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Biology
Anatomy and Physiology
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
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
Major Body Systems
Nervous System
Integumentary System
Skeletal System
Muscular System
Circulatory System
Functions of Body Systems
Nervous- coordinates the body’s 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.
Major Body System
Respiratory System
Endocrine System
Digestive System
Excretory System
Reproductive System
Lymphatic System
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
Homeostasis
Maintaining relatively stable conditions
within the body
Examples:
~maintaining constant body
temperatures
~maintaining “normal” amounts of
oxygen and carbon dioxide in the body
Body Systems Work Together to Maintain
Homeostasis
EXAMPLE
The bodies cells need nutrients to complete
tasks and perform chemical
Nutrient Delivery and Waste Disposal
reactions, when these nutrients are used wastes are created that must be
removed
Digestive System breaks down food and delivers nutrients
(glucose)
toand
Circulatory
Cells need
glucose
oxygen forSystem
cellular respiration to make more ATP
Oxygen moves from the air into the lungs (Respiratory System)
Carbon
dioxide
and waterto
are
created
in this process
and
is delivered
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!
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
The Nervous System Basics
Function of the Nervous System
Mediates (coordinates) communication
between different parts of the body and
the body’s interactions with the
environment
The Neuron
specialized cells within the nervous system
Nucleus
Axon terminals
Cell body
Myelin sheath
Nodes
Axon
Dendrites
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
Nerve Impulses Are Electrical As They Travel
Through The Neuron
Outside of cell
Cell membrane
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
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
Inside of cell
RESTING POTENTIAL NOW REACH WHEN
INSIDE HAS BECOME NEGATIVE
Movement of the “Action” Potential
Action Potential = A electrical charge moving through a neuron
CAUSED 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
At the leading edge of the impulse, the
sodium gates open. The membrane becomes
more permeable to Na+ ions and an action
potential occurs.
The action potential continues to move along
the axon in the direction of the nerve impulse.
Once Action Potential Passes Na + Gates Close and Na+
Pumped Back Out and Resting Potential Restored
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)
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?
Sense Organs
•
•
•
•
•
Nose=Smell
Mouth=Taste
Ears=Sound
Eyes=Sight
Skin=Touch
– All have specialized sensory neurons to pick
up or detect stimulus that transmit impulses to
the brain for processing
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
The Brain
• http://kidshealth.org/misc/movie/bodybasic
s/bodybasics_brain.html
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
The Immune System
Basics
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
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
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
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).
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.
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
– antibodies=substance 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
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
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.
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)
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
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)
The Digestive System
• Function- convert foods into
simpler substances that can be
used by cells.
Digestion
Breaking food particles down into simple substances
that cells can used by cells
Mechanical
• Moistening and
breaking food
particles into
smaller pieces
Chemical
• Breaking down chemicals within
food into simpler substances
– Proteins  amino acids
– Fats  lipids
– Carbs
• Polysachararides /starches 
monosacharrides / sugars (glucose)
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
Mouth
• Mechanical Digestion
– Chewing
– Moistening (saliva)
• Chemical Digestion
– Salivary Amylase
• Enzyme breaks down
carbs
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.
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)
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
Gall Bladder
• Stores Bile that is made by liver
– Releases bile Into small intestine
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
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
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
Large Intestine (Colon)
• Water absorption
• Production of vitamin K
– Accomplished by bacterial cells in digestive
tract