PRECISION EXAM STANDARD 7: Overview of the Nervous System and Special Senses

Sensory Input

Detects changes inside and outside the body

Integration

Interprets sensory input and makes decisions

Motor Output

Activates muscles or glands in response

Central Nervous System (CNS)

Brain and spinal cord; controls integration and command

Peripheral Nervous System (PNS)

Spinal nerves (31 pairs) and cranial nerves (12 pairs)

Somatic Division

Voluntary control of skeletal muscles

Autonomic Division

Involuntary control of smooth muscle, heart, glands

Sympathetic

Fight or flight

Parasympathetic

Rest and digest

Neuron

Transmits electrical impulses

Astrocytes

Support and regulate the environment for neurons

Microglia

Remove waste and protect neurons

Oligodendrocytes

Produce myelin in CNS

Ependymal cells

Line brain ventricles; help circulate CSF

Schwann cells

Produce myelin in PNS

Satellite cells

Support neurons in PNS

White matter

Myelinated axons (fast signal transmission)

Gray matter

Neuron cell bodies, dendrites, unmyelinated axons (processing)

Meninges

Protective membranes

Dura mater

Tough outer layer

Arachnoid mater

Middle layer, web-like

Pia mater

Delicate inner layer on brain and spinal cord

Cerebrospinal fluid (CSF)

Produced in the ventricles; circulates through subarachnoid space; cushions brain and spinal cord, removes waste, delivers nutrients

Cerebrum

Largest part; controls thinking, memory, and movement

Cerebellum

Coordinates balance and muscle movement

Brain Stem

Controls involuntary functions (breathing, heartbeat)

Thalamus

Sensory relay station

Hypothalamus

Regulates body temp, hunger, hormones

Reflex arc

Receptor detects stimulus; sensory neuron sends message to CNS; interneuron processes info in CNS; motor neuron sends message to effector; effector is muscle or gland that responds; reflex is automatic, rapid response to stimulus

ALS (Lou Gehrig's Disease)

Motor neurons degenerate

Alzheimer's Disease

Memory loss and brain shrinkage

Bacterial Meningitis

Inflammation of brain/spinal cord linings

Cerebral Palsy

Brain damage affecting movement

Epilepsy

Repeated seizures from abnormal brain activity

Multiple Sclerosis (MS)

Immune system attacks myelin

Guillain-Barré Syndrome

Rapid-onset muscle weakness

Parkinson's Disease

Affects movement due to low dopamine

CVA (Stroke)

Blocked or burst blood vessel in brain

Gustatory cells

Detect taste (located in taste buds)

Olfactory bulb

Processes smell; located in nasal cavity

Ametropia

Poor focusing of light (includes: Myopia, Hyperopia, Presbyopia)

Cataracts

Clouding of the lens

Conjunctivitis

Inflammation of conjunctiva ('pink eye')

Strabismus

Crossed eyes

Glaucoma

Increased eye pressure damages optic nerve

Macular degeneration

Loss of central vision

Vertigo

Spinning sensation

Tinnitus

Ringing in the ears

Otitis Media

Middle ear infection

Deafness

Conductive - Problem with outer/middle ear; Sensorineural - Damage to inner ear or nerve