Overview of Anatomy and Physiology
Anatomy – the study of the structure of body parts and their
relationships to one another
- Gross or macroscopic
- Microscopic
- Developmental
Gross Anatomy
- Regional – all structures in one part of the body (such as the abdomen or leg)
- Systemic – gross anatomy of the body studied by system
- Surface – study of internal structures as they relate to the overlying skin
Microscopic Anatomy
- Cytology – study of the cell
- Histology – study of tissues
- Traces structural changes throughout life
- Embryology – study of developmental changes of the body before birth
- Pathological anatomy – study of structural changes caused by disease
- Radiographic anatomy – study of internal structures visualized by X ray
- Molecular biology – study of anatomical structures at a subcellular level
Considers the operation of specific organ systems
- Renal – kidney function
- Neurophysiology – workings of the nervous system
- Cardiovascular – operation of the heart and blood vessels
Understanding physiology also requires a knowledge of
physics, which explains electrical currents, blood pressure, and the way muscle
uses bone for movement
Principle of Complementarity
- Function always reflects structure
- What a structure can do depends on its specific form
- Chemical – atoms combined to form molecules
- Cellular – cells are made of molecules
- Tissue – consists of similar types of cells
- Organ – made up of different types of tissues
- Organ system – consists of different organs that work closely together
- Organismal – made up of the organ systems
Organ Systems of the Body
Integumentary system
- Forms the external body covering
- Composed of the skin, sweat glands, oil glands, hair, and nails
- Protects deep tissues from injury and synthesizes vitamin D
- Composed of bone, cartilage, and ligaments
- Protects and supports body organs
- Provides the framework for muscles
- Site of blood cell formation
- Stores minerals
- Composed of muscles and tendons
- Allows manipulation of the environment, locomotion, and facial expression
- Maintains posture
- Produces heat
- Composed of the brain, spinal column, and nerves
- Is the fast-acting control system of the body
- Responds to stimuli by activating muscles and glands
- Composed of the heart and blood vessels
- The heart pumps blood
- The blood vessels transport blood throughout the body
- Composed of red bone marrow, thymus, spleen, lymph nodes, and lymphatic vessels
- Picks up fluid leaked from blood vessels and returns it to blood
- Disposes of debris in the lymphatic stream
- Houses white blood cells involved with immunity
- Composed of the nasal cavity, pharynx, trachea, bronchi, and lungs
- Keeps blood supplied with oxygen and removes carbon dioxide
- Composed of the oral cavity, esophagus, stomach, small intestine, large intestine, rectum, anus, and liver
- Breaks down food into absorbable units that enter the blood
- Eliminates indigestible foodstuffs as feces
- Composed of kidneys, ureters, urinary bladder, and urethra
- Eliminates nitrogenous wastes from the body
- Regulates water, electrolyte, and pH balance of the blood
- Composed of prostate gland, penis, testes, scrotum, and ductus deferens
- Main function is the production of offspring
- Testes produce sperm and male sex hormones
- Ducts and glands deliver sperm to the female reproductive tract
- Composed of mammary glands, ovaries, uterine tubes, uterus, and vagina
- Main function is the production of offspring
- Ovaries produce eggs and female sex hormones
- Remaining structures serve as sites for fertilization and development of the fetus
- Mammary glands produce milk to nourish the newborn
- The integumentary system protects the body from the external environment
- Digestive and respiratory systems, in contact with the external environment, take in nutrients and oxygen
Necessary Life Functions I
Maintaining boundaries – the internal environment remains
distinct from the external
- Cellular level – accomplished by plasma membranes
- Organismal level – accomplished by the skin
Responsiveness – ability to sense changes in the environment
and respond to them.
Digestion – breakdown of ingested foodstuffs.
Necessary Life Functions II
Metabolism – all the chemical reactions that occur in the
body.
Excretion – removal of wastes from the body.
Reproduction – cellular and organismal levels.
- Cellular – an original cell divides and produces two identical daughter cells
- Organismal – sperm and egg unite to make a whole new person
Growth – increase in size of a body part or of the organism.
Survival Needs
- Nutrients – chemical substances used for energy and cell building
- Oxygen – needed for metabolic reactions
- Water – provides the necessary environment for chemical reactions
- Maintaining normal body temperature – necessary for chemical reactions to occur at life-sustaining rates
- Atmospheric pressure – required for proper breathing and gas exchange in the lungs
- Homeostasis is the ability to maintain a relatively stable internal environment in an ever-changing outside world
- The internal environment of the body is in a dynamic state of equilibrium
- Chemical, thermal, and neural factors interact to maintain homeostasis
The variable produces a change in the body.
The three interdependent components of control mechanisms
are:
- Receptor – monitors the environments and responds to changes (stimuli)
- Control center – determines the set point at which the variable is maintained
- Effector – provides the means to respond to the stimulus
Homeostatic Control Mechanisms
Negative Feedback
- In negative feedback systems, the output shuts off the original stimulus
- Example: Regulation of blood glucose levels
Positive Feedback
Homeostatic Imbalance
- Disturbance of homeostasis or the body’s normal equilibrium
- Overwhelming of negative feedback mechanisms allowing destructive positive feedback mechanisms to take over
