Neurophys. Exam 2 - Ch. 3

What is the Central Nervous System?

The brain and the spinal cord.

What is the Peripheral Nervous System?

Connects the brain and the spinal cord to the rest of the body.

What is the Somatic Nervous System?

Consists of axons conveying messages from the sense organs to the CNS and from the CNS to the muscles.

What is the Autonomic Nervous System?

Controls the heart, intestines, and other organs.

* has some of its cell bodies within the brain or spinal cord and some in clusters along the sides of the spinal cord.
* contains neurons that receive information from and send commands to the heart, intestines, and other organs.

What are the two branches of the Peripheral NS?

1. Somatic NS.
2. Autonomic NS.

What does Dorsal mean?

Toward the back, away from the ventral (stomach) side.

What does Ventral mean?

Toward the stomach, away from the Dorsal (back) side.

What does Anterior mean?

Toward the front end.

What does Posterior mean?

Toward the rear end.

What does Superior mean?

Above another part.

What does Inferior mean?

Below another part.

What does Lateral mean?

Toward the side, away from the midline.

What does Medial mean?

Toward the midline, away from the side.

What does Proximal mean?

Located close (approximate) to the point of origin or attachment.

What does Distal mean?

Located more distant from the point of origin or attachment.

What does Ipsilateral mean?

On the same side of the body.

What does Contralateral mean?

On the opposite side of the body.

What is the Coronal Plane (AKA the Frontal Plane)?

A plane that shows structures as seen from the front.

What is the Sagittal Plane?

A plane that shows structures as seen from the side.

What is the Horizontal Plane (AKA the Transverse Plane)?

A plane that shows structures as seen from above.

What is Lamina?

A row or layer of cell bodies separated from other cell bodies by a layer of axons and dendrites.

What is a Column?

A set of cells perpendicular to the surface of the cortex, with similar properties.

What is a Tract?

A set of axons within the CNS, also known as a projection. If axons extend from cell bodies in structure A to synapses onto B, we say that the fibers “project” from A onto B.

What is a Nerve?

A set of axons in the periphery, either from the CNS to a muscle or gland or from a sensory organ to the CNS.

What is a Nucleus?

A cluster of neuron cell bodies within the CNS.

What is the Ganglion?

A cluster of neuron cell bodies, usually outside the CNS.

What is the Gyrus (plural: Gyri)?

A protuberance on the surface of the brain.

What is the Sulcus (plural: Sulci)?

A fold or groove that separates one gyrus from another.

What is a Fissure?

A long, deep sulcus.

If two structures are both on the left side of the body, they are ____________ to each other.

If one is on the left and the other is on the right, they are ______________ to each other.

1. Ipsilateral.
2. Contralateral.

The bulges in the cerebral cortex are called __________.

The grooves between them are called ___________.

1. Gyri.
2. Sulci.

What is the Spinal Cord?

The part of the CNS within the spinal cord.

* communicates with all the sense organs and muscles EXCEPT those of the head.
* each side of it has a sensory nerve and a motor nerve.

In regards to the cross-section of the spinal cord: The entering dorsal roots (axon bundles) carry __________ information and the exiting ventral roots carry ____________ information.

1. Sensory
2. Motor

What is the Dorsal Root Ganglia?

The cell bodies of the sensory neurons are in clusters of neurons outside the spinal cord.

What is Gray Matter?

H-shaped areas of the nervous system that are densely packed with cell bodies and dendrites.

What is White Matter?

Areas of the nervous system containing the myelinated axons.

The spinal cord delivers __________ information to the brain.

The brain sends ____________ commands to the spinal cord.

1. Sensory information.
2. Motor commands.

The autonomic NS has 2 parts:

1. Sympathetic NS.
2. Parasympathetic NS.

What is the Sympathetic Nervous System?

A network of nerves that prepare the organs for vigorous activity.

* consists of chains of ganglia just to the left and right of the spinal cord’s central regions.
* excites body.

What part of the nervous system is associated with Fight-or-Flight?

Sympathetic NS.

The sweat glands, the adrenal glands, the muscles that constrict blood vessels, and the muscles that erect the hairs of the skin all have ___________ input but no _________ input.

1. Sympathetic.
2. Parasympathetic.

What is the Parasympathetic Nervous System?

Facilitates vegetative, non-emergency responses.

* relaxes body.

What else is the PNS known as?

The craniosacral system b/c it consists of the cranial nerves and nerves from the sacral spinal cord.

What is the main NT involved in the PNS?

Acetylcholine.

What is the main NT involved in the SNS?

Norepinephrine.

Sensory Nerves enter which side of the spinal cord: Dorsal or Ventral?

Dorsal.

What are the three major divisions of the brain?

1. The Hindbrain.
2. The Midbrain.
3. The Forebrain.

What are the Greek roots for each division of the brain?

1. Rhombencephalon (Hindbrain).
2. Mesencephalon (Midbrain).
3. Prosencephalon (Forebrain).

What is the Hindbrain and what major structures are included?

The hindbrain is the posterior part of the brain.

Major Structures:

* “Rhombencephalon” (parallelogram-brain):
* Medulla .
* Pons.
* Cerebellum.

What is the Midbrain and what major structures are included?

DEFINITION

Major Structures:

* “Mesencephalon” (middle-brain):
* Tectum.
* Tegmentum.
* Superior colliculus.
* Inferior colliculus.
* Substantia nigra.

What is the Forebrain and what major structures are included?

DEFINITION

Major Structures:

* “Diencephalon” (between-brain):
* Thalamus.
* Hypothalamus.
* “Telencephalon” (end-brain):
* Cerebral cortex.
* Hippocampus.
* Basal Ganglia.

What structures make up the brain stem?

* Medulla.
* Pons.
* Midbrain.
* Certain central structures of the forebrain.

What is the role of the Medulla?

Controls vital reflexes through the cranial nerves:

* Breathing.
* Heart rate.
* Vomiting.
* Salivation coughing and sneezing.

What are the Cranial Nerves?

Nerves that control sensations from the head , muscle movements in the head, and much of the parasympathetic output to the organs.

Damage to what brain structure is frequently fatal?

The Medulla.

Receptors and muscles of the head and organs connect to the brain by 12 pairs of ___________ (one of each pair on the right and left sides).

Cranial nerves.

Where does each cranial nerve originate?

In a nucleus that integrates the sensory information and/or regulates the motor output.

What is the Pons and what is its specific location?

* Location = anterior and ventral to the medulla
* Axons from each side of the brain cross-over to the opposite side so that the left hemisphere controls the right side and the right hemisphere controls the left side.

What are the functions of the Cerebellum?

* Movement control.
* Balance and coordination.
* The shift between auditory and visual stimuli.
* Timing.

What is the Tectum?

The roof of the midbrain.

What are the swellings on each side of the tectum?

The superior and inferior colliculus.

What is the role of the Superior and Inferior Colliculus?

Both are important for sensory processing.

* Inferior = hearing.
* Superior = vision.

What is the function of the Substantia Nigra?

Gives rise to a dopamine-containing pathway that facilitates readiness for movement.

Cranial Nerves:

I. Olfactory.

Smell.

Cranial Nerves:

II. Optic.

Vision.

Cranial Nerves:

III. Oculomotor.

1 ) Eye movements 2) Pupil constriction.

Cranial Nerves:

IV. Trochlear.

Eye movements.

Cranial Nerves:

V. Trigeminal.

Jaw Movements for 1) chewing and 2) swallowing.

Cranial Nerves:

VI. Abducens.

Eye movements.

Cranial Nerves:

VII. Facial.

1) Facial expressions and 2) crying.

Cranial Nerves:

VIII. Statoacoustic.

1) Hearing and 2) Equilibrium.

Cranial Nerves:

IX. Glossopharyngeal.

Throat movements - 1) swallowing 2) salivation 3) speech.

Cranial Nerves:

X. Vagus.

Sensations from neck and thorax.

Cranial Nerves:

XI. Accessory.

Neck and shoulder movements.

Cranial Nerves:

XII. Hypoglossal.

Muscles of the tongue.

Limbic system structures are important for what functions?

Motivations and emotions such as..

* eating, drinking, sexual activity, anxiety, and aggression.

What structures are included in the Limbic System?

* Olfactory bulb.
* Hypothalamus.
* Hippocampus.
* Amygdala.
* Cingulate Gyrus of the Cerebral Cortex.

Most sensory information first goes to the _________ , which processes it and sends output to the ________.

The only exception to this is _______________.

1. Thalamus.
2. Cerebral Cortex.
3. Olfactory information.

Damage to any hypothalamic nucleus leads to abnormalities in….

* motivated behaviors such as..
* feeding, drinking, temperature regulation, sexual behavior, fighting, or activity level.

What does the Pituitary Gland do?

It synthesizes hormones that the blood carries to organs throughout the body.

What three major structures are included in the Basal Ganglia?

1. The Caudate Nucleus.
2. The Putamen.
3. The Globus Pallidus.

What happens when the Basal Ganglia is damaged?

Impaired movement.

What aspects of function does the Basal Ganglia have a role in?

* Movement.
* Learning and remembering.
* Skills and habits.

What is the function of the Nucleus Basalis?

Receives input from the hypothalamus and the basal ganglia and sends axons that release acetylcholine to widespread areas in the cerebral cortex.

What is the hippocampus critical for?

Certain types of memories.

What is the Central Canal?

A fluid-filled channel in the center of the spinal cord.

What are ventricles?

Four fluid-filled cavities within the brain.

* Each hemisphere contains 1-2 large lateral ventricles.

What is Cerebrospinal fluid (CSF)?

A clear fluid similar to blood plasma.

What are meninges?

Membranes that surround the brain and spinal cord.

What is Menengitis?

Inflammation of the meninges.

What is Hydrocephalus?

Obstruction of the flow of cerebral spinal fluid.

Causes of Hydrocephalus?

1. Increased pressure on the brain.
2. Skull bones (in infants) may spread, causing overgrown head
3. Associated with intellectual disabilities.

What occurs if the spinal cord is cut at any given segment?

The brain….


1. loses sensation from that segment & all segments below it.
2. loses motor control over parts of the body served by that segment and the ones below it.

The lower the spinal cord segment injury, the _______ the handicap.

The higher the injury, the __________ the handicap.

* less-severe.
* more-severe.

The pituitary gland is attached to what brain structure?

Hypothalamus.

Why do most cold remedies increase heart rate and blood pressure?

These drugs block the parasympathetic nervous system.

What is the cerebral cortex?

Layers of cells on the outer surface of the cerebral hemisphere of the forebrain.

What is the Corpus Callosum / Anterior Commissure?

Bundle of axons that connects the two hemispheres of the cerebral cortex.

The cerebral cortex contains up to ____ distinct laminae.

Six.

What are Laminae?

Layers of cell bodies that are parallel to the surface of the cortex and separated from each other by layers of fibers.