1. Body Organization
• Homeostasis – stable internal environment
• Tissue and organs (hox genes)
• All living organisms have cell(s)
• Multiple similar cells form tissue
• Tissue comes in 4 types
• Epithelial – skin
• Nervous – electrical messages
• Muscle – movement
• Connective – joins, supports, protects, insulates, nourishes
cushions (keeps organs from falling apart)

2. • Two or more tissues working together
form an organ
• Organs that work together are called
organ systems
• cells→tissue →organ →organ system
• The human body has 11 major organ
systems

3. Systems
• Integumentary – skin hair nails, protects
underlying tissue
• Muscular – move bones
• Skeletal – provides frame to support and
protect body parts (brain, heart, lungs and
spinal cord)
• Cardiovascular/circulatory – pumps and
transports fluids and blood

4. Sect 1 Cont.
• Nervous – receives and sends electrical
messages
• Lymphatic – returns leaked fluids to the
blood vessels and fights germs
• Digestive – breaks down food for
nutrients
• Endocrine – regulates body functions
through chemical messages (hormones –
ovaries and testes)

5. Sect 1 Cont.
• Respiratory – lungs absorb O2 and
release CO2
• Excretory – removes waste from the
blood and regulates body fluids
• Reproductive – male produces sperm,
female produces eggs
• S,L,I,M,E R,N C,R,E,D,
• Organ systems help the body maintain
homeostasis by working together

6. Skeletal System
• Skeletal system – bones, cartilage and
structures that connect bones to muscle
• Humans have 206 bones
• Bones are Living
• Used to support, protect, storage, and
blood cell production
• Composed of living cells called
osteoblasts

7. Cont.
• Two types of bone
– Compact – rigid and dense with no visible
space
– Spongy - contains many open space
• Provides strength and support
• Contains red marrow that makes red and
white blood cells (the blood cell factory)

8. Cont
• Cartilage – flexible tissue, the beginning of
bone
• By adulthood, cartilage is replaced by
bone
• Only the nose and ears remain cartilage in
adulthood
• Located between bones (joints) in adults
to cushion bones

9. Sec 2 Cont
• Joint – the place where two bones connect
• Depending on type of joint allows for
movement when muscles contract and
pull on bone
• Types of joints_
– Fixed – very little movement (skull)
– Ball and socket – movement in all directions
(shoulder)

10. Cont
– Hinge – movement in two directions (flex or
extend) knee or elbow
– Sliding – gliding movement, spine
• Ligament – strong bands of connective
tissue that keep joints together (bone to
bone)

11. Muscular System
• Muscular system – made of muscle and
connective tissue that attached muscle to
bone
• Three types of muscle:
– Smooth – found in the digestive track and
blood vessels
– Cardiac – found only in the heart
– Skeletal – attached to bone for movement

12. Cont.
• Muscle action:
• Voluntary – under your control
• Involuntary – not under your control
(smooth muscle and cardiac)
• Tendons – connects muscle to bone
• Muscle movement is caused by electrical
signals transmitted to the brain

13. Cont.
• Muscles pull on bone to create movement
• Muscle movement is in pairs and moves in
two directions
• Flexor – muscle bends
• Extensor – muscle is straightened
• Type of exercise:
• Aerobic – strengthens heart and increase
endurance

14. Cont.
• Resistance – muscle overcomes weigh
• Anabolic steroids – resembles
testosterone (male sex hormone)
• Causes heart, liver, kidney damage, high
blood pressure, stunted growth, roid rage,
infertility

15. Integumentary System
• Integumentary system – skin, hair and
nails
• Integumentary means “covering”
• Keeps H2O in and foreign particles out,
first line of defense for the body
• Largest organ in the body
• Not only on exterior of the body but also
on the interior

16. Cont.
• Melanin – darkening chemical in skin and
hair that determines color
• Located in the upper layer of skin
(epidermis)
• Absorbs UV light
• Two layers of skin:
• Epidermis – (“epi” means on top of) made
of epithelial tissue

17. Cont.
• Thick as two sheets of paper
• Most epidermal cells are dead and filled
with keratin, a protein that makes skin
tough
• Dermis - under the epidermis
• Fibers of protein called collagen
• Where structures of skin are located
• Nerve endings, sweat glands, hair follicles,
blood vessels, muscle fiber, oil glands

18. Cont.
• 75% of the air you breathe is dead skin
cells
• Body replaces skin every 3 weeks

19. Nervous system
• Nervous system – a command post
collecting and processing data
• Two divisions:
• 1. central nervous system (CNS)
– Includes the brain and spinal cord
– Processes all electrical messages coming into
and out of the brain

20. • 2. peripheral nervous system (PNS)
– Made of nerves that connect all areas of the body to
the CNS
• PNS – composed of neurons, specialized cells
that transfer messages in the form of fast
moving electrical signals
• Signals are called impulses, location of impulse
is the synapse
• Impulse can travel as fast as 150 m/s or as slow
as .2 m/s

21. • Neuron structure – neurons consist of a cell
body, dendrites and axons
• Cell body – large region in the center containing
a nucleus and organelles
• Dendrites – short branched extensions that
neurons usually use to gather info from other
cells
• Neurons may have many dendrites which allow
it to receive impulses from thousands of cells

22. • Axon very short or very long fiber used to
transmit info from the cell body
• Some axons have branches called axon
terminals that allow info to travel to other
cells
• Receptors – structures that detect
changes inside and outside the body

23. • Sensory neurons – specialized neurons that
gather info in and around the body
• Motor neurons – neurons that send impulses
from the brain and spinal cord to other systems
“motor” meaning to move
• Nerves – connect CNS to the rest of your body
• Axons bundled together with blood vessels and
connective tissue
• Most carry sensory and motor neurons

24. • CNS – brain, largest organ in the nervous
system
• Processes are describe as involuntary
since the response happens automatically
• Other actions are voluntary, movement is
made consciously

25. • Brain is composed of 3 parts, contains 100
billion neurons
• Cerebrum – largest part of the brain
• Where thinking and memories are stored
• Controls voluntary motion allows for the sense of
touch, light, sound, odors, taste, pain, heat and
cold
• Two hemispheres (halves) the left side directs
the right side of the body and the right side
directs the left side of the body

26. • Left hemisphere controls reading,
speaking, writing and problem solving
• Right side controls imagination,
appreciation, and creativity
• Cerebellum – second largest organ in the
CNS
• Located underneath the back of the
cerebrum

27. • Receives sensory impulses from skeletal
muscle and joints
• Controls balance
• Medulla (oblongata)– connects brain to
spinal cord
• About 3cm long controls all involuntary
activities like heart rate, breathing and
blood pressure

28. • Spinal cord – part of the CNS
• About the size of your thumb
• Composed of neurons and bundles of
axons that pass impulses to and from the
brain
• Protected by the vertebrae
• Injuries can stop sensory info from
traveling