Human Body in Health & Disease

Chapter 2

BRANCHES OF SCIENCE THAT STUDY THE HUMAN BODY

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 2nd to the 8th 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

BODY IN GENERAL

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.

ADDITIONAL 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