Human Physiology

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Human Physiology

• By Sydney Hollingshead
• Biology
• Mr. Thiel
• 7 period
• 4/23/07

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Skeletal
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Function

• Supports body
• Protection for organs
• Allows wide range of motion
• Place for muscles to attatch
• Stores mineral reserves
• Site for blood cell formation

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Structures

• Bone
• Stiff, brittle, dense outer and soft inner
• Has blood cells and nerves running through
• Cartilage
• Flexible, supportive connective tissue - cushions
  bones
• Ligaments
• Tough connective tissue - hold bones together
• Tendon
• Tough connective tissue - holds skeletal muscles
  to bones
• Marrow
• Inside bone cavities in center, soft tissue,
  yellow red

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Process

• Strong bones hold up body and deflect damage to
  organs
• Muscles attatch w/ tendons
• Bones store calcium
• When excess calcium in body, bones take it out of
  blood, grow or store
• 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

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Circulatory
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Structures

• Heart
• Blood vessels
• Blood

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Function

• Brings oxygen, nutrients, hormones to cells
• Fights infection
• Regulates body temperature

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Process

• Heart
• Pumps blood throughout the body
• Four chambers allows two seperate pathways for
  blood
• blood with different amounts of oxygen and carbon
  dioxide wont mix together,oxygenated blood is
  sent to muscles and CO2 blood sent to lungs
• Arteries
• Large vessels, carry blood to tissues,
  oxygen-rich blood
• Thick walls, can expand under pressure
• Smooth muscle in arteries control diameter
• Viens, cappilaries, blood cells, platelets,

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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

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Process continued

• Blood Cells
• 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
• White Blood Cells attack foreign substances and
  organisms
• Dont 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
• Aids in blood clotting

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Nervous
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Structures

• Brain
• Spinal Cord
• Peripheral Nerves
• Neurons, impulses, synapses

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Function

• Coordinates bodys response to changes in
  internal external environments
• Utilizes feedback loops to achieve homeostasis
• 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
• When temp. increases, brain tells body to slow
  down, stop movement, lethargy occurs, so body
  wont overheat
• Ex. Bones draw calcium from bloodstream or
  release back into bloodstream when needed

Standard 1c
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Process

• Carries messages to body from brain
• Brain control center
• Cerebrum voluntary actions
• Cerebellum coordinates balances motion
• Brain Stem connects brain spinal cord,
  regulate information flow, blood pressure, heart
  rate, breathing, swallowing
• Spinal Cord major telephone line
• Main link from brain to rest of body
• Controls reflexes

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Process continued

• Peripheral nerves
• Sensory(senses)
• 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
• Motor(movement) division
• Motor somatic and autonomic
• Somatic conscious movement, some reflexes
• Autonomic involuntary(heartbeat, digestion)
• Sympathetic and parasympathetic create a feedback
  loop

Standard 1b Standard 1c
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Process continued

• Neurons
• 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
• Standard 1d
• Standard 1e

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Muscular
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Structures

• Skeletal Muscle
• Smooth Muscle
• Cardiac Muscle

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Function

• Produces voluntary movement w/ help of skeletal
  system
• Helps circulate blood
• Helps move food through digestive system

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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)

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Muscular Contraction

• 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
• Standard 1h

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Digestive
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Structures

• Mouth
• Pharynx
• Esophagus
• Stomach
• Small/large intestines

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Function

• Converts foods into simpler molecules that can be
  used by the cells of the body
• Absorbs food

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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

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Process continued

• Stomach
• Stomach acid(hydrochloric), makes stomach
  contents acidic
• Triggers pepsin enzyme, pepsinhydrochloric acid
  begins protein digestion (standard 1f)
• Pancreas/Liver
• Pancreas produces more enzymes(lipases,
  proteases, nucleases) and neutralizes stomach
  acid so these enzymes wont be destroyed
• 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)

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Process continued

• Small Intestine
• Most chemical digestion is complete
• Small intestine absorbs nutrients through villi
• Large Intestine
• Food is mostly nutrient-free
• Removes water from indigestible material left

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Reproductive
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Structures

• Testes
• Epididymis
• Vas deferens
• Urethra
• Penis
• Ovaries
• Fallopian Tubes
• Uterus
• Vagina

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Function

• Produces reproductive cells
• (females) nurtures, protects developing embryo

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Process

• Males
• Sperm are produced in testes
• Cells in testes undergo meiosis to form haploid
  structure
• Sperm move into epididymis to fully mature and be
  stored
• Move to vas deferens, into urethra, then to penis
• Sperm are released through ejaculation(regulated
  by autonomic nervous system)

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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

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Process continued

• 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

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Endocrine
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Structures

• Hypothalamus
• Pituitary
• Thyroid
• Parathyroids
• Adrenals
• Pancreas
• Ovaries
• testes

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Function

• Controls
• growth
• development
• metabolism
• reproduction

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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

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Process continued

• Feedback loop
• 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

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Excretory
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Systems

• Skin
• Lungs
• Kidneys
• Ureters
• Urinary bladder
• Urethra

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Function

• Eliminates waste products of metabolism from body
• Maintains homeostasis

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Process

• Blood passes through the kidney and waste
  products are trapped and excreted as urine
• Many nutrients are returned to the blood after
  filtration through reabsorption
• 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)

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Process continued

• Skin excretes water, salts, and urea through
  sweat
• Lungs excrete carbon dioxide
• Blood returns carbon dioxide from body/heart
  through capillaries in lungs, receive oxygen and
  return to heart/body (standard 1a)

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Lymphatic
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Systems

• White blood cells
• Thymus
• Spleen
• Lymph nodes
• Lymph vessels

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Function

• Helps protect body from disease
• Collects fluid lost from blood vessels and
  returns fluid to circulatory system

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Process

• White blood cells attack foreign
  substances/organisms
• Network of vessels collect lymph(fluid lost by
  blood)
• Collects in lymphatic capillaries, slowly move
  into larger vessels, prevented from backwards
  flow by valves
• Returned directly to heart
• Lymph nodes filter lymph
• Trap bacteria disease-causing micro-organisms
• Become swollen with large amounts
• Nodes also absorb fat and fat-soluble vitamins
  from intestines and put it directly into blood

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Immune System

• Skin provides first, nonspecific defense against
  disease (standard 2a)
• Dead skin cells are hard to penetrate
• Oil sweat create an acidic environment
• Antibodies destroy pathogens that enter body
  through wounds or otherwise
• When attached en masse to an antigen, attract
  white blood cells to engulf entire mass

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Immune System continued

• Vaccinations introduce mild forms of a pathogen
• Stimulates body to create specific antibodies
  while not being strong enough to harm the human
• Bacteria V.S. Virus
• Bacteria reproduce through division
• Viruses inject their DNA into another cell to
  reproduce
• 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
• 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

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Immune System continued

• Phagocytes white blood cells
• Consume bacteria other foreign objects
• B-lymphocytes
• Produce antibodies
• T-lymphocytes
• Assist and regulate release of antibodies
• Attack antigen-bearing cells directly

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Respiratory
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Structures

• Nose
• Pharynx
• Larynx
• Trachea
• Bronchi
• Bronchioles
• Lungs

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Function

• Provides oxygen needed for cellular respiration
• Removes excess carbon dioxide from body

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Processes

• Air is sucked into mouth/nose
• Passes through pharynx and into trachea
  (windpipe) larynx produces sound
• Air enters bronchi, then to lungs
• Bronchi divides into bronchioles, then into dead
  ends called alveoli
• Each alveoli surrounded by net of capillaries,
  where gas exchange takes place
• Diaphragm
• 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 wont occur

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Integumentary
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Systems

• Skin
• Hair
• Nails
• Sweat/oil glands

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Function

• Barrier against infection/injury
• Regulates body temperature
• Provides protection against UV radiation from sun

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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

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Bibliography

• Miller, Kenneth and Joseph Levine. Biology. New
  Jersey Prentice Hall, 2002.
• Thiel, Eric. Biology teacher, Amador Valley High
  School. Lecture. 17 Apr. 2007.

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Standards

• 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 bodys 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, Ca2, and ATP
• 1i. Students know how hormones provide internal
  feedback mechanisms for homeostasis at the
  cellular level and in whole organisms.

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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
  bodys 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 bodys 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