module 5—nervous system

Neurons are masses of…

nerve cells that transmit information (functional unit of the system)

Cell body definition

contains the nucleus and other cell organelles

Dendrite definition

shorter, more numerous, receive information

Axon definition

single long fibers, conducts information away from the cell

Label 1, 2, and 3

1. cell body

2. dendrites

3. axons

The central nervous system (CNS) includes the…

brain

spinal cord

Peripheral nervous system (PNS) includes the…

nerves throughout the body

How many pairs of spinal nerves

31

How many pairs of cranial nerves

12

What is the overall function of the nervous system

coordinate the body’s systems by receiving and sending information

maintaining homeostasis

What does the sensory/afferent input do

gathers info from receptors in the body

What does the integrative system do

determines where information is sent

What does the motor/efferent output do

responds to signals

restores homeostasis

The peripheral nervous system is made up of the…

somatic nervous system
autonomic nervous system

enteric nervous system

The somatic nervous system involves the…

skeletal

Is the somatic nervous system voluntary or involuntary

voluntary

The autonomic nervous system involves the…

smooth muscles, glands

Is the autonomic nervous system voluntary or involuntary

involuntary

The enteric nervous system is responsible for controlling the…

smooth muscle and glandular tissue in the digestive system

What nervous system is a large part of the PNS, and is not dependent on the CNS?

enteric nervous system

It is valid to consider the enteric system to be a part of the autonomic system because…

the neural structures that make up the enteric system are a component of the autonomic output that regulates digestion

What does the brain perceive and process?

senesory stimuli (somatic/autonomic)

The brain (CNS) executes the…

voluntary motor responses (somatic)

The brain (CNS) regulates…

homeostatic mechanisms (autonomic)

The nerve (PNS) are…

fibers of sensory and motor neurons (somatic/autonomic)

The digestive tract (ENS) is located in the…

digestive tract

The digestive tract (ENS) is responsible for…

autonomous functions and can operate independently of the brain and spinal cord

The spinal cord (CNS) initiates…

reflexes from the ventral horn (somatic) and lateral horn (autonomic) gray matter

The spinal cord (CNS) gives rise to pathways for…

sensory and motor functions between periphery and brain (somatic/autonomic)

The ganglia (PNS) receive…

sensory stimuli by dorsal root and cranial ganglia (somatic/autonomic)

The ganglia (PNS) relay…

visceral motor responses by autonomic ganglia (autonomic)

What are the two branches of the autonomic nervous system?

parasympathetic and sympathetic

Which branch of the autonomic nervous system is responsible for rest and digest?

parasympathetic

What branch of the autonomic nervous system is responsible for fight or flight?

sympathetic

What happens during an autonomic conflict?

is the simultaneous activation of parasympathetic and sympathetic autonomic inputs

causes thing like arrythmias

What happens to the eyes in the parasympathetic branch?

pupils constrict

What happens to the salivary glands in the parasympathetic branch?

stimulates salivation

What happens to the heart in the parasympathetic branch?

heartbeat slows

What happens to the lungs in the parasympathetic branch?

bronchi constrict

What happens to the stomach in the parasympathetic branch?

stimulates digestion

What happens to the liver in the parasympathetic branch?

stimulates bile release

What happens to the intestines in the parasympathetic branch?

stimulates peristalsis and secretion

What happens to the bladder in the parasympathetic branch?

bladder contracts

What happens to the eyes in the sympathetic branch?

pupils dilate

What happens to the salivary glands in the sympathetic branch?

inhibition of salivation

What happens to the heart in the sympathetic branch?

heartbeat accelerates

What happens to the lungs in the sympathetic branch?

bronchi dilate

What happens to the stomach in the sympathetic branch?

inhibition of digestion

What happens to the liver in the sympathetic branch?

stimulates glucose release

What happens to the kidneys in the sympathetic branch?

stimulates epinephrine and norepinephrine release

What happens to the intestines in the sympathetic branch?

inhibition of peristalsis and secretion

What happens to the bladder in the sympathetic branch?

bladder relaxes

What is the chromatophilic substance (rough ER) in a neuron?

transport system

What does the myelin do in a neuron?

is insulation surrounding axons

What are nodes of Ranvier?

gaps in the insulation

If there is no myelin around the axon, what happens to signals?

they jump

Neurofibrils definition

fibers within the axon

Label the figure

Glial cells definition

supporting cells

The function of the glial cells

directed at helping neurons complete their function for communication

The name glia comes from the Greek word that means…

“glue”

The glia in the CNS are…

astrocytes

oligodendrocytes

microglia

ependymal cell

The glia in the PNS are…

satellite cells

schwann cells

Location and function of astrocytes

CNS

support

Location and function of oligodendrocytes

CNS

insulation, myelination

Location and function of microglia

CNS

immune surveillance and phagocytosis

Location and function of ependymal cell

CNS

creating CSF

Location and function of satellite cells

PNS

support

Location and function of schwann cells

PNS

insulation, myelination

Label the figure

Astrocytes connect…

blood vessels to neurons

Astro means…

star

Astrocytes have many…

processes extending from their main cell body

The processes on astrocytes extend to interact with…

neurons

vessels

connective tissue covering the CNS

Astrocytes maintain the concentration of chemicals in the extracellular space by…

removing excess signaling molecules

reacting to tissue damage by brining in a blood supply

Astrocytes contribute to the…

blood brain barrier (BBB)

Very little substances can pass through the BBB by diffusion, why?

it has tight junctions

Most substances that want to cross the wall of a blood vessel into the CNS must do so through…

active transport

Substances that need to pass through the BBB

glucose

amino acids

water

gases and ions

Oligodendrocytes definition

make myelin sheath that provides insulation around the axons

Name breakdown of oligodendrocyte

oligodendrocyte = “cell of a few branches”

oligo- = “few”

dendro- = “branches”

-cyte = “cell”

How do oligodendrocytes form myelin?

the few processes that extend from the cell will reach out and surround the axon to insulate it with myelin

One oligodendrocyte can provide myelin for…

multiple axon segments

Can an oligodendrocyte provide myelin for the same axon or for separate axons?

same and separate!

Microglial cells definition

immune function, digest debris, kills bacteria

Microglial cells are ______ than most of the other glial cells

smaller

Microglial cells may originate as…

macrophages

When do microglial cells become part of the CNS…

during early development

What is the function of microglial cells

related to what macrophages do in the rest of the body

When macrophages encounter diseased or damaged cells in the rest of the body they…

ingest and digest those cells or the pathogens that cause disease

Ependymal cells definition

forms membranes around tissue

Ependymal cells form the lining of the…

ventricular system in the brain

Ependymal cells are in direct contact with the…

cerebrospinal fluid (CSF)

Ependymal cells line each…

ventricle in the brain

The relation of the BBB and ependymal cells

considered a component of the BBB

a place where the BBB breaks down

How are ependymal cells similar to epithelial cells

make a single layer of cells with littel intracellular space

tight connections between adjacent cells

Ependymal cells have cilia on their apical surface to…

help move the CSF through the ventricular space

Where are satelliete cells found

in sensory and autonomic ganglia in the PNS

Satellite cells surround (satellite) the…

cell bodies of neurons