Download Human Body Systems

Human Body Systems
Section 35-1 pgs 891-896
Organization of the Body
● Every cell in the body is both an independent
unit and an interdependent part of a larger
community: the entire organism.
● The levels of organization in a multicellular
organism include cells, tissues, organs, and
organ systems.
Organization of the Body
● A cell is the basic unit of structure and function
in living things.
● Individual cells in multicellular organisms tend
to be specialized.
● Specialized cells are uniquely suited to perform
a particular function.
Organization of the Body
● Tissues are groups of similar cells that perform
a single function, such as connecting a muscle
to a bone.
● There are four basic types of tissue in the
human body.
Organization of the Body
● Epithelial tissue includes glands and tissues
that cover interior and exterior body surfaces.
● Connective tissue provides support for the body
and connects its parts.
● Nervous tissue transmits nerve impulses
throughout the body.
Organization of the Body
● Muscle tissue, along with bones, enables the
body to move.
● An organ is a group of tissues that work
together to perform a complex function.
Organization of the Body
● The eye is an organ made up of epithelial
tissue, nervous tissue, muscle tissue, and
connective tissue.
● All of these tissues work together for a single
function: sight.
Organization of the Body
● An organ system is a group of organs that
perform closely related functions.
● The eleven organ systems of the human body
work together to maintain homeostasis in the
body.
Human Organ Systems
● The nervous system recognizes and coordinates
the body’s response to changes in its internal
and external environments.
● The structures within this system include the
brain, spinal cord, and peripheral nerves.
Human Organ Systems
● Skin, hair, nails, and sweat and oil glands are
all structures within the integumentary system.
● This system serves as a barrier against
infection and injury, helps to regulate body
temperature, and provides protection against
ultraviolet radiation from the sun.
Human Organ Systems
● The respiratory system includes the nose,
pharynx, larynx, trachea, bronchi, bronchioles,
and lungs.
● This system provides oxygen needed for
cellular respiration and removes excess CO2
from the body.
Human Organ Systems
● The mouth, pharynx, esophagus, stomach,
small and large intestines, and the rectum are
all structures within the digestive system.
● The digestive system converts food into simpler
molecules that can be used by the cells of the
body, absorbs food, and eliminates wastes.
Human Organ Systems
● The excretory system eliminates waste
products from the body in ways that maintain
homeostasis.
● The skin, lungs, kidneys, ureters, urinary
bladder, and urethra are all structures in this
system.
Human Organ Systems
● Bones, cartilage, ligaments, and tendons are all
parts of the skeletal system.
● This system supports the body, protects
internal organs, allows movement, stores
mineral reserves, and provides a site for blood
cell formation.
Human Organ Systems
● The muscular system works with the skeletal
system to produce voluntary movement, helps
to circulate blood, and moves food through the
digestive system.
● Skeletal muscle, smooth muscle and cardiac
muscle are the structures in this system.
Human Organ Systems
● The heart, blood vessels and blood are
structures in the circulatory system.
● This system brings oxygen, nutrients, and
hormones to cells, fights infection, removes cell
wastes, and helps to regulate body temperature.
Human Organ Systems
● The endocrine system controls growth,
development, and metabolism, and maintains
homeostasis.
● Structures in this system include the
hypothalamus, pituitary, thyroid, parathyroids,
adrenals, pancreas, ovaries, and testes.
Human Organ Systems
● Testes, epididymis, vas deferens, urethra and
penis (in males) and ovaries, Fallopian tubes,
uterus, and vagina (in females) are structures
in the reproductive system.
● Produces reproductive cells, and, in females,
nurtures and protects developing embryo.
Human Organ Systems
● The lymphatic/immune system helps protect the
body from disease, collects fluids lost from blood
vessels and returns the fluid to the circulatory
system.
● The structures within this system include white
blood cells, thymus, spleen, lymph nodes, and lymph
vessels.
Maintaining Homeostasis
● You can get a glimpse of the interrelationship of
your body when you breathe deeply after climbing
a steep hill or when your blood clots to seal a cut.
● Your organ systems are working to maintain a
controlled, stable environment through
homeostasis.
Maintaining Homeostasis
● Homeostasis is controlled by a process called
feedback inhibition.
● Feedback inhibition, or negative feedback is the
process in which a stimulus produces a response
that opposes the original stimulus.
Maintaining Homeostasis
● An example of this process is easily seen in a home with
a good heating system.
● First, the room temperature decreases and the
thermostat senses that change and switches on the
heating system.
● Then, when the room temperature increases, the
thermostat senses that change and turns the system off.