The Human Body: An Orientation

Anatomy

The study of the structure, or physical form, of the body.

Gross Anatomy

The study of large body structures

Greek word meaning of Anatomy

cut (tomy) apart (ana)

Physiology

The study of how the body and its parts work or function

Greek word meaning of Physiology

nature (physio) the study of (logy)

Relationship of Anatomy and Physiology

Structure determines functions

Chemical level

Atoms combine to form molecules

Cellular level

Made up of molecules

Tissue level

Consist of similar types of cells

Organ level

Made up of different types of tissues

Organ system level

Consist of different organs that work together closely

Organismal level

Human organisms are made up of many organ systems

Integumentary System

The external covering of the body

Skeletal System

Protects and supports body organs; provides a framework the muscles use to cause movement

Muscular System

Allows manipulation of the environment (movement), locomotion, and facial expression

Nervous System

Fast-acting control system of the body; responds to internal and external changes

Endocrine System

Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use by body cells

Cardiovascular System

Blood vessels transport blood, which carries oxygen, nutrients, hormones, carbon dioxide, wastes; the heart pumps blood

Lymphatic System

Picks up fluid leaked from blood vessels and returns it to blood; disposes of debris in the lymphatic stream; houses white blood cells involved in immunity.

Respiratory System

Keeps blood constantly supplied with oxygen and removes carbon dioxide; gas exchange occurs through the walls of the air sacs of the lungs

Digestive System

Breaks food down into absorbable nutrients that enter the blood for distribution to body cells; indigestible foodstuffs are eliminated as feces

Urinary System

Eliminates nitrogen-containing wastes from the body; regulates water, electrolyte, and acid-base balance of the blood

Reproductive System

To produce offspring

Maintaining Boundaries

Every living organism must be able to maintain its boundaries so that its inside" remains distinct from its "outside."

Movement

All the activities promoted by the muscular system, such as propelling ourselves from one place to another and manipulating the external environment with our fingers.

Responsiveness,

Irritability or the ability to sense changes (stimuli) in the environment and then to react to them

Digestion

The process of breaking down ingested food into simple molecules that can then absorbed into the blood

Metabolism

Refers to all chemical reactions that occur within the body and all of its cells

Excretion

The process of removing excreta or wastes, from the body

Reproduction

The production of offspring, can occur on the cellular or, organismal level

Growth

An increase in cell size or an increase in body size that is usually accomplished by an increase in the number of cells

Nutrients

Which the body takes in through food, contain the chemicals used for energy and cell building

Carbohydrates

Major energy-providing fuel for body cells

Fats

Essential for building cell structures

Proteins

Large, vital macromolecules built from chains of amino acids

Minerals and vitamins

Required for the chemical reactions that go on in cells and for oxygen transport in the blood

Oxygen

The chemical reactions that release energy from foods require this, human cells can survive for only a few minutes without it

Water

Accounts for 60 to 80 percent of body weight

Water

Most abundant chemical substance in the body and provides the fluid base for body secretions and excretions

Normal body temperature

Must be maintained, 37°C (98.6°F)

Atmospheric Pressure

The force exerted on the surface of the body by the weight of air

Anatomical Position

The body is erect with the feet parallel and the arms hanging at the sides with the palms facing forward

Anatomical Position

To accurately describe body parts and position, we must have an initial reference point and use directional terms

Directional terms

Allow medical personnel and anatomists to explain exactly where one body structure is in relation to another

Superior

(Cephalic) toward the head or upper part

Inferior

(Caudal) Away from the head or toward the lower part

Anterior

(Ventral)