ch 16 nervous

Question 1

central nervous system

Answer 1

• brain
• spinal cord
• CNS will send motor message back

Question 2

Peripheral nervous system

Answer 2

• somatic (body) division: voluntary movements
• autonomic (going to organs and glands) division: sympathetic (fight or flight), parasympathetic (rest and digest and all other organs and glands), enteric: involuntary messages (all)

Question 3

sensory input

Answer 3

• detecting changes in environment internal and external
• detects and transmits changes internally and externally
• afferent pathway: towards brain/spinal cord

Question 4

integration

Answer 4

• analyze and store information, provide perception, make some decisions regarding response
• integration of incoming and outgoing info: (in grey matter = cluster of cell bodies (little protein makes it look grey), spinal reflexes, sensory comes in and automatic response

Question 5

motor output

Answer 5

• responds to integration decisions by sending excitatory or inhibitory messages to muscles, glands, etc
• efferent pathway: away from brain/spinal cord

Question 6

anatomy of nervous system

Answer 6

• nerve cells/ neurons: nerves, plexi
• neuroglia cells:
• sensory receptors: changes in environment
• effectors: skeletal muscles, smooth muscles (viscera, vessels), cardiac muscle, glands, smooth muscle of digestive system
• cranial nerves
• spinal nerves
• enteric plexuses in small intestine
• sensory receptors in skin
• everything outside CNS

Question 7

sensory receptors in nervous tissue

Answer 7

3 types of receptors based on:
- structure of their sensory receptors: free nerve endings, encapsulated nerve endings, separate cells) found on skin
- type of stimulus they detect: vibration (tactile senses like low frequency vibration), temperature, pressure, pain
- location of the receptors and the origin of the stimuli: exteroreceptors (eyes), interoreceptors (inside body ex: how full bladder and stomach is), proprioceptors (muscles, tendons, and joints)

Question 8

neurons/ nerve cells

Answer 8

• cell body (soma): nucleus, nissl bodies (organelles, high level of protein (grey color), synthesis organelles), axon hillock (electrical impulse is generated)
• nerve fibers attached to cell body: dendrites (variability, receiving part), axons: schwann cells, nodes of ranvier, synaptic end bulb

Question 9

sensory neuron: how message travels

Answer 9

• message is received by dendrite
• message travels down the axon away from cell body
• neuroglia or schwann cells supports and neruishes the nerve cell while keeping it myelinated. this allows for message to travel faster bc it jumps from node to node
• chemical messengers and neurotransmitters allow impulse to be transmitted to other neuron or effector (organs or muscles) at synaptic end bulb

Question 10

structural diversity in neurons

Answer 10

• can be super short or meters long
• (1) unipolar: one process, many sensory neurons found in sensory receptors
• (2) bipolar: (1 dendrite, cell body, axon) sending messages leaves through axon to eyeball
• (2+) multipolar: (cell body, dendrites, axon) lots of dendrites, motor neurons away to effectors
• purkinje and pyramidal: to brain

Question 11

types of neurons

Answer 11

• afferent/ sensory: from receptors to CNS
• interneurons: within CNS impulses move between sensory and motor mostly unipolar)
• efferent/ motor: from CNS to effector (skeletal or smooth glands)
• start: stimulus –> receptor –> sensory (afferent) –> CNS

Question 12

synapses - neuron junctions

Answer 12

types of synapses: receptor to neuron, neuron to neuron, neuron to effector (neuromuscular junction)
electrical synapses: gap junctions (cardiac muscle, super fast message transfer)
chemical synapse: synaptic cleft, requires neurotransmitter (NMJ = acetylcholine, one way traffic

Question 13

neuroglia

Answer 13

• protects neurons, keeps neurons healthy, cant send electrical impulses, huge volume of them, can multiply and divide in the mature nervous system
• neuroglia, glia, or glial cells constitute about half of the volume of the CNS
  6 types of neuroglia:
• CNS: astrocytes, oligodendrocytes, microglia, and ependymal
  PNS: schwann, satellite
  can form tumors (gleoma in cns)

Question 14

myelination

Answer 14

• send messages faster down axon
• unmyelinated = no schwann cells
• two types of neuroglia produce myelin sheaths: schwann PNS and oligodendrocytes CNS

Question 15

SENSORY NEURONS

Answer 15

send info to CNS

Question 16

EFFECTORS

Answer 16

motor info FROM CNS to the effector neurons that will cause muscle skeletal reaction (ex: spider on knee: the motor effectors will tell leg to swing out to try to get spider off)