Chapter 1: Organization of the Human Body PDF

Chapter 1: Organization of the Human Body © 2013 John Wiley & Sons, Inc. All rights reserved. Organization of the Human Body Anatomy and physiology defined Levels of organization and body systems Life processes Homeostasis Body cavities © 2013 John Wiley & Sons, Inc. All righ...

Chapter 1: Organization of the Human Body © 2013 John Wiley & Sons, Inc. All rights reserved. Organization of the Human Body Anatomy and physiology defined Levels of organization and body systems Life processes Homeostasis Body cavities © 2013 John Wiley & Sons, Inc. All rights reserved. Levels of Organization and Body Systems © 2013 John Wiley & Sons, Inc. All rights reserved. Organization and General Plan of Body Question: Which body system generates action potentials (nerve impulses) to regulate body activities; detects changes in the body’s internal and external environments, interprets the changes, and responds by causing muscular contractions or glandular secretions? © 2013 John Wiley & Sons, Inc. All rights reserved. Life Processes All living organisms have certain characteristics that set them apart from nonliving things The following are six important life processes of humans  Metabolism - sum of all the chemical processes that occur in the body  Responsiveness - the body’s ability to detect and respond to changes in its internal (inside the body) or external (outside the body) environment  Movement - includes motion of the whole body, individual organs, single cells, and even tiny organelles inside cells  Growth - increase in body size  Differentiation - the process whereby unspecialized cells become specialized cells  Reproduction - refers to either (1) the formation of new cells for growth, repair, or replacement or (2) the production of a new individual © 2013 John Wiley & Sons, Inc. All rights reserved. Homeostasis – Maintaining Limits Homeostasis ensures that the body’s internal environment remains constant despite changes inside and outside the body Homeostasis is a dynamic state of equilibrium Homeostasis is necessary for normal body function and life Homeostatic imbalance = disease © 2013 John Wiley & Sons, Inc. All rights reserved. Parts of a Feedback System © 2013 John Wiley & Sons, Inc. All rights reserved. Types of Feedback System Feedback mechanisms. (A)The negative feedback mechanism of regulation of metabolic rate by thyroxine. (B)The positive feedback mechanism triggered by a fever. © 2013 John Wiley & Sons, Inc. All rights reserved. Anatomical Terms – Directional Terms © 2013 John Wiley & Sons, Inc. All rights reserved. © 2013 John Wiley & Sons, Inc. All rights reserved. © 2013 John Wiley & Sons, Inc. All rights reserved. Anatomical Terms – Body Planes and Sections Sagittal section – divides body (or organ) into left and right portions Median, or midsagittal, section - divides body (or organ) into equal left and right portions Frontal section – divides body (or organ) into anterior and posterior parts  “cuts off your face” Transverse, or cross, section – divides body (or organ) into superior and inferior parts  “cuts off your legs” © 2013 John Wiley & Sons, Inc. All rights reserved. Planes and Sections (A) Planes and sections of the body. (B) Cross-section and longitudinal section of the small intestine Body Cavities © 2013 John Wiley & Sons, Inc. All rights reserved. Regions of the Abdominopelvic Cavity © 2013 John Wiley & Sons, Inc. All rights reserved. Quadrants of the Abdominopelvic Cavity © 2013 John Wiley & Sons, Inc. All rights reserved. Introduction to Chemistry – Chemical Elements and Atoms All forms of matter are made up of a limited number of building blocks called chemical elements, substances that cannot be broken down into a simpler form by ordinary chemical means Each element is designated by a chemical symbol © 2013 John Wiley & Sons, Inc. All rights reserved. ntroduction to Chemistry  Matter is made up of chemical elements. The elements oxygen (O), carbon (C), hydrogen (H), and nitrogen (N) make up 96% of the body’s mass.  Each element is made up of units called atoms, which consist of a nucleus that contains protons and neutrons, and electrons that move about the nucleus in electron shells.  The atomic number, the number of protons, distinguishes the atoms of one element from those of another element.  The combined total of protons and neutrons in an atom is its mass number.  An atom that gives up or gains electrons becomes an ion—an atom that has a positive or negative charge. © 2013 John Wiley & Sons, Inc. All rights reserved. ntroduction to Chemistry  A molecule is a substance that consists of two or more chemically combined atoms.  A compound is a substance that can be broken down into two or more different elements by ordinary chemical means.  A free radical is a destructive ion or molecule that has an unpaired electron in its outermost shell.  Chemical bonds hold the atoms of a molecule together. Electrons in the valence shell (outermost shell) are the parts of an atom that participate in chemical reactions (are involved in forming and breaking bonds). © 2013 John Wiley & Sons, Inc. All rights reserved. Chemical Elements and Atoms Introduction to Chemistry  Ionic bonds are formed when outer shell electrons are transferred from one atom to another, the transfer forms ions with unlike charges that attract the ions to each other. In a covalent bond, pairs of outer shell electrons are shared between two atoms.  Hydrogen bonds are weak bonds between hydrogen and certain other atoms.  Energy is the capacity to do work.  Potential energy is energy stored by matter due to its position.  Kinetic energy is the energy of matter in motion. © 2013 John Wiley & Sons, Inc. All rights reserved. Chemical Bonds –Ions and Ionic Bonds Formation of an ionic bond. An atom of sodium loses an electron to an atom of chlorine. The two ions formed have unlike charges, are attracted to one another, and form a molecule of sodium chloride.  Chemical Bonds – Covalent Bonds The polar covalent bonds that form between hydrogen atoms and other atoms can give rise to a third type of chemical bond, a hydrogen bond © 2013 John Wiley & Sons, Inc. All rights reserved. Chemical Compounds and Life Processes Organic compounds – all are carbon-based  Example: C6H12O6 (glucose) Inorganic compounds – Most lack carbon  Tend to be simpler compounds  Examples: H2O (water), NaCl (table salt), CO2 (carbon dioxide) © 2013 John Wiley & Sons, Inc. All rights reserved. Inorganic Compounds – Water Critical properties of water to sustain organisms  Water is an excellent solvent  Water participates in chemical reactions  Water absorbs and releases heat very slowly  Water requires a large amount of heat to change from a liquid to a gas  Water serves as a lubricant © 2013 John Wiley & Sons, Inc. All rights reserved. norganic Compounds – Acids, Bases nd Salts Acids - release highly reactive hydrogen ions (H+) into solution Bases - release highly reactive hydroxyl ions (OH–) into solution Neutralization reaction - acids and bases react to form water and a salt Salts - easily dissociate into ions in the presence of water, vital to many life processes (e.g. electrolytes conduct electrical currents) © 2013 John Wiley & Sons, Inc. All rights reserved. Inorganic Compounds – pH Neutral pH = 7 © 2013 John Wiley & Sons, Inc. All rights reserved. norganic Compounds – Buffers Chemical compounds that act quickly to temporarily bind H, removing the highly reactive, excess H from solution but not from the body Prevent rapid, drastic changes in the pH of a body fluid Less Reactive © 2013 John Wiley & Sons, Inc. All rights reserved. rganic Compounds – Carbohydrate Sugars and starches Categorized by size  Monosaccharides—simple sugars  Disaccharides—two simple sugars linked together  Polysaccharides—long-branching chains of linked monosaccharides © 2013 John Wiley & Sons, Inc. All rights reserved. Carbohydrates Carbohydrates. (A) Glucose, depicting its structural formula. (B) A disaccharide such as sucrose. (C) Cellulose, a polysaccharide. (D) Starch, a polysaccharide. (E) Glycogen, a polysaccharide. Each hexagon represents a hexose sugar such as glucose. © 2013 John Wiley & Sons, Inc. All rights reserved. Organic Compounds – Lipids There are 3 principle lipids in the human body  Neutral fats (triglycerides) – stored fat deposits  Phospholipids – form cellular membranes  Steroids – lipid-based hormones, cholesterol, bile salts, & vitamin D © 2013 John Wiley & Sons, Inc. All rights reserved. Organic Compounds – Proteins Consist of chains of amino acids Make up over half of a body’s organic matter Function as enzymes, hormones, and antibodies If a protein encounters a hostile environment in which temperature, pH, or ion concentration is significantly altered, it may unravel and lose its characteristic shape  This process is called denaturation  Denatured proteins are no longer functional © 2013 John Wiley & Sons, Inc. All rights reserved. Organic Compounds – Proteins Amino acid and protein structure. (A) The structural formula of an amino acid. The “R” represents the variable portion of the molecule. (B) A polypeptide. Several amino acids, represented by different shapes, are linked by peptide bonds. (C) The primary structure of a protein. (D) The secondary structure of a protein. (E) The tertiary structure of the protein myoglobin. Organic Compounds – Proteins Actions of an Enzyme The substrates attach to the active site of the enzyme molecule, the specific part of the enzyme that catalyzes the reaction, forming a temporary compound called the enzyme– substrate complex. The substrate molecules are transformed by the rearrangement of existing atoms, the breakdown of the substrate molecule, or the combination of several substrate molecules into products of the reaction. After the reaction is completed and the reaction products move away from the enzyme, the unchanged enzyme is free to attach to another substrate molecule. Active site theory. (A) Synthesis reaction. (B) Decomposition reaction. (C) The effect of heat. (D) The effect of poisons. © 2013 John Wiley & Sons, Inc. All rights reserved. rganic Compounds – Nucleic Acids DNA – provides the blueprint of life  Nucleotide bases: A=Adenine G=Guanine C=Cytosine T=Thymine RNA – intermediary between DNA and protein  Nucleotide bases: A=Adenine G=Guanine C=Cytosine U=Uracil Adenosine triphosphate (ATP)  Chemical energy used by all cells  Energy released when high energy phosphate bond is broken © 2013 John Wiley & Sons, Inc. All rights reserved. DNA © 2013 John Wiley & Sons, Inc. All rights reserved. rganic Compounds – Nucleic Acids © 2013 John Wiley & Sons, Inc. All rights reserved.