anat neuro hafiz 14122010

8/7/2019 anat neuro hafiz 14122010

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The HumanThe Human Brain:Brain: FunctionalFunctional

ABDUL HAFIZ ALIAS

H8


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Central Nervous SystemCentral Nervous System

The part of the nervous system that integrates the

information that it receives from, andcoordinates the

activity of, all parts of the bodies of bilateral animals,

It contains themajority of thenervous system andconsists of the brain and the spinal cord.

With the peripheral nervous system, it has a

fundamental role in thecontrol of behavior.

The CNS is contained within the dorsal cavity, withthe brain in the cranial cavity and the spinal cord in

the spinal cavity.


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Cerebrum (Forebrain)Cerebrum (Forebrain)

Parietal Lobe

Temporal Lobe

Frontal Lobe

Limbic Lobe

Occipital Lobe


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Frontal Lobe

Highercognitive functions

Examples : Problem solving, Spontaneity,Memory, Language (Broca), Motivation,Judgment, Impulsecontrol, Social and Sex

Temporal Lobe

Emotions, smelling, tasting, perception,memory,understandingmusic, aggressiveness, sexual behavior,Language

Parietal Lobe sensations of touch, smell, and taste

processes sensory and spatial awarenessa

eye-handco-ordination and armmovement

Wernickes area that is responsible formatching written

words with the sound of spoken speech.


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Occipital Lobe

Controls vision and recognition

Limbic Lobe

Makes up the limbic system

Limbic System

Regulates emotion andmemory.

It directly connects the lower andhigher

brain functions


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ThalamusThalamusThalamus means inner room in Greek,as it sits deep in the brain at the top of

the brainstem.

The thalamus is called thegateway to

thecerebral cortex, as nearly all

sensory inputs pass through it to the

higher levels of the brain.


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HypothalamusHypothalamus

Thehypothalamus sits under the thalamus at

the top of the brainstem. Although the

hypothalamus is small, it controls many critical

bodily functions:

Controls autonomicnervous system

Center foremotional response and behavior

Regulates body temperature

Regulates food intake

Regulates water balance and thirst

Controls sleep-wakecycles

Controls endocrine system

Thehypothalamus isshaded blue.The pituitary

glandextends from the

hypothalamus.


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The VentriclesThe Ventricles

Click image to play or pause video

The ventricles are a complex

series of spaces and tunnels

through thecenter of the brain.

The ventricles secrete

cerebrospinal fluid, which

suspends the brain in the skull.

The ventricles also provide a

route forchemical messengers

that are widely distributed through

thecentral nervous system.


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Cerebellum (Midbrain)Cerebellum (Midbrain)Thecerebellum is connected to the

brainstem, and is thecenter for

body movement and balance.


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The PonsThe Pons

The pons is the rounded

brainstem region between the

midbrain and themedulla

oblongata. In fact, pons means

bridge in Latin.

Themain function of the pons is

to connect thecerebellum to the

rest of the brain and to modify the

respiratory output of themedulla.

The pons is the origin of several

cranial nerves.


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The MedullaThe Medulla OblongataOblongata

(Hindbrain)(Hindbrain)Themedulla oblongata mergesseamlessly with the spinal cord and

creates the base of thebrainstem.

Themedulla is primarily a control

center for vital involuntary reflexes

such as swallowing, vomiting,

sneezing,coughing, and regulation of

cardiovascular and respiratory activity.

Themedulla is also the origin ofmany

cranial nerves.


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CEREBROSPINAL FLUID (CSF)CEREBROSPINAL FLUID (CSF)


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What is CSF ?What is CSF ?

A clear bodily fluid that occupies the subarachnoidspace and the ventricular system around andinside the brain and spinal cord.

Produced in the choroid plexus. The CSF occupies the space between

the arachnoid mater (themiddle layer of the braincover, meninges), and the pia mater (the layer ofthemeninges closest to the brain).

It constitutes thecontent of all intra-cerebral (insidethe brain,cerebrum) ventricles,cisterns,and sulci (singular sulcus), as well as the centralcanal of the spinal cord.


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FunctionsFunctions

Buoyancy: allows the brain to maintainits density without being impaired by itsown weight, which wouldcut off blood supply and

kill neurons in the lower sections without CSF. Protection: CSF protects the brain tissue from

injury when jolted orhit. Incertain situations suchas auto accidents or sports injuries, the CSFcannot protect the brain from forcedcontact with

the skull case,causing hemorrhaging, braindamage, and sometimes death.


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Chemical stability: CSF flows throughoutthe inner ventricular system in the brain and

is absorbed back into the bloodstream,rinsing the metabolic waste from the centralnervous system through the blood-brainbarrier.This allows forhomeostaticregulation of thedistribution of

neuroendocrine factors, to which slightchanges cancause problems ordamage tothenervous system.

Prevention of brain ischemia: The

prevention of brain ischemia is made bydecreasing the amount of CSF in the limitedspace inside the skull.This decreases totalintracranial pressure andfacilitates blood perfusion.


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The BrainstemThe Brainstem

The brainstem is themost

primitive part of the brain and

controls the basic functions of

life: breathing,heart rate,

swallowing, reflexes to sight or

sound, sweating, bloodpressure, sleep, and balance.

Click image to play or pause video


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SPINAL CORDSPINAL CORD


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FunctionsFunctions

Transmission of nerve impulses

Neurons in the whitematter of the spinal cord

transmit sensory signals from peripheral

regions to the brain andmotor signals from thebrain to peripheral regions.

Spinal reflexes

Neurons in thegray matter of the spinal cord

integrate incoming sensory information andrespond withmotor impulses that control

muscles (skeletal, smooth, orcardiac) or

glands.


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TractTract

Ascending (sensory) tracts transmit

sensory information from various parts

of the body to the brain.

Descending (motor) tracts transmit

nerve impulses from the brain to

muscles andglands.


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PERIPHERAL NERVOUSPERIPHERAL NERVOUSSYSTEMSYSTEM


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PNS

SNS ANS


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SOMATIC NERVOUS SYSTEMSOMATIC NERVOUS SYSTEM(SNS)(SNS)


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SNSSNS

controls voluntary activities

Includes both sensory andmotornerves

Sensory nerves convey nerve impulses

from the sense organs to the central

nervous system (CNS), whilemotor

nerves convey nerve impulses from theCNS to skeletal muscleeffectors


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The sensory division, also called the afferent division,

contains neurons that receive signals from the

tendons, joints, skin, skeletal muscles,eyes,nose,ears and tongue, andmany other tissues and organs.

These signals areconveyed to thecranial and spinal

nerves.Themotordivision, also called theefferent

division,contains pathways that go from the brain

stem and spinal cord to the lowermotorneurons ofthecranial and spinal nerves.When thesenerves are

stimulated, they cause the skeletal muscles to

contract.This is called voluntary contraction of the

skeletal muscles.


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NERVES OF THE SENSORYNERVES OF THE SENSORY--SOMATICSOMATIC

SYSTEM (CRANIAL NERVES )SYSTEM (CRANIAL NERVES )I. olfactory nerve, a sensory nerve for the sense ofsmell

II. opticnerve, a sensory nerve forvision

III. oculomotornerve, a motornerve foreyelid andeyeball musclecontrol

IV. trochlearnerve, a motornerve foreyeball musclecontrol

V. trigeminal nerve, a mixednerve, the sensory part for facial andmouth

sensation and themotor part forchewing

VI. abducens nerve, a motornerve foreyeball movement control

VII. facial nerve, a mixednerve, the sensory part fortaste and themotor

part for thecontrol of facial muscles and salivary glands

VIII.auditory nerve, a sensory nerve forhearing and balancecontrol

IX. glossopharyngeal, a mixednerve, the sensory part for taste and themotor part for thecontrol of swallowing

X. vagus, a mixednerve,mainPNS nerve that controls thegut, heart and

larynx

XI. accessory, a motornerve for swallowing andmoving thehead and

shoulders

XII. hypoglossal, a motornerve for thecontrol of tonguemuscles


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Autonomic Nervous SystemAutonomic Nervous System

(ANS)(ANS)


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ANSANS

The ANS is part of the peripheral

nervous system and it controls many

organs andmuscles within the body. Inmost situations, we are unaware of the

workings of the ANS because it

functions in an involuntary, reflexivemanner.


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ANS

Sympathetic Parasympathetic

involuntary system

often associated

with the flight orfight response.

responsible for

promoting internal

harmony such as

regular heartbeat

during normal activity.


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ComparisonComparisonFeatures Sympathetic division Parasympathetic

divisionLocation of pre

ganglioniccell body

Lateral horns of spinal

cordgray matter (T1-

L2)

Brainstem and lateral

parts of spinal gray

matter (S2- S4)

Outflow from the CNS Spinal nerves

Sympatheticnerves

Splanchnic nerves

Cranial nerves

Pelvic splanchnic nerves

Ganglia Sympatheticchain

ganglia along spinal

cord for spinal and

sympatheticnerves

Collateral ganglia for

splanchnicnerves

Terminal ganglia near or

oneffectors organ

Num of postganglionic

neurons foreach pre

ganglionicneuron

Many (much

divergence)

Few (less divergence)

Relative length of

neurons

Short preganglionic

Long postganglionic

Long preganglionic

Short postganglionic


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Effects of the sympathetic and parasympatheticEffects of the sympathetic and parasympathetic


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TQTQ

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