Chapter 9-11 A & P

Structure of Synovial (Diarthrosis) Joint

*Look at index #4

Most of Chapter 10 on Note Cards!

*Look at index, starts from #11!

Notes

-700 muscles -when contract alway peaks -increase number of myofibrils -ligament: bone crossing to bone -tendons: muscle to bone

Articulations (Joints)

-Joint Classification -Structure of Synovial Joints -Types of Synovial Joints -Movements at Synovial Joints

Synovial/ Diarthrosis Joints:

-Structure (ex. proximal interphalangeal joint- 2nd finger- PIPJ, MIPJ, DIPJ) -Subtypes -Movements *Look on index #1

Anatomy- Macroscopic/ microscopic view

-Whole muscle -Bundles (fascicles) -Cells (muscle fibers; myofibers) -Myofibrils (organelles) -Sarcomeres (compartments) -Filaments -Protein molecules

6) Ball & Socket Joint

-ball/ socket surface -triaxial (all motion): most mobile joints, combine angular movement & rotation ex. hip joint, shoulder joint *Look at index #10

2) Hinge Joints

-convex/ concave surface -monaxial: opening or closing motion -one direction on axis ex. elbow, knee, ankle, and interphalangeal joint *Look at index #6

Pollicis Brevis Muscle

-located at the skull -size: small -action: abducts -found in february 1995 -named in march 1996: sphenomandibularis officially added the 40th edition of Gray's Anatomy Nov. 2008 -where headaches form -problems with mandible

4) Ellipsoid (condylar) Joint

-oval surface or oval depressed surface -biaxial -side-to-side motion -up & down motion -flexion & extension -abduction: away -adduction: toward ex. radiocarpal, metacarpophalangeal (joints 2-5), and wrist articulates with radius *Look at index #8

3) Pivot Joint

-pointed or circular surface -monaxial (rotation) ex. C1 and C2 articulate with each other (rotate) *Look at index #7

Synovial Membrane

-produces a synovial fluid which fills the joint cavity -fluid is clear like the clear part of a cracked egg

5) Saddle (sellaris) Joints

-saddle surface -biaxial movement: along 2 axes -side-to-side movement -up & down movement ex. trapezium articulates with 1st metacarpal (opposite side of thumb), gasp & manipulate things *Look at index #9

1) Gliding (plane) Joints

-surfaces are flat or slightly curved -sliding movements (nonaxial/ multiaxial): ex. intercarpal, intertarsal, sacro-iilac, and acromioclavicular joint *Look at index #5

Naming Skeletal Muscles

...

Additional Structures

1) Accessory ligaments (cruciate ligaments): -more ligaments needed -hold bones together -some are found inside the joint called intracapsular ligament (ACL) -some are found outside the joint (bands) of connective tissue called extracapsular ligament

Group Actions of Skeletal Muscles

1) Agonist (prime mover) -causes desired action (contracts) ex. drinking coffee, biceps brachii 2) Antagonist -relaxes (lengthens) ex. drinking coffee, triceps brachii 3) Synergist -steady at movement -prevent unwanted movement -help agonist work better -located along side agonist 4) Fixator (s) -stabilize the origin of the prime mover -increase efficiency of prime mover

Each muscle has a beginning and an end:

1) Origin- at the beginning, and is stable, does not move 2) Insertion- movement is found

Functions of Skeletal Muscles

1) Produce skeletal movement (joints): -contract tissues: isotonic ("same" "tension"): motion (movement) ex. writing 2) Maintain posture & body position: -contract: isometric ("same" "measure"): stabilization (no movement) 3) Protects underlying organs 4) Guards entrances/ exits- forms sphincters (opens & closes) 5) Maintain body temp. (thermogenesis): -responsible for 85% body heat 6) Store nutrient reserves: -amino acids, calcium, protein, etc.

Muscle Tissue

1) Skeletal -bones (origin/ insertion) -voluntary -moves bones/ joints 2) Cardiac -heart (myocardium- wall of heart) -involuntary (autorhythmicity) -moves blood 3) Smooth -internal organs (wall of organs) -involuntary -moves internal substances (water, food, waste)

Skeletal Muscles

1) Strength- increase myofibrils (gives diameter/ strength) 2) Recuit more cells (activate large motor unit)

Movements at Synovial Joints

1) gliding 2) hinge joint 3) pivot joint 4) ellipsoid (condylar) joint 5) saddle (sellaris) joint 6) ball & socket joint

Joint Classification

2 Methods: 1) Structural Classification- based on their anatomical characteristics. 2) Functional Classification

Additional Structures

2) Articular discs (menisci- extra pieces): -inside the space -fibrocartilage -inside joint cavity -better fit: wedged inside a space to make bones fit together

Additional Structures

3) Bursae- filled with synovial fluid -sacs or compartments around the joint: not inside -cushion & protect joint -found outside of joint

Skeletal Muscles

Attach to bones using: 1) Tendon -cord like structure 2) aponeurosis -a sheet like structure (connective tissue, around the abdominal area)

Structural Classification

Based on their anatomical characteristics: 1) Structural -no joint cavity -fibrous tissue between bones ex. located only between the bones of the skull 2) Cartilaginous -no joint cavity -cartilage between bones ex. synchondrosis- (together + chondros, cartilage) cartilaginous bridge between two articulating bones 3) Synovial -joint cavity filled with fluid -surrounded by connected tissue

Functional Classification

Based on type of movement they permit: 1) Synarthrosis -immovable joint 2) Amphiarthrosis -slightly movable joint 3) Diarthrosis -freely moveable joint ex. knee joint

6 Subtypes of Synovial/ Diarthrosis Joints:

Classification is based on: -the shape of articulating surfaces -the type of movement allowed -nonaxial (small/ no movement) -monaxial (1 direction): on axis, rotation -biaxial (2 different directions): on axis -triaxial (3 different directions): on axis -multiaxial (any direction)

Structure of Synovial (Diarthrosis) Joint:

Functions: -lubrication -nutrition: nourishes the cartilage -shock absorption -antimicrobial: joints are sterile but can kill any germs: protect from infections *Look at index #2

Structure of Synovial (Diarthrosis) Joint:

Functions: -wt. bearing joints -frequently used joints -aging disease due to using and wearing down cartilage (usually middle age & elderly at risk) ex. hip is a wt. bearing joint -creapitis: audible sound or grinding of bones: you will never grow cartilage back -hip replacement: needed if the cartilage is damaged ex. new hip joint is replaced *Look at index #3

Biggest Muscle?

Gluteus Maximus

Chapter 9

Joints

Widest Muscle?

Latissimus dorsi

Arthroscopy

MIS- minimally invasive surgical procedure

Strongest Muscle?

Masseter

Chapter 10

Muscle Tissue

Longest Muscle?

Sartorius

Chapter 11

Skeletal Muscle

Combining the 2 Classifications:

Structural + Functional 1) Fibrous + Synarthrosis= Joint Suture 2) Cartilaginous + Synarthrosis= Synchondrosis ex. first rib attached to sternum- does not move 3) Fibrous + Amphiathrosis= Syndesmosis ex. distal end of tibia articulating with distal end of fibula (interosseous membrane= in between joints) theses are generally: -strong stable joints -dislocation (very rare) -not a lot of diseases in these joints found in axial skeleton 4) Cartilaginous + Amphiarthrosis= Symphysis ex. pubic symphysis (no movement)

Combining the 2 Classifications:

Structural = Functional Synovial (joint cavity) = Diarthrosis (freely moveable) -these joints tend to be weaker -weak joints -more dislocations (luxations; subluxation) -more disease (ex. arthritis & gout) -found in appendicular skeleton

Extra Ligament

after ACL joint injury, the knee becomes unstable: the tibia & femur separated (reinforced)

Collateral Ligaments

around ankle & knee

Osteoarthritis (OA)

articular cartilage worn away joint space: uneven; narrow bone to bone

Capsule Ligaments

holds bones in proper alignment

Bursitis

inflamed sacs ex. bunions: bone of big toe

Nonaxial

joints that permit gliding, allow only small amounts of movement and permit small gliding movements or restrict movement

Articular Cartilage

makes joint smoother

Ligament

moves from bone to bone to another cavity

Sprain

partial tear of ligament, bone are not held together or aligned correctly, and joints are unstable

Monaxial Articulation

permits movement along only one axis, angular movement in a single plane

Hypothermia

shivering increases body heats

Rheumatology

the study of joint disease

Arthrology

the study of joints