Bio final - nervous system

What is a nerve net

composed of neurons spread out, but in contact with one another

What is a ladder like nervous system

a concentration of ganglia and sensory receptors in the head

What is the CNS

brain and spinal cord W

What is PNS

somatic and autonomic nervous system

What does the PNS do

gathers info from sensors and conduct decision to effectors

nervous system functions

receiving input, performing integration, generating motor output

What is a neuron

cell body contains nucleus

What is dendrite

receive signals

What is axon

conducts nerve impulses

What are axons covered by

myelin sheath

What is a long axon called

nerve fiber

What do neurons contain

organelle and specialized structures like dendrites and axons

What are the types of neurons

sensory, motor interneurons

What do sensory neurons do

accept impulses from sensory recepters and transmit them to the CNS

What do motor neurons do

accept nerve impulses from the CNS and transmit them to muscles or glands

What do interneurons do

convey nerve impulses between various parts of the CNS

What do glial cells do

support, protect and nourish neurons, fulfill vital auctions

How do glial cells outnumber neurons

10 to 1

What are most brain tumors caused by

mutations in glia

What do oligodendrocytes do

form myelin sheath around axons

What do astrocytes do

provide nutrients and support

What do ependymal cells do

produce cerebrospinal fluid

What do microglia do

scavenge pathogens and dead cells

What do Schwann cells do

form the myelin sheath

What do satellite cells do

provide nutrients and structural support

What do voltage gates ion channels do

regulate the relative concentrations of different ions inside and outside of the cell

What is membrane potential

the difference in total charge between the inside and outside of a cell

What is resting membrane potential

is created and maintained by increasing the concentration of cations outside the cell relative to the inside of the cell

Explain action potential

a stimulus from a sensory cell depolarizes the target neuron, sodium channels in the axon hillock open

What are nodes of ranvier

gaps in myelin coverage along axons

What are meninges

spinal cord and brain are wrapped in three protective membranes

What is the three levels of meninges

dura, arachnoid and pia mater

Spaces between meninges are filled with what

cerebrospinal fluid

What does the spinal cord do

the means of communication between the brain and spinal nerves

Describe somatic nervous system

transmits sensory and motor signals to and from the CNS - controls skeletal muscles

describe autonomic nervous systems

controls smooth muscle, cardiac muscle, organs and glands

sympathetic activation prepares us for what

fight or flight

parasympathetic activation is associated with what

relaxed conditions

What are neurodegenerative disorders

loss of nervous system functioning caused by neuronal death