Biology

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Biology

• Anatomy and Physiology

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Organization Within the Body

• Cells- Basic unit of life, smallest functional
  unit within living things
• Cell Specialization- different types fo cells
  complete different tasks within the body
• Tissues- Group of cells working together to
  complete a common task (4 types)
• Organs- A structure made of 4 different types of
  tissues working together to complete a major task
• Organ System- A group of organs working together
  within the body to complete a number of major
  related tasks within the body

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Types of Tissues in the Body

• Epithelial- covers body, and lines digestive
  system and major organs of the body
• Nervous- relays messages within the body
• Connective-Holds organs in place and binds
  different parts of the body together
• Muscle- capable of contraction, causes internal
  and external movement

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Major Body Systems
Nervous System
Integumentary System
Skeletal System
Muscular System
Circulatory System
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Functions of Body Systems

• Nervous- coordinates the bodys response to
  changes in internal and external conditions
• Integumentary- serves as a barrier against
  infection and injury
• Skeletal- aids in movement, stores mineral
  reserves a provides a site for blood cell
  formation
• Muscular- voluntary movement, circulates blood,
  and moves food through digestive tract
• Circulatory- brings materials to and from cells,
  fights infection, and regulates body temperature.

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Major Body System
Respiratory System
Digestive System
Excretory System
Endocrine System
Reproductive System
Lymphatic System
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Functions of Body Systems (cont.)

• Respiratory- provides oxygen and removes carbon
  dioxide
• Digestive- converts food into glucose and other
  usable molecules for cells
• Excretory- eliminates wastes and maintains
  homeostasis
• Endocrine- controls growth, development,
  metabolism, and reproduction
• Reproductive- produces reproductive cells
• Lymphatic- helps protect the body from disease

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Homeostasis

• Maintaining relatively stable conditions within
  the body
• Examples
• maintaining constant body temperatures
• maintaining normal amounts of oxygen and
  carbon dioxide in the body

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Body Systems Work Together to Maintain
Homeostasis

• EXAMPLE
• Nutrient Delivery and Waste Disposal
• Digestive System breaks down food and delivers
  nutrients (glucose) to Circulatory System
• Oxygen moves from the air into the lungs
  (Respiratory System) and is delivered to the
  circulatory system
• Circulatory System delivers oxygen and glucose to
  cells
• Cells complete Cellular Respiration and breakdown
  glucose and use energy to regenerate ATP
• Waste products of cellular respiration (CO2 and
  H2O) are released from cells and taken back to
  lungs by circulatory system
• Lungs exhale waste
• The NERVOUS SYSTEM Coordinates all these
  interactions!

The bodies cells need nutrients to complete tasks
and perform chemical reactions, when these
nutrients are used wastes are created that must
be removed
Cells need glucose and oxygen for cellular
respiration to make more ATP Carbon dioxide and
water are created in this process
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Feedback Inhibition(Feedback Loops)

• The process by which the product of a system
  shuts down the system or limits its operation
• Example fat cells grow larger and larger.
• as the cells grow they release leptin
  (chemical messenger)
• leptin signals the brain to suppress the
  appetite

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The Nervous System Basics
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Function of the Nervous System

• Mediates (coordinates) communication between
  different parts of the body and the bodys
  interactions with the environment

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The Neuronspecialized cells within the nervous
system
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Neurons transmit messages

• Nerve impulse Message
• Dendrites- pick up message from environment or
  other neurons. Sends message to cell body
• Cell body-performs normal cell tasks for cell,
  relays message to next neuron through the axon
• Axon- Carries message from the cell body to the
  next neuron.
• myelin sheeth-coating that insulates and speeds
  up message.
• axon terminal- releases chemicals,
  neurotransmitters to stimulate the next neuron
  to fire or continue the nerve impulse.
• threshold- the minimal amount of stimulus
  required to cause the next neuron to fire or
  continue the impulse

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Nerve Impulses Are Electrical As They Travel
Through The Neuron
Outside of cell
Resting Potential-When a neuron is ready fire
if it is hit with a threshold stimulus
High Potassium Ion (K)Concentration Inside Low
Potassium Ion (K)Concentration Outside
Cell membrane
High Sodium Ion (Na) Concentration Outside Low
Sodium Ion (Na)Concentration Inside
1)Sodium is pumped out by a protein pump ATP
needed
2)Potassium ions leak through cell membrane
creating a negative charge inside cell
and positive charge outside cell
RESTING POTENTIAL NOW REACH WHEN INSIDE HAS
BECOME NEGATIVE
Inside of cell
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Movement of the Action PotentialAction
Potential A electrical charge moving through a
neuronCAUSED BY SODIUM GATES OPENING ALLOWING
Na IN
Action Potential
As the action potential passes, potassium gates
open, allowing K ions to flow out.
At rest.
Action Potential
Action Potential
The action potential continues to move along the
axon in the direction of the nerve impulse.
At the leading edge of the impulse, the sodium
gates open. The membrane becomes more permeable
to Na ions and an action potential occurs.
Once Action Potential Passes Na Gates Close and
Na Pumped Back Out and Resting Potential Restored
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Types of Neurons

• Sensory Neurons-detect stimulus send a nerve
  impulse to brain (sensation)
• Interneurons-located in the brain, process
  information received and formulate responses
  (thought)
• Motor Neurons- carry an action or response
  impulse from the brain back to the body (response)

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REFLEX ARC

• What is the pathway of nerve impulse as your hand
  touches a hot stove?
• SENSORY NEURON?INTERNEURON?MOTOR NEURON
• This is called the a reflex or reflex arc?
• This process can also occur with conscious
  control. Can you think of an example of this?

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Sense Organs

• NoseSmell
• MouthTaste
• EarsSound
• EyesSight
• SkinTouch
• All have specialized sensory neurons to pick up
  or detect stimulus that transmit impulses to the
  brain for processing

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The Central Nervous System

• Consists of the brain and spinal cord
• Both the brain and spinal cord is wrapped in 3
  layers of connective tissues called the meninges.
• dura mater, arachnoid, pia matter
• Between the meninges and the brain/spinal cord is
  cerebrospinal fluid
• Bathes brain and spinal cord
• Shock absorber
• Exchange of nutrients and waste between blood and
  nervous tissue

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The Brain
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• http//kidshealth.org/misc/movie/bodybasics/bodyba
  sics_brain.html

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The Spinal Cord

• Like a major telephone line
• 31 pairs of spinal nerves branch out from the
  spinal cord to the rest of the body.
• Reflexes may be processed directly by the spinal
  cord

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The Immune System Basics
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Pathogens of Disease

• Bacteria
• Bacteria are cellular (prokaryotic) and are
• Living organisms
• - 3 common shapes
• Bacilli (rod), cocci (circular), spirilli
  (spiral)
• Cause disease by
• Destroying cells and tissue
• Releasing toxins in body
• Examples
• Strep Throat, tetanus, anthrax, syphilis,
  tuberculosis, MRSA, food poisoning, chlamidia,
  gonorhhea
• Preventions
• Some have vaccines, personal hygiene, antiseptics
• Treatments
• Antibiotics- substances that can be administered
  that kill the bacterial cells causing infection
• Usually break down cell walls or interfere with
  metabolic processes

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Pathogens of Disease

• Viruses
• Noncellular particles
• Genetic material (DNA or RNA)
• Capsid-protective coating made of protein
• Not considered living
• Cannot reproduce on own, no metabolic processes,
  no response to stimulus
• Cause disease by
• Disrupting cellular activity and destroying cells
• Examples
• Common Cold, Flu, Small Pox, HIV, chicken pox,
  genital warts, herpes, hepatitis
• Prevention
• Some have vaccines, personal hygiene, antiseptics
• Treatments
• None- body must defeat on own, some the body
  cannot defeat EVER
• Some drugs (antiviral) can slow the spread of
  virus within the body

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Function of the Immune System

• to fight infections and protect the body from
  invaders.
• White Blood Cells-Specialized cells of the immune
  system
• fight disease

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Pathogens

• Bacteria (food poisoning, tuberculosis,
  pneumonia)
• Viruses (influenza, AIDS, colds,ect..)
• Protists (malaria and others)
• Infect body and cause disease!
• Antigen- a substance on the surface of a pathogen
  that triggers an immune response (DEFENSE).

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Nonspecific Defenses

• Skin- Creates barrier between external
  environment where pathogens exist and the inside
  of the body
• Pathogens must enter body to cause
  infection/sickness
• Inflammatory Response (Swelling)-Blood vessels
  expand and WHITE BLOOD CELLS (disease fighters)
  enter the wound or infection site
• Fever- Body raises core temp. to try to kill
  pathogen
• Some pathogens can only survive under certain
  temp.

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Specific Defenses

• Humoral Response
• Involve Special Types of White Blood Cells
• T-Helper Cells activate B-Cells when they detect
  invaders (pathogens)
• B- Cells (B lymphocytes) produce plasma cells
• Plasma cells produce antibodies
• antibodiessubstance that will cling to the
  antigen on the surface of a pathogen an
  immobilize the pathogen or cause them to cling
  together.
• Once infection detected by helper T many plasma
  cells are generated B cells to produce antibodies
• Macrophages (PHAGOCYTES)-engulf and destroy
  immobilized or inactivated pathogens

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Specific Defenses

• Cell Mediated
• Helper T Cells- recognize pathogens and activate
  B cells (Humoral Response) and Cytotoxic (Killer)
  T Cells
• Killer T Cells- Once activated kill pathogen
  directly

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Immunity

• Bodies ability to not become sick against a
  specific invader/pathogen
• It takes a while for plasma cells to figure out
  what antibody will kill a specific pathogen, many
  antibodies are produce in trial and error
  method
• Pathogen causes infection and sickness in
  meantime
• Eventually plasma cells produce an antibody that
  works.
• Special B memory cells remember the correct
  antibody that worked against that specific
  invader
• The next time the invader enters your body the
  Immune system knows how to destroy it before it
  can cause infection or disease.

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Vaccine

• Altered (weakened) form of the real pathogen
  Scientists alter in lab
• No longer capable of causing disease
• Injected in body
• Allows body to recognize and immune system build
  immunity to the pathogen
• When the real pathogen enters body your body is
  already immune (knows how to kill it before it
  can cause infection/sickness)

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Treatments for Diseases

• Bacterial Diseases- bacteria are living things
• Antibiotics-drugs that interfere with the
  chemical processes of living things
• Specifically harm bacterial cells without causing
  harm to us
• Viral Diseases-not living
• Body must defeat on own, no cures

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A.I.D.S and the Body

• AIDS infects and kills Helper T Cells
• Helper T Cells detect pathogens/invaders
• Once enough T Helper are killed by virus the body
  is no longer capable of recognizing invaders
• RESULT- Person becomes seriously infected or sick
  from pathogens that a healthy person may defeat
  rather easily
• Usually die from simple infections
  (cold,flu,pneumonia)

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The Digestive System

• Function- convert foods into
• simpler substances that can be
• used by cells.

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DigestionBreaking food particles down into
simple substances that cells can used by cells

• Mechanical

• Chemical

• Moistening and breaking food particles into
  smaller pieces

• Breaking down chemicals within food into simpler
  substances
• Proteins ? amino acids
• Fats ? lipids
• Carbs
• Polysachararides /starches ? monosacharrides /
  sugars (glucose)

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Digestive Enzymes

• Mouth
• Salivary Amylase- carbs
• Stomach
• Pepsin (proteins)
• Small Intestine (from Pancreas)
• Amylase- carbs
• Trypsin- proteins
• Lipase- fats
• Small Intestine
• Maltase, Sucrase, Lactase- carbs
• Peptidase- proteins

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Mouth

• Mechanical Digestion
• Chewing
• Moistening (saliva)
• Chemical Digestion
• Salivary Amylase
• Enzyme breaks down
• carbs

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Esophagus

• Epiglottis covers trachea (windpipe) and forces
  food into esophagus
• Tube that leads from throat to stomach (lined
  with smooth muscle)
• Peristalsis- wavelike muscular contraction that
  helps push food downward.

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Stomache

• Mechanical Digestion- HCl helps liquefy foods
  and churning motion also breaks food into smaller
  pieces
• Food is now chyme
• Chemical Digestion
• Pepsin (breaks down
• Proteins)

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Liver

• Produces Bile-
• Bile is a substance that acts as a detergent and
  breaks down fat molecules
• Bile is stored in gall bladder and then released
  into the small intestine
• Has over 500 other critical
• functions
• Mainly breaking down toxins
• And purifying blood

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Gall Bladder

• Stores Bile that is made by liver
• Releases bile Into small intestine

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Pancreas

• Produces many digestive enzymes
• These enzymes are released into the small
  intestine
• Also produces base
• Alkaline substance
• That neutralizes stomach
• Acid in small intestines

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Small Intestine

• Name refers to diameter, is actually much longer
  than large intestine
• 6 meters long
• Almost 20 feet!
• 3 Parts
• Duodenum-chemical digestion
• Jejenum-chemical digestion nutrient absorbtion
• Ileum- nutrient absorbtion

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Nutrient Absorption in Small Intestine

• takes place in jejenum and ileum
• Chyme is now well digested and rich in nutrients
• Folded surfaces are covered with fingerlike
  projections called villi
• Villi have are intervened with capillaries from
  circulatory system
• Nutrients are absorbed into bloodstream

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Large Intestine (Colon)

• Water absorption
• Production of vitamin K
• Accomplished by bacterial cells in digestive tract

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