skeletal, skin, muscle. nervous ppt
Post on 21-May-2015
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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)
• 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
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
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)
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
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
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)
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
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)
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)
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
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
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
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
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
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
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
Cont.
• 75% of the air you breathe is dead skin cells
• Body replaces skin every 3 weeks
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
• 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
• 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
• 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
• 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
• 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
• 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
• 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
• 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
• 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
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