Download Physiology Exam #2 | BIOL 2150 - PRINCIPLES OF PHYSIOLOGY and more Quizzes Physiology in PDF only on Docsity!
Neuroglia
non nervous cellsas well as primary support cellsTypes: Astrocytes Oligodendrocytes Microglia Ependymal Cells TERM 2
Astrocytes
DEFINITION 2 type of Star shaped cell non-nervous cells-considered "glue" of CNS (holds it together)-maintains (BBB) Blood Brain Barrier-they uptake and degrade neurotransmitters (clean- up)-help regulate potassium-help form scars/scar tissue- uptake and degrade beta amyloid (alzheimer's) TERM 3
Ependymal Cells
DEFINITION 3 type of non-nervous cells that areepithelial in originproduces cerebrospinal fluid (CSF)located in ventricles of brain and central canal TERM 4
Oligodendrocytes
DEFINITION 4 type of non-nervous cellsproduces MYELIN :(the fatty layer on nerves that keeps electrical impulses in cell.) TERM 5
Microglia
DEFINITION 5 -type of non nervous cells-protect brain (immune cells)- produce a nerve growth factor (NGF) for repair and development- excessive activity of these cells can produce ROS which are "free radicals" and can destroy nerves very fast, which maybe the cause of parkinson's orAlzheimer'sdisease.
Brain Tumor
when nerve cells don't duplicate or divide they can lead to tumorsex: "meningioma and glioma" which are connective tissues not workingmost brain tumors are metastatic though (which means they're in other areas) TERM 7
Brain
DEFINITION 7 -85% water-Not Sensitive-the center of the brain is the warmest part of the body-there are about 14 billion nerve cells in the brain- the warmest cell in body is motor neuron from spine to toes TERM 8
Membrane Potential
DEFINITION 8 is the difference in electrical potentialbetween the interior and the exterior of a biological cell.the insidecompositionvs. the outside.occurs in nerve and musclespotassium is 40 times morediffusiblethan sodium.sodium has a hard time getting across membranes without channels. TERM 9
Graded Potentials (type of Membrane
Potential)
DEFINITION 9 -seen in brain-are decremental (gradually slowing) in speed- associated with sort distances-vary according to the stimulus-can NOT become action potential TERM 10
Action Potential
DEFINITION 10 -strength remains strong and constant- associated with long distances- "all or none" concept , like dominos. you hit one the rest must go-generated in trigger zone
Na + Channel's Two GATES (part of action
potential)
- ACTIVATION : active gates close off side of channel aka connecting one channel to another2) INACTIVATION : inactive gates remain open and do not allow channels to be connected. TERM 17
Refractory
Period
DEFINITION 17 the period of time right after the Action potentialdealing with double gating of Na+ channelstwo types :1) Absolute Refractory Period2) Relative refractory period (immediately following the absolute) TERM 18
Frequency of Action Potential
DEFINITION 18
- a higher frequency will lead to a string of AP's since:-"all or none" = never going to be just one AP aka domino effect TERM 19
Conduction of an ACTION Potential: "what will
effect it?"
DEFINITION 19 TEMPERATURE-affects rate in poikilotherms (cold blooded organisms) to be slower-people slow down a small amount but not much because we are warm blooded.- an ice pack would slow it down for humans TERM 20
Conduction of an ACTION Potential:origin
within the cell
DEFINITION 20 TRIGGER zone
Conduction of an ACTION Potential: amount of
distance
an AP can travel less than 1mm to over 1 meter TERM 22
Conduction of an ACTION Potential: spreading
of AP: UNIDIRECTIONAL
DEFINITION 22 -due to the refractory period-AP's don't travel : instead, the inactive area of the axon is depolarized and a new AP is generated , one after another, like dominoes TERM 23
Conduction of an ACTION Potential: spreading
of AP: LOCAL CURRENT FLOW
DEFINITION 23 -Na+ channels open and ions travel away from the gate working its way down the channel.***ONLY OCCURS in UNMYELINATED nerves(a nerve that HAS myelin is insulated with a phospholipids on the outside membrane)- friction of nerve site increases nerve size-ex organisms: earth warms and squid (are unmyelinated creatures) TERM 24
Conduction of an ACTION Potential: spreading
of AP: SALTATORY CONDUCTION
DEFINITION 24
- "to jump"-only on myelinated nerves (with phospholipid membrane)- NODES OF RANVIER = are the open spaces where the Na+/K+ channels are.-these myelinated nerves are smaller in diameter than the local current flow's and go 50 times FASTER-less energy- get spread with increasing nerve size-fiber size can be smaller in vertebrates TERM 25
MS disease
DEFINITION 25 takes myelin away (the phospholipid membrane layer)
SYNAPSE: chemical
neurotransmitters - are the most common TERM 32
SYNAPSE: structure
DEFINITION 32 -presynaptic knob-synaptic cleft-post synaptic membrane TERM 33
SYNAPSE: events
DEFINITION 33 1st) AP to Knob (calcium channels open and calcium enters synaptic knob)2nd)calciumstimulates release of transmitters from vesicles3rd) those transmitters bind to receptors which opens the ion channel4th) transmitter than either: is taken back into presynaptic cell or diffuses away or is degraded TERM 34
IPSP
DEFINITION 34 -inhibited post synaptic potential-blocks Na+ channel = hyperpolarizes TERM 35
EPSP
DEFINITION 35 -excitatory post synaptic potential-block K+ channel = depolarizes
NEUROTRANSMITTERS
-must be rapidly eliminated-chemicals that transmit signals from a neuron to a target cell across a synapseTypes: - Peripheral neurotransmitters -Central neurotransmitters - Local neurotransmitters TERM 37
Peripheral Neurotransmitters
DEFINITION 37 No Enzymes-acetylcholine (Ach)-epinephrine (E)- norepinephrine (NE) TERM 38
Central Neurotransmitters
DEFINITION 38 Lots of these-serotonin-dopamine-GABA = "gamma amino butyric acid"-glycine-CCK = "cholecystokinase-glutamate TERM 39
Local Neurotransmitters
DEFINITION 39 -nitric oxide (NO) - paracrine-carbon monoxide - recent TERM 40
Modification of Nervous System / Synapse
DEFINITION 40 -presynaptic input on axon: modifies AP before it reaches synaptic knobcan: 1) facilitate and enhance OR 2) inhibitregulates amount ofneurotransmitters released
