section 4 nervous and endocrine system

8/8/2019 Section 4 Nervous and Endocrine System

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SVQ Level 3SVQ Level 3Instructing Physical ActivityInstructing Physical Activity

& Exercise& Exercise

Dr Sarah J Ramminger

Angus College



Section 4Section 4 ²² Nervous andNervous and

Endocrine systemEndocrine system

y Role of the Nervous systemy Anatomy and organisation

of the nervous systemy The Motor unity Neuromuscular junction ² a closer looky Endocrine anatomyy Glands and hormonesy Hormones and their role during exercise



Section 4Section 4 ²² The Nervous systemThe Nervous system

The nervous system of theThe nervous system of thehuman body is responsiblehuman body is responsiblefor sending, receiving andfor sending, receiving andprocessing nerve signalsprocessing nerve signals

throughout the bodythroughout the body

All of the muscles andAll of the muscles andorgans in your body rely onorgans in your body rely on

these signals from thethese signals from thenervous system to work.nervous system to work.



Sensory inputSensory inputSensory receptors

monitor externaland internal stimulie.g. Touch, temp,

taste, smell, sound

IntegrationIntegrationProcessingProcessing

informationinformation ²² mainmainorgans involved areorgans involved are

spinal chord andspinal chord andbrainbrain

HomeostasisHomeostasisMaintenance of aMaintenance of a

stable internalstable internalenvironmentenvironment

Mental ActivityMental ActivityConsciousness,Consciousness,

thinking, memorythinking, memoryand emotionsand emotions

Control of muscular tissueControl of muscular tissueand glandsand glands



AnatomyAnatomyof theof theNervousNervoussystemsystem



Nerve cellsNerve cells

The nervousThe nervoussystem is made upsystem is made upofof specialisedspecialised cellscells

called neurons.called neurons.

The human brainThe human brainhas about 100has about 100

billion neurons.billion neurons.

AxonAxon

DendriteDendrite MyelinMyelinsheathsheath



The Autonomic Nervous SystemThe Autonomic Nervous System

SympatheticSympatheticnervousnervoussystemsystem

arasympatheticarasympatheticnervousnervoussystemsystem

EntericEntericnervousnervoussystemsystem

Aids in the control of the internal organsAids in the control of the internal organsThree divisionsThree divisions



The sympathetic nervous system is programmed toprepare the body for stress or a ´fight or flightµ

situation. It is however, always active under basalconditions helping to maintain homeostasis.

The parasympathetic nervous system however,controls maintenance activities and helps conserve thebody·s energy.

Sympathetic and arasympatheticSympathetic and arasympathetic

nervous systemnervous system



Parasympathetic S ympatheticS ympathetic ganglia

Cervical

Thoracic

Lumbar

Constricts pupil Dilates pupil

Stimulates salivation Inhibits salivation

Inhibits heartactivity

Stimulatesheart activity

Constricts thebronchi

Dilates thebronchi

Stimulatesdigestiveactivity

Inhibits digestive activity

Stimulates gallbladder

Stimulatesglycogenolysis

Contractsbladder

Relaxesbladder

Relaxes rectum Contracts rectum

Stimulates nor /epinephrinerelease from adrenal gland



Formative task 4.1Formative task 4.1

Research the somatic nervous systemResearch the somatic nervous systemand write a brief overviewand write a brief overview



ProprioceptionProprioception

ThisThis term refers to the brainsterm refers to the brainsability to sense where ourability to sense where our

body is in space.body is in space.

The brainThe brain gathers and processes a range ofgathers and processes a range of

sensory information from areas such as«sensory information from areas such as«

The vestibular (balance) centre in the inner earThe vestibular (balance) centre in the inner ear

Auditory inputAuditory input

Visual inputVisual input

Sense of smellSense of smell Stretch receptors that monitor length, tension andStretch receptors that monitor length, tension andpressure in our tendons, muscles and ligamentspressure in our tendons, muscles and ligaments



The Motor UnitThe Motor Unit

The term ´motor unitµ was first introduced byThe term ´motor unitµ was first introduced bySir Charles Sherrington, a pioneer in the fieldSir Charles Sherrington, a pioneer in the field

of neurophysiology.of neurophysiology.

What does a ´mWhat does a ´motorotor unitµ refer to?unitµ refer to?

The term ´motor unitµ refersThe term ´motor unitµ refers to a single motorto a single motorneuroneneurone and all the muscleand all the muscle fibresfibres that it innervates.that it innervates.



The Motor UnitThe Motor Unit

Motorunit A

Motorunit B

Muscle Musclefibres

Spinal chord

Motor neuroncell body

Motorneuronaxon

Did you know?

One motor neuron can

innervate a number ofmuscle fibres.

A single muscle fibrehowever is suppliedby only one motor

neuron.



Motor Unit RecruitmentMotor Unit Recruitment

The number ofThe number of fibresfibres contracting within a muscle depends on thecontracting within a muscle depends on thenumber of motor units recruited.number of motor units recruited.

For a weak contraction of the whole muscle, only a few motor unitsFor a weak contraction of the whole muscle, only a few motor unitswill be activated whereas as more motor units are recruited,will be activated whereas as more motor units are recruited,

contractions become stronger and strongercontractions become stronger and stronger

Small or finemanipulations

Majormovements

Motor unitsmay contain asfew as a dozenmuscle fibres

Motor units inthe leg musclesmay contain1500 ² 2000muscle fibres



Motorunit A

Motorunit B

Muscle Musclefibres

Spinal chord

Motor neuroncell body

Motorneuronaxon

A muscleA muscle fibrefibre atatany given lengthany given lengthwhen stimulated willwhen stimulated willproduce the sameproduce the sameamount of tension.amount of tension.The muscleThe muscle fibrefibre isis

therefore Ónµ andtherefore ´

Onµ andproducing tension orproducing tension or

Óffµ and resting orÓffµ and resting orrecoveringrecovering

Áll or noneµ theoryÁll or noneµ theory

The theory can beThe theory can beapplied only at theapplied only at themusclemuscle fibrefibre level.level.



In response to a nerve impulsethe end of the motor nerve fibre

secretes a neurotransmittercalled Ach (acetylcholine)The neurotransmitter (Ach)

travels across the synapse andactivates receptors on the

muscle end plate

This stimulatesa sequence ofevents whichsends a signal

down thetransversetubules which

lead to a releaseof calcium fromthe sarcoplasmicreticulum (SR)

Calcium binds totroponin which

causes aconfimational

shift in positionof tropomysin.

This shiftexposes the

myosin bindingsites on the

actin filament

Cross bridgesare formedbetween the

myosin and actinfilaments. The

energy stored in

the myosin headfrom ATP

breakdown isused for the

´power strokeµ

Calcium ispumped back

into the SR bycalcium pumps.

When thecalcium levellowers myosin

can no longerattach to actinand the muscle

relaxes



Presynaptic terminal

Ach Vesicles

Sarcolemma Ach Receptors -ligand gated ion

channels

Mitochondria

Sodium pump



Presynaptic terminal

Ach Vesicles

Sarcolemma Ach Receptors -ligand gated ion

channels

Mitochondrion

Sodium pump

The arrival of an actionpotential at the presynaptic

terminal leads to release ofthe neurotransmitteracetylcholine (Ach)

Ach binds to the ligand gatedion channels which respond by

opening and allowing sodiumions to enter the cell andpotassium ions to leave.

More sodium moves in than potassiumout due to the electrochemicalgradients maintained by the sodiumpump. This causes a depolarisation ofthe membrane which is known as anEnd Plate Potential (EPP)

This depolarisation travelsalong the tranverse tubule and

evokes opening of calciumchannels.



Section 4Section 4 ²² The Endocrine systemThe Endocrine system

The Endocrine system worksclosely with the nervous systemto regulate bodily functions.

Chemical messengers known ashormones have far reachingeffects controlling processes atevery level, from energy uptake

of a single cell to growth anddevelopment of a body system.



EndocrineEndocrineAnatomyAnatomy

HypothalamusHypothalamus

Pineal GlandPineal Gland

Pituitary GlandPituitary Gland

Parathyroid GlandsParathyroid Glands

Thyroid GlandsThyroid Glands

ThymusThymus

LiverLiver

Adrenal GlandsAdrenal Glands

KidneyKidney

PancreasPancreas

Ovaries (female)Ovaries (female)

PlacentaPlacenta (during pregnancy)(during pregnancy)

Testes (Male)Testes (Male)



Gland Hormones produced Target cells

Hypothalamus Releasing and inhibitinghormones such as Growthhormone releasinghormone (GHRH).

Anteriorpituitarygland

Anterior

Pituitary

Thyroid stimulating

hormone

Adrenocorticoidstimulating hormone

Thyroid

gland

Adrenalgland

Pancreas Insulin

Glucagon

Most cells

Most cells



Gland Hormones produced Target cells

Parathyroid Parathyroid Bones,Kidney,Intestine

Thyroid Thyroid hormone Most cells

Adrenal Epinephrine andNorepinephrine

S ympatheticreceptorsites in thebody



Glucose metabolismGlucose metabolism

Carbohydrates are the most important short term fuel providers fororganisms since they are more easily metabolised than fats or proteins.

The most important carbohydrate is glucose, asimple monosaccharide..

Stored in the liver and musclein the form of glycogen

A fuel source for glycolysisand the aerobic energy system




Exocrine pancreas

The acini cells secrete

enzymes which aid the

process of digestion

Within the acinar tissuethere are millions of cell

clusters known as ´Islets ofLangerhansµ

Within the ´Islets ofLangerhansµ are two typesof cells. Alpha () and Beta() cells produce the twohormones involved in themetabolism of glucose.




InsulinInsulin

Produced byProduced by cellscells

Promotes uptake ofPromotes uptake of

glucoseglucose into cellsinto cells SpeedsSpeeds up theup the

conversion of glucoseconversion of glucoseinto glycogen for storageinto glycogen for storage

in the liverin the liver

Lowers blood glucoseLowers blood glucose

GlucagonGlucagon

Produced byProduced by cellscells

SpeedsSpeeds up theup the

breakdown of glycogenbreakdown of glycogeninto glucose by the liverinto glucose by the liver

Raises blood glucoseRaises blood glucose



Formative task 4.2Formative task 4.2

Completing table detailing hormone andCompleting table detailing hormone andprimary actionsprimary actions

section 4 nervous and endocrine system

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