BIOL 223A: EXAM 4 Neurons v2

How many cervical spinal nerves are there?

8

Where does the spinal cord begin?

Foramen magnum

What protects neurons from toxic substances in the blood?

Blood brain barrier (BBB)

Which structures have a distal portion that runs to form the presynaptic terminal?

Axons

What surrounds individual axons in their Schwann cells?

Endoneurium

In a cross-sectional view of the spinal cord, how is the white and gray matter arranged?

White matter is on the outside and gray matter is on the inside

During a spinal tap, from which location is cerebrospinal fluid (CSF) obtained?

The subarachnoid space

What space between the vertebral wall and dura mater is used for injecting anesthesia?

Epidural space

Where does the spinal cord end?

Sacral lumbar vertebrae

What is the phenomenon where amputees perceive pain in an amputated structure?

Phantom pain

What is the middle, thin, spider-like meninx called?

Arachnoid mater

What does the cerebral gyri increase?

Surface area of the cerebral cortex

What is the tapered cone-like region immediately inferior to the lumbar enlargement?

Conus Medullaris

What part of the brain connects the medulla to the midbrain?

The pons

Where are neurotransmitters released from?

Presynaptic terminal

How many pairs of cranial and spinal nerves are there?

12 pairs of cranial nerves and 31 pairs of spinal nerves

What part of the brain serves as a major control center for the autonomic nervous system and endocrine system?

Hypothalamus

What occurs if 5 potentials arrive at the same synapses in very close succession?

Temporal summation

Why is an IPSP considered inhibitory?

It hyperpolarizes the membrane, making it more negative

What is the neuron in the CNS that carries action potentials from one neuron to another called?

Interneuron

What is the effect of untreated hydrocephalus?

Increased intracranial pressure

What happens to the plasma membrane when sodium ions enter it?

It becomes more positive

During which period is a neuron insensitive to further stimulation?

Absolute refractory period

On a myelinated axon, where are action potentials conducted more rapidly?

Nodes of Ranvier

What type of neurological cells provide support and nutrients to sensory ganglia in the peripheral nervous system?

Satellite cells

What is the function of acetylcholinesterase?

To break down acetylcholine in the synapses

What is white matter composed of?

Myelinated axons

What structures are included in the Central Nervous System (CNS)?

The brain and spinal cord

Where is CSF formed?

In the tissue of the walls and roofs of the brain ventricles

What is the large C-shaped mass of white matter that connects the two cerebral hemispheres?

Corpus callosum

How many lobes does the cerebrum have?

5 lobes (Frontal, Parietal, Temporal, Occipital, Insula)

Where do most sensory inputs that ascend through the spinal cord and brain stem project?

Thalamus

What is the stalk that connects the hypothalamus to the pituitary gland?

Infundibulum

What is the branching network of white matter in the cerebellum called?

Arbor vitae

Which part of the brain stem is continuous with the spinal cord?

Medulla oblongata

What is the thickest of the meninges called?

Dura mater

What is the pathway formed when two or more presynaptic neurons synapse with a single postsynaptic neuron?

Convergent

What ion is necessary for the release of neurotransmitters from synaptic vesicles?

Calcium

What is the all-or-none principle?

A stimulus either causes an action potential or it does not

What is the gray matter on the surface of the brain called?

Cerebral cortex

Which neuroglial cells are damaged in multiple sclerosis?

Oligodendrocytes

What are the gaps in the myelin sheath called?

Nodes of Ranvier

What are neurons with a single axon and single dendrite called?

Bipolar neuron

What is the input part of the neuron called?

Dendrites

What is the junction of a neuron with another cell called?

Synapse

Which cells secrete CSF?

Ependymal cells

What does the cerebral aqueduct connect?

The 3rd and 4th ventricles

Which glial cell must be bypassed by drugs targeting neurons deep within the brain?

Astrocytes

What would happen if there was rapid or removal or destruction of neurotransmitters in the synaptic cleft?

Can't have an action potential

If a series of local potentials cause the membrane potential to move to -80 mV, what would result from that?

The neuron would be hyperpolarized

What is the sequence of the diencephalon from superior to inferior?

Midbrain, pons, medulla oblongada

What part of the brain connects the medulla to the mid brain?

The pons

A small lesion in the brain stem resulted in a rapid heart rate, intense vaso contribution and elevated blood pressure in your patient, where would this location be?

Medulla oblongata

What is the thermostat or nucleus responsible for monitoring and regulating blood temperature?

Hypothalamus

Suppose both excitatory and inhibitory neurons synapses with a single postsynaptic neuron, what determines if an action potential is initiated in the postsynaptic neuron?

EPSP need to be more in number than IPSP to generate an action potential (fraction by fraction)

If you have an influx of chloride or out flow of potassium ions what can result in this?

IPSP will result

If there is an EPSP what does that result from?

A local depolarization

What does saltatory conduction mean?

Nodes of ranvier to nodes of ranvier

What ensures completion of repolarization before another action potential (AP)?

Absolutely refractory period

A stimulus can cause an action potential or it doesn't, what is this called?

All or none principle

When does an action potential occur?

When threshold is reached

Depolarization of the nerve cell membrane occurs when there is a rapid influx of what ion?

Sodium ion

Your patient has a microglial infection attacking his brain, which cell type would you expect to proliferate and be most active during this time?

Microglial cells

What would you call a neuron that conducts pain sensations to the CNS?

Sensory or afferent neuron

Which division of the PNS transmits impulses to CNS to skeletal?

Motor or efferent

What is responsible for problem solving skills?

The central nervous system

What would happen if there is an injury to the thalamus?

Affect sensory projection to the cerebral cortex

A person with a lesion in the brain exhibited the following manifestations: normal tension in skeletal muscle, disturbed fine motor control, exhibited tremors when reaching for objects. What part of the brain is most likely damaged?

The cerebellum

Your patient has an eating disorder along with intense thirst and widely varying body temperatures, which means she may have dysfunction of the?

Hypothamus