How many organ systems
can you name?
 On your paper list as many organ
systems as you can.
 ****BELLRINGER*****
What are living things
made of?
Cells, Tissues,
Organs, and Organ
Systems
Living Things
 A living thing is an organism.
 A structure is a body part that does a
certain job for an organism.
 The function of a structure is the job it
does for the organism.
Living things have
five basic life functions:
 Grow and develop (mitosis:
asexual reproduction)
 Use energy (they get energy by
eating and breaking down food:
cellular respiration
or making food: photosynthesis)
 Reproduce
 Respond to the environment
 Get rid of waste
Cells, Tissues, Organs,
and Organ Systems
 A cell is the smallest unit of living matter;
the building block of a living thing.
 Tissues are groups of cells working
together to perform a certain job.
 Organs are groups of tissues that
perform a certain function.
 Organs working together to carry out a
certain life function are an organ system.
Organ Systems and Homeostasis
The Human Body!
Homeostasis
 All of the body systems work together
to maintain homeostasis.
 This is the process by which an
organism’s internal environment is
kept stable in spite of changes in the
external environment.
The 11 Human Body Systems
The 11 human body systems are as follows:
-- nervous system
-- integumentary system
-- respiratory system
-- digestive system
-- excretory system
-- skeletal system
-- muscular system
-- circulatory system
-- endocrine system
-- reproductive system
-- lymphatic (immune) system
The Digestive System
Purpose: to convert food particles into simpler
micromolecules that can be absorbed into the
bloodstream and used by the body
Major Organs and their Functions:
Mouth – to chew and grind up food
-- saliva also begins the chemical breakdown
Esophagus – pipe connecting mouth to stomach
Stomach – secretes an acid that breakdowns food
Pancreas – produces the hormone insulin that regulates
blood sugar levels
Liver – produces bile, which breaks down fats in foods
Gallbladder – pouch-like organ that stores bile for future use
Small Intestine – after digestion is complete, waste enters the
small intestine where it is absorbed into the bloodstream
Large Intestine – removes water from the waste and gets the
waste ready for excretion
Reproductive System
 Function: contains
organs that produce
sex cells (called
gametes) and
produces chemicals
that regulate physical
development of
maturing bodies.
 Females: Produces
eggs; grows and
nourishes the fetus
 Males: Produces
sperm
The Excretory (Urinary) System
Purpose: to rid the body of wastes, including
excess water and salts
The Respiratory System
Purpose: to provide the body with a fresh supply of oxygen
for cellular respiration and remove the waste product carbon
dioxide
Major Organs and Their Functions
Nose
Pharynx
Larynx
Trachea
Bronchi –
-- The diaphragm is the muscle that causes you to breath;
hiccups are involuntary contractions of the diaphragm
The Circulatory System
Purpose: to deliver oxygenated blood to the various cells and
organ systems in your body so they can undergo cellular
respiration
Major Organs
Heart, Arteries, Veins, Capillaries, Spleen
The Nervous System
Purpose: to coordinate the body’s response to changes in its
internal and external environment
Major Organs
Brain
Spinal Cord
Nerves
The Endocrine System
Purpose: to control growth, development, metabolism and
reproduction through the production and secretion of
hormones
Major Organs
-- hypothalamus
-- pituitary gland
-- thyroid
-- parathyroid
-- adrenal glands
-- pancreas
-- testes
-- ovaries
The Skeletal System
Purpose: to provide structure and support to the human
body
Bones are where new blood cells are generated (in the
marrow), and require the mineral calcium for strength
Major Bones of the Human Body
-- femur (thigh bone)
-- humerus (upper arm)
-- radius and ulna (lower arm)
-- cranium (skull)
-- sternum (breastbone)
-- clavicle (shoulder blade)
-- fibula and tibia (calf)
-- vertebrae (back)
-- scalpula (shoulder)
-- pelvic bone
-- coccyx (tail bone)
-- phalanges (fingers/toes)
The Muscular System
Purpose: works with the skeletal and nervous system to
produce movement, also helps to circulate blood through the
human body
-- muscle cells are fibrous
-- muscle contractions can be voluntary or involuntary
Major Muscles in the Human Body
-- biceps
-- triceps
-- glutes
-- hamstrings
-- deltoids
The Lymphatic (immune) System
Purpose: to remove infectious diseases and other pathogens
from the human body
Major Organs and Their Functions
Lymph Nodes – help restore fluid lost by the blood and return
it to the circulatory system
White Blood Cells-
fight diseases & pathogens
Integumentary System
 Purpose: provides a
barrier and protection
for your body.
 Organs: skin, hair,
and nails
 This is the largest
organ system!!!!
Review
 What are the 4 levels of organization of
living things?
 What are the 11 organ systems of the
human body?