Nervous System Overview

ganglia

clusters of cell bodies in the PNS

Sensory division of the nervous system

afferent division of the peripheral nervous system. Carries sensory information to the central nervous system.

motor division of the nervous system

carries nerve impulses from the central nervous system to muscles and glands throughout the body. The nerve impulses stimulate muscles to contract and glands to secrete hormones. (CNS to body)

glial cells

cells in the nervous system that support, nourish, and protect neurons

astrocytes

Provide structural and metabolic support for neurons.

microglia

Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system

ependymal cells

line cavities of the brain and spinal cord, circulate cerebrospinal fluid

Oligodendrocytes

Type of glial cell in the CNS that wrap axons in a myelin sheath.

schwann cells

Supporting cells of the peripheral nervous system responsible for the formation of myelin.

satellite cells

surround neuron cell bodies in PNS in myelin sheath

mechanoreceptors

detect physical deformation. Touch, pressure, etc

thermoreceptors

respond to changes in temperature

nociceceptors

pain receptors

proprioceptors

monitor the position and movement of skeletal muscles and joints

chemoreceptors

respond to chemicals

merkel complexes

detects structure, texture, and steady pressure

ruffini corpuscles

detect skin stretch and joint position

muscle spindles

receptors sensitive to change in length of the muscle and the rate of that change

golgi tendon organs

Receptors sensitive to change in tension of the muscle and the rate of that change

rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

exteroceptors

provide information about the external environment

interoreceptors

respond to stimuli within the body

proprioceptor

a receptor that responds to changes in the body position such as stretch on a tendon, or contraction of a muscle; the receptors allow us to be consciously aware of the position of our body parts

free nerve ending

serve as critical monitors for potential harm, detecting dangerous levels of heat, cold, or mechanical pressure (pain). They are "slowly adapting" in many cases, allowing for a persistent sensation of pain, though some mediate fast, acute pain.

encapsulate nerve endings

specialized sensory receptors where nerve terminals are enclosed by connective tissue or Schwann cells, enhancing their sensitivity to mechanical stimuli. They primarily act as mechanoreceptors

specialized cell receptor

istinct structural cells or proteins that detect specific environmental stimuliand convert them into electrical signals for the nervous system

transducer

convert physical or chemical environmental stimuli into electrical signals called action potentials.

receptor potential

a graded, local change in the membrane potential of a sensory receptor cell caused by stimulus transduction

receptor field

area monitored by a single sensory receptor

receptor specificity

the principle hat sensory receptors are designed to only respond to a certain type of stimulus

punctate distribution

he uneven, clustered arrangement of sensory receptors within the skin, rather than a uniform spread.

tactile acuity

the ability to perceive fine spatial details, textures, and small surface features through touch

two-point determination test

valuates the tactile nerve receptor density by measuring the smallest distance at which a patient can distinguish two distinct stimuli from one

tactile localization

the ability to accurately pinpoint the specific location of a touch sensation on the skin

adaptation

the process where sensory receptors in the skin reduce their response to constant, unchanging, or repetitive touch stimuli over time.