EXAM 2 Flashcards
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Photoreceptors convert light into _____
Membrane Potential
In invertebrates, an increase in light leads to _______ in Membrane Potential
Increase
In vertebrates, an increase in light leads to ________ in membrane potential
Decrease
Rhabdomeric Photoreceptors
- Light detection
- Help with circadian rhythms
- light leads to depolarization
Ciliary Photoreceptors
- Vision
- light leads to hyperpolarization
- Rod & Cone cells
Light signals are started with a GPCR called _______
opsin
Opsins covalently bind _____
chromophores
Photons cause ______ of chromophore
isomerization
Isomerization of chromophore leads to ____
changes in the opsin
2 opsin pathways:
- Rhabdomeric - depolarization
- Ciliary - hyperpolarization
___ chromophore is changed to ____
11-cis-retinal is changed to all-trans-retinal
The light absorbing layer in the back of the eye:
choroid
Light is focused on the:
fovea centralis
Blind spot is caused by the:
Optic disk
most of the light is focused in the:
cornea. the rest is focused by the lens
Light never pathway:
Rod/Cone cell > bipolar cells > ganglion > optic nerve
Rod cells converge on _____ bipolar cell (s)
Many rod cells per single bipolar cell. leads to more sensitivity.
Cone cells in the FC converge on ____ bipolar cell (s)
One cone cell per bipolar cell. Less sensitive but much better acuity.
Color discrimination is a result of ______
which wavelengths different cone cells absorb
_____ cells inhibit neighboring bipolar cells
horizontal
The functions controlled by the brain
- higher functions
- complex initiation
- perception
The functions controlled by the spine
- reflexes
- pathways for efferent/afferent signals
Location of the spinal afferent neuron cell bodies
Dorsal Root ganglion
Location of the spinal efferent neuron cell bodies
Ventral horn
_____ are bundles of _____ neuron axons
Nerves, peripheral
2 types of reflex arcs
- Simple reflex
- sensory-motor
- Most common reflexes
- sensory-association-motor
Most common reflexes use _______ to ensure coordinated responses
divergence
The Dorsal root ganglion is:
unipolar, sensory
Bundles of axons in CNS are called ______
tracts
2 kinds of CNS tracts
- ascending tracts
- sensory information
- PNS receptors to CNS
- descending tracts
- motor instructions
- CNS to effector organs
2 types of efferent signals (same side or different side of body)
- ipsilateral
- same side
- contralateral (most common)
- opposite side
3 fundamental divisions of vertebrate brain
- Hindbrain
- Midbrain
- Forebrain
Hindbrain
- Medulla oblongata
- Pons
- cerebellum
Medulla oblongata
- regulates breathing
- regulates heart rate
- regulates blood pressure
Pons
- communication center
- pathway for signals between medulla, forebrain, cerebellum
cerebellum
coordinates motor behaviors
Forebrain
“Higher processes”
- 4 lobes
- frontal (motor)
- parietal (sensory)
- temporal (auditory)
- occipital (vision)
2 hemispheres of the brain are connected by the ________
corpus callosum
Primary motor cortex
- movement of skeletal muscle
- voluntary
- damage is irreversible
Premotor cortex (ass’n area)
- integrates muscle signals
- muscle groups
- damage leads to a loss of skill
- damage is reversible
Primary somatosensory cortex
- gathers input from sensory receptors
- damage is irreversible
- damage leads to loss of touch
Somatosensory association area
- loss of touch identification
- reversible
Primary visual cortex
- primary input from optic tract
- some ipsilateral
- some contralateral
Thalamus
- sorts sensory inputs
- routes information
Hypothalamus
- homeostasis
- regulates pituitary gland
- Maintains ion + water balance
- Regulates body temperature
- Regulates food intake
- Involved in stress response
- regulates circadian rhythms
Hippocampus
- special processes
- long-term potentiation
Long term potentiation (LTP)
- underlies learning and memory
- after tetanus, LTP neuron pathways have increased reaction to the same (non-tetanus) stimulus
circadian rhythms are an example of ________
acclimatization
SCN
- in the hypothalamus
- controls endocrine system to regulate behavioral rhythms
3 branches of autonomic nervous system
- sympathetic
- parasympathetic
- enteric (digestive organs)
Each organ has both ____ and ____ control (with some exceptions)
parasympathetic, sympathetic
Muscle Cell RMP
-90mV (due to greater K+ gradient)
I-band
actin filamints (thin)
A-band
myosin filaments
