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