Upgrade to remove ads
PSYC 251 "2" Midterm 1
Terms in this set (42)
What are the functions of ASTROCYTES (CNS) & SATELLITECELLS (PNS)?
●Structural support for neurons.
●Help create the bloodbrain barrier. (BBB)
●Provide nutrients to neurons.
●Modulate neural activity through reuptake of neurotransmitters and regulation of ion concentration.
What are the functions of OLIGODENDROCYTES (CNS)
& SCHWANN CELLS (PNS) ?
Wrap axons in myelin to insulate them and speed conduction of action potentials
What is the function of EPENDYMALCELLS (CNS)?
Help produce & circulate cerebrospinal fluid. (CSF)
What is the function of MICROGLIA (CNS)?
Macrophages that devour and digest cellular debris.(phagocytosis)
Explain the directions?
In the brain:
up: dorsal "superior".
down: ventral "inferior".
back: caudal "posterior".
front: rostral "anterior".
In the spine:
front: ventral. (anterior)
back: dorsal. (posterior)
Define ipsilateral ?
On the same side of the brain.
"e.g. both are on the left hemisphere"
Define contralateral ?
On the opposite side of the brain.
"e.g. one on the left hemisphere the other on right hemisphere".
Define unilateral ?
Organ A is only on the left hemisphere.
Define bilateral ?
Organ D is on the left hemisphere and the right hemisphere.
What are the divisions of PNS?
●Voluntary control of action.
●Somatosensory: from skin to brain.
●Motor: from brain to muscles.
●Sympathetic & parasympathetic: regulation of involuntary functions, e.g.:
What are the functions of Sympathetic and Parasympathetic nervous system?
●"Fight or flight" and quick response.
●Increases blood flow to skeletal muscles.
●Increases heart rate.
●Dilates pupils for far vision.
●"Rest and digest", "feed and breed", and calmness.
●Increases blood flow to gut.
●Constricts pupils for near vision.
Define Dura mater?
Thick, tough membrane.
Define Arachnoid mater?
Thin fibrous membrane with trabeculae extending through the subarachnoid space to the pia mater.
Define Subarachnoid space?
Filled with CSF.
Define Pia mater?
Delicate membrane that follows the cortical surface.
Where is CEREBROSPINALFLUID produced?
Produced in choroid plexuses.
Where does the CEREBROSPINALFLUID circulate?
Circulates in ventricular system.
What are the functions of CEREBROSPINALFLUID ?
●Buoyancy and protection.
●Clearing of waste.
What causes confirmation change to the pump?
What triggers dephosphorylation of the pump?
Why is the sodium potsium pump said to be electrogenic?
Because of the small electro current produces from the process of loosing 3 sodium and gaining 2 potassium.
What happens to the membrane potential if you increase the potassium concentration out side?
The membrane potential becomes more positive.
Thus, potassium ions regulate membrane potential.
The difference between internal and external potassium levels decreases.
This causes the membrane potential to reach 0.
Why does the Nernst equation does not always give an accurate answer?
Because it doesn't take into account other ions.
Use Goldman equation.
Why we use 2 electrodes? Why not one?
1 will inject current. The other will record membrane potential.
What is the difference in charge between depolarizing and hyperpolarizing?
depolarizing is more positive.
"drives the membrane potential in the positive direction."
Hyperpolarizing is more negative.
"drives the membrane potential in the negative direction."
What are the phases of the action potential?
1. resting phase.
2. rising phase.
"sodium channels open, and sodium flows into the cell."
3. overshoot phase.
"sodium channels start to close"
4. falling phase.
"potassium channels open." (depolarization)
5. undershoot phase.
What does action potential conduction require?
Requires both active and passive current.
According to the Nernst Equation, which of the following does NOT help determine the equilibrium potential for potassium ions?
The permeability of other ions (e.g. sodium and chloride)
Why is there a diffusional force for potassium ions from inside to outside the cell membrane?
Because there is a higher concentration of potassium ions inside the membrane.
What process related to the resting membrane potential is a major consumer of energy in the brain?
The hydrolysis of ATP to actively pump ions across the cell membrane.
What are the facts of action potentials?
1. When an action potential travels down a myelinated axon, it is only generated at the Nodes of Ranvier, and not under the myelin sheath.
2. The initiation of an action potential depends on the opening of voltage-gated ion channels.
3. Unlike a subthreshold change in membrane potential, an action potential can propagate down an axon with no change in amplitude.
4. An action potential is usually an all or none phenomenon with approximately the same amplitude and duration every time in a given neuron.
What voltage-dependent process initiates an action potential?
Voltage-gated sodium channels open up, letting more sodium ions into the neuron.
Why do action potentials only travel in one direction down an axon?
Refractoriness: after an action potential occurs, that piece of membrane cannot generate another one for a short time, so the spreading current can only propagate the action potential in one direction, away from where it was previously.
What are typical time courses of the postsynaptic potentials produced by ionotropic and metabotropic receptors?
Ionotropic: start in one or two milliseconds, last tens of milliseconds.
Metabotropic: start in hundreds of millisecond, last seconds.
The right visual field is processed by which retina(s) and which hemisphere(s) of primary visual cortex?
both retinas, left primary visual cortex.
The inferior right quadrant of the visual field is projected to which area of primary visual cortex?
Complete the following analogy:
Location in the visual field is to primary visual cortex organization, as ________ is to primary auditory cortex organization.
frequency of the sound.
Match each sensory system with the corresponding nucleus of the thalamus that acts as its relay:
Auditory system - Medial geniculate nucleus.
Somatosensory system - Ventral posterior nucleus. Visual system - Lateral geniculate nucleus.
YOU MIGHT ALSO LIKE...
Psych 251 labs 1-3
AP Biology Chapter 37
AP Biology Chapter 48 Neurons
Campbell Biology Chapters 48/49
OTHER SETS BY THIS CREATOR
PSYC 201 Research Methods
BIOL 186 midterm 1