Transcript Biology
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 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/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