chapter 3.1

Question 1

peripheral nervous system (PNS)

Answer 1

division located outside the skull and spine; nerves etc.

Question 2

Somatic nervous system (SNS)

Answer 2

part of the PNS that interacts with the external environment

Question 3

afferent nerves (somatic NS)

Answer 3

carry sensory signals from the skin, skeletal muscles, joints, eyes, ears etc. to the CNS.

Question 4

efferent nerves (somatic NS)

Answer 4

carry motor signals from the CNS to the skeletal muscles.

Question 5

Autonomic nervous system (ANS)

Answer 5

part of the PNS that regulates the body’s internal environment

Question 6

central nervous system (CNS)

Answer 6

division of the nervous system located within the skull and spine

Question 7

afferent nerves (autonomic)

Answer 7

carry sensory signals from internal organs.

Question 8

efferent nerves (autonomic)

Answer 8

carry motor signals to internal organs

Question 9

sympathetic nerves

Answer 9

autonomic motor nerves that project from the CNS in the lumbar (small of the back) and thoracic (chest area) regions of the spinal cord. Synapse on second-stage neurons a substantial distance from from their target organs.

Question 10

parasympathetic nerves

Answer 10

autonomic motor nerves that project from the brain and sacral (lower back) region of the spinal cord. Synapse on second-stage neurons a very short distance from from their target organs

Question 11

para/sympathetic nerves

Answer 11

Both are two stage neural paths: both project from the CNS and go only part of the way to the target organs before they synapse on other neurons that carry the signals the rest of the way

Question 12

1st difference between para/sympathetic nerves

Answer 12

Sympathetic nerves stimulate, organize, and mobilize energy sources in threatening situations where parasympathetic nerves conserve energy

Question 13

2nd difference between para/sympathetic nerves

Answer 13

each autonomic target organs receives opposing sympathetic and parasympathetic input, and its activity is thus controlled by relative levels of sympathetic and parasympathetic activity

Question 14

3rd difference between para/sympathetic nerves

Answer 14

sympathetic changes are indicative of psychological arousal while parasympathetic changes are indicative of psychological relaxation.

Question 15

12 pairs of cranial nerves

Answer 15

project from the brain and include purely sensory such as the olfactory nerves (I), optic nerves (II) but most contain motor and sensory fibers. Longest cranial nerve are the vagus nerves (X) (contain motor and sensory fibers) traveling to and from the gut

Question 16

brain and spinal cord are protected by…

Answer 16

Three membranes aka three meninges

Question 17

(1) outer menix

Answer 17

touch membrane called the dura mater

Question 18

(2) arachnoid membrane

Answer 18

inside the three layers; Beneath is is a space called the subarachnoid space, which contains many large blood vessels and cerebrospinal fluid

Question 19

(3) innermost menix

Answer 19

delicate pia mater which adheres to the surface of the CNS

Question 20

Cerebrospinal fluid (CSF)

Answer 20

protects the CNS by filling the subarachnoid space, the central canal of the spinal cord, and the cerebral ventricles of the brain (all interconnected by a series of openings and form a single reservoir).

Question 21

central canal

Answer 21

small central channel that runs the length of the spinal cord

Question 22

Cerebral ventricles

Answer 22

four large internal chambers of the brain: the two lateral ventricles, the third ventricle, and the fourth ventricle

Question 23

Choroid plexus

Answer 23

where CSF is thought to be produced; networks of capillaries that protrude into the ventricles from the pia mater. Excess is continuously absorbed from the subarachnoid space into large blood-filled spaces, or dural sinuses, which run through the dura mater and drain into the large jugular veins of the neck

Question 24

hydrocephalus (water head)

Answer 24

Occurs If a tumor forms near one of the narrow channels (cerebral aqueduct) that link the ventricles, the buildup of fluid causes the walls of the ventricles and the entire brain to expand

Question 25

blood brain barrier

Answer 25

in the brain, blood vessel walls are tightly packed, forming a barrier to the passage of many molecules (unlike in the rest of the body). However, some large molecules, such as glucose, can still penetrate the walls