Biopsych EXAM 1

Multipolar neuron

Many dendrites one axon, function as motor neurons, in the autonomic nervous system, and as interneurons

Bipolar neuron

2 processes come out of the soma, function as sensory neurons in the retina and ear, olfactory sense, cochlea, vestibular sense

Unipolar neuron

Single process, found in the CNS of invertebrates, may be found in human brains in cerebellum

Pseudounipolar neuron

One process that immediately branches into 2, function in the spinal cord and as sensory neurons

Anaxonic neuron

Multipolar without an axon, cannot create an action potential, function as moderators in retina and olfactory bulb

Afferent

Arrives to CNS

Efferent

Exits CNS

Somatic nervous system

Motor (skeletal muscles) and sensory

Autonomic nervous system

Sympathetic and parasympathetic nervous systems

Reflex arc

Stimuli → sensory neuron → interneuron in the spinal cord → motor neuron → move

Interneuron

A neuron in the spinal cord that connects sensory neurons to motor neurons to form the reflex arc

Schwann cell

Glia found in the PNS, wrap around axons to form myelin sheaths, many are needed for one axon, can guide their axons to reconnect after damage

Oligodendrocyte

Glia found in the CNS, wrap around axons to form myelin sheaths, one of these covers many axons. Linked to learning, memory, and motor skills

Microglia

Glia found in the CNS, function as the immune system of the brain by destroying any pathogens, phagocytosis of damaged/dying neurons, remodel or prune unused synapses. Survey environment, will regenerate if depleted, release chemicals to communicate with neurons, promote repair. linked to schizophrenia, autism, depression, and anxiety

Astrocyte

Glia found in CNS, provides nutrients to neurons from blood, repairs damage to nervous tissue, protects blood brain barrier. connected to neuron communication and memory, replicate often so are more likely to cause tumors than other cells

Ependymal cell

Glia that makes up the choroid plexus and cerebrospinal fluid, and lines the ventricles

Satellite cell

Glia found in PNS, absorb harmful toxins to protect neurons, regulate environment of neurons, provide nutrient support, cling to somas

Dorsal

Top

Ventral

Bottom

Anterior

Front

Posterior

Back

Ipsilateral

Same side

Contralateral

Opposite side

What plane is this?

Coronal plane

What plane is this?

Horizontal plane

What plane is this?

Saggital plane

Midsaggital

View when the brain is sliced directly down the middle into the 2 hemispheres

What are the three meninges?

Pia mater, Arachnoid mater, Dura mater

What is #15?

Pia mater

What is #13?

Arachnoid mater

What is #14?

Subarachnoid space

What is #11?

Dura mater

What does the dura mater do?

What does the pia mater do?

What does the arachnoid mater do?

What do the meninges do?

Telencephalon

Diencephalon

Mesencephalon

Metencephalon

Myelencephalon

What are the embryological divisions?

Telencephalon, Diencephalon, Mesencephalon, Metencephalon, Myelencephalon

White matter

Myelinated axons, makes up the inner cortex

Grey matter

Somas and glia, make up the external cortex

Gyri

Hills

Sulci

Valleys

What are the lobes of the brain?

Frontal, temporal, parietal, occipital

Frontal lobe functions

Temporal lobe functions

Parietal lobe functions

Occipital lobe functions

What structures make up the limbic system?

Hippocampus, amygdala, cingulate cortex, fornix

Hippocampus

Amygdala

Cingulate cortex

Fornix

Limbic system functions

Basal ganglia function

Coordinating smooth movement, preventing unwanted movement, reward, motivated behaviors, addiction

Thalamus function

Sensory relay

Hypothalamus function

Regulating homeostasis, hunger, sleep,

Midbrain function

Pons function

Medulla function

Cerebellum function

What is #1?

Lateral ventricles

What is #3?

Third ventricle

What is #6?

Cerebral aquaduct

What is #7?

Fourth ventrical

What is #8?

Central canal

What is inside the ventricals?

Cerebrospinal fluid

Choroid plexus

Part of the ventricular system, this structure is made up of ependymal glia cells and filters blood to cerebrospinal fluid and cerebrospinal fluid back to blood

What is a postsynaptic potential?

The membrane potential of the postsynaptic neuron in the specific location that was part of the synapse. It’s caused by neurotransmitters binding to chemically gated ion channels, allowing ions into the neuron, which either raises or lowers the membrane potential slightly and locally (not whole neuron)

Excitatory postsynaptic potential (EPSP)

The local membrane potential of the postsynaptic neuron (area at the synapse) becomes depolarized (intracellular space is less negative)

Inhibitory postsynaptic potential (IPSP)

The local membrane potential of the postsynaptic neuron (area at the synapse) becomes hyperpolarized (intracellular space is more negative)

Summation

The culmination of all EPSPs and IPSPs into one overall signal

In a neuron at rest, where are K+ ions most concentrated?

Inside the cell

In a neuron at rest, where are Na+ ions most concentrated?

Outside the cell

In a neuron experiencing an action potential, what are Na+ ions doing?

Moving into the cell

In a neuron experiencing an action potential, what are K+ ions doing?

Exiting the cell

In a neuron experiencing depolarization, what is happening?

Na+ ions are moving into the cell, K+ ions are beginning to move out of the cell, the intracellular space is rapidly becoming less negative

In a neuron experiencing repolarization, what is happening?

Na+ channels have closed, K+ is exiting the cell, the intracellular space is becoming more negative

In a neuron experiencing hyperpolarization, what is happening?

K+ channels close slowly as the membrane potential returns to resting, causing the voltage to overshoot and become more negative than resting

What is the absolute refractory period?

This period is when it is physically impossible for the neuron to have another action potential, and refers to the time when the neuron is in depolarization and repolarization

What is the relative refractory period?

This period is when it is difficult but not impossible for the neuron to have another action potential, and refers to the time when the neuron is in hyperpolarization

When do K+ channels close?

When the membrane potential returns to resting

What is the threshold?

The voltage needed to open voltage gated Na+ channels

Sodium

Na+

Potassium

K+

Chloride

Cl-

Calcium

Ca++

Average resting potential of a neuron

-70mV, range from -40mV to -90mV

When are leak channels open?

All the time

When are voltage gated channels open?

When the electrical threshold is reached

When are chemically gated channels open?

When neurotransmitters bind the the receptors

What does the sodium potassium pump do?

This protein uses active transport to put 3 Na+ outside of the cell and 2 K+ inside of the cell. This returns the ions to their resting places so the neuron is ready for another action potential

Conduction of an action potential down a myelinated axon is called:

Saltatory conduction

The intracellular space of a neuron at rest is

MORE negative than the extracellular space

Why does increased myelin make an action potential travel faster?

Because the segments covered in myelin don’t have to open ion channels

The words inhibition/inhibitory and excitation/excitatory refer to what?

Neurotransmitters

Which ion is involved in the release of neurotransmitters into the synapse?

Calcium (Ca++)