intro to nervous system (4a)

Question 1

what are the functions of the nervous system

Answer 1

detecting sensory stimuli/input
integrating sensory imput
deciding if motor output is necessary

Question 2

what are examples of sensory input

Answer 2

pressure, taste, sound, light, blood pH, hormone levels

Question 3

was is a visceral sensory pathway

Answer 3

stimulus that is detected involuntarily (change in blood pH, organ pressure sensors)

Question 4

what is motor output

Answer 4

electrochemical signal that is transmitted to organs from the central nervous system that is converted into some form of action

Question 5

examples of motor output

Answer 5

movement
change in heart rate
release of hormones
sweating
release/storage of glucose

Question 6

what are the components of the nervous system

Answer 6

the central nervous system: brain and spinal cord
the peripheral nervous system: cranial and spinal nerves

Question 7

what are the functions of the brain and spinal cord

Answer 7

integration of information
interprets sensory information
sends outgoing instructions

Question 8

what are the functions of spinal and cranial nerves

Answer 8

carry impulses to and from spinal cord/brain
communication lines among sensory organs, brain and spinal cord and glands/muscles

Question 9

what is the sensory/afferent division and what are its components

Answer 9

nerve fibers that carry information to CNS
somatic sensory
visceral sensory

Question 10

what is the somatic sensory division

Answer 10

fibers that carry information from the skin, skeletal muscles and joints

Question 11

what is the visceral sensory division

Answer 11

fibers carry information from visceral organs (ventral cavities)

Question 12

what does somatic refer to regarding voluntary/involuntary control

Answer 12

somatic means voluntary control is present

Question 13

what is the motor/efferent division and what are its components

Answer 13

nerve fibers that carry impulses away from the CNS to effector organs (muscles and glands)
somatic nervous system
autonomic nervous system

Question 14

what is the somatic nervous system

Answer 14

system that controls skeletal muscles (voluntary)

Question 15

what is the autonomic nervous system and its components

Answer 15

system that controls smooth and cardiac muscles and glands (involuntary)
divided in sympathetic and parasympathetic nervous systems

Question 16

what is the one organ made of skeletal muscles that is not voluntary control

Answer 16

diaphragm

Question 17

what are the four types of neuroglia in the CNS

Answer 17

astrocytes
microglial cells
ependymal cells
oligodendrocytes

Question 18

what is the structure and function of astrocytes

Answer 18

star shaped
anchor neurons to blood capillaries and mediate exchanges between them
provides nutrients to neurons (glucose)
absorb excess potassium and neurotransmitters released from neurons and extracellular space

Question 19

function of microglia

Answer 19

monitor health of nearby neurons
engulf debris (dead brain cells) and bacteria (phagocytes)

Question 20

functions and location of ependymal cells

Answer 20

cilia on the cells help with the circulation of cerebrospinal fluid
secrete CSF
line cavities of the brain and spinal cord

Question 21

what are the components and functions of cerebrospinal fluid

Answer 21

blood plasma, ions, sugars
protects brain, regulates blood pressure, transport of chemicals

Question 22

structure and functions of oligodendrocytes

Answer 22

wrapped around neurons’ axons
produce myelin sheaths

Question 23

what are the types of neuroglia in PNS

Answer 23

satellite cells
schwann cells

Question 24

what is the function of satellite cells

Answer 24

surround the neuron cell body and provide cushioning

Question 25

what is the function of schwann cells

Answer 25

produce myelin sheaths around axon

Question 26

what are the differences between schwann cells and oligodendrocytes

Answer 26

oligodendrocytes wrap around multiple axons/neurons while schwann wrap only one axons schwann cells can be repaired/regenerated since they have neurilemma)

Question 27

characteristics of neurons

Answer 27

functional unit of the nervous system about 100 billion in the brain high metabolic rate (need constant supply of glucose and oxygen)

Question 28

function of a neuron

Answer 28

generating and conducting nerve impulses/action potential results in the excitation or inhibition of nearby neuron/muscle/gland

Question 29

what are the components of the neuron

Answer 29

cell body dendrites axon

Question 30

characteristics of the cell body of a neuron

Answer 30

metabolic center has organelles, neurofibrils for cell shape but no centrioles (neurons are non-mitotic)

Question 31

characteristics of dendrites (neuron)

Answer 31

fibers conduct impulses toward the cell body a neuron can have hundreds of dendrites

Question 32

neuron axon characteristics

Answer 32

fibers conduct impulses away from the cell body only one per neuron

Question 33

what are the components of the axon and what are they

Answer 33

axon hillock: beginning of axon axon terminals: contain neurotransmitters synaptic cleft: gap between terminals and next neuron synapse: junction where impulse is transmitted (between terminal and cell body/dendrites of next neuron)

Question 34

characteristics of myelin sheath

Answer 34

white fatty material that covers most of the axons in the PNS and some in the CNS (called myelinated axons) unmyelinated axons are usually smaller

Question 35

how are myelin sheath formed by schwann cells

Answer 35

it rolls around the axons at the same place multiple times to form layers the cytoplasm and nucleus are forced into the outer region away from the axon (called neurilemma)

Question 36

how does the impulse move across the axon

Answer 36

in saltatory conduction (jump from one node of ranvier to the other not in a straight line)

Question 37

what is a node of ranvier

Answer 37

space between schwann cells

Question 38

function of the myelin sheath

Answer 38

protects axon increases rate of conduction due to electrical insulation ions cant enter/exit axon where there is myelin

Question 39

what is multiple sclerosis and characteristics

Answer 39

autoimmune disease where the myelin sheath in the brain and spinal cord is progressively destroyed the scars (scleroses) slow the transmission of impulses, eventually stops completely can result in paralysis and loss of sensation treatment: drugs that affect the activity of the immune system mainly affects young adults

Question 40

what are the structural classifications of neurons and their characteristics

Answer 40

based on how many processes extend from the cell body multipolar: all motoneurons and interneurons bipolar: special sense organs (ears, eyes, nose) rare in adults unipolar: majority of sensory neurons

Question 41

characteristics of sensory, inter and motor neurons

Answer 41

sensory: sensory receptors to CNS, its receptors, dendrites and cell body are in the PNS inter: connects sensory and motor neurons, cell body is in the CNS motor: CNS to viscera, muscles and glands, its dendrites and cell body are in the CNS

Question 42

what are the characteristics of sensory receptors and its subcategories

Answer 42

specialized receptors made by the dendritic ends of sensory neurons there are cutaneous receptors and proprioreceptors

Question 43

where are cutaneous receptors and what do they sense

Answer 43

in the skin sense pain, temperature, touch and pressure

Question 44

where are proprioreceptors and what do they sense

Answer 44

located in muscles and tendons sense stretch/tension

Question 45

what is a cluster of cell bodies called in the CNS vs the PNS

Answer 45

CNS: nuclei PNS: ganglia

Question 46

what are bundles of fibers running together called in the CNS vs PNS

Answer 46

CNS: tract PNS: nerve

Question 47

what is a large area of nuclei/unmyelinated axons called

Answer 47

gray matter

Question 48

what is a large area of tracts called

Answer 48

white matter

Question 49

what are the components of a nerve (small to big)

Answer 49

endoneurium perineurium epineurium

Question 50

what is endoneurium

Answer 50

a connective tissue sheath that surrounds each myelinated axon

Question 51

what is perineurium

Answer 51

wraps groups of fibers into fascicles

Question 52

what is epineurium

Answer 52

wraps and binds groups of fascicles

Question 53

what are the types of nerves and an example of each

Answer 53

sensory: optic motor: trochlear (rotates eyeball) mixed: phrenic (senses stimuli from pleura and activates diaphragm)

Question 54

what are mixed nerves

Answer 54

nerves that contain both sensory and motor fibers spinal cord has mixed nerves