A&P Ch12 Nervous Tissue

(step 1 of) Reflex Arc

(step 1 of) Reflex Arc

what step of what process is when sense organs and sensory nerve endings pick up stimulus/s & send signals TO the CNS

(step 2 of) Reflex arc

what step of what process is when the CNS processes information & determines a response (after the message/signal from sense organs is recieved)?

(step 3 of) Reflex Arc

what step of what process happens when the CNS sends a response to muscles and/or gland cells?

Central Nervouse System (CNS)

-where information gets processed

-Includes the brain & spinal chord

Peripheral Nervous System (PNS)

-made up of nerves + ganglia

-split into Sensory division and the Motor division

Nerves

-a bundle of axons wrapped with CT

Ganglia

-the bulges/swellings in a nerve where soma are concentrated

Soma

Sensory/afferent division of PNS

-a division of the PNS

-split into the Visceral Sensory Division, and the Somatic Sensory Division

-carries signals TO the CNS

Motor/efferent division of PNS

-a division of the PNS

-split into Autonomic Nervous System (ANS) and Somatic Motor Division

-carrie’s signal away FROM the CNS

efferent

word meaning away from the CNS, associated with the word motor

Afferent

word meaning going TO the CNS, associated with the word sensory

Somatic Sensory Division of PNS

-apart of the sensory/afferent division of the PNS

-has to do with the general body (skin, muscles, bones)

-carries signals FROM recetpors in skin muscles joints etc TO the CNS

Visceral Sensory Division

-apart of the sensory/afferent division of the PNS

-has to do with internal organs sense shit (lungs, intestines, heart, etc)

-carries signals from the viscera of the thorax and abdomen TO the CNS

Autonomic Nervous System (ANS)

Somatic Motor Division

-apart of the motor/efferent division of PNS

-carries signals from CNS TO muscles

Sympathetic Division

-apart of the Autonomic Nervous System

-arouses body to action (fight or flight response

Neuron

Cell that communicates within brain, and with other non brian cells (eg muscles)

the axon of this cell can be up to 3 ft long

3

The axon of a neuron can be up to ___ feet long

Neurons

These are all properties of which type of cell?

-Excitability, Conductivity, secretion (of neurotransmitters),

-ability to communicate both chemically and electrically

Axon hillock

where the axon meets with the soma in a neuron

Motor Neurons

-soma

-dendrites

-axon hillock

-axon

Interneurons

thinking type of neurons

they also connect the sensory and motor neurons

Oligodendrocytes

cells with multiple branches that wrap around axons of multiple neurons to make myelin (this insulates the electrical signal to ve able to think faster)

myelin

Dendrites

attached to the soma

usually branching

receive signals

axon

shit that sends signals on the neuron; can be up to 3 feet long

ependymal cells

-cuboidal cells lining the cavities of the brain and spinal cord that secrete CerebralSpinal Fluid

Microglia

immune system cells

Astrocytes

-form blood-brain barrier + supportive framework

Schwann cells

-they insulate axons of PNS

Satellite cells

-they insulate somas of PNS

EndoNeurium

-similar to endomysium but with nerves

-thin sheath of fibrous CT that covers the Schwann cell