Human Body in Health & Disease Chapter 2

B RANCHES OF S CIENCE THAT S TUDY THE H UMAN B ODY

Anatomy Means “cutting apart” (dissection) Study of the structures of the body & the relationships of its parts to each other Dissection is used to study the structure of the human body

Biology Study of all forms of life and living things

Embryology Study of the origin and development of an organism Covers from 2 nd to the 8 th week after conception, the embryonic state After 8 weeks, the developing organism is known as a fetus

Histology Study of the body microscopically Studies the minute structures and their composition, plus the functions of normal cells, tissue and organs

Pathology Study of the changes in the human body which are caused by disease Study changes due to disease that alter the function of the body

Physiology Studies the normal activity and functions of the body

B ODY IN G ENERAL

Body in General Cells are the basic unit of life Trillions of cells that vary in size and shape according to the purpose Specialized cells are responsible for the functions of growth, secretions, excretions, nutrition, and reproduction Mechanical, chemical and nervous stimulation activate the cells

Body in General Cells group together to form tissues Tissues form organs Organs form body systems

Cell Types Epithelial cells Protective covering cells, linings May be square and flat Fat cells – contain large vacant spaces for fat storage Muscle cells – long and slender Nerve cells – may be long & have fingerlike extensions, which carry impulses

Tissues Connective tissue Supports and encases body structures Most widespread kind of tissue Holds organs in place and connects body parts to each other

Tissue Types Main types; Bone Cartilage Dense fibrous Loose Adipose – provides protective padding, insulation, and support and is a nutrient reserve. Made up of fat cells.

Epithelial tissue Found in the skin and lining of blood vessels Makes up the outer covering of external and internal body surfaces and the lining of the digestive, respiratory, and urinary tracts

Muscle Tissue Provides movement Main function is to contract Has the ability to contract and relax

Nerve Tissue Conducts impulse to and from the brain Is composed of nerve cells called neurons Needs more oxygen and nutrients than any other body tissue

Organs When 2 or more kinds of tissues work together Although they act as units, they do not function alone Several organs join together to form a system and perform a body function Each system has a special function

Systems Cardiovascular Includes the heart & blood vessels Carries the blood throughout the body Digestive or gastrointestinal Includes the mouth, esophagus, stomach, and small and large intestine Digests & absorbs food and excretes waste

Systems Endocrine Made up a variety of glands Manufactures & distributes hormones Integumentary system Includes hair, skin, nails, sweat glands, and oil glands Helps protect the body

Systems Lymphatic Works with the cardiovascular system Helps protect the body against disease- causing organisms Musculoskeletal Composed of bones, muscles, tendons, & ligaments Provides body framework (skeletal system) Supports organs Permits movement

Systems Reproductive Includes the uterus, ovaries, testes, and prostate Provides for reproduction Respiratory Includes the trachea, lungs, & bronchi Provides for the exchange of gases Absorbs O2 Expels CO2

Systems Sensory or special senses Made up of eyes, ears, nose, mouth, skin & nerves Acts as the body’s external perception/alarm system

Systems Nervous system Brain, spinal cord and nerves Allows the body to act and respond Urinary system Manufactures and excretes urine by filtering the blood and removing waste Includes the kidneys, ureter, urinary bladder, and urethra

All of the systems in the body work together to maintain homeostasis. Home/o ; like, similar, same -stasis; condition of balance, no change Homeostasis is the body’s constant internal environment. Ex. - Not too hot or cold. Plenty of water but not too much. Etc.

A DDITIONAL WORD PARTS

Cyt/o - cell Epitheli/o - epithelium Fibr/o - fibrous Hist/o - tissue Lip/o - fat Organ/o - organ Viscer/o – internal organs -cyte - cell -gen – agent that causes -genic - producing -oma – tumor -osis – abnormal condition -pathy - disease -plasm – growth or formation -sarcoma – malignant tumor