Week 1 -- Anatomical Position, Planes, Axes & Joint Classifications

Oblique Plane

*** The point at which the three midplanes of the body intersect is the Center of Gravity. Women have a lower center of gravity.

5. Synovial Membrane Location

. Location: deep to the fibrous collagenous capsule of dense irregular connective tissue 1) derived from the embryonic mesenchyme 2) found as the non-articular component of joints (i.e. bursae and tendon sheaths)

Synovial Membrane b. Composition (formed in two layers)

1) Lamina Intima consisting of 1 - 4 layers of synovial cells embedded in a granular fiber free matrix. This lamina functions to produce synovial fluid and absorb substances from the joint cavity. Type A and B cells (synoviocytes) are identified in this layer. Type A cells are thought to function in removal of debris from the synovial fluid. Type B cells resemble fibroblasts and are thought to secrete synovial fluid, rich in hyaluronic acid and the glycoprotein lubricin. Lamina Sub-intima is formed by a vascular fibrous layer where the collagen and elastin fibers run parallel to the surface and contains fibroblasts, macrophages and fat cells. Its elasticity prevents excessive folding of the synovial membrane during movement thereby preventing pinching. The fat imparts a firmness, deformability (rigid) and elastic recoiling mechanis

Diarthroses (Synovial) d. Properties:

1) as the temperature or rate of shear increases, the viscosity decreases (trixotrophy). 2) weight bearing capacity is unaltered by the rate of motion, and as rapid shearing is repeated, the flow time increases. 3) synovial fluid is a good conductor of heat. 4) synovial fluid has a low coefficient of friction (lubrication).

Diarthroses (Synovial) e. Function:

1) nutrition to the joint 2) lubrication to joint surfaces 3) heat dissipation

Anatomical Position

1. Arbitrarily accepted position adopted by anatomists, to give topographical relations. 2. An erect standing posture having face forward, arms at side, palms of hands forward with fingers and thumbs in extension and eyes directed to the horizon. 3. This position is reference for definitions and descriptions of body planes and axes.

Planes of the Body

1. Sagittal Plane 2. Coronal (or Frontal) Plane 3. Transverse (or Horizontal) Plane 4. Oblique Plane

Gross Anatomy / Dissection

1. The process of examining the cadaver in order that some insight may be gained into how the living body is constructed. 2. The study of structure or morphology, by means of dissection. 3. The oldest and most relevant of the basic sciences. 4. Vesalius "Father of Modern Anatomy" - 1561 Quoted - "I shall examine that true book of ours, the human body of man himself."

Surface Anatomy

1. The study of the living body 2. Palpation of skin, bones, muscles, joints, arteries, veins, and nerves of the human body. 3. Utilizing surface landmarks to evaluate and assess patients.

Microscopic Anatomy (Histology)

1. The study of the tissue that makes up the gross organ or part. 2. The study of structure with aid of a microscope to view the cellular level (cytology).

Embryology / Developmental Anatomy

1. The study that deals with the growth and differentiation of the organism for the single-celled ovum to birth. 2. These processes of development and maturation are also called ontogeny.

Bursae

A. Clefts in connective tissue between muscle, tendons, ligaments and bone. B. Made into closed sacs by synovial lining and may be continuous with the synovial cavity of a joint. C. Where a tendon runs in a tunnel (tendon sheath) and is subject to friction on all sides, as in the foot or hand, the bursa surrounds the tendon and is known as a synovial sheath (i.e. ganglion cyst) D. The inner wall surfaces rub together and produce synovial fluid for adequate lubrication E. Facilitates gliding of muscles or tendons over bony or ligamentous prominences and named according to their location.

How Joints Are Classified?

A. Definition B. By Anatomical Characteristics C. By Functional Criteria

Characteristics, Varieties and Examples of Joint Types

A. Synarthroses (Fibrous) B. Amphiarthroses (Cartilaginous) C. Diarthroses (Synovial)

Axes of the Body

Axes are lines, real or imaginary, about which movement takes place. Related to the planes of reference (above), there are three basic types of axes at right angles to each other. 1. Sagittal axis 2. Frontal (Lateral or Coronal) axis l 3. Longitudinal axis

closed chained movement.

If the distal end of the region is fixed and the muscle contracts and moves the more proximal attachment toward the distal attachment, it is termed a

Actions as described according to Anatomical Position

The actions of muscles defined in most texts are described as that muscle acting in isolation. The action is described in terms of moving the distal attachment (insertion) of the muscle toward the proximal attachment (origin) of the muscle. The movement around a joint, where the peripheral or distal part of the region is free to move toward the more central or proximal part of the region, is termed an open chained movement (moving the insertion toward the origin). If the distal end of the region is fixed and the muscle contracts and moves the more proximal attachment toward the distal attachment, it is termed a closed chained movement. The actions as described in textbooks are primarily open chained movements.

open chained movement

The movement around a joint, where the peripheral or distal part of the region is free to move toward the more central or proximal part of the region,

How Anatomy is Studied?

There are several avenues to explore for the student of human anatomy; each, by particular view it affords, can reveal an aspect of the subject that other avenues leave obscure. In this course, you will explore many avenues to learn what you are constructed of and to lie down a sturdy foundation for your future in Physical Therapy.

Definition

a place of union or junction between two or more bones.

Sagittal Plane

a. A vertical plane that extends from front to back, dividing the body into right and left portions. b. The most useful is the median sagittal plane (or midsagittal) which divides the body into perfect halves in the midline, deriving its name from the direction of the sagittal suture of the skull. c. When the plane runs lengthwise through a limb or other structure that has an orientation different than "cardinal" planes, the term longitudinal may be used.

Coronal (or Frontal) Plane

a. A vertical plane that extends from side to side, dividing the body into anterior and posterior portions. b. Its name is derived from the direction of the coronal suture in the skull.

Synarthroses (Fibrous) 1. Characteristics

a. All those articulations in which the surface of the bones are nearly in direct contact, and in which the adjoining bones are fastened together by fibrous connective tissue, cartilage or bone.

Transverse (or Horizontal) Plane

a. Any plane cutting across the long axis of a structure at right angles to both the sagittal and coronal planes, dividing the body into cranial and caudal portions. This is also used for individual planes that crossing a longitudinal axis.

Diarthroses (Synovial) 2. Varieties/Types (6)

a. Arthrodial / Gliding -- limited range of motion (i.e. intercarpal jt.) b. Ginglymus / Hinge -- motion in one plane (i.e. humeroulnar joint) c. Trochoid / Pivot -- rotation around one axis (i.e. prox. radiounlar joint) d. Condyloid -- movement occurs principally in one plane with a slight degree of rotation at an axis at right angles (i.e. tibiofemoral, MCP jts.). e. Enarthrodial / Ball & Socket / Spheroid -- the distal bone is capable of motion around an indefinite number of axes, which have one common center. Also allows for circumduction and rotation (i.e. glenohumeral joint). f. Saddle / Sellar -- the articular surface of the prox. bone is concave in one axis and convex in a perpendicular axis having motion in all planes (i.e. CMC joint of thumb).

Diarthroses (Synovial) 4. Synovial Fluid

a. Composition: 1) clear viscous fluid with a slight alkaline pH 2) large sugar molecules (hyaluronate) 3) proteins 4) electrolytes

Diarthroses (Synovial) 3. Ligaments

a. Connective tissue bands made of collagen fibers (or elastic fibers) joining two bony structures. These are flexible enough to permit motion, but strong enough not to yield to applied forces (most of the time). b. The varieties of movement that is possible to perform at any given joint depends on two factors: 1) the shape or configuration of the articulating surface 2) the presence of restraining ligaments

By Anatomical Characteristics - What joins or separates the ends of bone?

a. Fibrous Connective Tissue b. Cartilage c. Synovial Membrane and Fibrous Capsule with Ligaments

By Functional Criteria (Three Types)

a. Synarthroses (Fibrous) -- immovable or very slightly movable joint b. Amphiarthroses (Cartilaginous) -- slightly movable joint c. Diarthroses (Synovial) -- freely movable joint

Amphiarthroses (Cartilaginous) 2. Varieties/Types (2)

a. Synchondroses -- hyaline cartilage joins two bones to form a temporary joint before adult life (i.e. between the epiphyses and diaphyses of long bone). b. Symphyses -- union of two contiguous/touching bony surfaces connected by a broad, flattened disc of fibrocartilage (i.e. pubic symphysis).

Synarthroses (Fibrous) 2. Varieties/Types (3)

a. Syndesmoses -- dense fibrous connective tissue joins two bones (i.e. interosseous membrane of radius and ulna) b. Sutures/Synostoses -- bones fused together by a thin layer of fibrous tissue (i.e. some flat bones in the skull) c. Gomphoses -- insertion of conical process in a socket (i.e. fibrous union of the roots of the teeth with the alveoli of the mandible and maxilla)

Amphiarthroses (Cartilaginous) 1. Characteristics

a. bones are united either by a plate of hyaline cartilage or by a fibrocartilaginous disc.

Diarthroses (Synovial) 1. Characteristics

a. these joints are highly evolved articulations which permit free movement. b. possesses a joint capsule of dense irregular connective tissue and ligaments. c. ends of bones are covered with articular cartilage. d. ends of bones are separated by a synovial cavity. e. the synovial cavity is filled with synovial fluid. f. each synovial joint possesses a synovial membrane lying internal to the joint capsule. g. a disc may divide the synovial cavity into two compartments (i.e. TMJ, SC jt., or knee jt.)

4. Synovial Fluid

b. Immobilization: causes an increase in viscosity, decrease synovial fluid production and increases sugar crystallization. Movement in synovial joints is therapeutic, causing a pumping affect to increase nutrition, normalize viscosity and begins to produce synovial fluid (bursae). c. Hemarthrosis: Bloody effusion in the joint capsule produced by trauma to one or a combination of structures (i.e. knee = meniscus tear, cruciate tear, tibial plateau fx, or patella dislocation).

Sagittal axis

ies in the sagittal plane and extends anterior to posterior. This is also sometimes referred to as the X axis. The movements of abduction and adduction take place about this axis through a coronal plane. Trunk lateral flexion also occurs around this axis.

Longitudinal axis

is vertical extending in a cranial-caudal direction. This is also sometimes referred to as the Y axis. The movements of medial (internal) and lateral (external) rotation take place about this axis in a transverse plane. Horizontal abduction and horizontal adduction also occur around this axis.

Frontal (Lateral or Coronal) axis

lies in the coronal plane and extends horizontally from side to side or medial to lateral. This is also sometimes referred to as the Z axis. The movements of flexion and extension take place about this axis through a sagittal or parasagittal plane.