Intro to Nervous System Flashcards
What does the nervous system do? (3)
homeostasis
sense and respond to environment
survive
Three functions of the nervous system
SIM
sensory (collect info, afferent)
integrative (process, interpret, respond)
motor (instruct, efferent)
What does the central nervous system consist of? What is it lined by and what is it bathed in?
brain (in skull) spinal cord (in vertebrae)
lined by meninges
bathed in cerebrospinal fluid (CSF)
What is the peripheral nervous system made up of?
all other nerves except CNS
What is a nerve?
bundle of axons in connective tissue
cell processes
connectors
cranial and spinal
What is a ganglion?
group of nerve cell bodies (ganglia)
What does a nerve ending do?
innervate tissues and organs
What are the two divisions of the peripheral nervous system?
somatic (controls external actions of skin and muscles, involuntary and voluntary)
autonomic (controls internal activities of organs and glands, smooth muscles, involuntary)
What are the two divisions of the autonomic nervous system?
sympathetic (arousing)
parasympathetic (calming)
What is the sympathetic system known to do? What changes does it cause?
FIGHT OR FLIGHT
increase: mental alertness, metabolic rate, activation of energy reserves, respiratory rate, HR, BP, activation of sweat glands
decrease: digestive and urinary function
What is the parasympathetic system known to do? What changes does it cause?
(4 letter acronym)
REST AND DIGEST
increase: secretion, defecation, conservation of energy
decrease: metabolic rate, HR, BP
Salivation
Lacrimation (crying)
Urination
Defecation
Can neurons reproduce?
no
What do glial cells do? (3)
support, nourish, protect
can reproduce
can NOT send electrical signals
Glial cells: astrocytes (where and what)? (7)
CNS astro (star-shaped) structure blood-brain barrier regulate concentrations of ions, nutrients, gases in interstitial fluid around neurons absorb and recycle neurotransmitters Glial scars after CNS injury
Glial cells: microglia (where and what)? (5)
defence 'macrophages' of CNS scavengers involved in inflammation multiple extending processes
Glial cells: ependymal cells (where and what)? (5)
epithelial-like CNS form ependyma line ventricles of CNS produce CSF and circulate it through passageways
Glial cells: oligodendrocytes (where and what)? (5)
CNS produce myelin insulates wraps processes around neural axons cannot regenerate
Neuron structure: what do dendrites do?
receive information, sensors
Neuron structure: what does cell body do?
house nucleus and organelles (lots of mitochondria)
metabolic brain of cell
Neuron structure: what is an axon?
highway for electrical signaling, one axon per neuron, 2 way road
Neuron structure: what is the axon terminal?
site of synapse, communication point
Neuron structure: what is myelin sheath?
insulating coat
Neuron structure: what are nodes of Ranvier?
gaps in myelin
Three properties of a neuron
excitable (respond to environment changes)
conductive (send electrical signals)
secretory ( secrete neurotransmitters in order to communicate)
Three functional classification of a neuron
sensory (afferent) neurons: receive input, PNS to CNS
interneurons: store and process, in CNS
motor (efferent) neurons: send signal from CNS to organs to respond
Three structural classifications of neurons
LOOK HOW MANY BRANCHES ARE LEAVING THE CELL BODY
unipolar: single process, sensory
bipolar: two processes, sensory and interneurons
multipolar: multiple processes, sensory, interneurons and motor
What is myelin produced by in CNS and PNS?
oligodendrocytes (CNS) Schwann cells (PNS)
Glial cells: satellite cells (where and what)? (5)
PNS astrocyte-like cover nerve cell bodies support and protect nerves control extracellular environment
