lec1 anatomy

Anatomy Dr.Israa H. Mohsen

Lecture 1


ORIENTATION TO THE HUMAN BODY

The structure of the body, anatomy, is closely entwined with how it functions, physiology.

The study of the processes that disturb normal function is called pathophysiology. (Patho means suffering or disease; therefore, pathophysiology refers to diseased functioning.)

Organization of the Body
The human body is organized in a hierarchy, ranging from the very simple (a microscopic atom) to the very complex (a human being). Specifically:



ATOMS link together to form…


MOLECULES. Molecules are organized into various structures, including…

ORGANELLES, the metabolic units within a cell that perform a specific function necessary to the life of the cell. Examples include mitochondria—the powerhouses that furnish the cell’s energy—and the cell’s nucleus. Organelles are contained within…



ORGANS, which are structures of two or more tissue types working together to carry out a particular function. Examples include the heart, stomach, and kidney.
Organs then form…
TISSUES, which are specialized groups of cells with similar structure and function.Tissues come together to form…

CELLS, the smallest living units that make up the body’s structure. Cells group together to form…


ORGAN SYSTEMS, which are groups of organs that all contribute to a particular function. All of the organ systems together form…


A HUMAN ORGANISM: one complete individual.





Organ Systems
The human body consists of 11 organ systems. The organs of each system contribute to a particular function. However, some organs belong to more than one system. Specifically, the pharynx is part of both the respiratory and the digestive systems, and the male urethra belongs to both the reproductive and urinary systems.




Consists of skin, hair, and nails
Key functions:
• Protection
• Temperature regulation
• Water retention
• Sensation
Consists of bones, cartilage, and ligaments
Key functions:
• Protection of body organs
• Support
• Movement
• Blood formation
Consists primarily of skeletal muscles
Key functions:
• Movement
• Posture
• Heat production

Consists of lymph nodes, lymphatic vessels, lymph, thymus, spleen,
and tonsils
Key functions:
• Role in fluid balance
• Production of immune cells
• Defense against disease
Consists of the nose, pharynx, larynx, trachea, bronchi, and lungs
Key functions:
• Absorption of oxygen
• Discharge of carbon dioxide
• Acid-base balance
• Speech

Consists of the kidneys, ureters, urinary bladder,
and urethra
Key functions:
• Excretion of wastes
• Regulation of blood volume and pressure
• Control of fluid, electrolyte, and acid-base balance


Consists of the brain, spinal cord, nerves, and sense organs
Key functions:
• Control, regulation, and coordination of
other systems
• Sensation
• Memory
Consists of the pituitary gland, adrenals, pancreas, thyroid, parathyroids, and other organs
Key functions:
• Hormone production
• Control and regulation of other systems
Consists of the heart, arteries, veins, and capillaries
Key functions:
• Distribution of oxygen, nutrients, wastes, hormones, electrolytes, immune cells, and
antibodies
• Fluid, electrolyte, and acid-base balance

Consists of the stomach, small and large intestines, esophagus, liver, mouth, and
pancreas
Key functions:
• Breakdown and absorption of nutrients
• Elimination of wastes

Consists of the testes, vas deferens, prostate, seminal vesicles, and penis
Key functions:
• Production and delivery of sperm
• Secretion of sex hormones

Consists of the ovaries, fallopian tubes, uterus,
vagina, and breasts
Key functions:
• Production of eggs
• Site of fertilization and fetal development
• Birth
• Lactation
• Secretion of sex hormones




Directional Terms
Directional terms are generally grouped in pairs of opposites. The terms right and left always refer to the patient’s right and left side.




Body Planes
Body planes divide the body, or an organ, into sections.

Sagittal Plane
• Divides the body lengthwise into right and left sides
• Called a midsagittal plane if the section is made exactly at midline
• Often used in illustrations to reveal the organs in the head or pelvic cavity
Transverse Plane
• Divides the body horizontally into upper (superior) and lower (inferior) portions
• Also called a horizontal plane
• Used to reveal internal organs

Frontal Plane
• Divides the body lengthwise into anterior and posterior portions
• Also called a coronal plane
• Often used in illustrations to show the contents of the abdominal and thoracic cavities
Note:
The frontal plane is also called a coronal
plane because the line of the plane crosses
the top, or crown, of the head. The word
coronal comes from a Latin word meaning
crown.







Body Cavities
The body contains spaces—called cavities—that house the internal organs. The two major body cavities are the dorsal cavity and the ventral cavity. Each of these cavities is subdivided further, as shown below.



Abdominal Regions and Quadrants
Because the abdominopelvic cavity is so large, and because it contains numerous organs, it’s divided further into regions (which are used to locate organs in anatomical studies) as well as quadrants (which are used to pinpoint the site of abdominal pain).
Abdominal Regions
The illustration below shows the location of the nine abdominal regions. The chart beside it lists some (but not all) of the organs found in each quadrant. Note that some organs, such as the liver, stretch over multiple quadrants.

Abdominal Quadrants
Probably used most frequently, lines intersecting at the umbilicus divide the abdominal region into four quadrants