BiologyAnatomy 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 Digestive System Excretory System

Endocrine 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

HomeostasisMaintaining 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

EXAMPLENutrient 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 cellsCells complete Cellular Respiration and breakdown glucose and

use energy to regenerate ATPWaste products of cellular respiration (CO2 and H2O) are released

from cells and taken back to lungs by circulatory systemLungs 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

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 Neuronspecialized cells within the nervous system

Axon terminals

Myelin sheath

Nodes

Cell body

Axon

Nucleus

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

NeuronOutside of cell

Inside of cell

Cell membrane

High Potassium Ion (K+)Concentration InsideLow Potassium Ion (K+)Concentration Outside

High Sodium Ion (Na+) Concentration OutsideLow Sodium Ion (Na+)Concentration Inside

Resting Potential-When a neuron is ready “fire” if it is hit with a “threshold” stimulus

1)Sodium is pumped out by a protein pump

*ATP needed

2)Potassium ions leak through cell membrane creating a negative charge inside cell andpositive charge outside cell

RESTING POTENTIAL NOW REACH WHEN INSIDE HAS BECOME NEGATIVE

At the leading edge of the impulse, the sodium gates open. The membrane becomes more permeable to Na+ ions and an action potential occurs.

As the action potential passes, potassium gates open, allowing K+ ions to flow out.

The action potential continues to move along the axon in the direction of the nerve impulse.

At rest.

Action Potential

Action PotentialAction Potential

Movement of the “Action” PotentialAction Potential = A electrical charge moving through a neuronCAUSED BY SODIUM GATES OPENING ALLOWING Na+ IN

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 NEURONINTERNEURONMOTOR 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/bodybasics/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 SystemThe Digestive System

• Function- convert foods into

simpler substances that can be

used by cells.

DigestionBreaking 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 IntestineNutrient 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