Nervous System Part Study Guide (BIO 160)

Describe what happens at an axon terminal, synaptic cleft, and the dendrite of another neuron during the passing of an action potential from one neuron to another.

1. Axon potential reaches the axon terminal. 2. Vesicles fuse with plasma membranes. 3. Vesicles release a neurotransmitter. 4. Neurotransmitters bind to dendrites. 5. Ion channels open allowing Na+ to rush into the cell. 6. Neurotransmitter is broken down and ion channels close.

Describe the Arachnoid mater.

A fine, delicate membrane, the middle one of the 3 membranes or meninges that surrounds the brain and spinal cord.

What are nodes of Ranvier?

A gap in the myelin sheath of a nerve, between adjacent Schwann cells.

What are myelin sheaths? What is the function of myelin sheaths?

A material that covets most neuron fibers. They help to protect, insulate, and increase the rate of neuron transmission.

What does the synaptic cleft do?

A tiny gap that separates one neuron to the next.

What is the primary motor cortex?

Allows us to move our skeletal muscles, located on the frontal lobe.

What are efferent neurons?

Always located in the CNS, carry impulses from the CNS.

Which brain structure is part of the limbic system?

Amygdala, hippocampus, basal ganglia

Which glial cell provides nutrients to a neuron?

Astrocyte.

What is the most common structural neuron?

Astrocytes

Neurotransmitters are chemicals that can help to deliver messages. Where are neurotransmitter stored in a neuron?

Axon terminal.

What is the cerebellum?

Called the little brain, controls balance, provides precise timing for skeletal muscle activity.

What are the three major parts of a neuron?

Cell body, axon, and dendrites.

What are the two major structural subdivisions of the nervous system? What do they each include?

Central Nervous System (CNS) : brain and spinal cord. Peripheral Nervous System (PNS) : cranial nerves, spinal nerves, and all the nerves of thr limbs.

Describe the three major regions of the cerebral hemispheres.

Cerebral cortex: controls speech, memory, logical and emotional response Occipital lobe: visual center of the brain. Temporal lobe: primary auditory (hearing) part of the brain.

What does the axon do?

Conducts messages away from the cell, each neuron has 1 axon.

What are interneurons?

Connect the motor and the sensory neurons in neural pathways.

What does the dendrite do?

Convey incoming messages toward the cell body.

Which major part of a neuron will receive incoming nerve impulses?

Dendrites

What is a neural tube?

During embryonic development, the CNS starts to appear.

What is known as the motor division of the PNS?

Efferent.

What is the gyri?

Elevates the ridges of the cerebrum.

Which supporting cell will help circulate cerebrospinal fluid?

Ependymal cells.

What are all the major structures of the diencephalon?

Forebrain, thalamus, hypothalamus, and pineal gland.

What are afferent neurons?

Found in the ganglion in the PNS and the messages go toward the CNS.

What is the difference between ganglia and nuclei?

Ganglia: small clusters of smaller bodies found in places of the PNS. Nuclei: clusters of cell bodies and fibers on the CNS.

What is the reticular formation?

Gray matter that extends the entire length of the brain stem.

What are the sulci, gyri, and fissures?

Grooves in the cortex.

What is this the pons?

Just below the midbrain, means bridge, helps control breathing.

Draw and label a brain.

Label the occipital lobe, frontal lobe, temporal lobe, parietal lobe, diencephalon, cerebellum.

What is the medulla Oblongata?

Like the pons, regulate heart rate, blood pressure, swallowing, vomiting, and breathing.

What is the function of the ependymal cell?

Line central cavities and help circulate cerebral spinal fluid to form protective sheaths around CNS.

Which supporting glial cell will help fight bacteria?

Microglia.

What are all the major structures of the brain stem?

Midbrain, pins, and medulla.

Explain the major difference between the motor and sensory division of the PNS.

Motor sends impulses away from the CNS. Sensory sends impulses to the CNS.

What is the function of the astrocytes?

Nutrient supply and protect from harmful substances.

What is the blood brain barrier?

Prevent toxins and drugs from entering the blood within the brain.

What is the temporal lobe?

Primary auditory (hearing) center of the brain.

What are reflexes?

Rapid, predictable, and involuntary response to stimuli.

Multiple sclerosis will degrade myelin sheaths in the PNS. State which glial cell affect the rate of a nerve transmission.

Schwann cells, nerve transmission would be slower.

What are the two functional subdivisions of the nervous system? Explain what is included in each and how they are different.

Sensory (afferent) Division: sends messages to the CNS Motor (efferent) Division: carries messages from the CNS

Name and describe the five components of a reflex arc.

Sensory receptor: senses pain or stimulus. Afferent Neuron: sends stimulus to the CNS. Interneurons: helps respond to the initial stimulus. Efferent neuron: sends stimulus from the CNS. Muscle: responds to the initial stimulus.

What is the sulci?

Shallow grooves in the cerebrum.

What is the difference between the autonomic and somatic motor divisions of the nervous system? What parts of the body do each division serve?

Somatic: voluntary control-skeletal muscles Autonomic: involuntary control- cardiac and smooth muscles, and glands

What is the Broca's area?

Specialized area involved in the ability to speak.

What is the function of the microblog?

Spider like phagocytes that dispose of dead brain cells and bacteria.

Describe the steps of the nerve impulse.

Stimulus initiates local depolarization: changes permeability which allows Na+ to diffuse rapidly. Depolarization and generation action potential: the stimulus is strong enough that the polarity of the membrane changes completely. Propagation of an action potential: the entire length of the membrane changes polarity. Repolarization: neuron can not complete and other task also known as the refractory period. And K+ diffuses out of the cell. Restoring initial ion Concentrations: sodium potassium pump( 3 Na+ ejected for every 2 K+ injected) restored the cell.

What does the cell body do?

The cell body holds the nucleus and all the other organelles except for the centrioles. (Centrioles help the cell divide, and neurons can not divide.)

Which nervous system is the brain a part of?

The central nervous system.

Which nervous system is the spinal cord a part of?

The central nervous system.

Describe the Pia matter.

The delicate innermost membrane enveloping the brain and spinal cord.

What do the axon terminals do?

The end of the axons that branch out.

Which nervous system are the cranial nerves part of?

The peripheral nervous system.

Which nervous system are the spinal nerves part of?

The peripheral nervous system.

Which nervous system is the autonomic nervous system?

The peripheral nervous system.

Which nervous system is the nerves of the limbs part of?

The peripheral nervous system.

Describe the Dura Mater.

The tough outermost membrane enveloping the brain and spinal cord.

What is the function of a he Satellite cells?

To cushion the cells of the PNS.

What is the function of the Schwann cell?

To form myelin sheaths around nerve fibers around the PNS.

What is the difference between tracts and nerves?

Tracts: nerve fibers that run through the CNS. Fibers: nerve fibers that run through the PNS.

What is the hypothalamus?

Under the thalamus, plays a role in body temperature regulation, water balance, metabolism, drives, and emotions.

What are fissures?

Very deep grooves the cerebrum.

What is the occipital lobe?

Visual center of the brain.

What is the function of the Oligodendrocytes?

Wrap flat extensions around nerve fibers, produce a fatty insulated cover called myelin sheaths.