The Human Body: An Orientation

Anatomy Anatomy - Describes the locations, appearances, & relationships of body parts

Anatomy (cont'd) Gross Anatomy - Study of body structures that are visible without the aid of a microscope Systemic anatomy - Studies body structure within a given organ system. Ex. Skeletal system Regional anatomy - Examines all structures within a given region of the body. Ex. Leg Surface anatomy – Study of internal structures as they relate to the overlying skin surface. Ex. Locating a blood vessel to draw blood.

Anatomy (cont'd) Microanatomy (Microscopic anatomy)- Study of body structures that are not visible without the aid of a microscope. Cytology – cells of the body Histology - Study of tissues

Anatomy (cont'd) Developmental Anatomy - structural changes that occur throughout the lifespan of a body. Embryology – development before birth

Physiology Explains the mechanisms that operate body activities. How does the body work? Explained by chemical and physical principles.

Anatomical Position Anatomical reference point Terms “left” and “right” refer to those sides of the person being viewed, not those of the observer.

Directional Terms

Superior Inferior Inferior (Caudal) Away from the head or toward the lower part of the body Below The neck is inferior to the head. Superior (Cranial) Toward the head or upper part of body Above The head is superior to the neck.

The vertebral column extends down the posterior side of the body. Anterior Posterior Posterior ( Dorsal) Toward the back The vertebral column extends down the posterior side of the body. Anterior (Ventral) Toward the front or belly side The eyes are on the anterior side of the head.

Medial Lateral Medial Toward the midline The nose is medial to the ears Lateral Away from the midline The ears are lateral to the nose

Intermediate – between a more medial and a more lateral structure. The collarbone is intermediate between the breastbone and shoulder.

Inward from the surface of the body Deep Deep Superficial Deep (Internal) Inward from the surface of the body The heart lies deep to the rib cage. Superficial (external) Toward or at the surface of the body The location of the skin is superficial to the muscles.

Away from a structure’s origin or point of attachment to the trunk Proximal Distal Distal Away from a structure’s origin or point of attachment to the trunk The knee is distal to the thigh. Proximal Toward a structure’s origin or point of attachment to the trunk The upper arm is proximal to the wrist.

Body Planes

Sagittal Plane Extends parallel to the long axis of the body (along the body’s length) Extends in the vertical direction Midsagittal (median)- equal right and left sides Parasagittal - divided unequally

Frontal Plane A.K.A. coronal plane Extends along the body’s long axis Divides anterior and posterior

Horizontal Plane A.K.A. transverse plane A.K.A. cross section Divides the body into superior and inferior portions

Body Plan

Regional Terms Axial – main axis of body Head, neck, trunk Appendicular – appendages of the body

Body Regions Head - Face, Cranium Neck Trunk -Thorax, Abdomen, Pelvis, Back Upper appendages Lower appendages

Body Cavities Dorsal cranial cavity vertebral canal

Body Cavities Ventral cavity Viscera – group of internal organs within this cavity thoracic cavity 2 pleural cavities, pericardial cavity (within mediastinum) abdominopelvic cavity

Body Cavities

Other Body Cavities Oral and Digestive Cavities Nasal Cavity Mouth, digestive organs Nasal Cavity Nose, respiratory system passageways Orbital Cavities Eyes Middle Ear Cavities Temporal bone, tiny bones that transmit sound Synovial Joints

Landmarks

Anterior Abdominal Acromial Antebrachial Antecubital Axillary anterior body trunk inferior to ribs Acromial Point of shoulder Antebrachial forearm Antecubital anterior surface of the elbow Axillary armpit

Anterior (cont’d) Brachial Buccal Carpal Cervical Coxal Arm (upper) cheek area Carpal wrist Cervical neck region Coxal hip

Anterior (cont’d) Crural Digital Femoral Inguinal leg fingers, toes thigh Inguinal thigh meets body trunk; groin

Anterior (cont’d) Nasal Oral Orbital Patellar Peroneal (fibular) nose mouth Orbital eye Patellar anterior knee Peroneal (fibular) lateral part of leg

Anterior (cont’d) Pubic Sternal Tarsal Thoracic Umbilical genital region Sternal breastbone area Tarsal ankle region Thoracic chest Umbilical navel

Posterior Cephalic Deltoid Gluteal Lumbar Head (whole) curve of shoulder Gluteal buttock Lumbar back between ribs and hips

Posterior (cont’d) Occipital Olecranal Popliteal Sacral posterior surface of head; base of skull Olecranal Posterior elbow Popliteal posterior knee area Sacral Area between hips

Posterior (cont’d) Scapular Sural Vertebral shoulder blade region the calf Vertebral area of the spine

Structural Levels of Organization

Chemical Level

Cellular Level

Tissue Level

Organ Level

System Level

Complete Organism

Necessary Life Functions Maintaining boundaries Movement Responsiveness or irritability Digestion Metabolism Excretion Reproduction Growth

Survival Needs Nutrients Oxygen Water - 60-80% of body weight Normal body temperature Atmospheric Pressure

Homeostasis

Homeostasis Dynamic equilibrium (or balance) of the internal environment. All body systems contribute. Nervous and endocrine are most important. Necessary for health.

Elements of a Control System

Negative Feedback Causes variable to change in the direction opposite to that of initial change. Most homeostatic mechanisms are negative feedback. Body temperature, blood glucose levels, etc.

Negative Feedback

Positive Feedback Change occurs in the same direction as initial disturbance. Result or response enhances or exaggerates the original activity so that the activity is accelerated. Rarely contributes to homeostasis. Blood clotting, labor contractions.

Positive Feedback

Homeostasis and Disease

Disease Disruption of homeostasis leads to impairment of normal functions. This is called disease. Acute - short time Chronic - longer duration of time

Classification of Disease Congenital arise before birth inherited Immunological Involves responses by leukocytes Invasion by bacteria, viruses, protozoan, fungi, disease

Classification of Disease, (cont’d) Metabolic - Diabetes Endocrine diseases Trauma - fluid loss Neoplastic Tumors Cancer