Skeletal System/ Tissues, Joints, and Skeletal Muscle

Skeletal System

Skeletal Muscle

Joints

Major Functions

Structural Components

Fibrous Joints

Cartilaginous Joints

Synovial Joints

Functions

Properties

Bone types

Cranial Sutures

Syndesmosis

Bundles of dense regular connective tissue, like the distal tibiofibular joint. Not much movement

Interconnecting fibers. Sutures are only in the skull. No movement.

Gomphosis

Fibrous joint binding teeth to the Alveolus (bony tooth socket)

Synchondrosis

Made from Hyalin cartilage, immovable. Epiphyseal plates and between the 1st rib and manubrium

Symphysis

Pubilc symphysis and in intervertebral joints, slight movement. made of a little hyaline cartilage "sandwiching" fibrocartilage.

Joint Types

Plane Joint

Hinge Joint

Condylar Joint

Pivot Joint

Saddle Joint

Ball & Socket Joint

Gliding movement (intercarpal, intertarsal, vertebrae)

Flexion or extension movement (Such as the elbow)

pivoting movement, such as the atlantoaxial joint or the head or the radius

Abduction (away) or Adduction (together) movement, like spreading fingers apart and back together.

One part of the joint act as the "saddle" and the other the "rider", like the carpal-metacarpal joint of the thumb. Allows flexion, extentsion, adduction, abduction, and circumduction. No axial rotation.

Lateral & medial rotation, flexion, extension, adduction, abduction. Such as the shoulder or hip

Components

Joint Capsule

Outer Layer

Synovial Membrane

Dense irregular connective tissue running continuously along the periosteum

Inner layer of areolar connective tissue

Articular Cartilage

Cartilage at the ends of bones in a joint to reduce friction

Synovial Fluid

Slippery fluid made by the synovial membrane. Acts as a lubricant, to reduce shock, and to nourish articular cartilage

Bursae

Fibrous (dense irregular connective tissue) sacs filled with synovial fluid. Reside outside the joint and act similar to ball bearings

Tendon Sheath

A specialized bursa that wraps around tendons in malls spaces (like wrists and ankles)

Produce Movement

Open/close body passageways (sphincters)

Maintain posture and stabilize joints

Generate heat

Contractility

Excitability

Extensible

Elasticity

Can recoil to original form after extension or flexion

Can stretch, to some extent, without damage

Can create force or tension while pulling on an attachment point

Responds to stimuli to create an electrical impulse

Connective tissue layers

Endomysium

Perimysium

Epimysium

Deep Fascia

Endo (inside) Mysium (muscle), within the muscle, wraps up/ sheaths each myocyte. Mostly reticular connective tissue (loose tissue). Contain blood vessels to supply nutrients to muscles.

A layer of dense irregular connective tissue sheathing each fasicle (a bundle of myocytes)

Epi (upon) mysium (muscle), a layer of dense irregular connective tissue sheathing an entire muscle organ.

A layer of dense irregular connective tissue sheathing a group of muscle organs together, like the hamstring.

Components of skeletal muscle fibers

Myofibrils

T Tubule

Sarcolemma

Sarcoplasmic reticulum

Made of smooth endoplasmic reticulum

At its "terminal cisterns) (the sarcoplasmic reticulum around the T tubules) it stores calcium

The plasma membrane of muscles

little fibers within striated muscle cells (its an organelle)

Transverse tubule: An invagination of the sarcolemma into the myocyte. Electric currents run across the sarcolemma, T Tubules bring the sarcolemma into the cell to carry the current into the cell to excite it

Framework for the connection of soft tissues (tendons, ligaments)

Movement (with help from muscles)

Protection (Cranium, thoracic cage)

Mineral storage - calcium and phosphate

Blood cell formation - in red bone marrow

Energy Storage - in yellow bone marrow (fat)

Bone

Osteocytes and extracellular matrix (35% of bone)

Minerals (gives charateristic hardness (65% of bone)

Articulation

Joint (where 2 bones meet)

Elastic cartilage

Outer ear, epiglottis

Fibrocartilage

Intervertebral discs, pubic symphysis, menisci of knees

Hyaline Cartilage

Trachea, larynx, costal cartilage, articular cartilage

Long bone

Short bone

Flat bone

Irregular bone

Bones longer than they are wide

Bones in a cubic shape, like talus

They're flat, like the sternum

They odd ones, like vertebrae

Bone Characteristics/features

Compact bone

Spongy bone

Location: Outer part of every bone

Composition: Osteons packed together

Has perforating channels, canals that allow blood vessels to pass and spread nutrients and energy deeper into bone

Composition: No osteons, made of trabeculae, has osteocytes and extracellular matrix

Location: On the ends of long bones and inside every other bone

Red bone marrow in spongy bone

Trabeculae cover the endosteum

Components of long bone

Epiphyses: the bone ends (distal and proximal)

Diaphysis: the bone shaft

Articular cartilage: at articulations

Epiphyseal line: line of dense bone where the epihyseal plate was

Medullary cavity: the hollow middle where yellow bone marrow is found

Epiphyseal Plate: Hyaline cartilage site of endochondryl ossification (bone growth)

Periosteon: Dense irregular connective tissue outer layer. sharpey's fibers on the inner layer to hold tightly to the outside of the bone.

Marrow

Yellow bone marrow

Red bone marrow

Gelatinous material, the site of blood cell formation. in the vertebrae, hips, sternum, ribs, and many skull bones

Produces fat, cartilage and bone. Serves for nutrient storage

At birth bone cavities only contain red bone marrow, no yellow