Transcript Sydney

Human Physiology
By Sydney Hollingshead
Biology
Mr. Thiel
7 period
4/23/07
Skeletal
Function
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Supports body
Protection for organs
Allows wide range of motion
Place for muscles to attatch
Stores mineral reserves
Site for blood cell formation
Structures
 Bone
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Stiff, brittle, dense outer and soft inner
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Has blood cells and nerves running through
 Cartilage
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Flexible, supportive connective tissue - cushions bones
 Ligaments
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Tough connective tissue - hold bones together
 Tendon
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Tough connective tissue - holds skeletal muscles to bones
 Marrow
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Inside bone cavities in center, soft tissue, yellow + red
Process
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Strong bones hold up body and deflect damage to organs
Muscles attatch w/ tendons
Bones store calcium
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When excess calcium in body, bones take it out of blood, grow or store
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When not enough, body needs more, takes out of bones, bones become weaker, more
brittle (Osteoperosis)
Joints provide motion, versus shell or exoskeleton which limits motion
Red marrow produces blood cells
Circulatory
Structures
 Heart
 Blood vessels
 Blood
Function
 Brings oxygen, nutrients, hormones to cells
 Fights infection
 Regulates body temperature
Process
 Heart
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Pumps blood throughout the body
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Four chambers allows two seperate pathways for blood
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blood with different amounts of oxygen and carbon dioxide won’t mix
together,oxygenated blood is sent to muscles and CO2 blood sent to lungs
 Arteries
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Large vessels, carry blood to tissues, oxygen-rich blood
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Thick walls, can expand under pressure
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Smooth muscle in arteries control diameter
 Viens, cappilaries, blood cells, platelets,
Process continued
 Capillaries
 Smallest blood vessels
 Closest to cells of body, passes nutrients, oxygen, absorbs CO2 and
other waste, taken back to heart and into lungs to be disposed
of(standard 1a)
 Thin walls (one cell thick) help nutrients pass through
 Veins
 Bring blood away from body, back to heart
 One-way valves help contain blood against gravity
 Skeletal muscles squeeze veins to push blood back to heart
Process continued
 Blood Cells
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Red blood cells (most common) transport oxygen
 Contain hemoglobin to bind to oxygen
 Produced in red marrow, destroyed in Liver and Spleen
 Doughnut shape, fill with hemoglobin and force out organelles
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White Blood Cells attack foreign substances and organisms
 Don’t have hemoglobin
 Made in red marrow, body can drastically increase number of white
blood cells when fighting an infection
 Also called phagocytes(eating cells), engulf and digest foreign cells (i.e.
cancer cells, allergies, transplanted organs)
 Platelets - fragments of marrow enclose in cell membrane, released into
bloodstream
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Aids in blood clotting
Nervous
Structures
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Brain
Spinal Cord
Peripheral Nerves
Neurons, impulses, synapses
Function
 Coordinates body’s response to changes in internal + external environments
 Utilizes feedback loops to achieve homeostasis
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Ex. – Body temperature
 When temp. drops, involuntary actions occur – appendages are drawn
into the body, goosebumps (make “fur” stand up and trap air against
body for insulation), shivering
Standard 1c  When temp. increases, brain tells body to slow down, stop movement,
lethargy occurs, so body won’t overheat
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Ex. – Bones draw calcium from bloodstream or release back into
bloodstream when needed
Process
 Carries messages to body from brain
 Brain = control center
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Cerebrum = voluntary actions
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Cerebellum = coordinates + balances motion
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Brain Stem = connects brain + spinal cord, regulate information flow, blood
pressure, heart rate, breathing, swallowing
 Spinal Cord = major telephone line
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Main link from brain to rest of body
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Controls reflexes
Process continued
 Peripheral nerves
Standard 1b
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Sensory(senses)
Standard 1c
 Alert the brain to surroundings
 Pain in sensory receptors send message to central nervous system and
back to motor division, causing movement of muscles to remove the
body from pain source
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Motor(movement) division
 Motor = somatic and autonomic
 Somatic = conscious movement, some reflexes
 Autonomic = involuntary(heartbeat, digestion)
 Sympathetic and parasympathetic create a feedback loop
Process continued
 Neurons
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Transmit electrochemical impulses(messages)
 Sensory neurons send impulses from sensory organs to the brain/spinal
cord
 Motor neurons send impulses from brain/spinal cord to muscles and
glands
 Interneurons carry impulses between sensory and motor neurons
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Standard 1d
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Standard 1e
Muscular
Structures
 Skeletal Muscle
 Smooth Muscle
 Cardiac Muscle
Function
 Produces voluntary movement w/ help of skeletal system
 Helps circulate blood
 Helps move food through digestive system
Process
 Muscles produce contraction through chemical processes
 Skeletal muscles control most voluntary movement
 Skeletal muscles attatch to bones by tendons, and pull on bones like
levers
 Joint = fulcrum
 Muscle = force
 Most muscles work in opposing pairs
 Muscle movement helps push oxygen-depleted blood away from
limbs and back to heart against gravity(with prolonged rest, muscles
become “tingly”, due to lack of new, oxygenated blood)
Muscular Contraction
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Nerve impulse
Ca+ released in Endoplasmic Reticulum
Ca+ activates use of ATP by Myosin
Myosin uses ATP to attach to actin Filaments and pull together
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Standard 1h
Digestive
Structures
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Mouth
Pharynx
Esophagus
Stomach
Small/large intestines
Function
 Converts foods into simpler molecules that can be used by the cells of the body
 Absorbs food
Process
 Consumption is necessary – must obtain energy to operate chemical reactions in
the body
 Mouth begins mechanical digestion by breaking down food into fine paste –
molecules are split apart by force
 Digestive enzymes(amylase) in saliva begin chemical digestion – molecules
themselves are broken down (standard 1f)
 Pharnyx = passageway to esophagus
 Esophagus = uses muscles to push chewed food into stomach
Process continued
 Stomach
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Stomach acid(hydrochloric), makes stomach contents acidic
 Triggers pepsin enzyme, pepsin+hydrochloric acid begins protein
digestion (standard 1f)
 Pancreas/Liver
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Pancreas produces more enzymes(lipases, proteases, nucleases) and
neutralizes stomach acid so these enzyme’s won’t be destroyed
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Liver produces bile(fluid containing lipids and salts), dissolves pockets of
fat in fatty foods so enzymes can better break down fat molecules (standard
1f, 1g)
Process continued
 Small Intestine
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Most chemical digestion is complete
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Small intestine absorbs nutrients through villi
 Large Intestine
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Food is mostly nutrient-free
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Removes water from indigestible material left
Reproductive
Structures
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Testes
Epididymis
Vas deferens
Urethra
Penis
Ovaries
Fallopian Tubes
Uterus
Vagina
Function
 Produces reproductive cells
 (females) nurtures, protects developing embryo
Process
 Males
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Sperm are produced in testes
 Cells in testes undergo meiosis to form haploid structure
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Sperm move into epididymis to fully mature and be stored
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Move to vas deferens, into urethra, then to penis
 Sperm are released through ejaculation(regulated by autonomic nervous
system)
Process continued
 Female
 Begins in ovaries, where follicles(immature egg) are contained
 Under influence of FSH and estrogen, follicle gets larger and
undergoes meiosis
 Ovulation occurs – follicle breaks open and egg is released into a
Fallopian tube(can be fertilized here)
 After a few days, enters uterus
 Uterine lining develops, and blood supply increases to receive the
egg
Process continued
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If egg was fertilized, division begins
 After several divisions, egg(now called blastocyst) implants into uterine
lining
 Development begins – after thousands of divisions, cells begin to
specialize and form systems, now called embryo
 Placenta is formed in uterus – connects mother and embryo, provides
nutrition and waste removal
If egg was not fertilized, menstruation begins
 Uterine lining breaks down, discharged, along with blood and egg,
through vagina
Endocrine
Structures
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Hypothalamus
Pituitary
Thyroid
Parathyroids
Adrenals
Pancreas
Ovaries
testes
Function
 Controls:
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growth
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development
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metabolism
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reproduction
Process
 By use of hormones released into bloodstream from glands throughout
the body, messages are broadcast throughout the body and stimulate
certain events
 Internal Feedback Mechanisms
 Ex. When hypothalamus senses low levels of thyroxine in blood,
sends a hormone into bloodstream that only target cells in pituitary
can receive, which produces another hormone sent to the thyroid
gland which produces thyroxine.
 Presence of thyroxine in blood inhibits production of initial
hormone from hypothalamus
 Standard 1i
Process continued
 Feedback loop
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Blood Sugar
 When gets high, pancreas releases insulin to make cell walls more
permeable to sugar, cells take in excess sugar
 When gets low, liver releases glucagon, stored sugar
 Standard 1c
Excretory
Systems
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Skin
Lungs
Kidneys
Ureters
Urinary bladder
Urethra
Function
 Eliminates waste products of metabolism from body
 Maintains homeostasis
Process
 Blood passes through the kidney and waste products are trapped and excreted as
urine
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Many nutrients are returned to the blood after filtration through reabsorption
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Regulatory hormones are released due to the composition of the blood
 Ex. When you eat salty food, kidney will respond by letting less salt
return to the blood through reabsorption (standard 1g)
Process continued
 Skin excretes water, salts, and urea through sweat
 Lungs excrete carbon dioxide
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Blood returns carbon dioxide from body/heart through capillaries in lungs,
receive oxygen and return to heart/body (standard 1a)
Lymphatic
Systems
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White blood cells
Thymus
Spleen
Lymph nodes
Lymph vessels
Function
 Helps protect body from disease
 Collects fluid lost from blood vessels and returns fluid to circulatory system
Process
 White blood cells attack foreign substances/organisms
 Network of vessels collect lymph(fluid lost by blood)
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Collects in lymphatic capillaries, slowly move into larger vessels, prevented
from backwards flow by valves
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Returned directly to heart
 Lymph nodes filter lymph
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Trap bacteria + disease-causing micro-organisms
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Become “swollen” with large amounts
 Nodes also absorb fat and fat-soluble vitamins from intestines and put it directly
into blood
“Immune System”
 Skin provides first, nonspecific defense against disease (standard 2a)
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Dead skin cells are hard to penetrate
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Oil + sweat create an acidic environment
 Antibodies destroy pathogens that enter body through wounds or otherwise
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When attached en masse to an antigen, attract white blood cells to engulf
entire mass
“Immune System” continued
 Vaccinations introduce mild forms of a pathogen
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Stimulates body to create specific antibodies while not being strong
enough to harm the human
 Bacteria V.S. Virus
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Bacteria reproduce through division
 Viruses inject their DNA into another cell to reproduce
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Bacteria are “swallowed” by white blood cells
 Because Viruses takeover cells native to the body, the immune system
does not recognize them as foreign, and they are not attacked
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Bacteria can be treated through medical immune system boosters and
otherwise
 Viral infections cannot be treated after infection occurs; vaccinations
can be given, but viruses mutate and then the vaccination is ineffective
“Immune System” continued
 Phagocytes = white blood cells
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Consume bacteria + other foreign objects
 B-lymphocytes
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Produce antibodies
 T-lymphocytes
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Assist and regulate release of antibodies
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Attack antigen-bearing cells directly
Respiratory
Structures
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Nose
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Lungs
Function
 Provides oxygen needed for cellular respiration
 Removes excess carbon dioxide from body
Processes
 Air is sucked into mouth/nose
 Passes through pharynx and into trachea (windpipe) – larynx produces sound
 Air enters bronchi, then to lungs
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Bronchi divides into bronchioles, then into dead ends called alveoli
 Each alveoli surrounded by net of capillaries, where gas exchange takes
place
 Diaphragm
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Lungs are sealed into sacs, airtight
Diaphragm pulls/pushes at bottom of sacs,
forces air in or out
Chest wounds can puncture airtight sacs and
breathing won’t occur
Integumentary
Systems
 Skin
 Hair
 Nails
 Sweat/oil glands
Function
 Barrier against infection/injury
 Regulates body temperature
 Provides protection against UV radiation
from sun
Processes
 Epidermis
 keeps out bacteria and other outside dangers - waterproof
 Dermis
 Blood vessels can narrow/widen to conserve/release heat
 Sweat removes heat from your body when it evaporates
 Oil secretions keeps epidermis flexible/waterproof
 Hair
 Protects scalp from UV rays, cold insulation
 Nostril/ear canal/eye hair keeps out dirt
 Nails
 Protect end of fingers/toes
Bibliography
 Miller, Kenneth and Joseph Levine. Biology.
New Jersey: Prentice Hall, 2002.
 Thiel, Eric. Biology teacher, Amador Valley
High School. Lecture. 17 Apr. 2007.
Standards
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1a. Students know how the complementary activity of major body systems provides cells with oxygen
and nutrients and removes toxic waste products such as carbon dioxide
1b. Students know how the nervous system mediates communication between different parts of the
body and the body’s interactions with the environment
1c. Students know how feedback loops in the nervous and endocrine systems regulate conditions in the
body.
1d. Student know the functions of the nervous system and the role of neurons in transmitting
electrochemical impulses
1e. Students know the roles of sensory neurons, interneurons, and motor neurons in sensation, thought,
and response
1f. Students know the individual functions and sites of secretion of digestive enzymes, stomach acid,
and bile salts
1g. Students know the homeostatic role of the kidneys in the removal of nitrogeneous wastes and the
role of the liver in blood detoxification and glucose balance.
1h. Students know the cellular and molecular basis of muscle contraction, including the roles of actin,
myosin, Ca+2, and ATP
1i. Students know how hormones provide internal feedback mechanisms for homeostasis at the cellular
level and in whole organisms.
Standards cont.
 2a. Students know the role of the skin in providing nonspecific defenses against
infection
 2b. Students know the role of antibodies in the body’s response to infection
 2c. Students know how vaccination protects an individual from infectious
diseases
 2d. Students know there are important differences between bacteria and viruses
with respect to their requirements for growth and replication, the body’s primary
defenses against bacterial an viral infections, and effective treatments of these
infections.
 2e. Students know why an individual with a compromised immune system may
be unable to fight off and survive infetions by microorganisms that are usually
benign
 2f. Students know the roles of phagocytes, B-lymphocytes, and T-lympocytes in
the immune system