A & P Chapter 12: Nervous System

perineurium

A fascicle is surrounded by a layer of dense irregular connective tissue called:

postsynaptic potential

A graded potential caused by the opening of chemically gated channels on a postsynaptic membrane is known as a _______ ________.

cell body

A soma is another name for the:

anterograde

A substance synthesized at the cell body must undergo _______ transport to reach the synaptic knobs.

between a neuron and another cell

A synapse is a junction:

two

A unipolar neuron has one extension. A bipolar neuron has _____ extensions.

voltage; resistance

According to Ohms law, current is directly related to ________, and inversely directed to _________.

epineurium

An entire nerve is surrounded by a connective tissue covering called the:

* voltage gated calcium channel open * action potential reaches synaptic knob

Before a vesicle of neurotransmitter can be released which of the following must occur?

toward

Dendrites transfer information ________ the cell body.

sensory and motor

Interneurons facilitate communication between _______ neurons and ______ neurons.

extracellular: sodium and chloride intracellular: potassium and organic anions

Match the location with the larger concentration or ions.

unipolar

Most afferent neurons are classified functionally as _______.

greater amounts inside a neuron

Negatively charged proteins and other large organic molecules are found in __________.

macroscopic and microscopic

Nerves are usually ______ and neurons are usually _______.

glial

Nervous tissue is made of neurons and ______ cells.

functionally

Neurons are classified _____ depending on the direction the nerve impulse travels.

Myeline

Oligodendrocytes create the _____ sheath in the central nervous system.

1. Action potential reaches synaptic knob. 2. voltage gated calcium channels open. 3. calcium enters the synaptic knob. 4.calcium triggers exocytosis of vesicles. 5. neurotransmitter diffuses across synaptic cleft. 6. neurotransmitter binds to postsynaptic receptors.

Place the events of synaptic transmission from earliest to latest:

peripheral

Sensory and motor nerves are part of the _____ nervous system.

to the central nervous system.

Sensory nerves carry information:

electrical synapses and chemical synapses

Synapses are classified as:

other neurons, muscle cells, and gland cells

Synapses occur where axons contact:

inhibitory; negative

The "I" in IPSP stands for _______, meaning that the potential makes the inside of the postsynaptic cell more______.

involuntary nervous system

The autonomic nervous system is also known as the:

areolar connective tissue

The endoneurium is made of:

cerebrospinal fluid

The ependymal cells help produce:

lipids

The myelin sheath is made of a high percentage of:

bipolar

The neurons in the retina of the eye are:

structural

The peripheral nervous system is a ______ division of the nervous system.

axolemma

The plasma membrane of an axon is called the ________.

effectors

The tissues that receive nerve impulses from motor neurons are called:

1. a graded potential depolarizes the initial segment. 2. voltage gated sodium channels open. 3. sodium flows into the neuron at the initial segment. 4. further depolarization of the initial segment occurs. 5. sodium channels enter the inactive state.

The voltage gated sodium channels undergo changes in activity during the depolarization phase of an action potential. Place these in order from first to last.

effector

Tissue that responds to neural input by changing its activity is called a(n) ________.

False

True or False: Neurons far outnumber glial cells.

Neuron

What is the basic structural unit of the nervous system?

* There must be a change in the number of open ion channels. * There must be a change in ion flow across the membrane.

What must happen in order for a chemical signal to change the membrane potential of a neuron?

presynaptic neuron

What type of neuron transmits an impulse through its axon toward the synapse?

Neuroglial cells

Which cell type is considered "nerve glue"?

Autonomic motor

Which functional division of the nervous system provides involuntary control of smooth muscle?

Microglial cells

Which glial cell acts as a phagocyte?

* Sensory Neurons * Motor Neurons * Interneurons

Which of the following are functional classes of neurons?

* Replaces damaged neurons * Regulates the composition of interstitial fluid * Helps form the blood-brain barrier

Which of the following are functions of astrocytes?

* K+ * Na+

Which of the following have leak channels on the plasma membrane?

* Na/K * Ca2+

Which of the following pumps can you find in the plasma membrane?

Spinal and cranial

Which terms are used for the structural classification of nerves?

Multipolar

Which type of neuron is most common?

Neurotransmitter

_____ are chemical released from synaptic knobs and bind to receptors on postsynaptic membranes.

Sensory

_____ nerves always relay information the the CNS.

Hyperpolarization

_____ occurs when the inside of the cell becomes more negative than the resting membrane potential.

Voltage

________ is the measure of difference in electrical charge.

unipolar

pseudounipolar is another name for a _______ neuron.