Midterm Exam Study Guide

CHAPTER 1: Directional term practice  The umbilicus(belly button) is INFERIOR to the thoracic region.  The knee is PROXIMAL to the ankle.  The fingers are DISTAL to the shoulder.  The shoulders are LATERAL to the breastbone (sternum).  The abdominal muscles are ANTERIOR to the gluteal muscles.

Homeostasis is: the body’s ability to maintain an optimal internal environment although things are constantly changing.  What is homeostatic regulation and why is it important to the body? Maintain normal ranges of temperature, heart rate, blood levels, etc to prevent disease or disability.  What happens when homeostasis fails? Disease or sickness FEEDBACK MECHANISM  Receptor: Collects stimuli from outside and inside the body; special senses and internal receptors for temperature, blood pressure, etc.  Control Center: Integrates and make decisions about stimuli collected by receptors; brain and spinal cord.  Effector : Acts on information from control center to respond appropriately; muscles or glands.

 Positive Feedback Mechanisms: Negate or Enhance original stimulus? If its high, it goes higher; If its low, it goes lower. Example in body? Pain, headache, childbirth  Negative Feedback Mechanisms: Negate or Enhance original stimulus? Reverses original stimulus. If its low, it goes up; If its high, it goes down. Example in body? Most NORMAL body processes are controlled by negative feedback. Body temperature, blood sugar.

CHAPTER 2: Describe atomic structure, including location and charges of subatomic particles. Nucleus contains Protons (+) and Neutrons (no charge); Electrons (-) surround nucleus Describe the different types of bonds that atoms form and why bonds are formed.  Ionic bonds: Transfer of electrons from one atom to another; ion attraction allows them to be pulled close to one another.  Covalent Bonds: Equal/unequal sharing of electrons between atoms; difficult to separate.  Hydrogen Bonds: important, weak intramolecular bonds that hold structures together. What is the main difference between inorganic and organic compounds? INORGANIC: lacks carbon as a central atom, small, diffuses easily through cell membrane. ORGANIC: contains carbon as a central atom, large, must pass thorugh channels to enter/exit cell.  What are the important biological inorganic compounds? Water, gases, some acids and bases, electrolytes.  Describe the properties of water that make it an important inorganic biological molecule? Universal solvent Cushion/Protection Lubricant base High heat capacity – resists changes in temperature Participates in many chemical reactions  What are the four major organic macromolecules? 1. Carbohydrates: what does our body eventually break a glucose molecule into? ATP 2. Lipids: Know the general function of the following lipids: Triglycerides: ENERGY Phospholipids: CELL MEMBRANE STRUCTURE 3. Proteins: what 2 categories of proteins does the human body make? STRUCTURAL GLOBULAR Describe the four structures of protein molecules PRIMARY: Straight chain SECONDARY: alpha helix or beta-pleated sheet TERTIARY: alpha or beta chain folded on itself QUARTENARY: 2 or more tertiary structure held together by central molecule. What does an amino acid compound look like? What makes each amino acid different from another? The R group makes each Amino Acid different from another amino acid. Draw an amino acid below.

What kind of bonds link amino acids together? PEPTIDE BONDS

What kinds of bonds hold the structures of proteins together? HYDROGEN BONDS

4. Nucleic Acids: STUDY TABLE and KNOW STRUCTURE OF NUCLEOTIDE

Enzyme activity  What are enzymes? PROTEINS that act as BIOLOGICAL CATALYSTS. ALL ENZYMES ARE PROTEINS but NOT ALL PROTEINS ARE ENZYMES  Describe the structure of an enzyme, including the active site. ENZYMES ARE RELIANT ON SHAPE. THE FOLDING OF THE GLOBULAR PROTEIN, HELD TOGETHER BY HYDROGEN BONDS, PRODUCES AN ACTIVE SITE (LOCK) THAT A SPECIFIC CHEMICAL WILL FIT INTO (KEY) IN ORDER TO CATALYZE SPECIFIC CHEMICAL REACTIONS.  What happens when an enzyme is denatured? THE HYDROGEN BONDS ARE BROKEN AND THE PROTEIN/ENZYME LOSES SHAPE. This means the shape of the active site is lost and the enzyme can no longer function as designed.  Provide a biological example in the body of proteins being denatured. High fever is a good human biological example of enzyme denaturation. When we get a fever, the high body temperature causes functional enzymes to lose their shape and they can no longer perform important biological functions.

Chapter 3 What is a cell? Are all cells the same? How can we categorize cells?  A cell is the smallest living unit of structure and function for humans.  Not all cells are the same; size, shape, location, and organelle composition determine what the cell will do for a function and determine the longevity/life span of the cell.  Cells can be categorized according to location in the body and ability to undergo mitosis (labile, stabile, permanent).

What are the important functions of the cell membrane? Be specific.  Separates cells from their surrounding environments.  Selectively permeable; limiting what exits and enters the cell.  Proteins act as channels to allow passage of large particles and water-soluble molecules.  Carbohydrates act as cell surface markers to identify specific cells; self vs. nonself.

Describe the phospholipid bilayer and how its structural components (hydrophilic/hydrophobic) allow it to function as a barrier.  Cell membrane is composed of HYDROPHILIC heads that “like water” and make up the outermost and innermost parts of the phospholipid membrane due to the water content of the extracellular space and cytosol within the cytoplasm.  The inner portions of the cell membrane are HYDROPHOBIC fatty acid tails; facing toward each other due to their “water fearing” composition. This portion of the cell membrane is what limits the passage of water through diffusion. Water must move through a protein channel (aquapore) by facilitated diffusion.

What word do we use to describe the transport property of the cell membrane? Why?  SEMIPERMEABLE- this is the “gatekeeper” quality of the cell membrane, limiting the movement of molecules. A loss of membrane control is what leads to disease/disorders. The more control is lost - the more abnormality in the cell – the more disease/disorder.

What are the functions of membrane proteins? Carbohydrates/Glycocalyx? Cholesterol?  Proteins act as channels  Glycocalyx and Carbs act as cell surface identifiers  Cholesterol acts to stabilize the cell membrane and make it more rigid to maintain structure.

What is contained in the nucleus? Why is the nucleus important? The nucleus contains chromatin – long thin strands of DNA that contain info needed to make structural components for the cell and perform cell functions. The nucleus offers an additional membrane barrier to protect the DNA from mutations. Know the functions of the following organelles: Ribosomes: assemble amino acid sequences into proteins. Lysosomes: digest foreign particles to remove from cell interior or extracellular space. Nucleus: contains and protects DNA in cell interior. Mitochondria: creates energy (ATP) from glucose and oxygen = cell respiration.

Know Cell Clock information and what happens in each phase.  G1: growth and work  G0: quiescence- cells work but do not divide. Determined by cell type o Labile cells never quiesce; they are constantly in the cell clock ready to divide: Skin o Stabile cells enter quiescence after growth is completed; will divide if injured: Bone o Permanent cells enter quiescence after growth and will never divide again: Brain  S: synthesis/copy DNA for mitosis  G2: growth and work  M: mitosis/nuclear division usually followed by cytokinesis (division of cytoplasm, organelles, and cell membrane) leading to the creation of 2 new cells that will enter G1.

CANCER BIOLOGY What is the relationship between MITOSIS and CANCER? How is the cell clock of cancer different than a normal cell clock? The cell clock of a normal cell and a cancer cell are essentially the same; the main difference is the amount of time each type of cell spends in different phases of the cell clock. Normal cells spend most of their time in INTERPHASE (G1, S, G2) and little time in MITOSIS (M). Cancer cells spend most of their time in MITOSIS (M) and little time in INTERPHASE (G1, S, G2).

What is cancer? What is benign? Malignant?  Cancer is uncontrolled cell division (mitosis and cytokinesis)  Benign growths result from uncontrolled cell division; tumors have abnormal STRUCTURE but normal FUNCTION.  Malignant growths also result from uncontrolled cell division but have abnormal STRUCTURE and FUNCTION.  Metastasis: the ability of cells to break free from malignant growths, travel through the blood stream, and create a secondary tumor in a different location in the body. Explain the factors that influence the formation of cancer in the body.  Hereditary: o Genetic predisposition for “bad mitosis” can result in cancer of any tissue. o Inheritance of specific cancer-causing genes, for example BRCA-1 gene for breast cancer, can increase your chance of THAT specific cancer.  Environmental: o Risk factors such as smoking, diet, pollution, sun exposure can increase the chance of certain types of cancer. Describe proto-oncogenes, tumor suppressor genes, and oncogenes.  Proto-oncogenes control NORMAL cell division; without PO our cells would not be able to grow and divide. Think of PO as the gas pedal promoting cell division.  Tumor Suppressor Genes control the RATE of cell division; without TSG our cells would divide uncontrollably from the start. o It is the balance of PO and TSG that promotes NORMAL CELL GROWTH AND DIVISON.  Oncogenes are mutated PO’s that now divide at an uncontrolled rate. Genetic and Environmental factors cause the mutations that lead to cancer development. How do we diagnose and treat cancer? Are all cancers the same? TMN System of Diagnosis T= Tumor Size and Location M= Metastasis – has the cancer spread to other areas? N= Lymph Node involvement is another clue to metastasis. Not all cancers are the same. By grading the tumor with the TMN system and discovering the genetic cause of each person’s specific type of cancer doctors can provided targeted therapy to destroy cancer cells and leave healthy, labile cells alone. This helps the patient have a better quality of life during treatment and recovery.

Cut, Burn, Poison = Surgery, Radiation, and Chemotherapy What are the four main tissue types in the body? Functions?  Epithelial tissue lines internal and external body cavities for protection and secretion of products.  Connective tissue connects epithelial membranes to underlying tissues or connects internal structures together. This is the MOST diverse group; blood, bone, cartilage are examples.  Muscle tissue is designed to create movement. There are 3 types of muscle tissue: smooth, skeletal, and cardiac. Muscle tissue is categorized by control (voluntary vs involuntary) and the organization of cells (striated vs nonstriated).  Nervous tissue is designed to conduct an electrical current; found in the brain and spinal cord.

Understand wound healing, tissue regeneration, and inflammation. KNOW YOUR MEDIATORS OF INFLAMMATION!  Tissue regeneration is determined by 2 factors: o Severity of wound: how bad is the injury o Type of tissue damaged: labile, stabile, permanent  3 steps in wound healing o Capillaries become permeable, allowing needed nutrients to leave bloodstream and enter injured tissue; Scab forms. o Granulation tissue forms to support blood flow to injured area; phagocytes (“eating” white blood cells) keep area free of debris and infection. o Surface epithelium regenerates from the bottom up; a scar forms if needed to bridge the gap.  4 cardinal signs of inflammation and their chemical control o Redness: CHEMOTAXIC AGENTS allow for increased blood flow to the area, bringing needed materials for wound healing. More blood = more color (redness). o Heat: PYROGENS increase the local temperature destroying the proteins that allow pathogens to infect the area. o Swelling: HISTAMINE causes leaky capillaries, allowing plasma to leave the bloodstream and enter the tissue space bringing needed nutrients and white blood cells to the damaged tissue. The more plasma (water) the more it swells. o Pain: PROSTAGLANDINS are part of the “pain pathway” and initiates activation of pain receptors in the damaged tissue. Remember, ACUTE inflammation has a positive impact on the healing process. Short term inflammation is a necessary part of healing a wound or injury. Without inflammation we do not have the ability to get the materials damaged tissue needs to the area that is injured. CHRONIC inflammation, lasting longer than 2 weeks can cause more damage than good and needs to be addressed.

Chapter 4 Study Guide: The Integumentary System

What are the three layers of the Cutaneous Membrane (Skin) called? What are some important characteristics of these layers (vascular/avascular, nerves, accessory structures)?

1. EPIDERMIS: o Avascular o Contains KERATIN, a tough water-proof protein o Composed of several layers . Stratum corneum = outermost . St germinativum/basale = innermost mitotic layer; contains melanocytes for production of melanin when exposed to UV light. 2. DERMIS: o Highly vascular o 2 layers . Papillary layer = most superficial of dermis  Dermal papillae creates ridges and valleys for fingerprints with St germinativum.  Nerve receptors for pain and temperature. . Reticular layer = deepest layer, just above hypodermis  Nerve receptors for deep pressure. o Contains elastin (for stretch-ability) and collagen (like Velcro to hold skin together) o Contains accessory structures for production of secretions (see below) 3. HYPODERMIS: o Composed of adipose tissue . Allows for cushion, protection, and insulation o Slightly vascular

What are the functions of the skin?

 Protection against: HOW? o Mechanical damage: Keratin is tough o Chemical damage: Keratin is impermeable o Bacterial damage: Unbroken barrier; WBC’s prevent entry to underlayers o UV radiation: Melanin o Thermal damage: Contains heat, cold, pain receptors o Dessication: Keratin prevents water from LEAVING the body  Temperature control: Sweat glands and goose bumps  Excretion of waste products: Urea is released in sweat and other secretions  Synthesis of vitamin D: Fat (cholesterol) is turned to Vit D when exposed to sun

What are the functions of the MAIN proteins that are found in the skin? Keratin: tough, water-proofing protein that provides protection to the epidermis. Made by keratinocytes in thicker layers as cells move up from the stratum basale. Collagen: Velcro-like protein that holds/binds the epidermis to the dermis. Elastin: allows for stretching and re-coiling of the skin; loss of this protein as we age leads to sagging and wrinkles.

What are the main pigments that produce color in the skin? Abnormal pigments? Melanin: MAIN PIGMENT; ranges from yellow to brown to black; produced in response to UV exposure. Carotene: present in orange veggies; lipid soluble and can be stored in the hypodermis. Hemoglobin: red color present in blood cells; more prominent when blood vessels are dilated.

Name the two types of glands found in the skin. What is produced by each gland type?  Sebaceous glands: oil glands. o Attached to each hair follicle o Produces sebum to keep skin moist and control bacterial environment of epidermis  Sudoriferous glands: sweat glands o Spans entire thickness of skin but originates in Reticular layer of dermis. o Produces a watery substance to keep internal body temperature in normal range.

Describe the differences between apocrine and eccrine/merocrine sweat glands (products, locations). TYPES OF SUDORIFEROUS GLANDS  Eccrine/Merocrine: produces sweat. o Widely distributed through body; concentrated at palms and soles. o Used to control body temperature.  Apocrine: produces oily sweat. o Found in axillary and inguinal regions. o Becomes active at puberty

KNOW SKIN DISEASE POWERPOINT! Constructing a Table, if you haven’t done so already, may be helpful for the specifics of the diseases.

Category Disease Name Description Cause/Pathogen Treatment/Cure

Know which of the skin cancers is most common, least common, most deadly, least deadly. What does the “ABCD’s” of skin cancer signify? A= Asymmetry B= Border irregularity C= Color changes D= Diameter These changes can assist in diagnosing MALIGNANT MELANOMA

What is the two MAIN concerns when dealing with a burn patient? What is the Rule of Nines and how is it applied? DEHYDRATION and INFECTION. The Rule of Nines is applied to address percent of body burned.