Microsoft PowerPoint - 1312b Mus Tissue_pptx

8/8/2019 Microsoft PowerPoint - 1312b Mus Tissue_pptx

1/33


2/33

1.Purposeo

fmuscletissue

2.Typesofm

uscletissue

3.Generalanatomyofsk

eletalmusc

leorgans

4.Integrationofskeletal

muscleorganswiththe

skeleton

MuscleTissu

eTopics


3/33

M

ovementis

abasiccharacteristicoflivinganim

als.

M

ovementis

possiblebe

causemusc

letissuecells

c

ontractwhe

nstimulated

.

M

uscletissueisintegratedintoorgansinamann

er

thatfacilitate

s:

Locomotio

nmoveme

ntofthebody

Stability

maintenanceofposture

Movement

ofsubstanc

esinternally

Heatprodu

ction

Whydoweneed

muscletissue?


4/33

M

usclecells

contract(ge

tshorter)whenstimulat

ed.

C

ontractionofmusclece

llscausean

organto;

1

.Pullonab

odystructure

e

g.Askeletalmuscleorg

ancanpull2bonesclos

er

together.

2

.Reduceits

internalvolume

e

g.Contracti

onofcardiacmusclesq

ueezesbloo

d

o

utoftheheartchambers.

Whatd

oesmusc

letissuedo?


5/33

MuscleTissueStructu

re

Musclecells

canonlygetshorterwh

enstimulated

Canpullb

utnotpush

Musclecells

containnetworksofproteinfilamen

ts

(actin&myo

sin)thatfac

ilitatethecontraction

process.

3differenttypesofmuscletissue

Skeletal

Cardiac

Smooth


6/33

MajorMuscle

TissueTypes

S

triated,

cylindricalfibres

Striated

,

branchedfi

bres

Non-striated,

spindle-sha

ped

cells

Car

diac

S

keletal

Smooth


7/33

Typically,organscontain

ingskeletal

musclecell

s

arereinforce

dbyconnectivetissue&areattached

tobonesoftheskeleton.

Skeletalmus

cleorgansallowsusto;

Movefrom

placetoplace(locomotion)

Manipulateobjects

Communicate(eg.spe

ech)

Breathe

Maintainb

odyposture

Generateheat

SkeletalM

uscles


8/33

SkeletalMuscleAnatomy

A

skeletalmuscleorganis

composed

ofmusclefi

bres

(c

ells)reinforcedbylayersofconnect

ivetissue.

Bundles(10-1

00)ofskelet

almusclefibreswrappe

dby

co

nnectivetis

suearecalledfascicles.

Fa

scicle

B

one

Muscle

organ

Ten

don

Musclefibre

Marieb&

Hoehn,2007


9/33

Skeletalmu

sclecells(fi

bres)are;

Longcylinders(upto

30cmlong)

Striated(striped)

Multinucleated(100+nucleiinonefibre)

Specificske

letalmuscle

fibrestruct

ures;

Sarcolem

ma-muscle

fibreplasm

amembrane

Sarcoplas

m

-muscle

fibrecytoplasm

Myofibrils

longrod-

likestructur

esthatcontain

contractileproteins(makeup~80

%cellvolum

e)

TheStru

ctureofSk

eletalMusc

leCells


10/33

Musclefibrespossesmany

myofibrilsw

hichcontain

co

ntractileunits(sarcomer

es)thatgene

ratemovement.

Myofibril

Musclefibre

Nucleus

S

arcolemma

Marieb&

Hoehn,2007

Fascicle

SkeletalMuscleTissueStructure


11/33

Skeleta

lMuscleFibreStructure

Eachskeletal

musclefibrecontainsm

anyrod-like

m

yofibrils

M

yofibrilscontainrepeatingcontracti

leunitscalle

d

sarcomeresw

hichfacilita

temusclem

ovement.

Sarcomeres

Containinterlockingac

tin(thin)&m

yosin(thick

)

filamentproteins.

Contractwhenastimulatedbyasig

nalfroma

neurone(nervoustissu

ecell).


12/33

Actin

SkeletalMuscleFibreStru

cture

M

yofibrilscontainmanys

arcomeres

Myofibril

Myosin

S

arcomere

M

usclefibre

Marieb&

Hoehn,2007


13/33

Myofibril

Sarcome

re

Nucleus

Sarcopla

smic

reticulum

Sarcolem

ma

Endomysium

N

odeofRanvier

Motorn

eurone

S

chwanncell

Synaptic

knob

Motor

endplate

S

keletalMuscle

F

ibreModel


14/33

S

arcomereStructure

S

arcomere

Sarcomeresaremadefromtwotypes

offilamentous

protein;

Thickfilamentscomposedofmyosin

Thinfilamentscomposed

mostlyofactin

Filamentsover

lapeachothe

r

Thin

actinfilament

Thickmyosin

filament

Marieb&

Hoehn,200


15/33

3D

STRUCTUREOFSARCOMERE

In

sarcomeres

actinfilame

ntsareanch

oredtoaZ

disc

whilemyosinfilamentsare

anchoredtotheMline.


16/33

S

arcomere

Contraction

A

ctin

Myos

in

W

henaskeleta

lmusclecell

isstimulated

,actin

filamentsinthe

sarcomeres

lideovermyosinfilaments.

Thesarcomere

sshorten&t

hemuscleco

ntracts.

1.

Musclerelax

ed

2.

Musclecontracting


17/33

SkeletalMuscleFibreHistolo

gy

Nucleus

Musclefibres

Connectivetissue

Thearrangem

entofcontractileproteinsinsarcom

eres

givesskeletalmuscleits

striatedapp

earance.


18/33

Ho

warefunctionalmusc

leorgansc

onstructed

?

Askeletalmus

clecontains

morethanjustmuscle

cells.

Askeletalmus

cleorganalsocontains;

1.

Connective

tissue

La

yersofconnectivetissu

ewrap&reinforcemusc

le

fib

res

2.

Nervecells(neurones)

Su

pplysignals

thatstimulatemusclec

ellstocontract

3.

Epithelialtis

sue

Linesinnersu

rfaceofbloo

dvessels


19/33

C

onnectiveTissueLaye

rsinSkele

talMuscles

S

keletalmusclefibresarestrengthen

edby

interconnectedlayersofconnectivet

issue.

T

heseconnectivetissuelayersareth

eepimysium

,

p

erimysium&

endomysiu

m.

T

heseconnectivetissuelayers;

arecontinu

ouswithon

eanother

providestr

ucturalreinforcementfo

rthemuscle

provideaccessfornerves&blood

vessels


20/33

1

.DeepFasc

ia:Linesthe

bodywall&

separates

musclesintofunctionalgroups.

2

.Epimysium

:Surroundsanindividu

almuscle

organ&blendswithte

ndonsorde

epfascia.

3

.Perimysium:Bundlestogether10-100individual

musclefibresintostru

cturescalledfascicles.

4

.Endomysium:Thecon

nectivetissuewrapping

of

anindividu

almusclefibre.

Connective

TissueLay

ersinSkeletalMuscle

s


21/33

ConnectiveTissues

ofaSkeletalMuscle

Epimy

sium

Perimy

sium

Endo

mysium

Tendon

Deep

fascia

Muscle

fibre

Sala

din,2007


22/33

ConnectiveTissueinSkeleta

lMuscles

Nucleus

Musclefibres

Perimy

sium

Perimysiumisacollagen-basedconn

ectivetissue

liningthatsurrounds10

100muscle

fibres.


23/33

NerveSupplyto

SkeletalM

uscles

S

keletalmusclefibresarestimulated

tocontractby

s

ignalsfrom

neurones(n

ervecells).

A

singleneuronecanstim

ulatesever

alhundred

m

usclefibres

tocontract

atonce.

A

neurone&

allthemusc

lefibresitin

nervatesis

c

alledamoto

runit.

N

euronescommunicatew

ithmuscle

fibresat

n

euromuscularjunctions

;

asmallgap

separatesthe2cells(s

ynapticcleft)


24/33

T

heMotorUnit

S

pinalcord

Neurone

Muscle

fibre

Muscleorgan

N

euromuscular

junction

Marieb&

Hoehn,200


25/33

H

owdowes

etupaske

letalmuscleorganso

that

itcanmove

thebody?

T

ypically,askeletalmusc

leorganis;

1

.Attachedt

oatleast2bonesofthe

skeleton

2

.Arrangedsothatitcro

ssesamoveablejoint

jointstruct

uredeterminestypeofm

ovement

3

.Providedw

iththenece

ssarynerve

&bloodsup

ply

4

.Integrated

withotherm

usclessoth

atitcanassist

oropposespecificmovements.


26/33

GrossAnatomyofSke

letalMuscles

Thereareapproximately

600muscle

sinthebod

y

whichaccountfor40-5

0%oftotal

bodyweight.

Mostskeletalmuscless

panmoveab

lejointsofthe

skeleton&haveatleast

2pointsof

attachment;

Thelessmoveableen

dofaskeletalmuscle

attach

mentisthe

origin

Themore

moveablee

ndistheins

ertion

Attachment

ofmuscletoskeletoncanbedirect

or

indirect(epimysium

fuseswithaten

don).


27/33

Moveableelbow

joint

Abellyofthe

Bicepsbr

achii

muscle

Insertion

onradiu

s

Originson

scapula

O

rganisation

of

S

keletalMus

cles


28/33

Cardia

cMuscle

C

ardiacmuscleisfound

intheheart

&

iscontrolled

involuntarily(youdont

thinkaboutit).

Formsthe

bulkoftheh

eartwall

Striated

Containss

arcomeres

Cardiacfib

resarebran

chedcylinderswith1-2

nucleiperfibre

Cellsattachedtoeach

otherbyintercalateddis

cs

w

hichallowconductionofelectricalsignalsthat

triggercontractionofheartchambers.


29/33

C

ardiacMus

cle

Histology

Branchingcard

iac

fibres


30/33

CardiacMuscleHistology

Intercalateddiscs

In

tercalateddiscselectricallylinkheartm

usclefibres


31/33

SmoothMuscle

S

moothmuscleisfound

inthe

w

allsofmanyhollowvisceral

o

rgans&isc

ontrolledinvoluntarily

C

haracterisedby;

Spindle-sh

apedcellsw

ithjustone

nucleus

Cellsthatcontainactin

&myosinfilamentsbut

lacksa

rcomeres

Cellsappearnon-striated(nostripes)


32/33

SmoothMu

scleHistology

Arterywa

ll

Smooth

muscle


33/33

S

moothMuscle

Structure

Nucleus

DenseBody

Actin&Myosin

bundle

Contracted

Relaxed

Documents

Microsoft PowerPoint - 1312b Mus Tissue_pptx