Nervous system

Question 1

CNS

Answer 1

central nervous system, comprised of the brain and spinal chord. It a neuron is in the CNS, the whole neuron has to be included in either the brain of spinal cord. Dreaming and thinking and even memory storage can be kept entirely within the CNS without need for PNS stimulus

Question 2

PNS

Answer 2

peripheral nervous system, all nerves that extend out past the brain and spinal cord. Included afferent and efferent neurons

Question 3

Afferent neurons

Answer 3

sensory input

Question 4

Efferent neurons

Answer 4

somatic sensory neurons (sympathetic, parasympathetic), autonomic neurons

Question 5

Information transmission pattern

Answer 5

Stimulus-receptor-afferent pathway-control center-efferent pathway-effector-response. Sends information from the PNS to the CNS, if action is needed to maintain homeostasis, the CNS sends signal to PNS

Question 6

Somatic nervous system (PNS)

Answer 6

controls the voluntary movements of skeletal muscles

Question 7

Autonomic nervous system (PNS)

Answer 7

controls involuntary movements of muscles like lungs and heart and smooth muscle tissue. further subdivided into sympathetic and parasympathetic systems

Question 8

Enteric nervous system (PNS)

Answer 8

controls gastrointestinal tract, semi-independent, contains more neurons than the whole spinal chord

Question 9

Neuron structure

Answer 9

cell body (soma), dendrites, axon, and axon terminals. Have very high metabolic rates and require high levels of oxygen and glucose

Question 10

Cell body or soma

Answer 10

surrounds nucleus, major role in synthesizing proteins

Question 11

Dendrites

Answer 11

branches the shoots off of soma, receive information through numerous receptors on membrane, through chemical neurotransmitters

Question 12

Axon

Answer 12

long branch that goes off of soma, the point of origin where it branches off of the cell body is called the axon hillock which functions to send information. Axon can extend to more than a meter! Because of this the axon has microtubules surrounded by myelin.

Question 13

Anterograde transport

Answer 13

motor proteins “walk” along the microtubules in the axon away from the soma

Question 14

Retrograde transport

Answer 14

motor proteins “walk towards the soma through microtubules in he axon

Question 15

Myelin

Answer 15

totally separate cells that wind and coil around axon. Essential for insulation and sped up action potential propagation. Comes from oilgodendorcyte in CNS and schwann cell in PNS

Question 16

Axon terminals

Answer 16

The end of an axon. Converts electrical signal into a chemical one through synaptic transmission.

Question 17

Amitotic nuerons

Answer 17

most are this way, Neurons that have lost the ability to divide. Lifespan of more is 100 years. Exception neurons are olfactory (smell), and hippocampal (memory).

Question 18

Multipolar neurons

Answer 18

most common type in humans, 99%. Defined as having three or more processes (dendrites) that extend from the body

Question 19

Bipolar neurons

Answer 19

Rare, appear in retinas and olfactory, have a cell body and a process in both directions. One is called a dendrite and one is called and axon.

Question 20

Unipolar neurons

Answer 20

have a single, short process that branches into two more processes. One is directed in the peripheral direction and one in the central. Primarily associated with sensory neurons and are found in PNS

Question 21

Sensory neurons

Answer 21

afferent neurons transmit signals from external environment or organs to CNS for processing. Almost all are unipolar

Question 22

Motor neurons

Answer 22

Efferent neurons transmit information from CNS to effectors. Most are multipolar

Question 23

Interneurons

Answer 23

located between motor and sensory, most are confined to CNS

Question 24

Astrocyte

Answer 24

located in CNS, it is the protector/mother of the neuron. It wraps its processes around blood vessel and hooks onto neuron. It stores glycogen, absorbs extra K+, synthesizes neurotransmitters, secretes growth factor, and modulates blood flow.

Question 25

Oligodendrocyte

Answer 25

Found in CNS, it wraps its processes around neuron axons and creates the myelin sheath. Creates the node of Ranvier with the gaps in myelinating

Question 26

Ependymal

Answer 26

line cavities in CNS, creates barrier between cerebral spinal fluid and brains exterior space. Has cilia to circulate the fluid

Question 27

Microglia cell

Answer 27

cell located around neurons, can become phagocytic in response to inflammation or injury. They present antigens to lymphocytes

Question 28

Schwann cell

Answer 28

The myelinating cell of the PNS, each is a single cell

Question 29

Satellite cell

Answer 29

The astrocyte of the PNS, regulates external environment