Organization Of The Nervous System

Front 1

I. Oganization of the NS

Back 1

an overview

Front 2

A. Divisions of the NS

Back 2

CNS
PNS

Front 3

1. CNS

Back 3

a. Comprised of the brain and
spinal cord
b. The brain alone contains
approximately 100 billion
neurons

Front 4

2. PNS

Back 4

a. Nerves that exit and enter the CNS
b. Somatic NS
C. Autonomic NS

Front 5

Somatic NS

Back 5

1. Involved with somatic sensation (touch, limb movement, pain) and control of skeletal muscle contraction
2. Somatic Sensory Nerves-Travel from peripheral tissue (skin, muscle, joints) to spinal cord
3. Motor Nerves- travel from spinal cord to skeletal muscles

Front 6

C. Autonaumic NS

Back 6

1. Involved with regulation of the internal env. (control of BP, respiration, body temp, and other variables
2. Sympathetic NS
3. Parasympathetic NS

Front 7

Two branches of autonomic NS

Back 7

Parasympathetic and sympathetic

Front 8

B. Organization of the brain

Back 8

an overview

Front 9

Major anatomical divisions of the brain (Lowest to Highest)

Back 9

a. Hindbrain
b. Midbrain
c. Forebrain

Front 10

What stuctures of brain are included in the hindbrain?

Back 10

1. Medulla

2. Pons

3. Cerebellum

Front 11

1.Where is Midbrain located?
2.What is another name for midbrain?

Back 11

1. At the top of the pons
2. mesencephalon

Front 12

what are the 2 major stuctures of the forebrain?

Back 12

1. Diencephalon

2. Telencephalon

Front 13

The diencephalon includes two stuctures.....

Back 13

1. Thalmus

2. Hypothalmus (directly above pituitary gland)

Front 14

What three stuctures does the telencephalon include?

Back 14

1. Basal ganglia

2. Regions associated with the limbic system, a group of brain stuctures that produces emotions and motivation

3. cerebral cortex

Front 15

What stuctures are associated with the limbic system that produce emotions and motivation?

Back 15

1. amygdala
2. hippocampus
3. limbic cortex

Front 16

What are the stuctures located in the cerebral cortex?

Back 16

1. Motor cortex

2. Somatic sensory cortex

3. association cortex- hosts executive functions of the brain. allows brain to do more complex processes and have complex thoughts

Front 17

II Intro to the brain anatomy

Back 17

.......

Front 18

A. Brainstem
What are the 4 areas of the brainstem?

Back 18

1. Medulla
2. Pons
3. Midbrain
4. Reticular formation

Front 19

Medulla:
1. what kind of nerve tracts does it contain?
2. What are the clusters of neruons that are specific for function called? give examples.

Back 19

1. ascending and descending nerve tracts ( axon bundles )
2. Medulla contains several important brain nuclei. Brain nuclei are dense clusters of neurons--responsible for a specific function
a. cardiovascular centers- control heart rate and BP
b. respiratory centers- control activity of respiratory muscles

Front 20

A nucleus is.....

Back 20

a group of neurons that, together, are responsible for carrying out a specific function

Front 21

Pons:
Name the two parts to the pons and what they contain.

Back 21

1.Dorsal portion-contains nerve tracts (ascending and descending) and nuclei
2. Basal portion- faces front of neck. provides connections between the hemispheres of the cerebral cortex and the contralteral hemispheres of the cerebellum. These connections are essential for control of motor activities. Entry and exit point for info entering/leaving brainstem.

Front 22

Dorsal portion:
1. locus coeruleus
2. axons project from the locus coeruleus neurons to.....
3. what role does norepinepherine play in the locus coeruleus?

Back 22

1. (blue area) is an important nucleus of the pons *bilateral structure
2. ....the hypothalmus, thalamus, cerebral cortex, and play a role in arousal of these higher brain areas *vigilance
3. depletion of neurotransmitter norepi in the neurons of the locus coeruleus may play a role in depression-mood

Front 23

Midbrain:
1. Contains nerve tracts and nuclei
2. name two nucleus in the midbrain.

Back 23

1. ascending and descending tracts
2. substantia nigra
3. red nucleus

Front 24

Substantia nigra-bilateral in brain

Back 24

"black area" is found in midbrain.
patients with Parkinson's disease show degeneration of substantia nigra neurons. Involved with motor control & movement.

Front 25

Red nucleus

Back 25

located in midbrain. works closely with the motor cortex in the cerebellum--certain aspects of motor control

Front 26

Reticular Formation: RF
Where does it extend through?
Does it include nuclei and nerve tracts?

Back 26

through the brainstem: includes numerous nuclei as well as a diffuse network of neurons not included in specific nuclei or nerve tracts

Front 27

RF:
1.Where does it receive input from?
2.What type of info does it receive?
3. When the input is received, what does the RF activate?

Back 27

1.Receives input from nearly all sensory systems
2. pain, temp, touch, pressure, sensory endings in the viscera
3. these sensory inputs then activate the reticular formation neurons (

Front 28

RF:
1.Where does the RF neurons project axons to?
2. What is this projection called?

Back 28

1. provides axons to the thalamus, limbic system and cerebral cortex.
2. Called the reticular activating system (RAS)

Front 29

What does the RAS do?

Back 29

Provides a background of excitation of the higher brain areas

Front 30

Where does the RF receive info from?

Back 30

RF receives input from cerebral cortex: thoughts and motor activity generated in the cortex stimulate the RAS

Front 31

1. What class of drugs have specific action on the RF?
2. Describe how the drug class effects the RF.

Back 31

1. Barbiturates-sedative hypnotics
2. They have a specific depressant action on the RF and thus can depress cortical activity and even cause sleep. Depressed reticluar neurons

Front 32

RF: What can excessive activity in the RAS cause?

Back 32

May trigger a generalized tonic-clonic (grand mal) seizure

Front 33

RF:
What can injury to the RF cause?

Back 33

Coma

Front 34

B. Cerebellum

Back 34

.....

Front 35

Why is the cerebellum considered the silent area of the brain?

Back 35

electrical excitation does not cause sensation or movement

Front 36

What can injury to the cerebellum cause?

Back 36

can severely impair motor activities, without muscle paralysis

Front 37

1. Where is the cerebellum attached to the brainstem?
2. Where does it receive input from?

Back 37

1. cerebellum attached to the brainstem at the basal portion of the pons
2. receives input from many sensory systemts, as well as from the brainstem and motor cortex.

Front 38

What does the cerebellum do?

Back 38

coordinates skeletal muscle activity involved with maintenance of equilibrium and posture, locomotion, and rapid nonstereotyped movements based on individual experiences (typing, playing a musical instrument)

Front 39

Why is the function of the cerebellum to coordinate muscle activity particularly important in voluntary movements?

Back 39

even though the cerebellum does NOT initiate such movements, the cerebellum acts "behind the scenes" at a subconcious level. Not initiating, but facilitating proper movements.

Front 40

How does the cerebellum allow smooth coordination for movements?

Back 40

By using instantaneous feedback from muscle joints, the cerebellum can then provide indicidual movements that are necessary to complete some intentional actions without shakiness or oscillation ( touching a finger to nose, lifting food to the mouth, and more comlex mvmts)

Front 41

C. Forebrain (cerebrum)

Back 41

....

Front 42

2 major structures of forebrain
and their description

Back 42

Diencephalon
a. Thalmus
b. Hypothalmus
Telencephalon
a. basal ganglia
b. cerebral cortex

Front 43

Diencephalon

Back 43

central core of cerebrum

Front 44

Diencephalon structures
Thalamus: how much of diencephalon does thalamus occupy?
What is the function of the thalamus?

Back 44

Makes up about 80% of diencephalon
Functions primarlily as a "relay station" for sensory signals traveling to the cerebral cortex.

Front 45

Diencephalon:
Thalamus:
What is the genrealized thalamocortical system (GTS) in the thalamus?

Back 45

a. Continuous with tthe upper RF of the brainstem; receives input from the reticular formation
b. output is directed to most areas of the cerebral cortex and affects the overal level of activity in the cerebral cortex
c. excessive activity in the GTS may cause an ansence (petit mal) sz.

Front 46

Diencephalon
Thalmus has.....

Back 46

motor relay nuclei

Front 47

Diencephalon:
Hypothalmus is the principal regulator of 2 things

Back 47

a. Principal regulator of the autonomic N.S. and therefore....
b. Principal regulator of autonomic visceral functions such as blood pressure, body temp, feeding, thirst, hormone secretion
also important in the production of hormones

Front 48

Diencephalon:
Hypothalmus has nuclei that function to monitor what?

Back 48

Monitor change in certain internal variables e.g. plasma osmolarity, body temp, body energy stores, and others

Front 49

Diencephalon:
Hypothalmus is part of what network producing emotions?

Back 49

Limbic system

Front 50

Diencephalon:
Hypothalmus is directly connected to what other areas of the brain?

Back 50

Amygdala and hippocampus: involved with emotion, motivation, and behavior

Front 51

Diencephalon:
Output of the hypothalmus is directed to 2 areas:

Back 51

1. Autonomic nuclei in the brainstem
2. Pituitary gland (below hypothalmus)

Front 52

Diencephalon:
Hypothalmus provides a connection between _____ & _____ and versceral (inernal) functions associated with the carrying out of such drives

Back 52

emotion and basic drives
1. animal hunting prey -drive = need food
2. visceral changes: increase HR, CO, BP, dilate pupils etc

Front 53

Telencephalon

Back 53

cerebral hemispheres
Left and right
(part of forebrain)

Front 54

Telencephalon
Basal ganglia are...

Back 54

clusters of nerve cells (ganglia) that appear early in the develpment of the CNS; bilateral structures--located at the base of each cerebral hemisphere

Front 55

Telencephalon:
Components of basal ganglia

Back 55

a. striatum (caudate nucleus, putamen)
b. gobus pallidus (pallidum)-more medial than striatum
c. substantia nigra and subthalamic nuclei make connections with the basal ganglia, but are not anatomic components of teh basal ganglia (not in midbrain)

Front 56

Telencephalon (Telen):
basal ganglia (BG)
Striatum receives sensory in from 2 aras

Back 56

thalamus and sensory cortex

Front 57

Telen: BG:
Where does the striatum receive in from?
What area does it work in close association with?

Back 57

Cerebral cortex
Motor coretex

Front 58

Telen: BG:
striatum is one component of the extrapyramidal motor system.

Back 58

EMS denotes all portions of the brain and brain stem that contribute to motor control

Front 59

Telen: BG
Specific neurons that originate in the _____innervate the striatum.

Back 59

substantia nigra

Front 60

Telen:BG
Stratum substantia nigra connection degenerates in what disease?

Back 60

Parkinsons

Front 61

Telen:BG
Striatum plays a role in what initiation of what type of movements?
Altered activity, as in Parkinsons, causes what movement disorder?

Back 61

Intentional movements
akinesia (bradykinesia)

Front 62

Telen:BG
Degenerative lesions of the striatum may cause dyskinesias in which involuntary_____movements are prominent.

Back 62

Choreiform (jerky, purposeless movements)

Front 63

Telen: BG
What is an example of a hereditary disorder in which there is neuronal degeneration in the striatum?

Back 63

Huntington's chorea

Front 64

Telen
Cerebral Cortex: anatomy

Back 64

1. Outermost layer of the brain; arranged into folds (gyri) and grooves (sulci)
2. makes up about 40% of the TW of brain; contains about 70% of the 100 Billion neurons in the brain
3. most of telencephalon is composed of cerebral cortex

Front 65

Telen:
Cerebral Cortex (CC)
What are the sulci and gyri?

Back 65

Cerebral cortex aranges in to folds which are gyri and grooves that are sulci

Front 66

Telen: CC
Cortex of each hemisphere is divided into four lobes

Back 66

1. occipital lobe-vision
2. temporal lobe-hearing, language comprehension, memory (understand spoken/written)
3. parietal lobe-somatic sensory (somesthetic) cortex (pain, touch, pressure, limb mvmt)
4. frontal lobe-motor cortex, memory, behavior

Front 67

Telen: CC
each layer of cortical region contains how many layers of neurons and how are they arranged?

Back 67

six layers
arranged in columns

Front 68

Telen: CC
The majority of the human cortex is___ ____, rather than sensory and motor areas as in low animals. What are functions of that area?

Back 68

Association Cortex
Executive activities of brain, as well as the individuality of behavior, are functions of the association cortex.

Front 69

Telen: CC
Describe integrative function of association cortex

Back 69

current info is integrated with past experiences (memory) and emotion, allowing a person to think, make decisions, and plan.
Particularily a characterstic of the association areas of the frontal cortex(prefrontal cortex)

Front 70

Telen: CC
What other lobes does the prefrontal cortex of frontal lobe connect with

Back 70

Temporal and parietal lobes

Front 71

Telen: CC
What is the prefrontal cortex thoguht to monitor?

Back 71

behavior and to control behavior based on higher activities such as judgement and foresight.
(ADD kids have decreased activity in prefrontal cortex)

Front 72

Telen: CC
What are the Left and right cerebral hemispheres connected by

Back 72

corpus collosum (major pathway)

Front 73

Telen:CC
Functional differences betwen the cerebral hemispheres: Describe contralateral representation

Back 73

the right hemisphere controls somatic sensation and movement on the body's left side; the left hemisphere controls somatic sensation and movement on the body's right side.

Front 74

Telen:CC
Functional differences between the cerebral hemishpheres:
describe lateralization of function

Back 74

control of language is usually localized in one hemisphere(dominant hemisphere)

Front 75

Telen:CC
Functional differences between cerebral hemispheres:
What is the nondominant hemisphere thought to be mainly responsible for?

Back 75

perception of spatial relationships. "sees the whole picture"

Front 76

Telen:CC
In 95% of ___handed people, the ____hemisphere controls sppech and language

Back 76

Right
Left

Front 77

Telen:CC
What are the 5 structures of the forebrain associated with the limbic system?

Back 77

1. Hypothalmus
2.Amygdala
3. hippocampus
4. septum
5. limbic cortex

Front 78

Telen: structures of forebrain associated with limbic system
what is hypothalamus responsibel for?

Back 78

key central compnenet of the limbic system because everything else is connected to it

Front 79

Telen: structures of forebrain associated with limbic syst.
What is amygdala important for?

Back 79

"window " of limbic system
-important in the emotional response to threatening situations including feelings of fear. any sensory input-->amygdala-->response

Front 80

Telen: structures of forebrain associated with limbic syst.
What is role of hippocampus

Back 80

Important in learning and memory.
Precise role in emotion is unclear--role in anxiety?