The Human Body - An Orientation PDF

The Human Body: An Orientation  The Study of Anatomy Anatomy: the study of the structure of the human body Physiology: the study of body function BRANCHES OF ANATOMY: Microscopic anatomy -Histology - the study of tissues -Cytology - the study of cells Gross anat...

The Human Body: An Orientation  The Study of Anatomy Anatomy: the study of the structure of the human body Physiology: the study of body function BRANCHES OF ANATOMY: Microscopic anatomy -Histology - the study of tissues -Cytology - the study of cells Gross anatomy = The study of structures visible to the naked eye. -Regional anatomy = all structures in a single body region -Systemic anatomy = all organs with related functions studied together -Surface anatomy = shapes and markings in the surface of the body  An Overview of Anatomy OTHER BRANCHES OF ANATOMY: 1) Developmental anatomy - traces structural changes occurring in body throughout the lifetime -Embryology – study of developmental changes of the body before birth What is pathology?  An Overview of Anatomy OTHER BRANCHES OF ANATOMY: 2) Pathological anatomy – study of structural changes caused by disease -A medical specialty that is concerned with the diagnosis of disease based on the gross, microscopic, and molecular examination of organs, tissues, and whole bodies (autopsy). Invasive ductal carcinoma (breast) Bacterial meningitis (brain) Colorectal polyp (colon)  An Overview of Anatomy OTHER BRANCHES OF ANATOMY: 3) Radiographic anatomy – study of internal structures visualized by X ray studies and other imaging techniques -Functional morphology - explores functional properties of body structures and assesses efficiency of design The Hierarchy of Structural Organization atoms molecules The Hierarchy of Structural Organization The human body has many levels of structural complexity. 1) Chemical Level: -Atoms are the building blocks of matter. -Atoms combine to form molecules (small and large) What are the four classes of macromolecules found in the body? The macromolecules are the building blocks of the structures at the cellular level. The Hierarchy of Structural Organization 2) Cellular level: Cells and their functional subunits (organelles) -Cells are the smallest living things in the body How many cells make up the human body? 100 trillion The Hierarchy of Structural Organization General cell structure (animal cell): The Hierarchy of Structural Organization 3) Tissue level: A tissue is a group of cells that work together to perform a common function. What are the four tissue types that make up all of the organs of the human body? 1) Epithelial tissue: -Covers body surface and lines its cavities 2) Connective tissue: -Supports body and protects its organs 3) Muscle tissue: -Provides movement 4) Nervous tissue: -Communication The Hierarchy of Structural Organization 4) Organ level: a discrete structure made up of more than one tissue. -Most organs contain all four tissues. -Organs are “functional centers” that are responsible for an activity. Brain: control center of the CNS, responsible for behavior. Heart: pumping blood The Hierarchy of Structural Organization 5) Organ system: organs working together for a common purpose The Hierarchy of Structural Organization 5) Organ system: organs working together for a common purpose The Hierarchy of Structural Organization 5) Organ system: organs working together for a common purpose The Hierarchy of Structural Organization 5) Organ system: organs working together for a common purpose The Hierarchy of Structural Organization 6) Organismal level– the result of all simpler levels working in unison Scale: Length, Volume, and Weight (The Metric System)  The U.S. vs. THE The United States is one of the few countries of the world still using the English system of weights and measures. In this cumbersome system: Length → Mile Volume → Gallon Mass → Pound Temperature → ºF Why?…Because we are used to this system.  The Metric System In 1799, French scientists devised a simple system of quantifying the basic measurements used in the laboratory. The system has become universal in the scientific community and has become the everyday system of weights and measures in most countries of the world. The Metric System The name is derived from the basic unit of length: the meter (m). The basic unit of weight: gram (g) The basic unit of volume: liter (L) The Metric System: Ease of Use mega (M) X 1,000,000 larger than kilo (K) X 1,000 base unit hecto (H) X 100 deka (D) X10 Base Unit: gram, meter, liter deci (d) X 1/10 smaller than centi (c) X 1/100 base unit milli (m) X 1/1000 micro (µ) X 1/1,000,000 How do these prefixes relate to the base unit? megameter (Mm) = 1,000,000 meters larger than 1 kilometer (Km) = 1,000 meters base unit 1 hectometer (Hm) = 100 meters 1 dekameter (Dm) = 10 meters meter 1 decimeter (dm) = 1/10 of a meter smaller than 1 centimeter (cm) = 1/100 of a meter base unit 1 millimeter (mm) = 1/1000 of a meter 1 micrometer (µm) = 1/1,000,000 of a meter SI units are based on powers of 10 "http://www.anu.edu.au/Forestry/mensuration/rwg2/code/"  Anatomical Terminology -Based on ancient Greek or Latin; provides standard nomenclature worldwide Examples: Greek- brachium (“arm”) ; Latin - Femur (“thigh”) Anatomists have an accepted set of reference terms that are universally understood and allow body structures to be located and identified with a minimal use of words and a high degree of clarity. Purpose of this lecture: This exercise presents some of the most important anatomical terminology used to describe the body and introduces you to basic concepts of gross anatomy.  In the anatomical position the human body is erect, with the feet only slightly apart, head and toes pointed forward (toward observer), and arms hanging at the sides with palms facing forward. Gross Anatomy: Anatomical Terminology The following terms listed will be used in describing… a) the relative position b) type of section, or c) body region for a particular body part. Directional terminology – refers to the body in anatomical position -NOTE: The terms right or left refer to the person or body being viewed, NOT the observer Regional terms – names of specific body areas Anatomical Terminology: Directional Terminology Anatomical Terminology: Directional Terminology Anatomical Terminology: Directional Terminology Anatomical Terminology : Regional Terms Names of body areas: - Axial region: Relating to the head, neck, and trunk (the axis of the body) - Appendicular region: Relating to limbs and their attachments to the axis. Anterior & Posterior Body regions Anterior & Posterior Body regions  9 Abdominal Regions and 4 Quadrants Abdominal quadrants: divides abdomen into four quadrants  9 Abdominopelvic Regions Umbilical Region = centermost region Epigastric Region = superior to umbilical region Hypogastric (pubic) Region = inferior to umbilical region Right and left iliac or inguinal regions = lateral to hypogastric region Right and left lumbar regions = lateral to umbilical region Right and left hypochondriac regions = flank epigastric region laterally Body Cavities and Membranes  Body Cavities The axial portion of the body has two large cavities that provide protection to the organs within them. 1) The dorsal (posterior) body cavity 2) The ventral (anterior) body cavity  Dorsal Body Cavities The dorsal body cavity protects the nervous system and can be subdivided into the cranial cavity and the vertebral (spinal) cavity which are continuous with each other. -Cranial Cavity: the brain is enclosed within the skull -Vertebral Cavity: runs within the vertebral column and encases the spinal cord  Ventral Body Cavities The ventral body cavity is subdivided into the following cavities: -Thoracic cavity: Houses the heart and lungs. Separated from the rest of the ventral cavity by the diaphragm. -Abdominopelvic cavity: Although there is no further physical separation of the ventral cavity, we can describe this cavity in terms of: a) a superior abdominal cavity (stomach, intestines, liver, etc.) and b) an inferior pelvic cavity (reproductive organs, bladder, and rectum). Visceral organs (Viscera): an internal organ of an animal.  Thoracic Cavity: Mediastinum The thoracic cavity is subdivided into the pleural cavities and the mediastinum. -2 pleural cavities: each contains a lungs, which lie on either side of the heart. -Mediastinum: contains all of the thoracic organs except the lungs. Organs located in the mediastinum include the: heart (pericardial cavity), aorta, thymus gland, chest portion of the trachea, esophagus, lymph nodes and important nerves.  Serous Membranes of the Ventral Body Cavity The walls of the ventral body cavity and the outer surfaces of the organs it contains are covered with an thin, double-layered membrane called the serosa (serous membrane). -Parietal serosa: the part of the membrane lining the cavity walls -Viceral serosa: the part of the membrane covering the external surface of the organs within the cavity. These membranes produce a thin lubricating fluid that allows the viceral organs to slide over one another or to rub against the cavity wall without friction. They also compartmentalize the various organs so that infection of one organ is prevented from spreading to others.  Serous Membranes of the Ventral Body Cavity The walls of the ventral body cavity and the outer surfaces of the organs it contains are covered with an thin, double-layered membrane called the serosa (serous membrane).  Serous Membranes of the Ventral Body Cavity Note: The specific names of the serous membranes depends on the structures they envelop. - Peritoneum: the serosa lining the the abdominal cavity and covering its organs. -Pleura: the serosa lining the lungs. -Pericardium: the serosa lining the heart.  Other Body Cavities… Oral cavity: the mouth Nasal cavity: located within and posterior to the nose Orbital cavity (orbits): houses the eyes and present them in an anterior position Middle ear cavity: contain bones (ossicles) that transmit sound vibrations Synovial cavity: joint cavities Microscopic Anatomy/Body Sections & Planes Anatomical Terminology: Body Sections/Planes Objects can look odd when viewed in section -In order to recognize human organs in section, you have to anticipate how the organs will look when cut that way.  Anatomical Terminology: Body Sections/Planes Coronal (frontal) plane: -Lies vertically and divides body into anterior and posterior parts Transverse plane (Cross section): -Runs horizontally – divides body into superior and inferior parts Sagittal plane: -Runs longitudinally and divides the body into right and left parts. Median (midsagittal) plane -Divides the body into equal parts Parasagittal plane -All other sagittal planes Oblique section: cuts made diagonally  Microscopic Anatomy Microscopy: examining small structures through a microscope Preparing human tissue for microscopy… -Specimen is fixed (preserved) and sectioned -Specimen is stained to distinguish anatomical structures -Creates artifacts = minor distortions of preserved tissues; not exactly like living tissues and organs  Microscopic Anatomy Light microscopy (LM): Illuminates tissue with a beam of light (lower magnification); 2D Transmission Electron microscopy (TEM): Uses beams of electrons (higher magnification); 2D Scanning electron microscopy(SEM): Heavy metal salt stain – deflects electrons in the beam to different extents; 3D