Major Concepts of Anatomy and PhysiologyPart 1: Organization of the Human Body

What is A&P?

Anatomy: The study of the structure of the human body.

Physiology:The study of the function of the human body.

Subdivisions of Anatomy Gross Anatomy: Studies structures visible

to naked eye. Histology: Studies structure of tissues

visible through a microscope. Neuroanatomy: Studies the structures of

the human nervous system. Embryology: Studies the development of

human embryos. Radiographic Anatomy: Studies the

structures visible via x-ray.

Subdivisions of Physiology Neurophysiology: Studies the function of

the human nervous system Cardiophysiology: Studies the human

cardiovascular system. Immunology: Studies the structure &

function of the immune system. Endocrinology: Studies the function of

hormones and their effects. Pathophysiology: Studies the changes

brought on by disease and aging.

Homeostasis

Homeostasis: The healthy internal balance of the human

organism.The body will always attempt to return to

homeostasis if change occurs. Feedback Systems are used to maintain

homeostasis. E.g. blood glucose, body temperature, etc.Major fluctuations may indicate a problem!

Feedback Mechanisms Negative Feedback Mechanisms:

Maintains the body condition in question within a small “normal range” of its set point.

Examples: Blood sugar range (80-120mg/ml)Body Temperature (36.5-38*C)Blood pHYour thermostat!

Feedback Mechanisms

Positive Feedback Mechanisms:Strengthens of reinforces a change where the

response to a stimulus actually increases the original stimulus. Produces a fairly rapid change.

Examples: Labor

Hierarchy of Complexity

6 Levels of the HierarchyChemical LevelCellular LevelTissue LevelOrgan LevelSystem LevelOrganism Level

Moves from simple to complex.

Chemical Level

The atoms and molecules that make up the cells of the body.

Subatomic Particles: Smaller than atoms Include protons, neutrons & electrons

Atoms: The smallest unit of the elementsFormed by combinations of the subatomic particles

Chemical Level Elements:

Fundamental substances composed of atoms Chemically alike &cannot be separated into smaller

substances by typical methods Include Oxygen, hydrogen, carbon, & nitrogen

Molecules: Composed of groups of atoms Includes things like Glucose & Macromolecules

Macromolecules: Composed of hundreds or thousands of molecules Includes proteins, fats, carbohydrates, DNA, RNA

Cellular Level

Organelles: Microscopic structures contained inside cellsCarry out individual functions Include Mitochondria, endoplasmic reticulum,

lysosomes Cells:

The basic building block of all organic organisms (living things)

Tissue Level

Tissue: A mass of similar cells that perform the same

specific functionFOUR PRIMARY TISSUES

Epithelium Tissue Connective Tissue Muscle Tissue Nervous Tissue

Organ Level

Organ: Structure composed of two or more separate

tissue types working together to carry out a particular function

Distinct gross anatomical boundaries Include stomach, heart, brain, etc.

System Level

Organ System: A group of organs connected together to

accomplish a unique collective functionExample: Digestive system

Separate organs include the esophagus, stomach, small & large intestines

Functions include digestion, absorption, and excretion

Organism Level Organism:

A single complete individualComposed of a number of different organ

systems11 Systems in the HumanIntegumentary Skeletal MuscularCardiovascular Nervous EndocrineRespiratory Digestive LymphaticReproductive Urinary

Six Characteristics of Living Organisms

1. Metabolism: All chemical reaction occurring within living cells.

1. Anabolism: Synthesis reactions to combine small molecules to form larger ones. Requires an input of energy.

2. Catabolism: Reactions reduce large, complex substances into simpler ones. Releases energy.

2. Growth: An increase in size through division and/or enlargement of cells.

3. Differentiation: The process of developing unspecialized cells into specialized cells with specific structure and function.

Six Characteristics of Living Organisms1. Movement: Includes motion of a body part

or materials through the body.2. Responsiveness: The ability to detect and

respond to changes in the environment.3. Reproduction: The process of producing

a new organism or forming new cells.

Anatomical Position

The anatomical position is the standard reference position for A&P.

Requires a person to… Stand with feet flat on the floor Arms at the sides Palms, face, eyes, and feet face

forward All descriptions assume the body is

in this position.

Directional Terms Superior: Toward the top of the head Inferior: Below or toward the feet Anterior or Ventral: Front Posterior or Dorsal: Back Medial: Toward the midline/midsagittal

plane Lateral: Away from the midline Proximal: Closer to midline or the point of

limb attachment

Directional Terms

Distal: Farther away from the midline or point of limb attachment

Superficial: Closer to the surface of the body

Deep: Farther from the surface of the body

Anatomical Planes

Sagittal Plane: Extends vertically from head to toes; divides the body into left and right portions. Midsagittal Median Plane: Passes exactly

through midline (middle) of the body; divides the body into equal halves.

Parasagittal Plane: Any sagittal plane that passes through the body to the left or right of the midline; divides the body into unequal left & right portions.

Anatomical Planes

Frontal Coronal Plane: Vertically oriented planeAt right angles perpendicular to the sagittal

planeDivides the body into a front (anterior) and

back (posterior) portion

Anatomical Planes

Transverse Plane: Passes through the body horizontallyPerpendicular to the long axis of the bodyDivides the body into top (superior) and

bottom (inferior) portions. Typical plane of Computerized Tomography

(CT) scans

Anatomical Planes

Oblique Plane: Passes through the body at an angleBetween the transverse plan and either a

sagittal or frontal plane.

Surface Anatomy Axial Region: The area of the body

closest to the midline. Consists of..headneckTrunk

Thoracic region (chest above diaphragm) Abdominopelvic region (below diaphragm)

Surface Anatomy Appendicular Region: Are of body farthest away from

the midline. Consists of the Appendages (upper and lower limbs, extremities). Brachium: Arm from shoulder to elbow Antebrachium: Forearm from elbow to wrist Carpus: Wrist area Metacarpus: Hand between carpus & phalanges Manus: Hand Digits (Phalanges): Fingers Thigh: From hip to knee Crus (Shank): From knee to ankle Tarsus: Ankle between leg and metatarsus Metatarsus: Foot from ankle to toes. Pes: The foot Digits (Phalanges): The toes

Body Cavities Dorsal Cavity: Lined by the meninges (dura mater,

arachnoid mater, and pia mater). Cranial Cavity: Contains the brain; enclosed in the skull. Vertebral or Spinal Cavity: Contains the spinal chord; enclosed

in the vertebral column. Ventral Cavity

Thoracic Cavity: Contains the heart, lungs, & upper digestive system organs.

Abdominopelvic Cavity: Contains the stomach, liver, gallbladder, spleen, pancreas, urinary bladder, small & large intestine. Kidneys located BEHIND abdominopelvic cavity.

Organs located in these cavities are referred to as viscera.

Abdominopelvic Cavity

4 Abdominopelvic Quadrants: Right Upper QuadrantLeft Upper QuadrantLeft Lower QuadrantRight Lower Quadrant

Abdominopelvic Cavity 9 Abdominopelvic Regions

Right Hypochondriac Region: Liver, gall bladder Epigastric Region: Liver, stomach, pancreas Left Hypochondriac Region: Stomach, spleen Right Lateral or Lumbar Region: Ascending colon, gall

bladder Umbilical Region: Stomach, transverse colon, small

intestine, pancreas Left Lateral or Lumbar Region: Small intestine,

descending colon Right Inguinal or Iliac Region: Cecum, small intestine Hypogastric Region: Small intestine, rectum, urinary

bladder, reproductive organs Left Inguinal or Iliac Region: Small intestine, sigmoid colon