Anatomy and physiology



Anatomy and physiology


This content targets the sciences. This aspect of information provides the foundation for the validity of massage. Many, if not most, exam question found on licensing exams contain aspects of science knowledge. It is necessary to know this language to understand what the question is asking.



Medical terminology simplified


Tables 4-1 through 4-4 discuss common prefixes, root words, suffixes, and abbreviations.








Structural plan


The structural organization of the body follows a clear plan. Each human being has a vertebral column that supports the trunk and forms the central axis of the body. The spine also supports two body cavities: The dorsal cavity, which holds the brain inside the skull and the spinal cord in the vertebral column, and the ventral cavities, which are the combined thoracic, abdominal, and pelvic cavities (sometimes the abdominal and pelvic cavities are referred to as the abdominopelvic cavity). Human beings are bilaterally symmetrical beings, with left and right mirror images. Also, the body is segmented; this is most obvious in the vertebral column, ribs, and spinal regions of the body and surface anatomy (Figures 4-2 through 4-5).










Anterior region of the trunk


Ventral cavities are located in the trunk. They include the following:



• Thoracic cavity: Also known as the chest; found between the neck and the diaphragm and surrounded by the ribs. The mediastinum contains the heart, lungs, thymus gland, trachea, esophagus, and other structures and divides the chest into left and right parts.


• Abdominal cavity: Also known as “the belly,” it is located below the diaphragm and enclosed within the abdominal muscles. This cavity contains the liver, kidneys, spleen, pancreas, stomach, and intestines.


• Pelvic cavity: Inferior to the abdomen, inside the pelvic bones; contains a portion of the large intestine, as well as the bladder and the internal reproductive organs.


• Viscera: Internal organs of the thoracic, abdominal, and pelvic cavities that are considered to be under involuntary control.


• Membranes: Two types, associated with the regions of the trunk: Parietal membranes, lining the body cavities; and visceral membranes, covering the visceral organs.




Positions of the body


Terms related to the position of the body include the following:




Body planes


The body can be divided into parts by imaginary lines and various planes to identify the particular areas.


Movements are described as beginning in or returning to the anatomic position. Movement terms define the action as the body part passes through the various planes.


The sagittal plane is a vertical plane that divides the body into left and right parts. A midsagittal plane divides the body into equal left and right parts; a parasagittal plane divides it into unequal left and right parts. Movement in the sagittal plane consists of flexion and extension.


The frontal (coronal) plane also runs vertically but divides the body into anterior and posterior (front and back) parts. Movement in the frontal plane consists of abduction and adduction.


A transverse plane divides the body horizontally into two parts. These parts are described as superior (meaning above) and inferior (meaning below). The transverse plane runs perpendicular to the frontal and sagittal planes. Movement in the transverse plane consists of rotations—internal, external, and left and right rotation, and circumduction (Figure 4-7). Axis of movement An axis is a straight line around which an object rotates. Movement at the joint take place in a plane about an axis. There are three axes of rotation:




Examples:




Terminology of location and position


Kinesiology


By definition, kinesiology is the study of movement. Kinesiology brings together the study of anatomy, physiology, physics, and geometry in order to explain human movement. Kinesiology uses principles of mechanics, musculoskeletal anatomy, and neuromuscular physiology. Mechanical principles that relate directly to the human body are used in the study of biomechanics. This may involve looking at the static (nonmoving) or dynamic (moving) systems associated with various activities.


Dynamic systems can be divided into kinetics and kinematics. Kinetics refers to the forces that cause movement; kinematics consists of the aspects of time, space, and mass in a moving system. A movement that takes a part of the body forward from the anatomic position within a sagittal plane is called flexion; movement backward is called extension.



Movement terms


The following terms are commonly used to describe movement:



• Flexion: A decrease in the angle between two bones as the body part moves out of the anatomic position; flexion is a sagittal plane movement.


• Extension: An increase in the angle between two bones, usually moving the body part back toward the anatomic position; extension is a sagittal plane movement.


• Hyperextension: A term that has two definitions: (1) any extension beyond normal or healthy extension; (2) any extension that takes the part farther in the direction of the extension, farther out of the anatomic position.


• Abduction: Movement of the appendicular body part away from the midline; abduction is a frontal plane movement.


• Adduction: Movement of the appendicular body part toward the midline; adduction is a frontal plane movement.


• Right lateral flexion: Movement of the axial body part to the right; right lateral flexion is a frontal plane movement.


• Left lateral flexion: Movement of the axial body part to the left; left lateral flexion is a frontal plane movement.


• Right rotation: Partial turning or pivoting of the axial body part in an arc around a central axis to the right; right rotation is a transverse plane movement.


• Left rotation: Partial turning or pivoting of the axial body part in an arc around a central axis to the left; left rotation is a transverse plane movement.


• Medial rotation: Partial turning or pivoting of a body part of the appendicular body in an arc around a central axis toward the midline of the body; medial rotation is a transverse plane movement.


• Lateral rotation: Partial turning or pivoting of a body part of the appendicular body in an arc around a central axis away from the midline of the body; lateral rotation is a transverse plane movement.


• Circumduction: Not a movement, but a sequence of movements that turn or pivot the part through an entire arc, making a complete circle. (Note: Circumduction involves no rotation and is a multiplanar movement.)


• Protraction: Pushing of a part forward in a horizontal plane.


• Retraction: Pulling back of a part in a horizontal plane.


• Elevation: Moving a part upward (superiorly).


• Depression: Moving a part downward (inferiorly).


• Supination: Movement of the forearm (at the radioulnar joint, not the elbow joint) that turns the palm anteriorly (upward), as when cupping a bowl of soup.


• Pronation: Movement of the forearm (at the radioulnar joint, not the elbow joint) that turns the palm posteriorly (downward).


• Inversion: Movement of the sole of the foot inward, toward the midline.


• Eversion: Movement of the sole of the foot outward, away from the midline.


• Plantar flexion: Movement of the foot downward (may also be called flexion).


• Dorsiflexion: Movement of the foot upward (may also be called extension) (Figure 4-8).




Directional terms


Certain terms are used to describe the relationship of one body position to another. The following directional terms are organized in pairs of opposites:



• Anterior (ventral): In front of, or in or toward the front.


• Posterior (dorsal): Behind, in back of, or in or toward the rear.


• Proximal: Closer to the trunk or the point of origin (usually used on the appendicular body only).


• Distal: Situated away from the trunk, or midline, of the body; situated away from the origin (usually used on the appendicular body only).


• Lateral: On or to the side, outside, away from the midline.


• Medial: Relating to the middle, center, or midline.


• Ipsilateral: The same side.


• Contralateral: The opposite side.


• Superior: Higher than or above (usually used on the axial body only).


• Inferior: Lower than or below (usually used on the axial body only).


• Volar (palmar): The palm side of the hand.


• Plantar: The sole side of the foot.


• Varus: Ends bent inward; angulation of a part of the body such as the distal segment of a bone or joint inward toward the midline. For example, in a varus deformity of the knee, the distal part of the leg below the knee is deviated inward, resulting in a bowlegged appearance.


• Valgus: Ends of the distal segment of a bone or joint bent outward. For example, a valgus deformity at the knee results in a knock-kneed appearance, with the distal part of the leg deviated outward.


• Internal: An inside surface or the inside part of the body.


• External: The outside surface of the body.


• Deep: Inside or away from the surface.


• Superficial: Toward or on the surface.


• Dextral (dextro): Right.


• Sinistral (sinistro): Left; levo also is used to mean left.



Terms related to diagnosis and diseases


The massage practitioner must be able to understand medical terms related to diagnosis and various diseases. Two terms related to the diagnosis of a disease that massage professionals often encounter are indication and contraindication. These and other terms follow:


An indication is a condition for which an approach would be beneficial for health enhancement, treatment of a particular condition, or support of a treatment modality other than massage.


A contraindication is a condition or factor that may make an approach harmful. Contraindications may be further subdivided by severity:



Most contraindications are within the regional avoidance or caution category. The massage therapist must be able to determine contraindications and respond appropriately to protect the safety of the client. When in doubt about the safety of massage application, the massage therapist can either refer to the appropriate health care professional for recommendations or provide massage in a conservative and cautious manner.



The structure of the body


Tissues


The body is composed of tissues. A tissue is a collection of specialized cells that perform a special function. Histo is a root word meaning “tissue.” Histology is the study of tissue. The primary tissues of the body are the epithelial, connective, muscular, and nervous tissues (Figure 4-9).




Organs and systems


An organ is a collection of specialized tissues. An organ has specific functions, but it does not act independently of other organs (Table 4-5).



Organs make up systems. The body as a whole is made up of several systems. Some of these systems are concentrated in a particular part of the body (e.g., the urinary system), whereas others, such as the cardiovascular system, reach out to all parts of the body. The body consists of 10 general systems. Each system is made up of organs that collectively perform specific functions. (A more extensive description of these systems can be found in any complete anatomy and physiology textbook.)



The skeletal system


The skeletal system consists of three types of tissue: Bone, cartilage, and ligaments. Bone is a dense connective tissue that is composed primarily of calcium and phosphate; os-, ossa-, oste-, and osteo- are all combining forms that mean “bone.” The human skeleton is composed of approximately 206 bones, and massage professionals must be familiar with most of them. Some of these bones include skull or cranium, cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacral vertebrae, coccygeal vertebrae, ribs, sternum, manubrium, body, xiphoid process, clavicle, scapula, humerus, ulna, radius, carpal bones, metacarpal bones, phalanges, pelvis, ilium, ischium, pubis, femur, patella, tibia, fibula, tarsal bones, and metatarsal bones. Other terms related to bones and landmarks on bones include malleolus, process, crest, insertion, joint, olecranon, origin, spine, trochanter, and tuberosity (Figure 4-10).




The articular system


As mentioned, articulations are joints at which two or more bones meet. The articular system concerns all of the anatomic and functional aspects of the joints. Joints are places where bones come together, where limbs are attached, and where the motion of the skeletal system occurs. Some joints are rigid, and some allow a great degree of flexibility. The joints allow motion of the musculoskeletal system; they bear weight and hold the skeleton together.


Terms related to the articular system include articulation, flexibility, synarthrodial, amphiarthrodial, diarthrodial, symphysis pubis, sacroiliac, symphysis, articular cartilage, articular disks, ligaments, synovial fluid, and tendon.





Diarthrodial joints

Types of movement permitted by diarthrodial/synovial (freely movable) joints include the following:



• Flexion: Bending that reduces the angle of a joint.


• Extension: Straightening or stretching that increases the angle of a joint.


• Abduction: Movement away from (ab-) the midline.


• Adduction: Movement toward (ad-) the midline.


• Pronation: Turning of the palm downward.


• Supination: Turning of the palm upward (you can hold a bowl of soup in a supinated hand).


• Eversion: Turning (-version) of the sole of the foot away from (e-) the midline (when you evert your foot, you move your little toe toward your ear).


• Inversion: Turning (-version) of the sole of the foot inward (in-).


• Plantar flexion: Bending of the plantar surface of the sole of the foot downward (plant your toes in the ground).


• Dorsiflexion: Bending of the top or dorsal surface of the foot toward the shin.


• Rotation: Rolling to the side (internal rotation: Rolling toward the midline; external rotation: Rolling away from the midline).


• Circumduction: Making a cone; the ability to move the limb in a circular manner.


• Protraction: Thrusting a part of the body forward (pro-).


• Retraction: Pulling a part of the body backward (re-).


• Elevation: Raising a part of the body.


• Depression: Lowering a part of the body.


• Opposition: The act of placing part of the body opposite another, as in placing the tip of the thumb opposite the tips of the fingers.



Bursae

Bursae are closed sacs or saclike structures (bursa) that usually are found close to the joint cavities. The lining of bursae often is similar to the synovial membrane lining of a true joint. Some bursae are continuous with the lining of a joint. The function of a bursa is to lubricate an area between skin, tendons, ligaments, or other structures and bones, where friction would otherwise develop (Figures 4-11 and 4-12 and Box 4-1).






The muscular system


The muscular system is made up of contractile tissues. The three types of muscle tissue are cardiac muscle, smooth muscle, and skeletal muscle. Many of the body’s organs contain muscle tissue. Muscle tissue also makes up the muscles, which are individual organs. These muscles give the body shape and produce movement. Muscle function is determined by the shape and location of the muscle and by the density and pliability of all fluid, fibers, and connective tissue of the muscles; the term muscle tone is used to describe this aspect of muscle. The nervous system also controls how long or short a muscle is, by regulating the degree of muscle fiber contraction; this is called motor tone.



Skeletal muscle

Each skeletal muscle is made up of parts. Most muscles have two ends (proximal and distal), which are attached to other structures, and a belly. Muscles cause and permit motion through the actions of contraction and relaxation. Table 4-6 presents a list of terms that are used to describe the movements of different types of muscles (Figure 4-13).




Contraction refers to a reduction in size or shortening of a muscle. When one muscle contracts, another, opposite muscle is stretched and is put in a state of tension. Relaxation occurs when tension is reduced, which allows the muscle to return to its normal resting length.


Muscles work in pairs of agonists and antagonists. Agonists are muscles that are responsible for the primary desired movement. The agonist is the prime mover, which shortens to produce movement. Antagonists are the muscles that oppose the action of the agonist and lengthen and control the movement produced by the agonist.


Synergists are muscles that assist the agonists by holding a part of the body steady, thereby providing leverage. In some cases, synergists also produce the same action as the prime mover.


The agonist-antagonist-synergist relationship permits the skeletal muscles to work in a purposeful manner and gives fluidity to motion. This fluid movement is called coordination.


Skeletal muscle: This contractile body, the muscle proper, usually is attached to two or more bony points. Attachments may be



Tendons are an integral part of muscle, virtually invariable in length. They are made of collagen fibers with occasional flattened fibroblasts.


Tendons take the form of cords or strips consisting of bundles (fascicles) of collagen, mainly parallel, and often are large enough to see with the naked eye; they are striated in appearance. Around the outside of the bundle is an epitendineum with elastic fibers, which obviously causes a little drag as tendons run through connective tissue. When they have to move independently of other tissues, various friction-reducing devices such as bursae are used.


A very flattened tendon often is called an aponeurosis (neurosis because it is white, like nervous tissue). It usually has the appearance of a flattened sheet of collagen fibers, or often of several sheets running onto each other in different directions, like plywood.


A fleshy insertion is what it sounds like—muscle joined to bone without the intervention of a collagenous tendon or aponeurosis. The collagen is still there, but it is in among the muscle fibers, or it forms a very short tendon.



Attachment terminology


Terminology changes frequently occur; currently, the names of muscle attachments, sometimes called origins and insertions, are undergoing change. In some circumstances, origin and insertion can be interchanged, so it is easier to talk of attachments. Proximal muscle attachments (closer to the midline and the body center) have been called origins but are more correctly called proximal attachments; insertions are now called distal attachments. Often a muscle arises from more than one place; it then is said to have two or more attachments (e.g., biceps brachii, triceps brachii).



Forms of muscles


Muscles exhibit wide functional variation in terms of size and shape, according to their job. The simplest is probably the strap muscle, which has a fleshy, wide attachment at each end. Strap muscles thus have good range but little power.


To get more power, the muscle structure becomes fusiform (three-dimensional) or produces more heads, resulting in the effect of two, three, or four muscles pulling the same tendon.


In a unipennate muscle, fibers insert all along one side of a tendon. In a bipennate or multipennate arrangement, compound muscles have a short range but plenty of power.


Spiralized muscles are special in that they not only pull the attachments together when they contract, but they also twist or untwist the area. The twisting action often occurs because the muscle attachments are wrapped around a bone (Figure 4-14).




Actions of muscles


Muscles undergo transition from relaxation to contraction. At any given time, some functional units (motor units, groups of fibers) will be contracting, some will be relaxing, and some will stay static to provide muscle motor tone.


When an individual fiber contracts, it tends to approximate (bring closer together) its ends, but whether or not this results in contraction depends on the force generated and the forces opposing contraction. The net result for the whole muscle may be shortening—concentric action, lengthening—eccentric action, or an increase in tension, but with no movement—isometric action.


A muscle that tries to initiate contraction is opposed by the following:


< div class='tao-gold-member'>

Stay updated, free articles. Join our Telegram channel

Jun 22, 2016 | Posted by in MANUAL THERAPIST | Comments Off on Anatomy and physiology

Full access? Get Clinical Tree

Get Clinical Tree app for offline access