Chapter 1 An Introduction to Anatomy and Physiology

Chapter 1 An Introduction to Anatomy and Physiology © 2012 Pearson Education, Inc.

Introduction to Studying the Human Body • Humans are vertebrates- having a segmented vertebral column • Anatomy • The study of the relationship of body parts to one another • Body structure is concrete- it can be seen, felt, and examined • Location, composition • Is the oldest medical science (1600 B. C) • Physiology • Is the study of function • Explains how the body works and accomplishes its life-sustaining activities • Anatomical information provides clues about functions and physiological mechanisms can be explained only in terms of the underlying anatomy. • Homeostasis • A state of equilibrium and balance, maintained by selfregulating processes. The goal of physiological regulation and the key to survival in a changing environment. © 2012 Pearson Education, Inc.

Anatomy Gross/Macroscopic anatomy: examines large, visible structures • Systemic anatomy studies functional body system • Regional anatomy examines particular regions of the body • Surface anatomy focuses on superficial anatomic markings and internal body structures • Comparative anatomy examines anatomical similarities and differences in different species • Embryology studies developmental changes from conception to birth § Physical examination § Inspection- vital signs, Palpation (lightly pushing against patient skin to detect lumps etc. ) , Auscultation (use of an instrument to listen to interior sounds), Percussion (light tapping on body regions to detect presence of air or fluid – dull or hollow sounds) § Lab tests § Medical imaging (CT scan, MRI, Radiology-x-rays, PET scan) § Pathology - Study of structural changes associated with disease Microscopic anatomy examines cells and molecules • Cytology (cyt- = cell) : study of cells and their structures • Histology: study of tissues and their structures © 2012 Pearson Education, Inc.

Medical Imaging Radiography – Xrays penetrate soft tissues and darken photographic film • Dense tissues absorb X-rays so film remains white • Radiograph: picture that results; also called an X-ray • Poor resolution of soft tissues • Major use is osteology Radiography: Digital Subtraction Angiography (DSA) • is a type of fluoroscopy technique used to visualize blood vessels in a bony or dense soft tissue environment. • Radiopaque substances injected or swallowed • Intestinal tract: barium sulfate swallowed or inserted through enema Sonography • High-frequency sound waves echo back from internal organs • Avoids harmful x rays • Used in obstetrics, cardiology • 2 nd most commonly used of the techniques © 2012 Pearson Education, Inc.

Computed Tomography. CT Scan Positron Emission Tomography (PET scan). • Low-intensity X rays are analyzed by computer Nuclear Medicine • Assesses metabolic state • Labeled glucose injected into patient • The collision of positrons and electrons produces gamma rays that are analyzed by a computer • Images glucose usage and thus reflects metabolic rate • Damage tissues show less glucose uptake and appear dark • Slice images can be viewed singly or the computer can stack them to give a three dimensional picture. Multiple scans used to build 3 D views • Used to identify: ü tumors ü aneurysms ü kidney stones ü cerebral hemorrhages • Sharper image © 2012 Pearson Education, Inc. • Expensive

Magnetic Resonance Imaging - MRI • Best for soft tissue • MRI scanner forms a strong magnetic field 3000 – 60, 000 times stronger than the earth’s around target area. The human body is made mostly of water (H 2 O). When you lie under the powerful scanner magnets, the protons in the hydrogen atoms in your body line up in the same direction termed a vector. • Short bursts of radio waves are discharged into the vector knocking the protons out of alignment. • When the radio waves are turned off, the protons realign; emitting radio signals which generate the MRI image. • The signals provide information about the exact location of the protons in the body and help to distinguish between the various types of tissue in the body. The protons align at different speeds and produce distinct signals based on the type of body tissue. • Can not use on patient with metal in their body. Metal interferes with the ability of the protons to align. © 2012 Pearson Education, Inc.

Physiology-Study of Function • Cell physiology: processes within and between cells • Organ physiology: functions of specific organs • Systemic physiology: functions of an organ system • Pathological physiology: effects of diseases © 2012 Pearson Education, Inc.

Hierarchy of complexity • Molecular • Cells-life begins • Tissues group of similar cells working together • Epithelia • Connective tissues • Muscle tissue • Nervous tissues • Organs group of different tissues working together • Organ systems • Organism © 2012 Pearson Education, Inc. 8

Eleven (11) Organ Systems • • • Integumentary Skeletal AP 1 Muscular Nervous Endocrine Respiratory Cardiovascular/Circulatory Lymphatic Digestive Urinary Reproductive © 2012 Pearson Education, Inc. AP 2

Homeostasis • Homeostasis is a state of equilibrium or balance • All body systems working together to maintain a stable internal environment • Systems respond to external and internal changes to function within a normal range (body temperature, fluid balance) • Homeostasis failure results in disease or death • Mechanisms of Regulation • Auto-regulation (intrinsic) • Automatic response in a cell, tissue, or organ to some environmental change • Ex: O 2 levels decline; blood vessels dilate • Extrinsic regulation • Responses controlled by nervous and endocrine systems • Ex: hormones regulate the increase or decrease of organs activities- digestive organs; heart; lungs © 2012 Pearson Education, Inc.

Homeostasis Regulatory Mechanism Components • Receptor • Receives the stimulus • Ex: step on a nail sensors • Control center (brain) • Processes the signal and sends instructions • Ex: sensation of nail in foot sent to brain and other sensory processing centers • Effector • Carries out instructions • Ex: brain sends signals to foot muscles to remove foot from object (nail) © 2012 Pearson Education, Inc.

Negative and Positive Feedback • The Role of Negative Feedback • Primary mechanism of homeostasis • Response of the effector negates the stimulus • Body is brought back into homeostasis • Normal range is achieved • Ex: Temperature, blood pressure, heart rate, fluid balance • The Role of Positive Feedback • The response of the effector increases change of the stimulus • Body is moved away from homeostasis • Normal range is lost • Used to speed up processes • Ex: Labor contractions, blood clotting © 2012 Pearson Education, Inc.

Orientation to Anatomy • Superficial Anatomy • Locating structures on or near the body surface • Anatomical Landmarks • Anatomical position • Body positions (supine/prone) • Anatomical planes • Directional terms • Body regions/quadrants • Body cavities and membranes 13 © 2012 Pearson Education, Inc.

Anatomical Position • Person stands erect • Feet flat on floor • Arms at sides • Palms, face & eyes facing forward • Standard frame of reference for anatomical descriptions & dissection Body position • Supine- Face up • Prone – Face down A-14 © 2012 Pearson Education, Inc.

Forearm Positions • When supinated • palms face forward or upward • radius & ulna are parallel • When pronated • palms face rearward or downward • radius & ulna are crossed A-15 © 2012 Pearson Education, Inc.

Frontal or forehead Cranial or skull Cephalic or head Otic or ear Buccal or cheek Facial or face Cervical or neck Oral or mouth Acromial -Shoulder Thoracic or thorax, chest Axillary or armpit Mammary or breast Brachial or arm Abdominal (abdomen) Umbilical or navel Antecubital or front of elbow Anterior view © 2012 Pearson Education, Inc. Nasal or nose Ocular, orbital or eye Trunk

Figure 1 -5 a Anatomical Landmarks Antebrachial or forearm Pelvic (pelvis) Trunk Carpal or wrist Palmar or palm Manual or hand Pollex Digits or thumb (phalanges) or fingers (digital or phalangeal) Inguinal or groin Pubic Patellar (pubis) or kneecap Femoral or thigh Crural or leg Tarsal or ankle Digits (phalanges) or toes (digital or phalangeal) Hallux or great toe © 2012 Pearson Education, Inc. Pedal or foot Anterior view

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Figure 1 -6 a Abdominopelvic Quadrants and Regions Right Upper Quadrant (RUQ) Left Upper Quadrant (LUQ) Right Lower Quadrant (RLQ) Left Lower Quadrant (LLQ) Abdominopelvic quadrants. The four abdominopelvic quadrants are formed by two perpendicular lines that intersect at the navel. The terms for these quadrants, or their abbreviations, are most often used in clinical discussions. © 2012 Pearson Education, Inc.

Figure 1 -6 b Abdominopelvic Quadrants and Regions Right hypochondriac region Epigastric region Right lumbar region Umbilical region Right inguinal region Hypogastric (pubic) region Left hypochondriac region Left lumbar region Left inguinal region Abdominopelvic regions. The nine abdominopelvic regions provide more precise regional descriptions. © 2012 Pearson Education, Inc.

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Directional Terms • Ventral/Dorsal • Superior/Inferior • Anterior/Posterior • Superficial/Deep • Parietal/Visceral • Cephalic/Caudal • Proximal/Distal • Medial/Lateral • Ipsilateral • Contralateral © 2012 Pearson Education, Inc.

Anatomical Planes and Sections Transverse plane © 2012 Pearson Education, Inc. • Plane: a three-dimensional axis imaginary flat surface passing through the body • Section: implies actual cut or slice parallel to a plane to reveal internal anatomy • SAGITTAL divides body into right and Frontal left regions plane • median (midsagittal) plane divides body or organ into equal halves • parasagittal divides into two unequal halves • FRONTAL (CORONAL) divides body into anterior (front) & posterior (back) Sagittal portions plane • TRANSVERSE (horizontal) divides the body into superior (upper) & inferior (lower) portions • OBLIQUE: body part cut at an angle

Typical Sectional Views of the Body 24 © 2012 Pearson Education, Inc.

Body Cavities and Membranes • Protect organs from accidental shocks • Permit changes in size and shape of internal organs • Lined by serous membranes • Filled with viscera (organs) Serous Membranes – produce watery secretions • Line body cavities and cover organs • Squamous epithelium lying atop connective tissue • Parietal layer (lines cavity) and • visceral layer (covers the organs) © 2012 Pearson Education, Inc.

Body Cavities and Membranes Cranial cavity Vertebral canal Thoracic cavity Diaphragm Abdominal cavity Pelvic cavity (a) Left lateral view © 2012 Pearson Education, Inc.

Body Cavities and Membranes Dorsal Ventral • cranial cavity • Contains the respiratory, circulatory, digestive, urinary and reproductive systems • brain • Diaphragm divides into two separate cavities • vertebral canal • Spinal cord • Thoracic cavity • Right and left pleural cavities • meninges • Right and left lungs covered by pleura • Mediastinum • blood vessels, trachea, esophagus, thymus • Pericardial cavity - heart surrounded by the pericardium sac • Abdominopelvic cavity • Peritoneal cavity: Parietal / visceral peritoneum • Abdominal cavity -digestive organs, pancreas, kidneys, ureters • Pelvic cavity -reproductive organs, rectum, and bladder © 2012 Pearson Education, Inc.

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Pleural Membranes Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Parietal pleura Pleural cavity Visceral pleura Lung Diaphragm (b) Pleurae A-29 © 2012 Pearson Education, Inc.

Pericardial Membranes Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Parietal pericardium Pericardial cavity Visceral pericardium Heart Diaphragm (a) Pericardium A-30 © 2012 Pearson Education, Inc.

Figure 1 -10 a The Ventral Body Cavity and Its Subdivisions- Sagittal View © 2012 Pearson Education, Inc.