An Overview of Anatomy & Physiology

Chapter 1

Keys Skills for Success Mastery of the medical terminology

Development of excellent observation skills

Anatomy is the study of the structure of body parts and their relationships to each other

Physiology is the study of the function of the body parts

Topics of AnatomyGross (Macroscopic) – the study of structures

large enough to see with the unassisted eye- 3 subcategories: Regional, Systemic and

Surface

Microscopic - study of structures too small to be seen with the unassisted eye

- 2 sub categories: Cytology and Histology

Developmental – study the changes of structures over the course of a lifetime- Embryology

Specialized Branches – - 3 subcategories: Pathological,

Radiographic, and Molecular Biology

Topics of PhysiologyCovers several topics; most of which are particular to the function of a specific organ system

Focuses on the cellular and molecular events

Complementarity of Structure & FunctionFunction is dependent on the structure and the form of the structure relates to its function

Addage: “Form vs. Function”

Levels of Organization 6 different levels of organization

Each level has specific functions and features

Chemical Level of OrganizationAtoms are the tiny building blocks of

matter which combine to form molecules

Molecules combine in specific ways to form organelles, which are the basic unit of living cells

Cellular Level of OrganizationCells are the smallest unit of life

Vary widely in size and shape based on the function of the cell

Tissue Level of OrganizationGroups of cells that perform a common function

Organ Level of OrganizationA groups of discrete structures

composed of at least 2 groups of tissue that work together to perform a specific function

Examples include: Lungs, Heart, Liver, Small Intestine

Organ System Level of OrganizationGroup of organs that work in conjunction

with each other to accomplish a specific goal or purpose

Examples are: Skeletal, Digestive, Respriratory, Circulatory, Muscular, Nervous, Reproductive

Organismal Level of OrganizationThe total of all the level working

together to promote and maintain life

Maintaining LifeNecessary Life Functions- Maintaining boundaries- Movement- Responsiveness- Digestion- Excretion- Reproduction- Growth

Survival Needs- Nutrients- Oxygen- Water- Normal Body Temperature- Atmospheric Pressure

HomeostasisHomeostasis - the ability of the

body to maintain a relatively constant internal environment regardless of the external environment.

Most homeostatic imbalance is result of disease

Homeostatic ControlComponents- Variable: the regulated factor or event- Receptor: Structure that monitors changes in

the environment and sends information to the control center

- Control Center: Structure that determines the set point for the variable, analyzes input and coordinates an appropriate response

- Effector: Structure that carries out the response directed by the control center

Negative feedback mechanisms- Most homeostatic control mechanisms are

classified as negative feedback mechanisms- Causes the variable to change in a way the

opposes the initial change- Nervous and Endocrine systems are

importance to the maintenance of homeostasis

- The goal is to prevent sudden, severe changes in the body

Positive Feedback Mechanisms- Causes the variable to change in the same

direction and the original change resulting in a greater deviation for the start point

- Typically activate self perpetuating events

- Most are not related to the maintenance of homeostasis

Language of Anatomy- must know the terms on pgs 12 & 15

Anatomical Position and Directional Terms

- Directional terms are used to explain EXACTLY where on body part is in relation to another

- Anatomical Position is the position in which the body is erect, palms face forward, and thumbs point away from the body- Terms left and right refer to the sides of

the person viewed not the observer- Anatomical position is ALWAYS assumed

regardless of the position of the body

Regional Terms- Two fundamental divisions of the body

- Axial region includes the head, neck and trunk- Appendicular region include the upper and

lower limbs

- Regional terms designate specific areas within the axial and appendicular divisions

Body Planes and Sections- Planes are flat surfaces that lie at right angles

to each other - Frontal plane: a vertical plane the separates the

body into anterior and posterior parts- Transverse plane: a horizontal plane that

separates the body from right to left into superior and inferior parts

- Sagittal: vertical plane that separates the body into left and right parts- Median (midsagittal): lies exactly along the body’s

midline- Parasagittal: lies offset from the midline of the body

Sections are cuts made along specific planesTransverse: is a cut made along the transverse planeOblique: is a cut made at anglesbetween the horizontal and vertical planes

Body Cavities and Membranes- Body cavities are spaces w/in the body that

are closed to outside and contain internal organs

- The dorsal cavity is the space that houses the central nervous system and has two subdivisions- Cranial Cavity - Vertebral / Spinal

Cavity- The ventral cavity is the anterior space that

is larger and has two subdivisions- Thoracic Cavity - Abdominopelvic

Cavity

Ventral body cavity houses the body organs or visceraMembranes

-Serosa membranes cover the inner walls of ventral cavity and outer surfaces of the organs- Parietal serosa line body cavity walls and is named for the specific cavity it is associated with- Visceral serosa cover the outer surfaces of organs and is named for the specific organ associated with

Secrete and are separated by a thin layer of lubrication called Serous Fluid, allows organs to slide without friction in the cavity

Abdominpelvic Region and Quadrants- There are 9 abdominopelvic regions used by

anatomists

- There are 4 quadrants used by medical personnel

Other body cavities- Oral and digestive: extend from the mouth

through the anus- Nasal: within and posterior to the nose- Orbital: houses the eyes- Middle ear: house the ear bones and

transmit sound- Synovial: joint cavities that secrete

lubricating fluid, found in all movable joints