Organization of the Human Nervous System

Question 1

1. What is the Central Nervous System? (CNS)
2. What does the CNS do?

Answer 1

1. The CNS is the part of the nervous system that is located within the skull and spine.
2. The CNS functions as the sensory processing center and sends instructions to the PNS.

Question 2

1. What is the Peripheral Nervous System (PNS)?
2. What does the PNS do?

Answer 2

1. The PNS is the part of the nervous system located outside the skull and spine.
2. The PNS sends sensory signals to the CNS for processing and performs motor functions.

Question 3

What are the four regions of the spine?

Answer 3

1. Cervical Region
2. Thoracic Region
3. Lumbar Region
4. Sacral Region

Question 4

What are the two primary divisions of the PNS? What do they do?

Answer 4

1. The Somatic Nervous System (Interacts with the external environment and sends/receives sensory signals to the CNS)
2. The Autonomic Nervous System (regulates the internal environment, aka. telling the heart to beat and such)

Question 5

What are the two primary divisions of the CNS?

Answer 5

1. The Brain
2. The Spinal Cord

Question 6

What is…
1. Spinal Gray Matter
2. Spinal White Matter

Answer 6

These tissues make up the spinal cord.
1. Spinal Gray Matter is the H-shaped tissue that makes up the center of the spinal cord.
2. Spinal White Matter is surrounded by spinal gray matter and is the tissue at the back of the spinal cord.

Question 7

Differentiate between Motor Nerves and Sensory Nerves.

Answer 7

1. Motor Nerves are bundles of nerve fibers that send signals from the Central NS to the muscles and glands. (C->P)
2. Sensory Nerves are bundles of nerve fibers that send signals from sensory receptors to the Central NS. (P->C)

Question 8

What are the Dorsal Roots?

Answer 8

-The 31 pairs of SENSORY nerves that enter the spinal cord conduct signals from the Peripheral NS to the Central NS.
-Dorsal roots attach at the back of the spinal cord.

Question 9

What are Ventral Roots?

Answer 9

• The 31 pairs of MOTOR nerves that exit the spinal cord, conducting signals from the Central NS to the Peripheral NS.
• Ventral roots attach at the front of the spinal cord.

Question 10

What is the Autonomic Nervous
System?

Answer 10

This is a division of the Peripheral NS that participates in the regulation of the body’s internal environment.
(maintains homeostasis)

Question 11

What are the two divisions of the Autonomic Nervous System?

Answer 11

1. The Sympathetic Nervous System (STRESS)
2. The Parasympathetic Nervous System (PEACE)

Question 12

What is the Sympathetic Nervous System?
Where in the body do the nerves of this system originate?

Answer 12

1. This is a division of the Autonomic NS that regulates energy during periods of stress.
2. The Sympathetic nerves originate from the thoracic and lumbar regions of the spinal cord.
   (stress=middle of the back)

Question 13

What is the Parasympathetic Nervous System?
Where in the body do the nerves of this system originate?

Answer 13

1. This is a division of the Autonomic NS that regulates energy during periods of peace.
2. The Parasympathetic nerves originate in the brain and sacral region of the spinal cord.
   (peace= brain and tailbone)

Question 14

Differentiate between:
1. Exocrine Glands
2. Endocrine Glands

Answer 14

1. Exocrine Glands are glands that secrete their products via ducts to the outside world.
2. Endocrine Glands are glands that secrete hormones straight into the bloodstream.

Question 15

Where can the Pituitary Gland be found?
What is it’s primary function?

Answer 15

1. The Pituitary Gland hangs from the hypothalamus.
2. This gland is known as the “master gland” for it’s primary role in hormone production. (produces a lot of important hormones)

Question 16

Where can the Hypothalamus be found?
What is it’s primary function?

Answer 16

1. The Hypothalamus is a brain structure from which the pituitary gland hangs.
2. The Hypothalamus instructs the pituitary gland to release certain hormones. (it does it by releasing, releasing hormones-yeah yeah)

Question 17

How many Adrenal Glands do we typically have and where are they located?

Answer 17

We have two, one on top of each Kidney.

Question 18

What is the anatomy of an Adrenal Gland?

Answer 18

The core of the gland is called the Adrenal Medulla and the outer layer is called the Adrenal Cortex.

Question 19

What is the Adrenal Medulla?

Answer 19

This is the name of the core of an Adrenal Gland, it secrete hormones such as adrenaline and works with the Sympathetic NS.

Question 20

What is the Adrenal Cortex?

Answer 20

This is the name of the outer layer of an Adrenal Gland, and secretes hormones used day to day. (ex. metabolism, reproductive behavior, mineral balance)

Question 21

What are the Gonads?
What is their primary function?

Answer 21

1. This is what we call the sex glands, testes in men and ovaries in women.
2. They release hormones that develop female/male reproductive systems.