Table of Contents
Exploring Life And Science
Chemistry of Life
Cell Structure and Function Organization
Organization and Regulation of Body Systems
Exploring Life and Science
Biology is the scientific study of life and human biology is a specialty in this field. Human beings are part of the natural world. All living things share the characteristics of life:
- are organized, from atoms to the biosphere
- take materials and energy from the environment
- reproduce
- grow and develop from fertilization to death
- are homeostatic
- respond to stimuli
- have an evolutionary history and have adapted modifications to a particular way of life
Atoms join together to form molecules that make up cells. A cell is the smallest structural and functional unit of an organism. Human beings are multicellular: composed of many different types of cells. A tissue is a group of cells that perform a particular function. Several types of tissue make up an organ and each organ belongs to an organ system. Organisms are a collection of of organ systems.
Levels of biological organization extend beyond the individual. A species is a group of interbreeding organisms in a particular area that belong to a population. Populations of various animals and plants make up a community. The community of populations interact with the physical environment to form an ecosystem and in turn, all the ecosystems of earth form the biosphere.
Levels of biological organization extend beyond the individual. A species is a group of interbreeding organisms in a particular area that belong to a population. Populations of various animals and plants make up a community. The community of populations interact with the physical environment to form an ecosystem and in turn, all the ecosystems of earth form the biosphere.
Reproduction is a fundamental characteristic of life. Living things reproduce and create a copy of themselves. The presence of genes in the form of DNA allow cells and organisms to reproduce. DNA contains the hereditary information that direct the cell structures and the metabolism, all the chemical reactions in the cell. DNA replicates so exact copies of genes are passed to the offspring.
www.scq.ubc.ca/wp-content/dna.gif
Development in humans includes the changes from egg fertilization until death. Development also encompasses repair that takes place after an injury.
Organs maintain homeostasis: an internal environment that varies within certain limits. All systems of the human body assist in maintaining homeostasis. Living things respond to external stimuli, often by moving toward or away from the stimuli. Homeostasis would be impossible without the body's ability to respond to stimuli.
Evolution is the process by which a species changes through time. Adaption is the process by which the species changes, by each successive generation, to variation. Evolution has been ongoing since the origin of time and will continue.
Living things are classified into three domains: Eukarya, Archaea, and Bacteria. Domain Eukarya contains four kingdoms: Animalia (including humans,) Plantae, Fungi, and Protista.
Organs maintain homeostasis: an internal environment that varies within certain limits. All systems of the human body assist in maintaining homeostasis. Living things respond to external stimuli, often by moving toward or away from the stimuli. Homeostasis would be impossible without the body's ability to respond to stimuli.
Evolution is the process by which a species changes through time. Adaption is the process by which the species changes, by each successive generation, to variation. Evolution has been ongoing since the origin of time and will continue.
Living things are classified into three domains: Eukarya, Archaea, and Bacteria. Domain Eukarya contains four kingdoms: Animalia (including humans,) Plantae, Fungi, and Protista.
faculty.southwest.tn.edu/rburkett/classi6.jpg
Culture encompasses human activity and products that are passed on from one generation to the next. Among animals, only humans have a language that allows us to communicate information and experiences symbolically.
All living things on Earth are part of the biosphere: a living network that spans the surface of the earth from the atmosphere to the soil and sea. The human population tends to modify existing ecosystems for their own purpose. Almost all natural ecosystems are altered by human activities, reducing biodiversity. Extinction is the death of a species or larger group of organisms.
http://www.valeofglamorgan.gov.uk/living/environment/biodiversity.aspx
Science is a way of knowing about the natural world. Scientists aim to be objective, rather than subjective. Scientific theories are concepts that tell us about order and pattern within the natural world. Evolution is the unifying concept of biology.
http://brasilmagic.wordpress.com/2007/10/
Scientific information is acquired through the process of the scientific method. The scientific method has five steps: observation, hypothesis, experiment/observations, conclusion, and scientific theories. Scientists perform controlled experiments to test their hypothesis and upon conclusion, publish their results.
http://www.sciencebuddies.org/mentoring/project_scientific_method.shtml
When evaluating scientific studies, consider the type of data which supports the information. Graphs and statistical data are important, as is the methodology of the study.
Science is a systematic way of acquiring knowledge. Scientists should avoid value judgments of experiments. Modern technology has risks and everyone should make informed decisions regarding how and when technology should be used.
Chemistry of Life
Matter refers to anything that takes up space and has mass. An element is one of the basic building blocks of matter that cannot be broken down by chemical means. An atom is the smallest unit of element that retains the chemical and physical properties of the element.
http://www.rfcafe.com/references/general/periodic_table.htm
The subatomic particles of an atom located in the nucleus are the protons and neutrons. The electrons orbit around the nucleus shell. Protons have a positive charge and electrons have a negative charge. The atomic number for an element tell you how many protons there are. The atomic mass for an atom allows you to determine the number of neutrons.
http://www.chem4kids.com/files/atom_structure.html
http://www.chem4kids.com/files/atom_structure.html
Isotopes of the same type of atom differ in the number of neutrons, therefore mass. Radioisotopes release radiation during the breakdown of the isotope. Different levels of radiation play a part in biology from tracer isotopes to the destruction of malignant cells.
http://www.freethought-forum.com/forum/showthread.php?t=11572&garp
Water is the most abundant molecule in living organisms, usually making up 60-70% of total body weight. Water is a polar molecule, the oxygen end has a slight negative charge and the hydrogen a slight positive charge. A hydrogen bond occurs when a covalently bonded hydrogen is slightly positive and attracted to a negatively charged atom some distance away. Water molecules are cohesive and have beneficial characteristics:
http://ghs.gresham.k12.or.us/science/ps/sci/ibbio/chem/notes/chpt2/waternotes.html
When water molecules dissociate, they release an equal number of hydrogen ions and hydroxide ions. The dissociation is measured in moles. A mole is a unit of scientific measurement for atoms.
Acidic solutions have a high H+ concentration. Base solutions have a low H+ concentration. The pH scale is used to indicate the acidity or alkalinity of a solution. Pure water with an equal number of hydrogen and hydroxide ions has a pH of 7.
When evaluating scientific studies, consider the type of data which supports the information. Graphs and statistical data are important, as is the methodology of the study.
Science is a systematic way of acquiring knowledge. Scientists should avoid value judgments of experiments. Modern technology has risks and everyone should make informed decisions regarding how and when technology should be used.
Chemistry of Life
Matter refers to anything that takes up space and has mass. An element is one of the basic building blocks of matter that cannot be broken down by chemical means. An atom is the smallest unit of element that retains the chemical and physical properties of the element.
http://www.rfcafe.com/references/general/periodic_table.htm
The subatomic particles of an atom located in the nucleus are the protons and neutrons. The electrons orbit around the nucleus shell. Protons have a positive charge and electrons have a negative charge. The atomic number for an element tell you how many protons there are. The atomic mass for an atom allows you to determine the number of neutrons.
http://www.chem4kids.com/files/atom_structure.html
http://www.chem4kids.com/files/atom_structure.html
Isotopes of the same type of atom differ in the number of neutrons, therefore mass. Radioisotopes release radiation during the breakdown of the isotope. Different levels of radiation play a part in biology from tracer isotopes to the destruction of malignant cells.
Atoms bond with one another to form molecules. There are two different types of bonding: ionic bonding and covalent bonding. During ionic bonding, atoms give up or take electrons in order to achieve a stable outer shell. During covalent bonding the atoms share electrons.
http://www.freethought-forum.com/forum/showthread.php?t=11572&garp
Water is the most abundant molecule in living organisms, usually making up 60-70% of total body weight. Water is a polar molecule, the oxygen end has a slight negative charge and the hydrogen a slight positive charge. A hydrogen bond occurs when a covalently bonded hydrogen is slightly positive and attracted to a negatively charged atom some distance away. Water molecules are cohesive and have beneficial characteristics:
- Water is a liquid at room temperature.
- The temperature of water rises and falls slowly.
- Water has a high heat of vaporization.
- Frozen water is less dense than liquid ice.
- Water molecules are cohesive.
- Water is a solvent for polar molecules.
http://ghs.gresham.k12.or.us/science/ps/sci/ibbio/chem/notes/chpt2/waternotes.html
Ions and molecules that interact with water are hydrophilic. Nonionized and nonpolar molecules that do not are hydrophobic.
When water molecules dissociate, they release an equal number of hydrogen ions and hydroxide ions. The dissociation is measured in moles. A mole is a unit of scientific measurement for atoms.
Acidic solutions have a high H+ concentration. Base solutions have a low H+ concentration. The pH scale is used to indicate the acidity or alkalinity of a solution. Pure water with an equal number of hydrogen and hydroxide ions has a pH of 7.
http://bcn.boulder.co.us/basin/data/BACT/info/pH.html
In living things, the pH of body fluids needs to be maintained within a narrow range. The body and environment have buffers to prevent pH changes. Buffers are chemical combinations that keep the pH within normal limits due because they are chemical or combinations that take up excess hydrogen or hydroxide ions.
The four classes of molecules unique to cells are carbohydrates, lipids, proteins, and nucleic acids. Each molecule is composed of subunits called macromolecules. Macromolecules are created by a dehydration reaction in which a hydroxyl group and a hydrogen atom are removed as the molecule reforms. To breakdown a macromolecule, a hydrolysis reaction is used.
Carbohydrates (H-C-OH) are molecules in which the ratio of hydrogen atoms to oxygen atoms is about 2:1.
Monosaccharides have between 3 and 7 carbon atoms. A disaccharide is made by by joining two monosaccahrides together by the dehydration reaction. Polysaccharides contain many glucose units.
http://science9.wordpress.com/2007/04/
Lipids contain more energy per gram than other biological molecules. Lipids do not dissolve in water and contain little oxygen. The most familiar lipids are fats (animal)and oils (plant.) Emulsifiers can cause fats to mix with water. There are different kinds of fatty acids: saturated, unsaturated, and trans fats.
http://www.biosynth.com/index.asp?topic_id=221&g=19&m=272
Phospholipids are constructed like fats, but have a phosphate group in place of the third fatty acid. They are primary components of cellular membranes. Steroids are lipids that have an entirely different structure than fats. Cholesterol is a precursor of several steroids.
Proteins are important in the structure and function of cells. Proteins have many functions in humans:
http://publications.nigms.nih.gov/structlife/chapter1.html
In living things, the pH of body fluids needs to be maintained within a narrow range. The body and environment have buffers to prevent pH changes. Buffers are chemical combinations that keep the pH within normal limits due because they are chemical or combinations that take up excess hydrogen or hydroxide ions.
The four classes of molecules unique to cells are carbohydrates, lipids, proteins, and nucleic acids. Each molecule is composed of subunits called macromolecules. Macromolecules are created by a dehydration reaction in which a hydroxyl group and a hydrogen atom are removed as the molecule reforms. To breakdown a macromolecule, a hydrolysis reaction is used.
Carbohydrates (H-C-OH) are molecules in which the ratio of hydrogen atoms to oxygen atoms is about 2:1.
Monosaccharides have between 3 and 7 carbon atoms. A disaccharide is made by by joining two monosaccahrides together by the dehydration reaction. Polysaccharides contain many glucose units.
http://science9.wordpress.com/2007/04/
http://www.biosynth.com/index.asp?topic_id=221&g=19&m=272Proteins are important in the structure and function of cells. Proteins have many functions in humans:
- Support
- Enzymes
- Transport
- Defense
- Hormones
- Motion
http://publications.nigms.nih.gov/structlife/chapter1.htmlThere are two types of nucleic acid: DNA and RNA. DNA and RNA are polymers of nucleotides. Every nucleotide is a molecular complex of three subunit molecules: phosphate, a pentose sugar, and a nitrogen contaning base. DNA contains deoxyribose sugar and RNA contains ribose. DNA has four different bases: adenine, thymine, guanine, and cytosine. In RNA uracil replaces thymine. The nucleotides form a strand which has a phosphate-sugar-phosphate-sugar backbone. DNA is double stranded and RNA has a single strand.
http://www.acmecompany.com/Pages/stock_science.html
http://www.acmecompany.com/Pages/stock_science.html Cell Structure and Function Organization
Organisms, including humans, are composed of cells. One of the fundamental principles of modern biology is the cell theory. The cell theory states that a cell is the basic unit of life. Nothing smaller than a cell is alive. Life has a cellular nature.
www.cellsalive.com/cells/cellpix/cell_model.jpg
Most cells are not visible to the naked eye. The small size of cells are explained by the surface area to volume ratio. Nutrients enter a cell and waste exits at its surface, therefore the greater the ability to get material in and out of the cell. Larger cells require more nutrients. However, the larger a cell gets in volume, the proportionate amount of surface area decreases.
staff.jccc.net/pdecell/cells/surface.gif
Micrographs and photographs of objects are obtained using a compound light microscope, a transmission electron microscope, of a scanning electron microscope. A compound microscope uses a set of glass lenses and light rays passing through the eye to magnify objects. A transmission electron microscope has a higher rate of magnification and higher resolving power: the ability to make out detail in enlarged images. A scanning electron microscope provides a three dimensional view of the surface of an object. The light microscope is the only one to view living specimens as the electron microscope must maintain a strong vacuum.
- All living things are made up of cells
- New cells arise only from preexisting cells
www.cellsalive.com/
Most cells are not visible to the naked eye. The small size of cells are explained by the surface area to volume ratio. Nutrients enter a cell and waste exits at its surface, therefore the greater the ability to get material in and out of the cell. Larger cells require more nutrients. However, the larger a cell gets in volume, the proportionate amount of surface area decreases.
staff.jccc.net/pdecell/
Micrographs and photographs of objects are obtained using a compound light microscope, a transmission electron microscope, of a scanning electron microscope. A compound microscope uses a set of glass lenses and light rays passing through the eye to magnify objects. A transmission electron microscope has a higher rate of magnification and higher resolving power: the ability to make out detail in enlarged images. A scanning electron microscope provides a three dimensional view of the surface of an object. The light microscope is the only one to view living specimens as the electron microscope must maintain a strong vacuum.
www.hometrainingtools.com/misc/compound%20par...
Cells have an evolutionary history. The first cells to arise were prokaryotic cells which lack a nucleus. Bacteria and archaea represent prokaryotic cells. Eukaryotic cells have a nucleus are known for living in extreme environments that mirror the first Earth environments. Both of these cells have a plasma membrane, an outer membrane which regulates what enters the cell. A plasma membrane is a phospholipid membrane which is selectively permeable. All cells also contain cytoplasm: a semifluid medium that contains water and various types of molecules suspended or dissolved in that medium. The cytoplasm contains organelles which are small structures that perform specific functions.
The internal structure of eukaryotic cells have evolved over time. Unlike prokaryotes, eukaryotes have DNA surrounded by a membrane: the endomembrane system.
The internal structure of eukaryotic cells have evolved over time. Unlike prokaryotes, eukaryotes have DNA surrounded by a membrane: the endomembrane system.
micro.magnet.fsu.edu/.../images/animalcell.jpg
The plasma membrane is selectively permeable. It marks the boundary between the inside and outside of a cell. The integrity of the membrane is necessary to cellular life. The plasma membrane is a phospholipid bilayer with attached or embedded proteins. The phospholipid molecule has a p0lar head and nonpolar tails. When placed in water they for a spherical bilayer. The polar head are hydrophilic and the tails are hydrophobic. The plasma membrane keeps the cell intact.
Diffusion is the random movement of molecules from an area of higher concentration to the area of lower concentration, until they are equally distributed. Osmosis is the diffusion of water across the plasma membrane. Tonicity is the concentration of the solute in a solution stated by percentage. Many solutes do not diffuse across the plasma membrane, but are transported by protein carriers. During facilitated transport, a molecule is transported across the membrane at a higher than usual rate to the side of lower concentration. During active transport, a protein carrier and cellular energy from the breakdown of ATP, the molecule moves against the normal travel direction from lower to higher concentration.
Diffusion is the random movement of molecules from an area of higher concentration to the area of lower concentration, until they are equally distributed. Osmosis is the diffusion of water across the plasma membrane. Tonicity is the concentration of the solute in a solution stated by percentage. Many solutes do not diffuse across the plasma membrane, but are transported by protein carriers. During facilitated transport, a molecule is transported across the membrane at a higher than usual rate to the side of lower concentration. During active transport, a protein carrier and cellular energy from the breakdown of ATP, the molecule moves against the normal travel direction from lower to higher concentration.
kvhs.nbed.nb.ca/gallant/biology/water_balance.jpg
www.linkpublishing.com/exocytosis5.jpg
www.linkpublishing.com/
During endocytosis, a portion of the plasma membrane invaginates to envelop a substance and fluid. The membrane then pinches off to form an endocytic vesicle inside the cell. Some white blood cells take up pathogens during this process: phagocytosis. During exocytosis, a vesicle fuses with the plasma membrane as secretion occurs.
micro.magnet.fsu.edu/.../endocytosisfigure1.jpg
The nucleus is a prominent structure in a cell and stores genetic information. The nucleus is separated from the cytoplasm by a double membrane known as the nuclear envelope.
www.modares.ac.ir/.../week2/nucleus_1%5B1%5D.gif
Ribosomes are organelles composed of proteins and rRNA. Protein synthesis occurs at the ribosomes.
www.williamsclass.com/.../Ribosomes.gif
The endomembrane system consists of the nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysomes, and vesicles. The endoplasmic reticulum has two portions. The Golgi apparatus is named for Camillo Golgi who discovered it in 1898.
The cytoskeleton of a cell is composed of several types of protein fibers. It helps maintain the cells shape. Microtubules are much larger than the actin filaments. Each microtubule is a cylinder that contains 13 longitudinal rows of proteins called tubulin. The microtubules are regulated by the cetrosome. Actin filaments are made of protein called actin. They are long thin fibers, usually in bundles or groupings.
Cilia and flagella are involved with movement. Cilia are about 20x longer than flagella, but both have the same organizational structure. Cilia and flagella grow from basal bodies: structures located in centrosomes called centrioles.
Mitochondria are the cells powerhouses. They convert the chemical energy of glucose into the chemical energy of ATP: cellular respiration. Cellular respiration is very important in metabolism: all the chemical reactions which occur in a cell. Cellular respiration includes three pathways: glycolysis, the citirc acid cycle, and the electron transport cycle.
www.nature.com/.../v24/n50/images/1209097f1.jpg
Enzymes speed up the reaction in a cell and are usually named for their substrates. Enzymes have a specific region (active site) where the substrates are brought together to react. Coenzymes are nonprotein the assist the activity of an enzyme and may accept or contribute atoms to the reaction.
Fermentation is an anaerobic process (not needing oxygen.) Fermentation produces little ATP and lactate build up occurs.
staff.jccc.net/pdecell/cellresp/fermentation.gif
Cilia and flagella are involved with movement. Cilia are about 20x longer than flagella, but both have the same organizational structure. Cilia and flagella grow from basal bodies: structures located in centrosomes called centrioles.
Mitochondria are the cells powerhouses. They convert the chemical energy of glucose into the chemical energy of ATP: cellular respiration. Cellular respiration is very important in metabolism: all the chemical reactions which occur in a cell. Cellular respiration includes three pathways: glycolysis, the citirc acid cycle, and the electron transport cycle.
www.nature.com/.../
Enzymes speed up the reaction in a cell and are usually named for their substrates. Enzymes have a specific region (active site) where the substrates are brought together to react. Coenzymes are nonprotein the assist the activity of an enzyme and may accept or contribute atoms to the reaction.
Fermentation is an anaerobic process (not needing oxygen.) Fermentation produces little ATP and lactate build up occurs.
staff.jccc.net/pdecell/
Organization and Regulation of Body Systems
A tissue is composed of specialized cells of the same type that perform a common function. The tissues of the human body are categorized into four major types:
www.nlm.nih.gov/.../ency/fullsize/8682.jpg
Connective tissue has 3 components: specialized cells, ground substance, and protein fibers. The fibers are broken into collagen, reticular, and elastic. The cells in both loose fibrous and dense fibrous connective tissues are called fibroblasts. Matrix is the term that includes ground substance and fibers. Loose fibrous connective tissue supports internal organs. Adipose tissue is a special type which the cells enlarge and store fat. Dense fibrous connective tissue contains collagen fibers packed together such as in tendons and ligaments. Supportive connective tissues are the cartilage: hyaline, elastic, and fibrocartilage. Bone is the most rigid of connective tissues. The matrix consists of inorganic salts (mostly calcium) around protein fibers (usually collagen.) Compact bone makes of the shaft of long bones and has cylindrical units called osteons. Spongy bone appears as open, bony latticework with numerous bony bars and plates. Fluid connective tissues consist of blood and lymph. Blood consists of erythrocytes, leukocytes, and thrombocytes. Lymph is a clear, watery fluid that contains white blood cells.
Nervous tissue consist of nerve cells and neuroglia. Neurons are specialized cells that consist of dendrites, a cell body, and an axon. A dendrite is an extension that receives signals from sensory receptors. The cell body contains most of the cell's cytoplasm and the nucleus. The axon is an extension that conducts nerve impulses. Long axons are covered by myelin. Outside the brain and spinal cord, fibers bound by connective tissue are called nerves. Neuroglia are cells that outnumber neurons 9:1 and take up more than half the volume of the brain. The primary function is to is to support and nourish neurons. Types of neurons in the brain are microglia, astrocytes, and oligodendrocytes.
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/neurons_1.gif
The integumentary system is associated with particular organs. An organ is composed of two or more types of tissues working together. An organ system contains many different organs. Skin is the most conspicuous organ in the body. The skin has 2 regions, the epidermis and dermis. A subcutaneous layer is found between the skin and underlying muscle or bone.
A tissue is composed of specialized cells of the same type that perform a common function. The tissues of the human body are categorized into four major types:
www.nlm.nih.gov/.../
http://www.daviddarling.info/images/types_of_connective_tissue.jpg
Muscular Tissue is composed of cells called muscle fibers. Muscle fibers contain protein filaments called actin and myosin filaments. The 3 types of vertebrate tissue are skeletal, smooth, and cardiac.Nervous tissue consist of nerve cells and neuroglia. Neurons are specialized cells that consist of dendrites, a cell body, and an axon. A dendrite is an extension that receives signals from sensory receptors. The cell body contains most of the cell's cytoplasm and the nucleus. The axon is an extension that conducts nerve impulses. Long axons are covered by myelin. Outside the brain and spinal cord, fibers bound by connective tissue are called nerves. Neuroglia are cells that outnumber neurons 9:1 and take up more than half the volume of the brain. The primary function is to is to support and nourish neurons. Types of neurons in the brain are microglia, astrocytes, and oligodendrocytes.
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/neurons_1.gif
Epithelial tissue covers the body and lines its cavities. There are different types of epithelial tissue:
- Simple sqaumous
- Simple cuboidal
- Simple columnar
- Pseudostratified ciliated columnar
- Stratified sqaumous
media.wiley.com/Lux/70/21770.nfg001.jpg
The integumentary system is associated with particular organs. An organ is composed of two or more types of tissues working together. An organ system contains many different organs. Skin is the most conspicuous organ in the body. The skin has 2 regions, the epidermis and dermis. A subcutaneous layer is found between the skin and underlying muscle or bone.
www.racingsmarter.com/.../SkinTissue.jpg
The epidermis is made up of stratified squamous epithelial tissue. New epidermal layers derive from stem (basal) cells. 2 types of specialized cells are located are located deep in the epidermis: Langerhans and the melanocytes. The dermis is a region of dense fibrous connective tissue beneath the epidermis. The dermis contains collagen and elastic fibers. The subcutaneous layer is not really part of the skin, but is composed of loose connective tissue and adipose tissue.
An acronym I use to remember the organ systems is MURDERS INC:
M Muscular system: posture, moves body and internal organs, produces heat
U Urinary System: excretes metabolic waste
R Respiratory system: maintains breathing, exchanges gases at lungs and tissues
D Digestive system: ingests and digest food, absorbs nutirents
E Endocrine system: produces hormones, regulates metabolism
R Reproductive system: produces and transports gametes, produces sex hormones
S Skeletal system: supports the body, protects body parts
I Integumentary System: protects body, receives sensory input, helps control temperature
N Nervous system: receives sensory input, helps coordinate motor systems
C Cardiovascular system: transports blood, nutrients, gases, and waste, defends against disease
www.agen.ufl.edu/.../lect/lect_19/147a.gif
The epidermis is made up of stratified squamous epithelial tissue. New epidermal layers derive from stem (basal) cells. 2 types of specialized cells are located are located deep in the epidermis: Langerhans and the melanocytes. The dermis is a region of dense fibrous connective tissue beneath the epidermis. The dermis contains collagen and elastic fibers. The subcutaneous layer is not really part of the skin, but is composed of loose connective tissue and adipose tissue.
An acronym I use to remember the organ systems is MURDERS INC:
M Muscular system: posture, moves body and internal organs, produces heat
U Urinary System: excretes metabolic waste
R Respiratory system: maintains breathing, exchanges gases at lungs and tissues
D Digestive system: ingests and digest food, absorbs nutirents
E Endocrine system: produces hormones, regulates metabolism
R Reproductive system: produces and transports gametes, produces sex hormones
S Skeletal system: supports the body, protects body parts
I Integumentary System: protects body, receives sensory input, helps control temperature
N Nervous system: receives sensory input, helps coordinate motor systems
C Cardiovascular system: transports blood, nutrients, gases, and waste, defends against disease
www.agen.ufl.edu/.../
www.agen.ufl.edu/.../lect/lect_19/147b.gif
Homeostasis is the relative constancy of the internal environment, which is tissue fluid and blood. Negative feedback mechanisms keep the environment relatively stable. When a sensor detects change, a control center brings about an effect that reverses the change to bring the system to normal. Positive feedback mechanisms bring about rapid change in the same direction as the stimulus and does not achieve relative stability.
Citations
Biology Project: Cell Biology. (2008) http://www.biology.arizona.edu/CELL_BIO/cell_bio.html
Folding @ Home Distributed Computing. (2008) http://folding.stanford.edu/English/Science
Hyperphysics:Chemical Bonding. (2008) http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html
Mader, S. (2008) Exploring Life and Science, Chemistry of Life, Cell Structure and Function, and
Regulation and Organization of Body Systems. Human Biology, 10th ed. (p 1-84)
Microbiology. (2008) http://www.scienceprofonline.org/
Water Molecule. (2008) http://www.aquadyntech.com/watermolecule.html
Hyperphysics:Chemical Bonding. (2008) http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html
Mader, S. (2008) Exploring Life and Science, Chemistry of Life, Cell Structure and Function, and
Regulation and Organization of Body Systems. Human Biology, 10th ed. (p 1-84)
Microbiology. (2008) http://www.scienceprofonline.org/
Water Molecule. (2008) http://www.aquadyntech.com/watermolecule.html
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