Term
| ___: study of how drugs affect the nervous system |
|
Definition
|
|
Term
five stages of synaptic transmission:
- can be __ at each step |
|
Definition
1. synthesis
2. storage
3. release
4. receptor binding
5. removal/inactivation
- modified |
|
|
Term
Lidocaine
- blocks ___
--interferes with ___
- is a ___
- ___ drug
- effect is greatest on ____ fibers
-- drug must ___ |
|
Definition
- voltage gated Na+ channels
-- action potential
- local anesthetic
- antiarrhythmic
- small active
-- gain access to open channels |
|
|
Term
Modify Transmitter Synthesis
- L-Dopa
-- precursor of ___
--- increases ___
-- treatment for ___ in ___ |
|
Definition
-- dopamine
--- dopamine synthesis
-- loss of dopamine in parkinson's disease |
|
|
Term
Modify transmitter storage: reserpine
- reserpine is an ___ and ___
- inhibits ____
-- transports __,__,___ into __
-- reserpine depletes the ___ of these transmitters
- rarely used, because ___ |
|
Definition
- antipsychotic and antihypertensive (blood pressure)
- vesicular monoamine transporter
-- ne, serotonin, dopamine, into presynaptic storage vesicles
-- vesicular content
- better drugs now available |
|
|
Term
modify transmitter release: botulinum toxin and tetanus toxin
- inhibit ___ by ___ |
|
Definition
| - transmitter release by cleaving proteins involved in exocytosis |
|
|
Term
|
Definition
1. blepharospasm (eyelid twitch)
2. strabismus (squint eyed)
3. muscle spasms
4. sweating
5. chronic migraine |
|
|
Term
___: mimic actions of naturally ocurring neurotransmitters
___: inhibitors of neurotransmitters |
|
Definition
|
|
Term
Atropine
- ___ antagonist
- from the plant __
- used to ___
- also used in treatment of ___
- ___ syndrome |
|
Definition
- muscarinic receptor
- deadly nightshade (atropa belladonna)
- dilate pupils - blocks contraction of the puillary sphincter muscle
- bradycardia (slow heart rate_
- anticholinergic |
|
|
Term
| ___ receptor is influence by several drugs |
|
Definition
|
|
Term
| ___: regulation by molecules binding at sites other than the receptor binding site |
|
Definition
|
|
Term
GABA a receptor can be regulated by:
1.
2.
3.
4. |
|
Definition
1. benzodiazepines
2. barbiturates
3. ethanol
4. steroids |
|
|
Term
Cannabinoid receptors
- named after ___:
-- ___ and ___
- ___ receptors
-- ___ - mainly in brain
-- ___ - mainly in immune tissues in body
- most abundant ___ in brain
-- bind ___
-- ___ molecules
- ___ useful for nausea, pain, muscle relaxants, glaucoma, seizures, appetite stimulants
- __ proposed as appetite suppressants |
|
Definition
- ligand
-- cannabis and THC
- G-protein coupled
-- CB1
-- CB2
- GPCR
-- endogenous cannabinoids (transmitters
-- small lipid
- agonists
- antagonists |
|
|
Term
LSD
- ___ drug
- binds to several ___
-- receptors include ____
- psychedelic effects thought to be due to ___ properties at ___ receptors
- ___ played prominent role in LSD history |
|
Definition
- psychedelic drug
- GPCR
-- serotinin, dopamine, norepinephrine
- agonist; serotonin 5HT-2A
- lexington |
|
|
Term
cocaine
- blocks ___ on ___
- causes ___ in the ___ |
|
Definition
- dopamine transporter on nerve terminal
- buildup of dopamine in the synapse |
|
|
Term
selective serotonin reuptake inhibitors (SSRIs)
- treatment of __ and ___
- examples include ___,___,___ |
|
Definition
- depression and anxiety disorders
- prozac, paxil, zoloft |
|
|
Term
| dopamine pathways functions |
|
Definition
| reward/motivation, pleasure/euphoria, motor functioning, compulsion, perseveration |
|
|
Term
| serotonin pathways functions |
|
Definition
| mood, memory processing, sleep, cognition |
|
|
Term
| some drugs for alzheimer's inhibit breakdown of ___ by ___ |
|
Definition
| acetylcholine by acetylcholinesterase |
|
|
Term
somatic motor system
- ___ movement
- ___ and the ___ |
|
Definition
- voluntary
- skeletal muscle and the parts of the nervous system that control them |
|
|
Term
skeletal muscle
- each muscle fiber is innervated by ___
- muscle fibers are ___ at birth, then ___ |
|
Definition
- a single axon
- innervated by multiple axons; all but one are eliminated |
|
|
Term
| muscles can only ___ on a joint, they can't ___ |
|
Definition
|
|
Term
| ___: cause contraction of the joint |
|
Definition
|
|
Term
|
Definition
|
|
Term
| two types of motor neurons |
|
Definition
| alphs motor neurons and gamma motor neurons |
|
|
Term
alpha motor neurons
- trigger ___
- innervate ___ |
|
Definition
- muscle contraction
- extrafusal muscle fibers |
|
|
Term
gamma motor neurons
- involved in ___ |
|
Definition
|
|
Term
| ___: alpha motor neuron and all the muscle fibers it innervates |
|
Definition
|
|
Term
| ___: all of the alpha motor neurons that innervate one muscle |
|
Definition
|
|
Term
neuromuscular junction
- all or none: action potential always triggers ____
- transmitter is ___
- nicotinic ach receptors are located ___ in the ___
- alpha bungarotoxin _____ at the neuromuscular junction |
|
Definition
- muscle contraction
- acetylcholine
- within folds in the motor end plate
- binds to and blocks the nicotinic receptor |
|
|
Term
___ and ___ observed the neuromuscular junction
- used ____
- motor axons labeled with ___ or ___
- allows viewing of the neuromuscular junction in ____
- examined ___ |
|
Definition
lichtman and Sanes
- transgenic mice
- green fluorescent protein or yfp
- live animals
- sternomastoid muscle |
|
|
Term
| the cell bodies of ___ are located in the ___ and exit through the ___ |
|
Definition
| lower motor neurons; ventral horn of the spinal cord; ventral root |
|
|
Term
| recall that sensory info enters the ___ through the ___ |
|
Definition
|
|
Term
| spinal nerves contain both ___ and ___ |
|
Definition
|
|
Term
| graded control of muscle contraction via ____ |
|
Definition
| frequency of action potentials in a single motor unit |
|
|
Term
single action potential =
multiple action potentials = |
|
Definition
twitch
sustained contraction |
|
|
Term
graded control of muscle contraction via recruitment of ___
- most muscles have a ____
-- ____ can innervate 3-1000 muscle fibers
-- recruited in order of ___
-- provides _____ |
|
Definition
additional motor units
- range of motor unit sizes
-- single alpha motor neuron
-- smallest first and largest last
-- fine control over contraction force |
|
|
Term
|
Definition
|
|
Term
slow
- __ to contract
- slowly ___
- ___ fibers
-- many ___
-- ____
- found in __ in leg, also ___ in birds
- innervated by ___ |
|
Definition
- slow
- fatiguing
- red
-- mitochondria
-- aerobic
- antigravity muscles; flight muscles
- slow motor neurons |
|
|
Term
fast
- ___ to contract
- rapidly ___
- ___ fibers
-- few __
-- ___
- found in muscle important for ___
- innervated by ____ |
|
Definition
- fast
- fatiguing
- white
-- mitochondria
--anaerobic
- brief, strong exertion such as running or jumping
- fast motor neurons |
|
|
Term
three major sources of input to alpha motor neurons
1. input from ___
2. sensory input from ___
3. input from ___ in the ___ |
|
Definition
1. spinal interneurons
2. muscle spindles
3. upper motor neurons in the brain |
|
|
Term
___ (stretch receptors)
- myotatic =
- fusus is a latin word for ___
- ___ in a fibrous capsule (intrafusal)
- ___ wrap the muscle fibers
-- detect changes in ___
-- project to ___
--- ___ that innervate ___
- increase ___ when ___ |
|
Definition
muscle spindles
- myotatic = muscle stretch
- spindle
- specialized muscle fibers
- la sensory axons
-- muscle length
-- lower motor neurons in spinal cord
--- alpha motor neurons; the same muscle
- action potential frequency when stretched |
|
|
Term
| la sensory axons are the ___, ___, and conduct action potentials ___ |
|
Definition
| largest axons; myelinated; very rapidly |
|
|
Term
1. stetching of muscle stimulates ___
2. activation of ___
3. information processing of ___
4. activation of ___
5. ___ of ___ |
|
Definition
1. muscle spindles
2. sensory neuron
3. motor neuron
4. motor neuron
5. contraction of muscle |
|
|
Term
Knee Jerk Reflex
- example of ___
- it is ___ |
|
Definition
- myotatic reflex
- monosynaptic |
|
|
Term
Gamma motor neurons
- innervate ___ at the ____
- activation causes ___
- role is to ____ |
|
Definition
- intrafusal muscle fibers; two ends of the spindle
- contraction of the poles of the muscle spindle
- maintain sensitivity of muscle spindles during contraction |
|
|
Term
| alpha motor neurons and gamma motor neurons have ____ |
|
Definition
| opposite effects on la output |
|
|
Term
Golgi Tendon Organ
- monitors ___
-- ___ detects muscle length
- at junction between ___ and ___
- innervated by ____
-- ___ than la |
|
Definition
- muscle tension
-- muscle spindle
- muscle and tendon
- group lb sensory axons
-- slightly smaller |
|
|
Term
Golgi Tendon Organ
- synapse on ___ in ___, which synapse on ___ that innervate ___ |
|
Definition
| - inhibitory interneurons; spinal cord; alpha motor neurons; the same muscle |
|
|
Term
Golgi Tendon Organ
- very sensitive to ___ from ___, but relatively insensitive to ___ |
|
Definition
| - increase in muscle tension; active muscle contraction; passive stretch |
|
|
Term
Golgi Tendon Organ
increased ___ activity > ___ > activates ___ > ____ > ____ |
|
Definition
| alpha motor neuron; muscle contraction; Golgi Tendon Organ; inhibits alpha motor neuron; slows muscle contraction |
|
|
Term
Golgi Tendon Organ
- ___ reflex
_ ___ reflex in contrast to monosynaptic myotatic reflex
- prevents muscle from ___
- helps muscle ____ |
|
Definition
- reverse myotatic reflex
- polysynaptic
- generating excessive tension
- maintain constant force |
|
|
Term
| The usual role of the golgi tendon organ is to help ___, such as when holding a paper cup. |
|
Definition
| maintain a constant force |
|
|
Term
| golgi tendon organs are arranged in series with ___ because of their location at the ___ |
|
Definition
| extrafusal muscle fibers; junction of muscle and tendon |
|
|
Term
| the two types of muscle receptors, the ___ and the ___, have different responses to passive muscle stretch and active muscle contraction |
|
Definition
|
|
Term
| both afferent discharge in response to ___, although the ____ is much less than that of the ___ |
|
Definition
| passively stretching the muscle; golgi tendon organ; muscle spindle |
|
|
Term
| when the extrafusal muscle fibers are made to contract by stimulation of their ___, however, the ___ is unloaded and therefore falls silent, whereas the rate of ___ firing increases |
|
Definition
| motor neurons; spindle; golgi tendon organ |
|
|
Term
muscle spindle
- sensitive to ___
- ties to maintain ___
-- maintain ___
- ___synaptic
-- large ___
-- ___ reflex
- ___ reflex |
|
Definition
- stretch
- a constant length
-- position
- mono
-- la sensory axons
-- fast
- myotatic |
|
|
Term
golgi tendon organ
- sensitive to ___
- tires to maintain ___
- ___synaptic
-- involves ___
-- ___ axons
- ___ reflex |
|
Definition
- tension
- a constant force
- poly
-- inhibitory interneuron
-- lb sensory axons
- reverse myotatic reflex |
|
|
Term
Spinal interneurons
- ___: reciprocal inhibition of muscle groups |
|
Definition
| - inhibitory interneurons |
|
|
Term
also ___ interneurons
- ___ reflex
- ___ (multiple neurons)
- slower than ___ |
|
Definition
excitatory interneurons
- flexor
- complex
- myotatic reflex |
|
|
Term
| ___: excitatory and inhibitory interneurons |
|
Definition
|
|
Term
| ___: sets up rhythmic patterns |
|
Definition
| central pattern generator |
|
|
Term
|
Definition
high: strategy
Middle: tactics
low: execution |
|
|
Term
high: strategy
- goal of the ____
- strategy that ___
- ___ areas, ___ ganglia |
|
Definition
- movement
- best achieves the goal
- neocortex asociation; basal |
|
|
Term
middle: tactics
- sequence of ___ to ___
- ___, ___ |
|
Definition
- muscle contraction; achieve strategic goal
- motor cortex, cerebellum |
|
|
Term
low: execution
- activation of ___ to ___, also any ___
- ___, ___ |
|
Definition
- motor neurons; generate the movement; adjustments to posture
- brain stem, spinal cord |
|
|
Term
| ____: defined based on cytoarchitectonics or structure and organization of cells |
|
Definition
|
|
Term
electrical stimulation of ___, elicits movement on ___ side
- ____ |
|
Definition
primary motor cortex; contralateral
- wilder penfield |
|
|
Term
stimulation of ___ produced complex movement on either side of the body
- ___ consists of ___ and ___ |
|
Definition
area 6
- area 6; premotor area; supplemental motor area |
|
|
Term
___ also sends information to area 6
- involved in ____ |
|
Definition
prefrontal cortex
- planning of movement |
|
|
Term
| ____ to ___: major tracts |
|
Definition
| motor cortex; spinal cord |
|
|
Term
voluntary movement
- distal ___
- distal ___ |
|
Definition
- musculature
- cortical control |
|
|
Term
control of posture and locomotion
- ___ control |
|
Definition
|
|
Term
| brain stem control = control of ___ and ___ |
|
Definition
|
|
Term
corticospinal tract
- ___ to ___ (___)
- also called _ due to ___ (__)
- ___movement
- one of the ____ |
|
Definition
- motor cortex to spinal cord (upper motor neurons)
- pyramidal tract; bulge it forms on the medulla (medullary pyramid)
- voluntary movement
- longest and largest tracts in the CNS |
|
|
Term
| ____: plays minor role in humans |
|
Definition
|
|
Term
plantar reflex/Babinski sign
- indicates ___ and ___
- observed in ___ prior to ___ |
|
Definition
- upper motor neuron lesion; damage to corticospinal tracts
- infants; maturation of corticospinal tracts |
|
|
Term
Basal Ganglia
- group of ___
- ___
--___ and ___
- ___ |
|
Definition
- nuclei
-striatum
-- caudate nucleus and putamen
- globus pallidus
- subthalamic nucleus
- substantia nigra |
|
|
Term
| basal ganglia is a ___ loop |
|
Definition
|
|
Term
basal ganglia: motor loop
- involved in ____ of ___
- normally exerts ___ influence on motor systems, release of ____ allows ___ |
|
Definition
- 'Action Selection' selection and initiation of voluntary movements
- inhibitory; inhibition; the motor system to become active (brake hypothesis) |
|
|
Term
Basal Ganglia: motor loop
- provides link between ___ and ___; feedback from ___ is to ___ of cortex.
- ___ to boost signal in ___ |
|
Definition
- cortex and thalamus (VL nucleus); thalamus to supplementary motor area
- positive feedback; SMA |
|
|
Term
| ___: is latin for little brain |
|
Definition
|
|
Term
cerebellum
- contribute to ___ of ___ movement
-- ___ and ___
- ___ learning |
|
Definition
- coordination of mulit-joint
-- precision and timing
- motor |
|
|
Term
cerebellar motor loop
1. axons from ___ in areas __ and ___ project to ___ which in turn projects to ___
2. ___ projects to ___
3. ___ projects to ___ |
|
Definition
1. motor neurons; 4 and 6 + other areas; pontine nuclei (pons); cerebellum
2. cerebellum; ventrolateral nucleus of the thalamus (VL)
3. VL; motor cortex |
|
|
Term
| ____: massive pathway, 20X more axons than corticospinal tract |
|
Definition
| corticopontocerebellar projection |
|
|
Term
|
Definition
1. motor cortex
2. putamen (basal ganglia)
3. thalamus
4. cerebellum |
|
|
Term
Parkinson's disease
- "the ____"
- cause is loss of ___ in ___
motor symptoms
- resting ___
- muscular ___
- ___ movment
- ___ gait
- postural ___
- later cognitive symptoms include __ and ___ |
|
Definition
- shaking palsy
- dopamine neurons in substantia nigra
- tremor
- 'cogwheel' rigidity
- slowness - bradykinesia- of
- shuffling
- instability, stooped posture
- dementia, depression |
|
|
Term
parkinson's disease - epidemiology
- incidence of ___ but up to ___ after 60
-- around ___ in US
- usually ___, but some ___ forms
- onset usually after age ___, mean age of onset = ___
- ___ induced form (MPTP) |
|
Definition
- .3%; 10%
-- 1 million
- sporadic; genetic
- 40; 57
- drug |
|
|
Term
parkinson's disease - pathology
- degeneration of ___ (>80% loss)
- __ bodies in ___ |
|
Definition
- dopaminergic nigrostriatal pathway
- lewy; substantia nigra |
|
|
Term
treatments for parkinson's disease
- ___, ___ agonists
- ___ stimulation
- ___ lesions
- __ factors (__) |
|
Definition
- L-DOPA (precursor for dopamine), dopamine
- thalamic (deep brain)
- subthalamic
- growth (GDNF - glial derive neurotrophic factor) |
|
|
Term
huntington's disease
- symptoms
-- ___ movments
-- progressive ___, ___ changes
- ___ ___ ___ disorder
-- chances are ___, around ___ cases in us
- onset ___ years, mean of ___
- chromosome ___
-- normal function is ___
- ___ repeat
-- ___ normal; ___ pathogenic |
|
Definition
-- involuntary jerky (chorea)
-- dementia, personality
- autosomal dominant inherited
-- 1 in 175,000; 1500
- 5-50; 38
- 4
-- unclear
- CAG (polyglutamine)
-- 6-35; >35 |
|
|
Term
huntington's disease pathology
- loss of small and medium sized neurons in __ and ___
- also pathology in ___, ___, and ___ |
|
Definition
- caudate; putament (striatum)
- cerebral cortex, globus pallidus, thalamus |
|
|
Term
____; lou gehrig's disease
- disease of ___; other ___ are ___
-- dying ___ often show ___
- initial signs are ___ and ___
- ___, ___, ___, ___ and other basic functions become more difficult with time.
- duration of ___ years, death often due to ___, but ~10% live ___ or more |
|
Definition
amyotophic lateral sclerosis
- upper and lower motor neurons; neurons in CNS; spared
-- proteins; inclusions of aggregated proteins
- muscle weakness and atrophy
- walking, talking, eating, swallowing
- 1-5; respiratory failure; 10 years |
|
|
Term
lou gehrig's disease
- does not affect ___, ___
- incidence is __, slightly more in __
- can occur __; but more common at __
- treatment is ___
- about 10% of cases are ___
- cause of sporadic case is ___ |
|
Definition
- cognitive function, sensation
- 1 in 50,000; men
- at any age; ages 40-60
- largely related to symptoms; no effective treatment to date
- genetic
- unknown |
|
|
Term
| ___ is the first system to start developing and the last to stop |
|
Definition
|
|
Term
|
Definition
ectoderm: outermost
mesoderm
endoderm: innermost |
|
|
Term
what do the germ layers become
1. ectoderm:
2. mesoderm:
3. Endoderm: |
|
Definition
1. skin, nervous system
2. muscle, skeletal system
3. organs, linings |
|
|
Term
| ___ becomes the central nervous system while ___ becomes the peripheral nervous system |
|
Definition
| neural tube; neural crest |
|
|
Term
| The rostral (front) part of the neural tubes becomes ___, the rest becomes the ___ |
|
Definition
|
|
Term
| three primary brain regions from front (rostral) to back (caudal) |
|
Definition
1. prosencephalon or forebrain
2. mesencephalon or midbrain
3. rhombencephalon or hindbrain |
|
|
Term
| differentiation of the forebrain is the process by which ___ |
|
Definition
| structures become complex and specialized |
|
|
Term
| two subsections of the prosencephalon |
|
Definition
1. telencephalon
2. diencephalon |
|
|
Term
| the telencephalon forms ___, ___, and ___ |
|
Definition
| cerebral hemispheres, olfactory bulbs, and basal telencephalon |
|
|
Term
| the diencephalon forms ___ and ___ |
|
Definition
| thalamus and hypothalamus |
|
|
Term
| mesencephalon structures include ___ and ___ |
|
Definition
| tectum (inferior and superior colliculus) and tegmentum |
|
|
Term
| hindbrain structures include: |
|
Definition
| cerebellum, pons, and medulla |
|
|
Term
| differention of the spinal cord: |
|
Definition
| grey matter, white matter, dorsal horn, and ventral horn |
|
|
Term
grey matter:
white matter:
dorsal horn:
ventral horn: |
|
Definition
gm: cell bodies
wm: axons
dh: sensory info
vh: motor info |
|
|
Term
| ___: fluid filled caverns and canals inside the brain |
|
Definition
|
|
Term
| ventricular system is filled with ___ |
|
Definition
|
|
Term
| rat and human brain are similar in ____ |
|
Definition
| basic arrangement of various structures |
|
|
Term
| ___ and ___ both play a role in sculpting brain size and shape |
|
Definition
| cell proliferation and cell death |
|
|
Term
| what decides what fate a particular cell adopts |
|
Definition
|
|
Term
| ___: substance generated by one cell type that causes change in another |
|
Definition
|
|
Term
|
Definition
a) gap junctions
b) release into environment
c) membrane spanning proteins |
|
|
Term
| ___: expression of receptor for inducing substance, availability of second messenger system or carrier protein |
|
Definition
|
|
Term
| underlying ___ induces ___ to take a ___ |
|
Definition
| mesoderm; ectoderm; neural fate |
|
|
Term
| ___ put into explant culture at beginning of gastrulation will produce ___ - ____. wait a few more hours, forms ___ |
|
Definition
| dorsal ectoderm; charicteristics of epidermis - keratin and filamentous proteins; neural structures |
|
|
Term
| default pathway for ectoderm is to ___ |
|
Definition
|
|
Term
| seperate prospective ectoderm and culture as individual cells, all ____, because ___ |
|
Definition
| becomes neural tissue; ectodermal cells signal one another to become ectoderm |
|
|
Term
| as the brain matures, ___ are pruned and ___ die |
|
Definition
| neural connections; neurons |
|
|
Term
| brain areas performing basic functions ___ |
|
Definition
|
|
Term
| brain areas for higher order functions (emotion, self-control) ____ |
|
Definition
|
|
Term
| the pre-frontal cortex, which handles reasoning, is ____ |
|
Definition
|
|
Term
| five major sensory modalities |
|
Definition
| vision, hearing, touch, taste, smell |
|
|
Term
vision
1. ___ generalities
2. the eye as a ___
3. coverting light to ___
4. ___ blindness |
|
Definition
1. sensory system
2. camera
3. neural activity
4. color |
|
|
Term
| three things common to all senses |
|
Definition
1) physical stimulus
2) set of events by which stimulus is transduced into a message of nerve impulses
3) response to message |
|
|
Term
| ___: initial contact with external world. they __ the stimulus, i.e. ____ |
|
Definition
| sensory receptors; transduce; change it into electrical activity |
|
|
Term
| ___: space within receptive sheet in which sensory receptor is located and in which it transduces stimuli |
|
Definition
|
|
Term
eventually stimulus is represented by a ___. important:
1. mean ___
2. time interval between ___
3. distribution of ___ |
|
Definition
action potentials
1. impulse activity
2. impulses
3. activated receptors |
|
|
Term
|
Definition
| mechanoreceptors, chemoreceptors, photoreceptors |
|
|
Term
| ___: local potential propagating electronically. often ___ |
|
Definition
| receptor (generator) potential; depolarizing |
|
|
Term
| ___ deforms membrane causing opening of channels |
|
Definition
|
|
Term
| ___: specific receptor ligand interaction leads to generation of second messenger that opens channels |
|
Definition
|
|
Term
| ___: opening where light enters eye |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| light is projected to the ___ where it is converted to ___, signals than sent to __ for ___ |
|
Definition
| back of the eye; electrical signals; brain; higher processing |
|
|
Term
camera vs eyes: similarities
- both have ___ that focus images onto a ___
- ___ (transparent membrane that covers front of eye) and ___ focus light on retina |
|
Definition
-lenses; light sensitive surface
- cornea; lens |
|
|
Term
| ___: a clouding that develops in the crystalline lens of the eye obstructing the passage of light |
|
Definition
|
|
Term
corneal transplants
- an injured cornea may become ___, and lose its ___
- scars, swelling, or an irregular shape can cause the cornea to ___, resulting in ___
- second most common transplant after blood donors |
|
Definition
- swollen or scarred; smoothness and clarity
- scatter or distort light; glare or blurred vision |
|
|
Term
cameras vs. eyes similarities
- both can adjust the ___
-- ___ adjusts the amount of light entering the ___ (which functions like aperture of a camera) |
|
Definition
- amount of entering light
-- iris; pupil |
|
|
Term
the pupillary light reflex
- connections between ___ and ___ control muscle around ___ to allow adjustment to different ambient light levels |
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Definition
| retina; brain stem; pupil |
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Term
| ___: change electromagnetic radiation to neural signals |
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Definition
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Term
| four main regions of photoreceptors |
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Definition
| outer segment, inner segment, cell body, synaptic terminal |
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Term
types of photoreceptors:
- ____: responsible for night vision
-___: mediate color vision |
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Definition
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Term
photoreceptors in the vertebrate retina
-___: protein portion of rhodopsin embedded in membrane
-___: light absorbing portion of complex |
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Definition
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Term
| ___ in the dark and ___ in the light |
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Definition
| depolarization; hyperpolarization |
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Term
| ___: glassy transparent external surface |
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Definition
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Term
| ___: bundle of axons from the retina |
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Definition
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Term
| ___: center black of eye where light enters |
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Definition
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Term
| ___ change electromagnetic radiation to neural signals |
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Definition
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Term
| two types of photoreceptors |
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Definition
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Term
| photoreceptors in the vertebrate retina: ___ and ___ |
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Definition
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Term
___: light absorbing portion of complex
___: protein portion of rhodopsin embedded in membrane |
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Definition
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Term
| ___ in the dark and ___ in the light |
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Definition
| depolarization; hyperpolarization |
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Term
| photoransduction in cones is similar to phototransduction in rods but different ___: ___,___,___ |
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Definition
| opsins: red (L), green (M), blue (S) |
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Term
young-helmholtz trichromacy theory of colory vision:
- ___ three ___ types are preferentially sensitive to ___
- all contribute to ___ |
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Definition
- retina's ; cone; red, green, blue
- retinal signal |
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Term
| the human eye can distinguish about ___ different colors |
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Definition
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Term
| ___: caused by the complete absence of green cones |
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Definition
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Term
| ___: caused by the complete absence of red cones |
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Definition
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Term
| ___: caused by the complete absence of blue cones |
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Definition
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Term
| the opsins present in the __ and __ cones are encoded on the __ chromosome |
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Definition
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Term
Phototransduction: dark and light adaptation
- ___ can detect a single photon of light
- in bright sunlight, response to light in rods becomes ___
- the rod's response __ when only a ___
- cone pigments require ___ |
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Definition
- saturated
- saturates; small amount of the pigment is bleached
- more light to become bleached |
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Term
dark and light adaptation: dark adaptation factors
- dilation of ___
- regeneration of ____ returns it to ___ (most important) |
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Definition
- pupils
- unbleached rhodopsin-conformational change; light absorbing state |
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Term
calcium's role in light adaptation
- calcium concentration changes in ___
- indirectly regulates levels of ___
1. calcium inhibits enzyme that makes __
2. flow of calcium is decreased when __
3. __ is uninhibited |
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Definition
- photoreceptors
- cGMP channels
1. cGMP
2. channels close
3. enzyme |
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Term
so when channels close, a process is initiated that ___ even if ___
- the result is that you can ___ but your eye senses ____ |
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Definition
opens them; light levels do not change
- always see no matter what the light level; relative not absolute levels of light |
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Term
camera vs. eyes dissimilarity
- retina senses __ amount of light while the light detecting system of a camera is sensitive to ___ light levels |
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Definition
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Term
___: amount of space viewed by the retina when the eye is fixated straight ahead
- ___ of image on the retian |
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Definition
the visual field
- inversion |
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Term
| ___: ability to distinguish two nearby points |
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Definition
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Term
Laminated structure
- ___: cell bodies
-___: synaptic contacts |
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Definition
-nuclear layers
- plexiform layers |
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Term
retinal cell types
1.
2.
3.
4.
5. |
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Definition
1. photoreceptors
2. bipolar cells
3. amacrine cells
4. horizontal cells
5. retinal ganglion cells |
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Term
the retina: outer segments
1.
2.
3.
4.
5. |
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Definition
1. outer nuclear layer
2. outer plexiform layer
3. inner nuclear layer
4. inner plexiform layer
5. ganglion cell layer |
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Term
| ___ provide only output of retina |
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Definition
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Term
| ___ and ___ pathways of information |
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Definition
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Term
| ___: the area of the most acute vision |
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Definition
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Term
| fovea centralis: a depression in the center of the macula of the ___, where only ___ are present, and where blood vessels are ___ |
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Definition
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Term
peripheral retina
- higher ratio of ___
- higher ratio of ___
- more sensitive to ___ |
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Definition
- rods to cones
- photoreceptors to ganglion cells
- light |
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Term
| ___: the area in space from which the activity of a given retinal neuron can be affected |
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Definition
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Term
retinal ganglion cells have:
1. circular ___ that consist of a ___ and ___
2. two types: ___ and ___ |
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Definition
1. receptive fields; center; an antagonistic surround
2. on center and off center |
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Term
for an on center receptive field:
1. maximal firing achieved by a ____
2. maximal hyperpolarization achieved by a ___
3. diffuse illumination of the whole receptive field results in only a ____ |
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Definition
1. stimulus confined to and covering all of the center area
2. stimulus confined to and covering all of the surround area
3. minimal increase in firing |
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Term
| bipolar cells have the same receptive field structure as ___ (___) |
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Definition
| retinal ganglion cells (i.e. on center or off center) |
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Term
for on center bipolar cells
1.dark > ___(glutamate) > ___
2. light > ___ > ____ |
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Definition
1. cone depolarized > on center in hyperpolarized state
2. cone hyperpolarized > on center depolarizes |
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Term
the effect of light on synapses between rod cells and bipolar cells
- photoreceptors release ___
- whether they depolarize or hyperpolarize target cells depends upon the kind of ___ on the ___ |
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Definition
- glutamate
- glutamate receptors; postsynaptic membrane |
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Term
| most visual input from the eye goes to the ___ and then to ___ in the cortex |
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Definition
| lateral geniculate nucleus; V1 |
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Term
the retina also projects to ___ targets
- ___: biological rhythms, including sleep and wakefulness
- ___: size of the pupil; certain types of eye movement
- ___: orients the eye in response to new stimuli |
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Definition
nonthalamic
- hypothalamus
- pretectum
- superior colliculus |
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Term
| the retinofugal projection includes the ____ |
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Definition
| optic nerve, optic chiasm, and optic tract |
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Term
right and left visual hemifields
- retinal ganglion cell axons from the ___ of each retina __ at the optic chiasm
- ___ remains on the ___ |
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Definition
- nasal region; cross
- temporal; same side |
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Term
binocular field
- enables all of info from a region of visual space seen be both eyes to be analyzed on ____
- info is ___: info from neighboring regions of visual space sent to neighboring regions of ___ and then ___ |
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Definition
- one side of the brain
- mapped; lgn; v1 |
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Term
| ___: map of the visual field onto a target structure over-representation of central visual field |
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Definition
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Term
the lateral geniculate nucleus
- __ specific layers
- receptive fields are identical to the ___ that feed them |
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Definition
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Term
| retinal ganglion cells axons are not the main source of ___ to the ___ |
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Definition
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Term
nonretinal inputs to the LGN:
1) ___: 80% of the synaptic inputs
2)___: modulatory influence on neuronal activity |
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Definition
1. primary visual cortex
2. neurons in the brain stem |
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Term
| ___ is experienced as a sequence of visual sensations, each resulting from the image falling on a different position in the ___ |
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Definition
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Term
| ____ processing is evidence for the existence of a special visual system for the detection of motion |
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Definition
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Term
| ___ are identical to the ganglion cells that feed them |
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Definition
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Term
receptive fields
- layer IVC: ____, ____
- layers superficial to IVC: first ___ in the ___ |
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Definition
- monocular; center surround
- binocular receptive fields; visual pathway |
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Term
| ___ and ___: specific cells respond to specific visual features |
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Definition
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Term
receptive fields of the striate cortex
- ___ and ___ selctivity
-- in ___ selectivity the neuron fires ___ in response to moving bar of light |
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Definition
-orientation and direction
- direction; action potentials |
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Term
| hierarchy of receptive fields |
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Definition
- retinal ganglion cells
- area 17 (striate cortex)
- extrastriate cortical areas |
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Term
| retinal ganglion cells: ___ structure |
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Definition
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Term
| area 17 (___): ___, ___, and ___ |
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Definition
| (striate cortex): orientation selectivity; direction selectivity; binocularity |
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Term
| extrastriate cortical areas: ___ to ___ |
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Definition
| selective responsive to complex shapes |
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Term
beyond primary visual cortex
- ___: analysis of visual motion and the visual control of action
- ___: perception of the visual world and the recognition of objects |
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Definition
- dorsal stream
- ventral stream |
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