A&P nervous system study guide

Nervous System

Gathers stimuli, processes decisions, and helps you respond to stimuli.

Neurons

Cells that receive and transmit impulses for communication and responding to stimuli.

Reflex Arc Order

Receptor => sensory neuron => interneuron => motor neuron => effectors.

CNS

brain and spinal cord.

PNS

nerves.

SNS

skeletal and voluntary.

ANS

cardiac muscle, smooth, involuntary.

Neuroglia

Support and protect neurons.

Sympathetic Division

In control in times of stress and fear.

Parasympathetic Division

In control of rest.

White Matter

Helps conduct nerve impulses around the body (myelin sheaths).

Gray Matter

Helps CNS make decisions.

Na+ Ion

Outside of a resting neuron.

K+ Ion

Inside of a resting neuron.

Depolarization

Neuron becomes less negative on the inside of the cell membrane

Repolarization

Positive potassium ions flow out of the membrane of neuron making the inside slightly negative

Sodium-Potassium Pump

Transports 3 sodium ions out and 2 potassium ions into the neuron to restore balance and keep the membrane at resting potential.

Efferent Neurons

Carry effect away from CNS.

Afferent Neurons

Carry signals toward CNS.

Meninges

Dura mater, Arachnoid, Pia mater.

Frontal Lobe

Primary motor area and reasoning.

Occipital Lobe

Visual processing.

Parietal Lobe

Primary somatic sensory area (touch, temperature, pressure, pain).

Temporal Lobe

Auditory (hearing).

Cerebellum

Regulates coordination and balance.

Cerebrum

Consists of right and left cerebral hemispheres for controlling voluntary movement, sensory, intellectual reasoning, and memory.

Brain Protection

Skull and vertebral column, watery cushion (cerebrospinal fluid).

Dendrites

Processes (fibers) of a neuron that receive signals.

Axons

Processes (fibers) of a neuron that transmit signals.

Thalamus

Relays sensory information to the correct lobe.

Hypothalamus

Controls the release of hormones.

Epithalamus

Controls the endocrine system and circadian rhythm.

Thermoreceptor

Responds to hot and cold temperature.

Chemoreceptor

Responds to chemicals, like taste buds.

Nociceptor

Responds to pain.

Proprioceptor

Detects position of body and movement, like vestibular in ear.

Mechanoreceptors

Respond to touch, pressure, and vibrations, like Pacinian corpuscles.

Photoreceptor

Converts light into electrical signals to the brain, like rods and cones.

Astrocytes

Taste substances before allowing them into neurons.

Ependymal Cells

Circulate cerebrospinal fluid (CSF).

Microglia

Destroys germs.

Oligodendrocytes

Found in the central nervous system (CNS).

Schwann Cells

Found in the peripheral nervous system (PNS).

Nodes of Ranvier

Speeds up impulses.

Gyrus

Raised ridge in the brain.

Sulcus

Depression/crevice in the brain.

Corpus Callosum

Connects right and left hemispheres.

Medulla Oblongata

Controls respiratory and cardiac responses.

Order of Light Passage in Eye

Cornea-aqueous humor-pupil-lens-vitreous humor-retina.

Rods

Help detect gray tones and dimness, located in the retina.

Cones

Enable color vision.

Three Layers of the Eye

Retina-choroid (vascular)-sclera.

Olfactory Sense

Molecules dissolve in mucus and activate chemoreceptors for smelling.

Cochlea

Detects sounds.

Vestibule

Detects head orientation and straight movements.

Semicircular Canals

Detect angled/rotary movement.

Order of Sound Passage in Ear

Pinna-external auditory canal-tympanic membrane-ossicles-oval window-cochlea.