the cell stops, and K+ movement out of the

cell increases, causing —-

End of repolarization and

afterpotential

Diffusion of K+ through open voltage-gated channels

produces the——.

resting membrane potential

The —— is reestablished by the Na+/K+

pump after the voltage-gated K+ channels close. Na+ is pumped

out of the cell and K+ is pumped into the cell.

Cerebrospinal Fluid

forms a watery cushion

to protect the brain and

spinal cord; and provides

nutrients.

choroid plexus

is produced by the

— of each

ventricle.

Cerebrum

what section of the brain is responsible for: Interpret sight, sounds, touches; regulates emotions, reasoning, learning

Cerebellum

what section of the brain is responsible for: Posture; Balance;

Coordination of movement

Brainstem

what section of the brain is responsible for: Consciousness; Breathing;

Heart rate

Frontal

what lobe of the brain is responsible for: Movement; Problem-solving;

Concentrating; Thinking;

Behavior, personality, mood

Parietal

what lobe of the brain is responsible for: Sensation; Language;

Perception; Body Awareness;

Attention

Temporal

what lobe of the brain is responsible for: Hearing; Language; Memory

Occipital

what lobe of the brain is responsible for: Vision; Proprioception

Right

(Creativity)

what hemisphere of the brain is responsible for:

Receives info from and

controls L side of the

body.

• (Dancer) spatial,

Kinesthetic, body

image, hand-eye,

holistic process.

• (Creative) imaginative,

express feelings,

understand music.

what hemisphere of the brain is responsible for:

Left

(Analysis)

• Receives info from and

controls R side of the

body.

• (ACADS) language,

logical, math, leader,

analytical rational,

written and spoken

words.

• Sequence and perform

movement.

Dura Mater

meninges; Outermost layer; form folds that separate

right half of the brain from the left.

Arachnoid Mater

meninges; Middle layer; fragile layer that covers the

entire brain.

Pia Mater

Innermost layer; contains blood vessels

that runs into the brain’s surface

Thalamus

The switchboard of the CNS; relays sensory

information to the cortex from the rest of the body.

Hypothalamus

Regulates hormonal functions, autonomic function,

hunger, thirst and sleep.

Pituitary Gland

Sends out hormones to different organs in the

body.

Basal Ganglia

Group of nuclei in the cerebrum; controls

movement, including motor learning and planning.

The Brain

Homunculus

portrays the anatomical divisions of the primary motor cortex and the

primary somatosensory cortex.

Dyskinesia

General term for movement problems; often

involves basal nuclei.

Parkinson's

disease

Muscle rigidity, slow movement, resting

tremors, and shuffling gait; linked to basal

nuclei lesions.

Huntington

Disease

Hereditary disorder causing involuntary

movements and degeneration of basal

nuclei.

Cerebral Palsy

Caused by brain damage during pregnancy

or birth; includes muscle tone issues,

tremors, and difficulty speaking or moving.

Cerebellar

Lesions

Jerky, ataxic (uncoordinated) movements

and tremors when trying to control

movements.

Alzheimer

Disease

Dementia with memory loss, confusion, and

disorientation; caused by neuron loss in the brain.

Tay-Sachs

Disease

Hereditary lipid-storage disorder; leads to paralysis, blindness, and death in infants.

Epilepsy

Seizures due to abnormal electrical activity in the

brain, causing convulsions.

Headaches

Pain caused by inflammation, muscle tension, or

unknown factors.

Dyslexia

Reading difficulties due to impaired ability to

recognize letters and words.

Stroke

Caused by blood supply loss to the brain;

symptoms include paralysis and speech loss.

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pairs of spinal nerves,

which exit the vertebral column

through intervertebral and

sacral foramina.

Cervical Enlargement

Nerve fibers supplying

the Upper limbs enter/exit.

Lumbosacral Enlargement

Nerve fibers supplying the Lower

limbs enter/exit.

Conus Medullaris

tip is the inferior end of the

spinal cord; extends to L2.

Cauda Equina

Horse’s tail; lumbosacral roots

Filum Terminale

Prolongation of pia mater

Reflex Arc

an automatic response to a stimulus; unconscious thought.

Monosynaptic

Polysynaptic

—- Reflexes- without interneurons

—- Reflexes- has interneurons

Stretch Reflex

reflex contraction of muscles in response to stretching of that same muscle.

(1) the endoneurium -

(2) the perineurium -

(3) the epineurium - binds the

nerve fascicles together to form a

nerve

There are three layers of

connective tissue:

endoneurium

surrounds each axon, or nerve

fiber, and its Schwann cell sheath

perineurium

surrounds

groups of axons to form nerve

fascicles

epineurium

binds the

nerve fascicles together to form a

nerve

Ascending Pathways

Carry sensory

information to the brain.Body to Brain

Descending Pathways

Carry motor commands from the

brain to the body. Brain to Body

Spinal

Stenosis

Narrowing of the spinal canal compressing nerves; causes

pain, numbness, or weakness in the neck or lower back.

Encephalitis

Brain inflammation caused by viruses or, less commonly,

bacteria; symptoms include fever, coma, and seizures.

Meningitis

Inflammation of meninges due to infection; symptoms include

stiff neck, headache, fever; severe cases lead to paralysis or

death.

Rabies

Viral disease from animal bites; affects brain and nerves,

causing aggression, paralysis, and death if untreated.

Tetanus

Bacterial toxin affects motor neurons, causing rigid muscles

("lockjaw"); can lead to fatal respiratory spasms.

Multiple

Sclerosis

Autoimmune disease damaging nerve sheaths; symptoms

include tremors, speech issues, and exaggerated reflexes.

Anesthesia

Loss of sensation, either pathological or induced for

medical procedures.

Neuritis

Inflammation of nerves; can cause motor function loss

(motor nerves) or loss of sensation (sensory nerves).

neuralgia

Nerve pain with spasms or stabbing sensations; often

due to inflammation or nerve damage.

Sciatica

Pain radiating down the back of the leg from the sciatic

nerve; often caused by a herniated lumbar disk.

Leprosy

Bacterial disease causing skin and nerve damage; leads

to disfiguring lesions and tissue death.

Herpes

Virus causing painful skin sores (e.g., cold sores,

shingles); different forms can attack sensory ganglia.

Poliomyelitis

Viral CNS infection damaging motor neurons;

causes paralysis and muscle atrophy.

Diabetic

Neuropathy

Nerve damage from high blood sugar levels;

affects extremities with pain, numbness, and

weakness.

Charcot-Marie-To

oth Disease

Hereditary disorder causing progressive nerve

damage and muscle weakness.

Neurofibromatosis

Genetic condition causing benign tumors in

nerve tracts and skin growths.

Myasthenia

Gravis

Autoimmune disorder affecting nerve-muscle

communication; leads to fatigue and paralysis.

Somatic Nervous System

Voluntary control from

cerebral cortex, with

contributions from basal

ganglia, cerebellum, brain

stem, and spinal cord.

Autonomic Nervous System

Involuntary control from

hypothalamus, limbic system, brain

stem, and spinal cord; limited

control from cerebral cortex.

Autonomic tone:

The balance between sympathetic and

parasympathetic activity; regulated by the hypothalamus.

Sympathetic response:

“Fight or flight,” happens during physical

and emotional stress. Favors body functions that support

vigorous physical activity over the storage of energy.

Parasympathetic response:

“Rest and digest,” supports body

functions that conserve and restore body energy during times of

rest and recovery.