Chapter 36Chapter 36The Integumentary, Skeletal, The Integumentary, Skeletal, & Muscular System& Muscular System

John HiznyLexi CoolbaughSarah SchultzJames AveryAdam Werner

Section 36-1Section 36-1

SkinLargest organ in the body Part of integumentary system Integumentary includes skin, hair, nails, and number of important glands in skin.

Skin has three layers1.1. Outer layer - Outer layer - Epidermis2.2. Inner Layer -Inner Layer -Dermis3.3. Lowest Layer - Lowest Layer - Hypodermis

Supports the EpidermisContains important cells for:

Nerve endingsBlood VesselsSmooth Muscle

The body’s Sweat/Oil Glands are located here also

Produces cells that are pushed toward the surface. Produces keratin as they move upward.

Keratin – Tough, flexible protein◦Major protein found in fingernails ◦Forms a tough waterproof layer on

top of skin

•Hair is produced from columns of cells that are filled with keratin and then…. DIEDIE.•Clusters of cells make up Hair Hair FolliclesFollicles.•Toenails/fingernails are formed by keratin-forming cells for a flattened flattened plate.plate.

Section 36-2Section 36-2

BonesBonesAll vertebrates have an internal

skeletal systemBones store supplies of calcium and

phosphorousInternal Skeletal System

◦ Provides support for the upper body◦ Attachment sites for muscles◦ Protects internal organs

Bone StructureBone StructurePeriosteum- tough layer

surrounding bonesInside the periosteum is a dense

layer of compact bone.Spongy bone is found inside the

compact bone.Osteocytes- Cells found in C & S

bone.◦Help build and maintain bones

Bone GrowthBone GrowthBones are produced by Cartilage.

Cartilage is produced at growth plates & gradually is replaced by bone as the skeleton enlarges.

JointsJointsA place where two bones meet.3 kinds of joints:

◦Fixed Little or no movement between bones

Mostly located in the skull

◦Slightly Moveable Small amount of movement

Mostly located in a Spinal Column or Ribs

◦Freely Moveable Wide Range of movement

Ex: Shoulders and hips

Joints ContinuedJoints ContinuedJoints are enclosed by a Joint

Capsule. Inside the capsule is Synovial

Fluid◦Natural lubricant that reduces

friction & allows the cartilage coated bones slip past each other easily

Section 36-3Section 36-3

Muscle TissueMuscle TissueThere are 3 types of muscle

tissue:◦Skeletal◦Cardiac◦Smooth

Each of these three types muscle, have a different cellular structure.

Skeletal Muscle TissueSkeletal Muscle TissueGenerally attached to the bones

of the skeleton and is usually under voluntary control.

Skeletal muscle tissue is behind every conscious movement you make◦Ex: Lifting a weight

This is because most skeletal muscle tissue is controlled directly by the nervous system.

Cardiac Muscle TissueCardiac Muscle TissueCardiac muscle tissue is found in

just one place : The HeartCardiac muscle tissue is striated,

but the smaller Cardiac muscle cell have just one nucleus, and they are not under the direct control of the Central Nervous System

Smooth Muscle TissueSmooth Muscle TissueSmooth muscle tissue is found in the

walls of many internal organs, except the heart.

The cells of the smooth muscle tissue are spindle shaped, have a single nucleus, and are not striated.

Not always under the conscious control of the nervous system.

Responsible for actions not under voluntary control.

Muscle StructureMuscle StructureMyosin- Thick filaments that are

made of protein.Actin- Thin filaments that are

made up of another protein.

Sliding Filament Theory Sliding Filament Theory When hundreds of thousands of

actin-myosin cross-bridges go through their cycle in a fraction of a second, the muscle cell contracts with siderable force.

Muscle ContractionMuscle ContractionTo make well-coordinated

movement, muscle contractions must be carefully controlled.

A single motor neuron may form synapse to one or several muscle cells. An impulse in the motor neuron causes the release of a neurotransmitter acetylcholine.◦This causes a new action potential. In

turn causes the release of calcium ions into the cytoplasm of muscle cells. When calcium flows into the cytoplasm,

cross-bridges form, and the muscle contracts.

Muscles and MovementsMuscles and MovementsMuscles produce force by contracting.Attached to bones by tendons, a

muscle can pull two bones together, using the joint between them as a lever.

An individual muscle can pull by contracting, but cannot push.◦If that’s true, then how can you push a

door open or do a pushup? The answer is that skeletal muscles are

arranged in pairs. These pairs oppose each other and produce forceful movements in either direction.

Section 36-4Section 36-4

Specialized Skeletal Muscle Specialized Skeletal Muscle FibersFibersSkeletal muscles contain two

main types of muscle fibers◦RedRed◦WhiteWhite

Whose properties make them specialists at different kids of exercise.

Red Muscle FibersRed Muscle FibersContain large amounts of reddish

oxygen-storing protein myoglobinmyoglobin.

Red fibers have rich blood supplies and plenty of mitochondria to produce ATP.

White Muscle FibersWhite Muscle FibersCalled fast- twitch muscle fibers and

can generate powerful contractions.The contain few mitochondria ,

these fibers contain greater densities of contractile proteins than red fibers do.◦The powerful fibers fatigue easily,

however, which means that they can produce maximum contractions for only a few seconds at a time.

Exercise Muscle CellsExercise Muscle Cells