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 diseasecausing 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