Introduction to Human Body PDF

ANATOMY & PHYSIOLOGY I An Introduction to Human Body Anatomy and Physiology Defined Anatomy The science of body structures and relationships First studies by dissection (cutting apart) Imaging techniques Physiology The science of body functions Subspecialties...

ANATOMY & PHYSIOLOGY I An Introduction to Human Body Anatomy and Physiology Defined Anatomy The science of body structures and relationships First studies by dissection (cutting apart) Imaging techniques Physiology The science of body functions Subspecialties of Anatomy and Physiology Levels of Structural Organization Levels of structural organization 1) CHEMICAL LEVEL / BASIC LEVEL  Atoms  Molecules 2) CELLULAR LEVEL  Cells: basic structural and functional units of an organism  Muscle cells, nerve cells, epithelial cells, etc. 3) TISSUE LEVEL  Tissues are groups of cells and materials surrounding them  4 basic types of tissues: Epithelial : surface lining and exchange Connective : connecting and supporting Muscular : contracting and generating tension Nervous : impulse production and transmission Levels of structural organization 4) ORGAN LEVEL  Organs: composed of two or more different types of tissues  Specific functions and recognizable shapes Heart, lungs, kidneys, stomach 5) SYSTEM LEVEL (11)  A system: related organs with a common function  Organ-system level Digestive system breaks down and absorbs food It includes organs such as the mouth, small and large intestines, liver, gallbladder, and pancreas 6) ORGANISMAL LEVEL  An organism or any living individual  All parts of the body functioning together Systems of Human Body Clinical Connection: Noninvasive Diagnostic Techniques Inspection  Observe any changes Palpation  Gently touching body surfaces with hands Percussion  Tapping on the body surface with fingertips and listening to echoes Auscultation  Listening to body sounds (stethoscope) Characteristics of Living Human Organism Basic Life Processes  Distinguish living from non-living things  6 important life process: Metabolism Responsiveness Movement Growth Differentiation Reproduction Metabolism, Responsiveness & Movement 1) Metabolism  Sum of all the chemical process that occur in the body Catabolism (breakdown): complex  simpler Anabolism (building up): simpler  complex 2) Responsiveness  Body’s ability to detect and respond to changes Body temperature, sound Nerve (electrical signals) and muscle cells (contracting) 3) Movement  Motion of the whole body Organs, cells, and tiny subcellular structures Leg muscles move the body from one place to another Growth, Differentiation & Reproduction 4) Growth  Increase in body size Due to an increase in existing cells, number of cells, or both 5) Differentiation  Development of a cell from an unspecialized to specialized state Cells have specialized structures and functions that differ from precursor cells Stem cells give rise to cells that undergo differentiation 6) Reproduction  Formation of new cells (growth, repair or replacement)  Production of a new individual Homeostasis A condition of equilibrium (balance) in the body’s internal environment Dynamic condition Narrow range is compatible with maintaining life Example:  Blood glucose levels range between 70 and 110 mg of glucose/dL of blood  Whole body contributes to maintain the internal environment within normal limits Homeostasis and Body Fluids Maintaining the volume and composition of body fluids are important Body fluids are defined as dilute, watery solutions containing dissolved chemicals inside or outside of the cell  Intracellular Fluid (ICF) Fluid within cells  Extracellular Fluid (ECF) Fluid outside cells Interstitial fluid is ECF between cells and tissues ECF and Body Location Blood Plasma  ECF within blood vessels Lymph  ECF within lymphatic vessels Cerebrospinal fluid (CSF)  ECF in the brain and spinal cord Synovial fluid  ECF in joints Aqueous humor and vitreous body  ECF in eyes Interstitial Fluid and Body Function Cellular function depends on the regulation of composition of interstitial fluid Body’s internal environment Composition of interstitial fluid changes as it moves  Movement back and forth across capillary walls provide nutrients (glucose, oxygen, ions) to tissue cells and removes waste (carbon dioxide) Control of Homeostasis Homeostasis is constantly being disrupted:  Physical insults Intense heat or lack of oxygen  Changes in the internal environment Drop in blood glucose due to lack of food  Physiological stress Demands of work or school, social  Disruptions Mild and temporary  balance is quickly restored Intense and Prolonged (poisoning or severe infections) Feedback System Cycle of events: Body is monitored and re- monitored Each monitored variable is termed a controlled condition 3 Basic components: Receptor Control center Effector Feedback Systems 1) Receptor:  Body structure that monitors changes in a controlled condition  Sends input to the control center Nerve ending of the skin in response to temperature change 2) Control Center (Brain)  Sets the range of values to be maintained  Evaluates input received from receptors and generates output command Nerve impulses, hormones 3) Effector  Receives output from the control center  Produces response or effect that changes the controlled condition Body temperature drops  brain sends an impulse to the skeletal muscles to contract  shivering to generate heat Negative and Positive Feedback Systems Negative Feedback systems  Reverses a change in a controlled condition Regulation of blood pressure (force exerted by blood as it presses again the walls of the blood vessels) Positive Feedback systems  Strengthen or reinforce a change in one of the body’s controlled conditions Normal child birth Negative Feedback: Regulation of Blood Pressure External or internal stimulus increase BP Baroreceptors (pressure sensitive receptors)  Detect higher BP  send nerve impulses to brain for interpretation  response sent via nerve impulse sent to heart and blood vessels  BP drops and homeostasis is restored  Drop in BP negates the original stimulus Positive Feedback: Normal Childbirth Uterine contractions cause vagina to open  stretch- sensitive receptors in cervix send impulse to brain  oxytocin is released into the blood  contractions enhanced and baby pushes farther down the uterus Cycle continues to the birth of the baby (no stretching) Homeostatic Imbalances Normal equilibrium of body processes are disrupted  Moderate imbalance Disorder: abnormality of structure and function Disease: specific for an illness with recognizable signs and symptoms (local @ systemic) Signs are objective changes such as a fever or swelling Symptoms are subjective changes such as headache  Severe imbalance Death Areas of Science: Epidemiology & Pharmacology Clinical Connection: Autopsy Postmortem (after death) examination of the body and internal organs Several uses:  Determine the cause of death  Identified diseases not detected during life  Determine the extent of injuries and contribution to death  Hereditary conditions Clinical Connection: Diagnosis of Disease Distinguishing one disorder or disease from another  Signs and symptoms  Medical history Collecting information about event Present illnesses and past medical problems  Physical examination Orderly evaluation of the body and its function Noninvasive techniques and other vital signs Basic Anatomical Terminology Common language referring to body structures and their functions Anatomists use standard anatomical position and special vocabulary in relating body parts  Body Positions Anatomical position  Body upright  Standing erect facing the observer  Head and eyes facing forward  Feet are flat on the floor and forward  Upper limbs to the sides  Palms turned forward Regional Names Directional Terms Common Directional Terms Planes and Sections Sagittal @ Median (Midsagittal & Parasagittal)  A vertical plane that divides the body into right and left sides Frontal @ Coronal  Divides the body or an organ into anterior (front) and posterior (back) portions Transverse @ Cross-sectional @ Horizontal  Divides the body or an organ into superior (upper) and inferior (lower) portions Oblique  Passes through the body or an organ at an angle Section  Cut of body @ one of its organ Body Cavities Spaces within the body that help protect, separate, and support internal organs  Cranial cavity  Thoracic cavity  Abdominopelvic cavity Body Cavities Thoracic Cavity = Chest cavity Formed by:  Ribs  Muscles of the chest  Sternum (breastbone)  Vertebral column (thoracic portion) Thoracic Cavity Pericardial cavity  Fluid-filled space that surround the heart Pleural cavity  Two fluid-filled spaces that that surround each lung Mediastinum  Central part of the thoracic cavity  Between lungs  Extending from the sternum to the vertebral column  First rib to the diaphragm  Diaphragm Separates the thoracic cavity from the abdominopelvic cavity Abdominopelvic Cavity Extends from the diaphragm to the groin Encircled by the abdominal wall and bones and muscles of the pelvis  Abdominal cavity Stomach, spleen, liver, gallbladder, small and large intestines  Pelvic cavity Urinary bladder, internal organs of reproductive system, and portions of the large intestine Thoracic and Abdominal Cavity Membrane VISCERA  Organs of the thoracic and abdominal pelvic cavities  Serous membrane: Slippery membrane that covers the viscera Parietal layer  Lines the wall of the cavities Visceral layer  Covers the viscera within the cavities Thoracic and Abdominal Cavity Membrane Pleura  Serous membrane of the pleural cavities Visceral pleura clings to surface of lungs Parietal pleura lines the chest wall Pericardium  Serous membrane of the pericardial cavity Visceral pericardium covers the heart Parietal pericardium lines the chest wall Peritoneum  Serous membrane of the abdominal cavity Visceral peritoneum covers the abdominal organs Parietal peritoneum lines the abdominal wall Other Cavities Oral (mouth) cavity  Tongue and teeth Nasal cavity  nose Orbital cavities  eyeball Middle ear cavities  Small bones of the middle ear Synovial cavities  Joints Abdominopelvic Regions Abdominopelvic Regions  Used to describe the location of abdominal and pelvic organs Tic-Tac-Toe grid Two horizontal and two vertical lines partition the cavity  Subcostal line (top horizontal)  inferior to rib cage  Transtubercular line (bottom horizontal)  inferior to top of the hip bone  Midclavicular lines (two vertical lines)  midpoints to clavicles and medial to the nipples 9 Abdominopelvic Regions Right and left hypochondriac Epigastric and Hypogastric (pubic) Right and left lumbar Right and left inguinal (iliac) Umbilical Quadrants Vertical and horizontal lines pass through the umbilicus  Right upper quadrant (RUQ)  Left upper quadrant (LUQ)  Right lower quadrant (RLQ)  Left lower quadrants (LLQ) Medical Imaging Techniques and procedures used to create images of the human body  Allow visualization of structures inside the body  Diagnosis of anatomical and physiological disorders  Conventional radiography (X-rays) have been in use since the late 1940’s Radiography X-rays  produce image of interior structures  Inexpensive and quick  Hollow structures appear black or gray  Do not pass easily through dense structure (bone) At low dose, useful for soft tissue (breast)  Mammography (breast)  Bone densitometry (bone density) Magnetic Resonance Imaging (MRI) High energy magnetic field  Protons in body fluid align with field Color image on a video monitor  2D and 3D blueprint Relatively safe procedure  Not used on patients containing metal Used for differentiating normal and abnormal tissues  Tumors, brain abnormalities, blood flow Computed Tomography Computer-Assisted radiography (CT-Scan)  3-D structures  Visualize soft tissue in more detail than conventional radiography  Tissue intensities show varying degrees of gray  Whole-body CT scan Lung and kidney cancers, coronary artery disease Ultrasound Scanning Ultrasound Scanning  High frequency sound waves Sonogram Noninvasive, painless, no dyes Pregnancy (fetus) Radionuclide Scanning Radionuclide Scanning Radioactive substance (radionuclide) given intravenously Gamma rays detected by camera Radionuclide image displays on video monitor Color intensity represents uptake  Single-photo-emission computerized tomography (SPECT)  Specialized technique used for brain, heart, lungs, and liver Positron Emission Tomography (PET) Positron (positively charged particles) emitting substance injected into the body  Collision between positrons and negatively charged electron in body tissues  Gamma rays produced  Computer constructed a PET scan image in color  Used to study physiology of body structures (metabolism) Endoscopy Endoscope  Lighted instrument with lens  Image projected onto a monitor Colonoscopy  Interior of colon Laparoscopy  Organs in abdominopelvic cavity Arthroscopy  Interior of joint (knee)