Lecture 6: Nervous System Introduction, Brachial Plexus

Question 1

What are the functions of the nervous system?

Answer 1

-sensory -motor -cognitive

Question 2

What are the divisions and subdivisions of the nervous system?

Answer 2

Central Nervous System (CNS) -brain -spinal cord Peripheral Nervous System (PNS) -cranial nerves -spinal nerves Autonomic Nervous System -sympathetic -parasympathetic

Question 3

What is the difference between afferent and efferent pathways?

Answer 3

Afferent (sensory): carries information to the CNS Efferent (motor): carries information away from the CNS

Question 4

How many cranial and spinal nerve pairs are there?

Answer 4

Cranial: 12; I-XII Spinal: 31; C1-8, T1-12, L1-5, S1-5, Co

Question 5

What is the function of the autonomic nervous system?

Answer 5

Efferent pathways innervating smooth muscles and glands.

Question 6

What are the subdivisions of the autonomic nervous system? Compare them.

Answer 6

Sympathetic (thoracolumbar): fight or flight Parasympathetic (craniosacral): feed and breed

Question 7

Describe the development of the neural tube.

Answer 7

Neural plate is formed by thickening of the tissue stimulated by the notochord. The ends of he neural plate pinch together forming neural folds and the neural groove. The neural folds fuse to create the neural tube. This fusion starts from the middle and spreads towards the ends.

Question 8

What are the divisions of the tripartite brain?

Answer 8

-prosencephalon -mesencephalon -rhombencephalon

Question 9

What are the divisions of the pentapartite brain?

Answer 9

-telencephalon -diencephalon -mesencephalon -metencephalon -myelencephalon

Question 10

What do the different parts of the telencephalon develop into?

Answer 10

Lumina: -lateral ventricles Floor: -basal ganglia -olfactory nerves Roof -cerebral hemispheres

Question 11

What do the different parts of the diencephalon develop into?

Answer 11

Lumen: -third ventricle Roof -epithalmus Walls -thalamus Floor -hypothalamus and infundibulum

Question 12

What do the different parts of the mesencephalon develop into?

Answer 12

Lumen: -cerebral aqueduct Roof: -tectum Floor: -tegmentum

Question 13

What do the different parts of the metencephalon develop into?

Answer 13

Lumen: -fourth ventricle Roof: -cerebellum Floor: -pons

Question 14

What do the different parts of the myencephalon develop into?

Answer 14

Lumen: -forth ventricle Main part: -medulla oblongota Roof: -choroid plexus

Question 15

What are the parts of a neuron?

Answer 15

Cell body Dendrites Axon

Question 16

What are the features of the cell body?

Answer 16

-contains the nucleus, Golgi body and endoplasmic reticulum -maintains the rest of the cell

Question 17

What are the features of the dendrites?

Answer 17

-consists of several to many short branches coming of the cell body -have receptors for neurotransmitters -conduct local potentials

Question 18

What are the key features of the axon?

Answer 18

-single, relatively long structure -conducts action potential -ends branch into telodendria which end in a terminal bouton -cell membrane is called axolemma; cytoplasm is called axoplasm

Question 19

Define nucleus

Answer 19

Aggregation of dendrites and cell bodies in the CNS

Question 20

Define ganglion

Answer 20

Aggregation of dendrites and cell bodies in the PNS

Question 21

Define nerve

Answer 21

Bundle of axons in the PNS

Question 22

Define tract

Answer 22

Bundle of axons in the CNS

Question 23

Define commissary

Answer 23

Tracts in the CNS that cross from one side to the other

Question 24

Define white matter

Answer 24

Areas of myelinated axons

Question 25

Define gray matter

Answer 25

Areas of unmyelinated axons, cell bodies, and dendrites

Question 26

Identify the colored structures

Answer 26

Yellow: dorsal ramus Orange: ventral ramus Red: white ramus communicans

Question 27

Describe the structure of a synapse.

Answer 27

Presynaptic membrane: releases vesicles containing neurotransmitters Synaptic cleft: gap between pre- and postsynaptic membranes Postsynaptic membrane: contains neurotransmitter receptors

Question 28

Distinguish between afferent and efferent pathways.

Answer 28

Afferent: sensory; carries information towards the CNS Efferent: motor; carries information away from the CNS

Question 29

Differentiate between a monosynaptic and polysynaptic reflex arc.

Answer 29

Monosynaptic: one synapse consisting of only an afferent pathway and an efferent pathway; no processing, cannot be inhibited Polysynaptic: more than one synapse; contains interneurons; there can be processing and inhibition

Question 30

Label the indicated structures

Answer 30