BIOL 3204 Exam 2

The binding of glutamate to excitatory receptors on a neuron's cell body would....

cause the interior of the cell to become more positive

Which cells are located ONLY in the central nervous system and act to connect other neurons?

interneurons

Which statement accurately describes why a graded potential loses amplitude as it moves away from its stimulus?

Charged ions leak out of the membrane before reaching the trigger zone.

Both the cell body and the axon have Na+ channels. Are these channels the same or different? if so, how?

Different, cell body has chemically-gated channels and axon has voltage-gated channels

A neuronal pathway emerging from the cranial region that slows the heart rate must be a...

parasympathetic pathway

What levels of hormone production would you expect at each tier of the Hypothalamic-Pituitary-Thyroid (HPT) axis if a person has a functioning pituitary tumor?

High levels of thyroid stimulating hormone from the anterior pituitary, high levels of thyroid hormone from the thyroid, and low levels of thyrotropin-releasing hormone from the hypothalamus

The total amount of neurotransmitter released at the axon terminal is directly related to the...

total number of action potentials

Together the brain and spinal cord form the...

central nervous system

The nervous system's ability to communicate is primarily dependent on the movement of...

charged particles

How does electroencephalography (EEG) detect brain activity?

free electrons in the metal electrodes respond to the flow of ions in and out of neurons

Which of the following is secreted by neurons AND acts via diffusion across a synapse?

Neurotransmitters

The brain area described as the center for emotions is the...

the limbic system

During sexual intercourse, secretion and lubrication of the vagina is accomplished via parasympathetic innervation to the uterus, while contraction of the uterus (and/or vagina) is accomplished via sympathetic innervation. Similar to the male orgasm, these are best described as ________

Synergistic (or cooperative) effects

The brain is mostly composed of...

neuroglial cells

Which of the following statements is FALSE?

A neurotransmitter that hyperpolarizes the cell makes the body more positive

In order for an action potential to be propagated, the threshold membrane potential in the cell body must be reached...

Once, at the axon hillock

Agonistic effects on the primary endocrine gland will typically cause ______ production of the primary hormone, ___ production of releasing hormone from the hypothalamus, and ______ production of tropic hormone from the anterior pituitary.

increased; decreased; decreased

Which neurocrine behaves as a neurohormone in the PNS and as a neurotransmitter in the CNS?

Epinephrine

The state of the neuronal membrane in which its internal environment is negative relative to its external environment is called?

the resting membrane potential

You are assessing a patient who presented with intersex genitalia. You find that this individual is genetically male (has) 1 X chrom. & 1 Y chrom.) & possesses the testis-determining factor (SRY gene). Further, they are producing adequate levels of GRnH, FSH, and testosterone. What is the most likely explanation for this individual's intersex genitalia?

absent or inactive testosterone receptors

During a dissection, you observe a motor neuron that exits the spinal column at the level of thoracic vertebrae #3. It reaches its autonomic ganglion almost immediately upon exiting the spinal column. This must be a:

Sympathetic pathway

Which of the following is true about efferent info in the CNS?

carries from CNS by motor neurons

A presynaptic neuron releases excitatory neurotransmitter into the synaptic cleft twice in a span of ms. The resulting graded potential in the postsynaptic neuron reaches threshold & fires an action potential. This is an ex. of?

Temporal Summation

What is the sequence of cellular events that correctly describes a neuron firing an action potential?

A stimulus causes a graded potential; The graded potential reaches threshold at the axon hillock; Voltage-gated Na channels open near the axon hillock; Additional voltage-gated Na channels open along the axon; The Na-K pump establishes resting membrane potential.

Info coming into the CNS is transmitted along ______ neurons.

afferent

Imagine a scenario where a presynaptic neuron's voltage-gated Ca+ channels failed to open in response to the neuron's depolarization. Which of the following would result from this situation?

Neurotransmitter would not bind to receptors on the postsynaptic neuron.

This part of the brain processes general sensory info & the size of the area dedicated to each part of the body is correlated with receptor concentration...

somatosensory cortex

In a complex endocrine pathway, long-loop negative feedback inhibits...

the hypothalamus and/or the pituitary

Which statement about the myelin sheath is FALSE?

Every neuron is wrapped in a myelin sheath

A neurohormone releases ACH into the synaptic cleft at its target tissue. The ACH binds muscarinic receptors initiating a response in the target tissue. Which autonomic pathway is this?

parasympathetic

If the white matter of the spinal cord is damaged, what symptoms would you expect?

impaired movement; impaired sensory relay

Which if the following is NOT true of the peripheral nervous system (PNS)?

It is considered the major integrating center of the body

During the rising phase of the action potential...

Na+ moves down both a concentration and electrical gradient

Which of the following is/are FALSE regarding the sodium-potassium (NaK) pump?

The pump moves 3 Na ions into the cell for every 2 K it moves out.

Which of the following is FALSE regarding the blood-brain barrier?

Protects the medulla oblongata from vomit-inducing chemicals

Considering a neuron with excitatory post-synaptic potential, you would predict that a drug binding and inactivating the breakdown enzyme for its neurotransmitter would result in...

more post-synaptic action potentials