Chapter 17 & Chapter 17 & 1818

Musculature & Musculature & Digestive Digestive

SystemsSystems

The Musculature SystemThe Musculature System

Includes 3 types of Muscle:Includes 3 types of Muscle: Striated, Smooth & Striated, Smooth &

CardiacCardiac Function of the Muscles:Function of the Muscles:

Provide means of Provide means of MovementMovement

Keeps blood pumpingKeeps blood pumping Moves food thru Digestive Moves food thru Digestive

SystemSystem Skeletal Muscle usually in Skeletal Muscle usually in

Antagonistic PairsAntagonistic Pairs FlexorFlexor (bicep) (bicep) Extensor Extensor (tricep)(tricep)

The Musculature SystemThe Musculature System

The The Musculature Musculature

SystemSystem

Skeletal Skeletal StriatedStriated VoluntaryVoluntary

Organ Organ SmoothSmooth InvoluntarInvoluntar

yy

HeartHeart CardiacCardiac InvoluntarInvoluntar

yy

3 Types of Muscle Tissue

Skeletal, Smooth and Cardiac

How Muscles How Muscles WorkWork

Muscles can only Muscles can only contractcontract & & get shorterget shorter

They cannot push things, they They cannot push things, they only pull. only pull.

They are attached to two They are attached to two different bones and cause different bones and cause them to bend at the jointthem to bend at the joint

OriginOrigin – place the muscle – place the muscle attaches or begins (proximal)attaches or begins (proximal)

InsertionInsertion – place on the other – place on the other side of joint muscle attaches side of joint muscle attaches (distal side)(distal side)

They work in Antagonistic PairsThey work in Antagonistic Pairs Flexors Flexors – cause the joint to – cause the joint to

bend – bicepbend – bicep ExtensorExtensor – causes the joint to – causes the joint to

extend ( straighten out) - tricepextend ( straighten out) - tricep

Muscles are attached to bones Muscles are attached to bones w/ w/ tendonstendons

Origin

Insertion

Smooth & Cardiac MuscleSmooth & Cardiac Muscle Smooth MuscleSmooth Muscle – usually are not voluntarily controlled. Found in the – usually are not voluntarily controlled. Found in the

walls of hollow organs of the digestive tract & blood vessels. walls of hollow organs of the digestive tract & blood vessels. They assist in the movement of food thru the digestive system They assist in the movement of food thru the digestive system

((peristalsisperistalsis) and movement of blood thru the circulatory system. ) and movement of blood thru the circulatory system. Cardiac MuscleCardiac Muscle – found only in the heart. Similar to both Striated & – found only in the heart. Similar to both Striated &

Smooth Muscle tissue. Involuntarily controlled by brain.Smooth Muscle tissue. Involuntarily controlled by brain.

Skeletal Muscle StructureSkeletal Muscle Structure Skeletal Skeletal musclesmuscles are made up of are made up of bundlesbundles of of muscle fibersmuscle fibers which in turn which in turn

are made of are made of myofibralsmyofibrals (multi-nucleated muscle cells). (multi-nucleated muscle cells). Each myofibral is made of Each myofibral is made of

thin thin filamentsfilaments called called ActinActin and thick filaments called and thick filaments called MyosinMyosin.. Muscle Muscle Bundle Bundle Fibers Fibers Myofibrils Myofibrils Filaments Filaments Actin & Myosin Actin & Myosin Each fiber is divided into functional units called sarcomeresEach fiber is divided into functional units called sarcomeres

tendon

Muscle

BundleBundle

Fiber

Myofibril

Filaments

Sarcomere

Skeletal Muscle Skeletal Muscle SarcomereSarcomere

SarcomereSarcomere is divided is divided into various zones. into various zones.

Each Sarcomere is Each Sarcomere is separated by separated by Z discsZ discs

Light colored bands Light colored bands are are I bands I bands

Dark colored bands Dark colored bands are are A bandsA bands

Middle of the dark Middle of the dark A band is A band is H zoneH zone

Middle of H zone is Middle of H zone is the the M line M line

MyosinActin

Muscle contraction begins Muscle contraction begins after a nerve stimulates the after a nerve stimulates the muscle fiber.muscle fiber.

Skeletal Muscle Skeletal Muscle ContractionContraction

MyosinActin

Muscle contraction begins Muscle contraction begins after a nerve stimulates the after a nerve stimulates the muscle fiber.muscle fiber. Impulse causes Impulse causes ActinActin filaments to slide over (like filaments to slide over (like a ratchet) the a ratchet) the Myosin Myosin filaments.filaments. This shortens the length of This shortens the length of the the sarcomere.sarcomere. Once contracted, the H Once contracted, the H zone closes up.zone closes up.This shortening isn’t much This shortening isn’t much until you add up the until you add up the thousands of sarcomeres in thousands of sarcomeres in each muscle bundle. each muscle bundle.

Need-to-Know Skeletal MusclesNeed-to-Know Skeletal MusclesKnow these muscles: Masseter, Trapezius, Deltoid, Pectoralis, Latissimus dorsi,

intercostals, Rectus abdominis, External obliques, Biceps brachii, Triceps, Gluteus, Rectus femoris, Biceps femoris, gastronemius

General info:General info: Basic “tube-within-a-tube”Basic “tube-within-a-tube” Digestion by mechanical & Digestion by mechanical &

chemical meanschemical means Mechanical DigestionMechanical Digestion from from

cutting, grinding, chewing in cutting, grinding, chewing in mouth. From churning by mouth. From churning by peristalsis in stomachperistalsis in stomach

Chemical DigestionChemical Digestion beginning in mouth through beginning in mouth through stomach & small intestines. stomach & small intestines.

Acidic pHAcidic pH in mouth & in mouth & stomachstomach

Switches to Switches to basic pHbasic pH in in small intestinesmall intestine

Accessory OrgansAccessory Organs – food – food doesn’t pass thru them. doesn’t pass thru them. They supply digestive They supply digestive “juices”.“juices”.

Salivary glands, Liver, gall Salivary glands, Liver, gall bladder & pancreasbladder & pancreas

The Digestive SystemThe Digestive SystemMouthpharynxesophagusstomachduodenumjejunumileumcecum ascending colontransverse colondescending colonsigmoid colonrectumanus

Upper Digestive TractUpper Digestive Tract Mouth & PharynxMouth & Pharynx

Teeth Teeth IncisorsIncisors- slice- slice CaninesCanines – tear – tear PremolarsPremolars – grind – grind Molars Molars - grind- grind

Tooth StructureTooth Structure Crown, neck & rootCrown, neck & root EnamelEnamel – hard for protection – hard for protection Dentine Dentine – softer, alive bone-– softer, alive bone-

likelike Pulp Pulp – soft blood & nerve – soft blood & nerve

tissuetissue Cementum & PeriodontalCementum & Periodontal

membrane “glue” tooth to membrane “glue” tooth to the bony socket the bony socket

Chewed Food (smaller Chewed Food (smaller pieces w/ higher surface pieces w/ higher surface area) mixes w/ saliva area) mixes w/ saliva becomes becomes bolusbolus. Enzyme . Enzyme AmylaseAmylase begins begins Carbohydrate chemical Carbohydrate chemical digestion.digestion.

Swallowed food passes thru Swallowed food passes thru pharynx, past pharynx, past epiglottisepiglottis & & into esophagusinto esophagus

The EsophagusThe Esophagus Involuntary contractions Involuntary contractions

and relaxation of smooth and relaxation of smooth muscle surrounding muscle surrounding esophagus moves food esophagus moves food down esophagus: down esophagus: PeristalsisPeristalsis

Cardiac SphincterCardiac Sphincter: Ring : Ring shaped muscle shaped muscle separating the esophagus separating the esophagus from the stomachfrom the stomach

sphincters sphincters are muscles that squeeze the digestive tube closed and help move material in only one direction.

The StomachThe Stomach Mechnical & Chemical Mechnical & Chemical

digestion digestion Stomach secretes Stomach secretes HCl HCl – very – very

acidicacidic Mucus secretions protect Mucus secretions protect

lining from self-digestionlining from self-digestion Stomach lining w/ folds to Stomach lining w/ folds to

increase surface areaincrease surface area Bolus is mixed w/ acids for Bolus is mixed w/ acids for

several hours – now called several hours – now called chyme.chyme.

Carbohydrate and protein Carbohydrate and protein digestion takes place. digestion takes place.

Enzyme Enzyme PepsinPepsin used in used in protein digestionprotein digestion

Leaves thru Leaves thru Pyloric SphyncterPyloric Sphyncter to the duodenum.to the duodenum.

Cardiac Sphincter

Small IntestineSmall Intestine About 20 ft long, 1”-2” in diameterAbout 20 ft long, 1”-2” in diameter Most chemical digestion takes Most chemical digestion takes

place hereplace here 3 regions – duodenum, jejunum 3 regions – duodenum, jejunum

and ileumand ileum Chemical pH 8 – protein, fats & Chemical pH 8 – protein, fats &

carbohydrates are digestedcarbohydrates are digested Increased surface area by millions Increased surface area by millions

of villi and microvilliof villi and microvilli Absorption into blood stream by Absorption into blood stream by

highly vascular integration highly vascular integration surrounding digestive tract.surrounding digestive tract.

Large Intestine (aka Colon)Large Intestine (aka Colon) 5-6 feet in length, 3”-4” in 5-6 feet in length, 3”-4” in

diameterdiameter Main FunctionsMain Functions

Reabsorption of waterReabsorption of water Reabsorption of vitaminsReabsorption of vitamins Waste elininationWaste elinination Very little digestion (most is Very little digestion (most is

done in the stomach & done in the stomach & small intestine)small intestine)

Divided into Divided into Cecum,Cecum, Ascending, Transverse, Ascending, Transverse, Descending, and Sigmoid Descending, and Sigmoid ColonColon

Undigested food & Wastes Undigested food & Wastes stored in the stored in the rectumrectum before before being eliminated thru the being eliminated thru the anusanus..

Accessory Digestive OrgansAccessory Digestive Organs Salivary GlandsSalivary Glands – –

secretes saliva and secretes saliva and enzyme enzyme amylaseamylase. Mixes . Mixes w/ food forms w/ food forms BolusBolus. .

Liver-Liver- filters blood & filters blood & secretes secretes BileBile used to used to emulsify & digest Fatsemulsify & digest Fats

Gall BladderGall Bladder – stores – stores bile until neededbile until needed

PancreasPancreas- 3 functions- 3 functions Release & control of Release & control of

insulin in the insulin in the Islets of Islets of LangerhansLangerhans. Controls . Controls sugar blood levelssugar blood levels

Release Release digestive digestive enzymesenzymes

Produce Produce sodium sodium bicarbonatebicarbonate to convert to convert stomach acid to a basic stomach acid to a basic solution in the solution in the duodenumduodenum

Chapter 17Chapter 17

Muscle Muscle

& Digestive & Digestive SystemsSystems

That’s all folks!!That’s all folks!!