Melissa Ruiz
Biology Review
Rasmussen College
10/07/2011

1. Describe the interdependency of structure and function in the human body.
Physiology depends on anatomy; anatomy is study of the structures in the body, physiology is the study of the functions of those structures. In other words, without structure there is no function. Physiology depends on anatomy, the operation or function of a structure is dictated by its anatomy. Anatomy and physiology are really inseparable because function always reflects structure. For example, oxygen and carbon dioxide are exchanged across the thin membranes of the lungs but not across the skin.
(Marieb and Hoehn, 2010, page 3) 2. Describe the three patterns of chemical reactions.
Synthesis reaction is when atoms or molecules combine to form a larger, more complex molecule. It always involves bond formation and can be represented as A+B→AB. This is the basis of constructive activities in body cells. Amino acids are joined together to form a protein molecule.
Decomposition reaction occurs when a molecule is broken down into smaller molecules. It can be represented as AB→A+B. Decomposition reactions are the reverse of synthesis reactions. This underlies all degradative processes in body cells. Bonds are broken in larger molecules, resulting in smaller, less complex molecules.
Glycogen is broken down to release glucose units.
Exchange reactions involve both synthesis and decomposition. Bonds are both made and broken, which is also called displacement reactions. During the exchange reaction, parts of the reactant molecules change patterns producing different product molecules; resulting in AB+C→AC+B and AB+ CD→AD+CB. ATP transfers its terminal phosphate group to glucose to form glucose phosphate. The ATP becomes ADP at the same time. This is an important reaction and occurs whenever glucose enters a body cell, which traps the glucose fuel molecule inside the cell.
(Marieb and Hoehn, 2010, page 36) 3. Differentiate between diffusion and osmosis.
Diffusion is when molecules travel from a higher concentration to a lower concentration. Diffusion is the movement of molecules, by kinetic energy. Osmosis moves down its concentrated gradient, but diffusive substances can move away from their concentrated gradient by the help of a protein in the cell membrane called a sodium-potassium pump. Osmosis is movement of water molecules that travel from higher concentration to a lower concentration. Osmosis moves through a semi permeable membrane.
(Marieb and Hoehn, 2010, page 68-70) 4. Differentiate between inorganic and organic compounds.
Most inorganic compounds do not contain carbon. Inorganic compounds found in the body include water, salts, and inorganic acids and bases. Inorganic compounds come principally from mineral sources of non-biological origin. Organic compounds contain carbon. Organic compounds found in the body include carbohydrates, lipids, proteins, and nucleic acids.
(Marieb and Hoehn, 2010, page 38-42) 5. List and describe the general characteristics of the four primary tissue types.
Tissues are groups of cells with a common structure and function. There are four main tissues in the body – epithelial tissue, connective tissue, nervous tissue, and muscle tissue.
Epithelial tissue is a sheet of cells that covers a body surface or lines a body cavity. It forms boundaries between different environments, and nearly all substances received by the body must pass through an epithelium. As an interface tissue, epithelium accomplishes many functions, including: 1) Protection, skin 2) Absorption, stomach and intestinal lining 3) Filtration, the kidney 4) Excretion 5) Secretion, forms glands and 6) Sensory Reception. Epithelial tissues have many characteristics that distinguish them from other tissue types. Special Characteristics of Epithelium: 1) Polarity- all epithelial exhibit apical-basal polarity; the cell regions near the apical surface differ from those near the basal surface in both structure and function. 2) Specialized contacts- attaches closely together forming continuous sheets. Adjacent cells are bound together, including tight junctions and desmosomes; which helps keep proteins in the apical region of the plasma membrane and from diffusing into the basal region. This helps to maintain epithelial polarity. 3) Supported by Connective tissue- all epithelia sheets rest upon and are supported by connective tissue. There are a basal lamina and a reticular lamina, which forms the basement membrane. This reinforces the epithelial sheet, helping it to not stretch and tear. 4) Avascular but innervated- is supplied by nerve fibers and has no blood vessels. It can soak up nutrients from blood vessels in connective tissue underneath. 5) Regeneration- has a high regenerative capacity. If apical-basal polarity and lateral contacts are destroyed, cells begin to reproduce rapidly. Very good at fixing itself, for example sunburn or a skinned knee.
Connective tissue is found everywhere in the body. Its major functions include: 1) binding and support 2) protection 3) insulation, blood and 4) transportation of substances within the body.
Main classes of connective tissue:
Cartilage
Functions:
1) Provides strength with flexibility while resisting wear 2) Cushions and shock absorbs where bones meet
Bone
Functions: 1) provides framework and strength for body
2) Allows movement 3) Stores calcium
4) Contains blood-forming cells
Blood
Functions:
1) Transports oxygen, carbon dioxide, and nutrients around the body
2) Immune response
Connective tissues have some common characteristics that set them apart from other primary tissues: 1) Common Origin- all connective tissue are from embryonic tissue. 2) Degrees of vascularity- connective tissues run the entire range of vascularity. Cartilage is avascular. Dense connective tissue is poorly vascularized. The other types have a rich supply of blood vessels. 3) Extracellular matrix-connective tissues are nonliving extracellular matrix, which separates the living cells of the tissue. Connective tissue is the only tissue that is able to withstand weight, tension, and abuse.
Nervous tissue is the main component of the nervous system, which contains the brain, spinal cord, and nerves. This regulates and controls body functions. The nervous tissues function is to transmit electrical signals from sensory receptors and to effectors which control their activity.
Characteristics of nervous tissue:
1) Neurons- generate and conduct nerve impulses
2) Neuroglia- non- conducting, support and protect the neurons, their presence does speed up conduction
Muscle tissues are highly cellular, vascularized tissues that are responsible for most body movement. The functions of muscle tissue consist of: 1) Responsible for body movement 2) Moves blood, food, and waste through organs and 3) Responsible for mechanical digestion. There are three types of muscle tissue:
Smooth Muscle – organ walls and blood vessel walls, involuntary, spindle-shaped cells for pushing things through organs
Skeletal Muscle – large body muscles, voluntary, striated muscle packed in bundles and attached to bones for movement
Cardiac Muscle – heart wall, involuntary, striated muscle with intercalated discs connecting cells for synchronized contractions during heartbeat.
Characteristics of muscle tissue: 1) Excitability - the ability to receive and respond to a stimulus 2) Contractility - the ability to shorten 3) Extensibility - the ability to be stretched 4) Elasticity - the ability to resume normal length after contraction or having been stretched
(Marieb and Hoehn, 2010, page 115-136) 6. List and describe the three tissue membranes.
Mucous membranes line cavities that connect with the exterior, including the digestive, respiratory, reproductive, and urinary tracts. The epithelial surfaces are kept moist at all times. The connective tissue portion of a mucous membrane is called the lamina propria. The mucous membranes are usually lined with simple epithelia that perform absorptive or secretory functions.
Serous membranes line the sealed, internal cavities of the body. There are three such membranes with each consisting of a simple epithelium supported by loose connective tissue: * the pleura lines the pleural cavities and covers the lungs * the peritoneum lines the peritoneal cavity and covers the surfaces of enclosed organs such as the liver and stomach * The pericardium lines the pericardial cavity and covers the heart.
A serous membrane also has parietal and visceral portions. Parietal lines the outer wall of the internal chamber. The visceral portion covers organs within the body cavity. Serous fluid covers the surfaces to minimize friction between opposing surfaces.
Cutaneous membranes cover the surface of the body; it is your skin. It is an organ system that consists of stratified squamous epithelium and the underlying connective tissues. Cutaneous membranes are thick, relatively waterproof, and dry.
(Marieb and Hoehn, 2010, page 139)

7. Describe the steps in tissue repair.
Inflammation- Severed blood vessels bleed and inflammatory chemicals are released. Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins and other plasma proteins to seep into the injured area. Clotting occurs; surface dries and forms a scab.
Organization restores the blood supply- The clot is replaced by granulation tissue, which restores the vascular supply. Fibroblasts produce collagen fibers that bridge the gap. Macrophages digest the original blood clot and collagen fiber deposit continues. Surface epithelial cells multiply and migrate over the granulation tissues.
Regeneration and fibrosis effect permanent repair- the fibrosis area matures and contracts; the epithelium thickens. Resulting in a fully regenerated epithelium with an underlying area of scar tissue.
(Marieb and Hoehn, 2010, page 139-140) 8. Differentiate between the two classifications of neoplasms (tumors).
Neoplasms are classified as benign or malignant. A benign tumor is basically a tumor that doesn't come back and doesn't spread to other parts of the body. A tumor is a mass of tissue that serves no useful purpose and generally exists at the expense of healthy tissues. Benign tumors tend to grow more slowly than malignant tumors and are less likely to cause health problems, as long as they are removed before they compress vital organs. A malignant tumor is aggressive and can eventually kill you. They invade their surroundings and resemble immature cells. Unlike benign tumors that generally stay put, malignant tumors tend to survive and travel through the blood or lymph to other body organs. Malignant tumors (cancer cells) take large amounts of nutrients from the body and this leads to weight loss and tissue wasting that contributes to death.
(Marieb and Hoehn, 2010, page 142) 9. Discuss the role carcinogens have in the increase risk of developing cancer.
Carcinogens cause mutations that alter the expression of certain genes. It takes several genetic changes to turn a normal cell into a cancerous cell. Some carcinogens do not affect DNA directly, but lead to cancer in other ways. They may cause cells to divide at a faster than normal rate, which could increase the chances that DNA changes will occur. Carcinogens do not cause cancer in every case. Some may cause cancer only after prolonged, high levels of exposure.
(Marieb and Hoehn, 2010, page 142) 10. How would you differentiate between carcinoma and sarcoma? Give examples of each.
Carcinomas and sarcomas develop and spread in the body differently. Sarcoma is cancer of the soft tissue or the bone. Sarcomas are rare and affect only 1% of the people. Sarcoma is cancer arising in the mesenchyme-derived tissues, in connective and muscle tissues. One example osteosarcomas arise from bone; sarcomas are considered primary bone cancers and are named based on the site from which they arise. Carcinoma is cancer arising in an epithelium, accounts for 90% of human cancers. One example is that of breast cancer (carcinoma) where after afflicting the breast, the cancer spreads to the bones of the patient. Sarcomas tend to grow in the shape of a ball and tend to push nearby structures such as arteries, nerves and veins away. Sarcomas arise from one bone and spread to other bones of the body. Carcinomas infiltrate all nearby structures. They easily invade nearby nerves, veins, muscles and blood cells. Carcinomas do not have a ball like mass and therefore doctors find it difficult to anticipate their spread when removing an affected organ from inside the body.

http://www.news-medical.net/health/What-are-Carcinomas.aspx http://www.oncolink.org/types/article.cfm?c=17&s=80&ss=817&id=9533&CFID=34517286&CFTOKEN=64626454 Reference:
Human Anatomy & Physiology Eight Edition, Marieb and Hoehn, 2010 http://www.news-medical.net/health/What-are-Carcinomas.aspx http://www.oncolink.org/types/article.cfm?c=17&s=80&ss=817&id=9533&CFID=34517286&CFTOKEN=64626454