PART I: PRICIPLES AND CONCEPTS OF ANATOMY AND PHYSIOLOGY

Anatomy

– The scientific discipline that investigates the body’s structures (shape, size, etc.) and its relationship to its function.

Physiology

The science that seeks to explain the physical and chemical mechanisms that are responsible for the origin, development, and progression of life. Human physiology attempts to explain the specific characteristics and mechanisms of the human body that make a living being. Its goals are to understand how the body maintains conditions within a narrow range of values in a constantly changing environment.

Kinesiology

The study of human motion and the mechanics of body movements. Clinical kinesiology is the application of kinesiology to environments of the healthcare professional. Its goal is to understand movement and the forces acting on the human body.

Chemical Level.

This involves interactions between atoms, which are tiny building blocks of matter. Atoms combine to create molecules such as water and proteins. These molecules, in turn, associate in specific ways to form organelles that are the basic components of a cell.

Cellular Level.

the basic structural and functional units of plants and animals.

Tissue Level.

composed of a group of similar cells and materials surrounding them. The characteristics of the cells and the surrounding materials determine the function of the tissue.

Organ level

composed of two or more tissue types that perform one or more common functions.

Organ System Level

a group of organs that together perform a common function or set of functions and are therefore viewed as a unit. The different organ systems in the human body include: the integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive systems.

Organism Level

is any living thing considered as a whole and is the sum total of all the structural levels working together to keep a human alive.

Anatomical Position

is a standard body position that serves as a reference point for accurate and standard description of body parts and positions.

Right

toward the right side of the body

Left

toward the left side of the body

Superior

a structure above another

Inferior

a structure below another

Cephalic

closer to the head than another structure

Caudal

closer to the tall than another structure

Anterior

the front of the body

Posterior

the back of the body

Ventral

toward the belly

Dorsal

toward the back

Proximal

closer to the point of attachment to the body than another structure

Distal

farther from the point of attachment to the body than another structure

Lateral

away from the midline of the body

Medial

Toward to the midline of the body

Superficial

toward or on the surface

Deep

Away from the surface , internal

Plane

divides, or sections the body, making it possible to “look inside” and observe the body’s structure.

Sagittal Plane

Runs vertically through the body and divides it into right and left

halves.

frontal/coronal

Runs vertically from right to left and divides the body into anterior

and posterior parts

Transverse/Horizontal plane

Runs parallel to the surface of the ground and divides the body

into superior and inferior parts

Flexion

Bending movement that decreases the angle of the joint to bring articulating bones closer together.

Extension

Straightening movement that increases the angle of the joint, thereby moving two bone segments away from each other.

If extension goes past the anatomic reference point, it is called hyperextension.

Hyperextension

the movement of a joint beyond its normal range of motion in a straightening or backward direction

Abduction

Movement away from the midline

Adduction

movement towards the midline

Rotation

Movement of a bony segment around its longitudinal axis.

External Rotation

rotation wherein the anterior surface of the bone rotates away from the

midline.

Internal (Inward/Medial) Rotation

: rotation wherein the anterior surface of the bone rotates toward the

midline.

Circumduction:

This is a circular movement that is a combination of flexion, extension, abduction, and adduction. It occurs at freely moveable joints.

Pronation

is the rotation of the forearm turning the hand into a palm down position

Supination

rotation of the forearm turning the hand into palm up position

Elevation

: movement of a structure superiorly

Depression

movement of a structure inferiorly

Protraction

gliding motion that moves a structure in an anterior direction

Retraction

gliding motion that moves a structure posteriorly

Opposition

movement unique to the thumb. Occurs when the thumb and the tip of a finger on the same hand are brought towards each other across the palm.

Reposition

returns the thumb to the neutral, anatomical position.

inversion

Turns the ankle so that the plantar aspect of the foot faces medially, towards the opposite foot, with the weight on the outside edge of the foot.

Eversion

turns the ankle so that the plantar aspect of the foot faces laterally, with the weight on the inside edge of the foot.

Horizontal Adduction

movement of the shoulder towards the midline of the body.

Horizontal abduction

movement of the shoulder away from the midline

Dosiflexion

: movement of the dorsum of the foot towards the tibia (flexion of the ankle)

Plantarflexion

: movement of the dorsum of the foot away from the tibia (extension of the ankle)

Medical imaging

refers to techniques and procedures used to create images of the human body

Conventional radiograph (X-Rays)

Uses ionizing radiation to produce high-resolution images on specialized films.

 The primary means of diagnostic imaging for musculoskeletal problems.

 Advantages: readily available, cheap, provides good anatomical resolution.

 Disadvantages : exposes the patient to radiation, offers poor differentiation of soft tissues, not sensitive to subtle pathology.

Computed Tomography (CT Scan)

Merges x-ray technology with the computer to provide detailed digital crosssectional images of the body relatively free from superimposition of the different tissues.

 Administers multiple x-ray beams projected at different angles

Magnetic Resonance Imaging (MRI)

A noninvasive, painless imaging technique with high contrast resolution that uses exposure to magnetic fields, not ionizing radiation, to obtain an image of bone and soft tissues

Radiodensity

 It is the combination of physical qualities of an object that determine how much radiation it absorbs from the X-ray beam.

 An object’s radiodensity is determined by (1) its composition and (2) its thickness.

Radiographic Density

 It is a technical term that refers to the amount of blackening on the radiograph.

Radiopaque

as “not easily penetrated by x-rays”, no x-rays reach the image receptor, so the radiographic representation of the object is white.

Radiolucent

Defined as “easily penetrated by x-rays.” A radiolucent object attenuates very small amounts of x-rays, therefore most of the x-rays reach the image receptor, so the radiographic representation of the object is dark.

Anatomy in Four Shades of Gray

1. Air (black)

2. Fat (gray to black)

3. Water (gray)

4. Bone (white)

Air (black)

radiolucent and possesses the least radiodensity of all body structures. Air is seen normally in the trachea, lungs, stomach, and digestive tract.

Fat (gray to black)

– fat is normally present subcutaneously, along muscle sheaths and surrounding viscera

Water (gray

all of the soft tissues and fluids of the body – including blood, muscle, cartilage, tendons, ligaments, nerves, and fluid filled organs – share approximately the same radiodensity as water.

Bone (white)

bone is the most radiodense tissue of the body.

Homeostasis

is the maintenance of relatively stable conditions in the body’s internal environment. It occurs because of the ceaseless interplay of the body’s many regulatory systems.

Body Temperature.

a variable that can change depending on the external environment. Homeostatic mechanisms, such as sweating (when in a hot environment) and shivering (when in a cold environment), normally maintain body temperature near an ideal normal value.

Feedback Mechanisms

includes three basic components: a receptor, a control center, and an effector organ.

Negative Feedback Mechanism

Most systems in the body are regulated by negative feedback mechanisms, which maintain homeostasis. This mechanism reverses a change in a controlled condition.

Example of feedback mechanism regulation: blood pressure, body temperature, blood sugar levels

Positive Feedback Mechanism

This type of feedback mechanism occurs when a response to the original stimulus results in the deviation from the set point becoming even greater. Unlike the negative feedback mechanism, this mechanism tends to strengthen or reinforce a change

Cell

the smallest unit of life. They are the structural and functional building blocks of an organism.

Plasma Membrane

This is the outermost component of a cell. It functions as a boundary separating the intracellular substances, substances inside the cell, from extracellular substances, those substances outside of the cell.

Lipid Bilayer

This is the basic structural framework of the plasma membrane. The lipid bilayer are two back-to-back layers made up of three types of lipid molecules – phospholipids (75%), cholesterol (20%), and glycolipids (5%).

Membrane Proteins

are seen on the surface of the phospholipid molecules (peripheral proteins) and, in some cases, extends to the inner surface of the plasma membrane (integral proteins).

Marker Molecules

 Allows cells to identify other cells or other molecules.

 They are mostly glycoproteins (proteins attached to carbohydrates) or glycolipids  Example: allows immune cells to distinguish between selfcells and foreign cells such as bacteria

Attachment Proteins

Integral proteins that allow cells to attach to other cells (cadherins) or to extracellular molecules (integrins).

Receptor Proteins

 Functions as binding sites for chemical signals in the extracellular fluid

 Binding of chemical signals to receptor triggers cellular responses \

 Example: Acetylcholine receptor of ligand-gated Na+ channel

Enzymes

 Are protein catalysts which increase the rate of chemical reactions on either the inner or outer surface of the plasma membrane

Transport Proteins

Moves ions or molecules across the plasma membrane. Since most non-lipid soluble molecules and ions do not pass readily through the lipid bilayer, transport proteins will need to move these substances across it.

Cytoplasm

consists of all the cellular contents between the plasma membrane and the nucleus.

Cytosol

 This is the fluid portion of the cytoplasm that surrounds the organelles and constitute to about 55% of the total cell volume

Cytoskeleton

A network of protein filaments that extends throughout the cytosol that supports the cell and holds the nucleus and other organelles in place.

The Nucleus

 It is a spherical or oval-shaped, membrane bound structure that usually is the most prominent feature of a cell located at its center.

Diffusion

is the tendency for ions and molecules to move from an area of higher concentration to an area of lower concentration (towards the concentration gradient).

Osmosis

This is the diffusion of water across a selectively permeable membrane, from a solution with higher water concentration (low solute/ less concentrated solution) to a solution with low water concentration (high solute/ more concentrated solution).

Active transport

is a mechanism by which there is movement of ions or molecules across the membrane from an area of lower concentration to an area of higher concentration (against a concentration gradient).

The Sodium-Potassium Pump

This is a transport process that pumps sodium ions outward through the cell membrane of all cells and at the same time pumps potassium ions from the outside to the inside.

Primary Active Transport

In this type of active transport, the energy is derived directly from breakdown of adenosine triphosphate (ATP) or some other high-energy phosphate compound.

Secondary Active Transport

In this type of active transport, the energy is derived secondarily from the energy that has been stored in the form of ionic concentration differences between two sides of the membrane, which is created originally by the primary active transport.

Vesicular Transport

This is the movement of larger volumes of substances across the plasma membrane through the formation or release of vesicles, membrane-bound sacs, in the cytoplasm.

Endocytosis

This occurs when material moves through the plasma membrane and into the cytoplasm by the formation of a vesicle.

Phagocytosis

also known as “cell eating,” is a form of endocytosis in which the cell engulfs large solid particles, such as worn-out cells, whole bacteria, or viruses. This is a vital defense mechanism that helps protect the body from diseases.

Pinocytosis

also known as “cell drinking,” a form of endocytosis in which tiny droplets of extracellular fluid are taken up.

Exocytosis

Vesicular transport process that ejects substances from the cell interior into the extracellular fluid. Exocytosis accounts for hormone secretion, neurotransmitter release, mucus secretion, and ejection of wastes.

Tissues

are groups of cells that are similar in structure and perform a common or related function.

 classified into 4 categories: epithelial tissues for covering, connective tissue for support, muscle tissue for movement, and nervous tissue for control

Epithelial Tissues

 Also known as epithelium, covers and protects surfaces, both outside and inside the body.

 They provide protection to underlying structures, permits the passage of substances through it, secretion of substances, and absorption of substances.

NOTE!

Cell Shapes o Epithelial shapes vary in shape depending on their function

Note!

Arrangement of Cells in Layers o The cells are arranged in one or more layers depending on function

Simple epithelium

This is a single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption.