Unit I. The Human Organism.pdf

MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 I. THE HUMAN ORGANISM 1.1 ANATOMY A scientific discipline that investigates the structure of the body To dissect or to cut apart or separate the parts of the body f...

MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 I. THE HUMAN ORGANISM 1.1 ANATOMY A scientific discipline that investigates the structure of the body To dissect or to cut apart or separate the parts of the body for study. Types of Study 1. Systemic Anatomy – study of the body by systems such as the cardiovascular, nervous, skeletal and muscular system and the like. 2. Regional Anatomy – study of the organization of the body by areas such as the head, abdomen, arms and the like 3. Surface Anatomy – study of external features such as bony projections which serves as a landmark for locating deeper structures. Anatomical Imaging – involves the use of x-rays, ultrasounds, magnetic resonance imaging (MRI) and other technologies to create pictures of internal structures such as when determining of a bone is broken or a ligament is torn. 1.2 PHYSIOLOGY A scientific discipline that deals with the processes or functions of living things. Major goals of studying physiology 1. To understand and predict the body’s responses to stimuli. 2. To understand how the body maintains internal conditions within a narrow range of values in the presence of continually changing internal and external environments. Types of Study 1. Human Physiology – study of specific organism – human 2. Cellular and systemic physiology - they emphasize specific organizational levels STRUCTURAL AND FUNCTIONAL ORGANIZATION Six Structural levels 1. Chemical - it involves how atoms such as hydrogen and carbon interact and combine into molecules - it is important because a molecule’s structure determines its function Atoms – the smallest unit of matter that participate in chemical reactions Molecules – two or more atoms joined together Organelles- smallest structures that make up some cells 2. Cell - body’s basic building block and the smallest living component of an organism - the human body consists of millions of cells grouped into specialized units that function together throughout the organism’s life A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 3. Tissues - grouping of similar cells and the material surrounding them that work together to perform a particular function Four basic types of tissues A. Epithelial – covers body surfaces, lines hollow organs and cavities and form glands B. Connective - connects, support and protects body organs while distributing blood vessels to the tissues C. Muscular - contracts to make body parts move and generates heat D. Nervous - carries information from one part of the body to another through nerve impulses 4. Organ - different types of tissues that are joined together, they have specific functions and usually have recognizable shapes. (Example: stomach, skin, bones, heart, lungs, brain) 5. System - related organ with a common function a. Integumentary system – (skin and other associated structures such as the hair, toe nails, sweat glands) protects the body and helps regulate body temperature. b. Skeletal system – (bones and joints of the body) supports and protects the body c. Muscular system - (skeletal muscle tissue) participates in body movements d. Nervous system - (brain, spinal cord) generates action potentials to regulate body activities e. Endocrine system - (hormone producing glands) regulates body activities by releasing hormones f. Cardiovascular system – (blood, heart, blood vessels) heart pumps blood through the blood vessels; blood carries nutrients to cells g. Lymphatic system – (lymphatic fluids and vessels) returns, proteins and fluid to blood h. Respiratory system - (lungs) transfer oxygen from inhaled air to blood and carbon dioxide from blood to exhaled air i. Digestive system - (GIT) achieves physical and chemical breakdown of food j. Urinary system - (kidneys, ureters, urinary bladder and urethra) produces, stores and eliminates urine; eliminates waste products. k. Reproductive system – (testes and ovaries) gonads produce sperm that unite to form a new organism 6. Organisms - any living thing considered as a whole A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 CHARACTERISTICS OF THE LIVING HUMAN ORGANISM 1. Organization - refers to the specific interrelationships among the parts of an organism and how those parts interact to perform specific functions. 2. Metabolism – is the ability to use energy to perform vital function such as growth, movement and reproduction Catabolism – breakdown of complex substances into simpler component Anabolism – building up of complex chemical substances from smaller, simpler components 2. Responsiveness - body’s ability to detect and respond to changes Example: movements towards food and water; away from danger or poor environmental conditions 3. Development - includes the changes an organism undergoes through time - human development starts when the egg is fertilized by the sperm and ends with death - it involves growth and differentiation DIFFERENTATION – change in cell structure and function from generalized to specialized 4. Growth - increase in body size that results from an increase in the size of existing cells - it can result from an increase in cell number, cell size or the number of substances surrounding the cells 5. Reproduction - formation of new cells or tissue growth, repair or replacement and the production of a new individual HOMEOSTASIS - existence and maintenance of a relatively constant environment within the body despite fluctuations in either the external environment or the internal environment Homeostatic Control Mechanisms The body uses three main components to maintain homeostasis: Receptors - Detect changes in the internal environment and send this information to the control center. Control Center - Processes the information received from the receptors and determines the appropriate response. It often involves the brain or endocrine glands. Effectors - Carry out the response directed by the control center to restore balance. Effectors include muscles and glands. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Feedback Systems 1. Negative Feedback - This is the most common mechanism, where the response reduces or reverses the effect of the initial stimulus. For example, if body temperature rises, mechanisms like sweating and vasodilation are activated to cool the body down. 2. Positive Feedback - Less common and involves the enhancement or amplification of a change. It moves the system away from its equilibrium. An example is childbirth, where contractions lead to increased release of oxytocin, which intensifies contractions until delivery. Examples of Homeostatic Regulation Thermoregulation: Maintaining body temperature within a narrow range. Blood Glucose Regulation: Involving insulin and glucagon to keep blood sugar levels stable. Fluid and Electrolyte Balance: Managing the levels of fluids and electrolytes to ensure proper cellular function. TERMINOLOGIES AND BODY PLANES - Terms are derived from Latin or Greek - Point of origin of words – etymology - The meaning of terms is identified from root words, prefixes or suffixes Body Positions Anatomic Positions – refers to a person standing upright with the face directed forward and upper limbs hanging to the sides and the palms of the hands facing forward A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 1. Terminology Directional Terms: Superior: Toward the head or upper part of the body Inferior: Away from the head or toward the lower part of the body Anterior (Ventral): Toward the front of the body Posterior (Dorsal): Toward the back of the body Medial: Toward the midline of the body Lateral: Away from the midline of the body Intermediate: Between a more medial and a more lateral structure Proximal: Closer to the point of attachment or origin Distal: Farther from the point of attachment or origin Ipsilateral: On the same side of the body as another structure Contralateral: On the opposite side of the body from another structure Superficial: Near the surface of the body Deep: Away from the surface of the body A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Regional Terms: Cephalic: Head region Thoracic: Chest region Abdominal: Abdomen region Pelvic: Pelvis region The Abdominal Regions 4 Quadrants of the Abdomen 2. Body Planes Sagittal Plane: Divides the body into left and right parts. If it divides the body into equal left and right halves, it is called the midsagittal plane. Any sagittal plane that is not in the middle is known as a parasagittal plane. Mid-sagittal Plane or Median Plane: Passes through the midline of an organ or the body and divides the organ or the body into equal right and left halves Parasagittal Plane: Does not pass through the midline but divides an organ or the body into unequal halves A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Frontal Plane (Coronal Plane): Divides the body into anterior (front) and posterior (back) parts. It is perpendicular to the sagittal plane Transverse Plane (Horizontal Plane): Divides the body into superior (upper) and inferior (lower) parts. It is perpendicular to both the sagittal and frontal planes. Oblique Plane: A plane that passes through an organ or the body at an angle between the transverse plane and either sagittal or frontal plane Body Cavities Body Cavities – spaces within the body that helps protect, separate and support internal organs Cranial cavity – formed by cranial bones and contains the brain Vertebral canal – formed by the vertebral column and contains the spinal cord and the beginnings of the spinal nerves Thoracic cavity – chest cavity – formed by the ribs, the muscles of the chest, the sternum and the thoracic portion of the vertebral column Pleural cavity – surrounds the lung Pericardial cavity – surrounds the heart Mediastinum – central portion of the thoracic cavity between the lungs Abdominopelvic cavity- extends from the diaphragm to the groin and is encircled by the abdominal muscular wall and the bones and muscles of the pelvis Abdominal Cavity – contains the stomach, spleen, liver, gallbladder, small intestines and most of the large intestines Pelvic Cavity – contains the urinary bladder, portions of the large intestines, internal organs of reproduction A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Table 1. Major Body Parts and Their Description BODY PART DESCRIPTION Head Includes the skull and the face Skull The bony part of the head that encloses and protects the brain. Face The anterior (front) portion of the head where the eyes, nose, mouth, forehead, cheeks, and chin are found Neck (cervical) Supports the head and attaches it to the trunk; found between the head and the trunk Trunk Consist of the chest, abdomen, pelvis, and back Chest Found between the neck and abdomen anteriorly Abdomen Found between the chest and pelvis anteriorly Back Posterior of the trunk that is between the neck and the buttocks Upper limbs Each upper limb is attached to the trunk by the shoulder girdle, comprised of the clavicle anteriorly and the scapula posteriorly Shoulder Part of the body where the upper limb is attached to the shoulder girdle Upper arm Part of the upper limb from the shoulder to the elbow Forearm Part of the upper limb from the elbow to the wrist. Wrist Part of the upper limb which connects the hand to the forearm Lower limbs Each lower limb is attached to the trunk by the pelvic girdle consisting of the ilium, ischium and pubis Buttocks Posterior rounded area in the pelvis where the thigh is attached Thigh Part of the lower limb that is attached to the pelvis Leg Part of the lower limb from the knee to the ankle Ankle Portion of the lower limb that attaches the foot to the leg Foot Part of the lower limb which is composed of the sole and toes Table 2. List of Different Anatomical Terms ANATOMICAL TERM OTHER TERM Axial Central part of the body which includes the head and the trunk Cephalic Head Cranial Portion of the skull surrounding the brain Facial Face Orbital Eye A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Frontal Forehead Otic Ear Nasal Nose Buccal Cheek Oral Mouth Mental Chin Occipital Back of the head Cervical Neck Thoracic Chest Sternal Breast bone Mammary Breast Abdominal Anterior body trunk inferior to the ribs Umbilical Navel Coxal Hip Pelvic Pelvis Pubic Genital area Dorsal Back Scapular Shoulder blade Pectoral Chest Nuchal Back of neck Sacral Between hips Clavicular Collar bone Vertebral Area of spine Lumbar Area of back between ribs and hips Appendicular Extremities or limbs Acromial Highest point of shoulder Axillary Armpit Brachial Upper arm Antecubital Anterior surface of elbow Olecranal Elbow Antebrachial Forearm Volar Antero-medial aspect of the forearm Carpal Wrist Palmar Palm Digital Digits or fingers (upper limb); toes (lower limb) Inguinal Groin Gluteal Buttocks Femoral Thigh Patellar Anterior surface of the knee / knee cap Popliteal Posterior surface of the knee Crural Anterior surface of the leg Sural Posterior surface of the leg Fibular/peroneal Lateral side of the leg Tarsal Ankle Pedal Foot Plantar Sole of foot Calcaneal Heel A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 II. CELL PHYSIOLOGY 1. Cell Structure and Functions Cell Theory: o All living organisms are composed of cells. o The cell is the basic unit of life. o All cells arise from pre-existing cells. Basic Cell Structure: o Plasma Membrane: A flexible outer boundary that regulates what enters and exits the cell. o Cytoplasm: The jelly-like substance within the cell, excluding the nucleus, that contains organelles and cytosol. o Nucleus: The control center of the cell containing DNA. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Functions of Cells: o Metabolism: All chemical reactions that occur within the cell. o Energy Production: Through processes like cellular respiration in the mitochondria. o Synthesis of Molecules: Production of proteins, lipids, and nucleic acids. o Communication: Cells communicate through chemical signals and receptors. o Reproduction and Inheritance: Cells contain genetic material that is passed on during cell division. 2. Cell Membrane and Transport Cell Membrane Structure: o Composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates. o Functions as a selective barrier, allowing only certain molecules to enter or leave the cell. Types of Transport: o Passive Transport: Movement of substances across the membrane without the use of energy. ▪ Diffusion: Movement of molecules from an area of higher concentration to an area of lower concentration. Example: Oxygen and carbon dioxide exchange in the lungs. ▪ Osmosis: Diffusion of water across a selectively permeable membrane. Example: Water absorption in the intestines. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 ▪ Facilitated Diffusion: Movement of molecules across the membrane via transport proteins. Example: Glucose transport into cells. o Active Transport: Movement of substances against their concentration gradient, requiring energy (ATP). ▪ Primary Active Transport: Direct use of ATP to transport molecules. Example: Sodium-potassium pump. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 ▪ Secondary Active Transport: Uses the energy from the primary active transport to move other substances. Example: Glucose-sodium cotransport in the intestines. o Vesicular Transport: Transport of large particles and macromolecules across membranes. ▪ Endocytosis: Process of taking substances into the cell via vesicles. Example: Phagocytosis of bacteria by white blood cells. ▪ Exocytosis: Process of expelling substances from the cell via vesicles. Example: Secretion of neurotransmitters from nerve cells. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 3. Organelles Nucleus: Contains the cell's genetic material and regulates activities such as growth, metabolism, and reproduction. Ribosomes: Sites of protein synthesis, found in the cytoplasm or attached to the endoplasmic reticulum. Endoplasmic Reticulum (ER): o Rough ER: Studded with ribosomes, involved in protein synthesis and modification. o Smooth ER: Lacks ribosomes, involved in lipid synthesis and detoxification. Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles. Mitochondria: Powerhouses of the cell, responsible for ATP production through cellular respiration. Lysosomes: Contain digestive enzymes to break down waste materials and cellular debris. Peroxisomes: Contain enzymes that detoxify harmful substances and break down fatty acids. Cytoskeleton: Network of protein filaments that provide structural support, aid in cell movement, and assist in cell division. o Microfilaments: Involved in cell movement and shape changes. o Intermediate Filaments: Provide mechanical support. o Microtubules: Involved in intracellular transport and cell division. Centrioles: Involved in organizing microtubules during cell division. Cilia and Flagella: Hair-like structures that aid in cell movement. Cilia move substances across cell surfaces, while flagella propel cells. 4. Cell Cycle Overview: The cell cycle is the series of events that cells go through as they grow and divide. Interphase: Period of growth and preparation for cell division. o G1 Phase: Cell growth and normal functions. o S Phase: DNA replication. o G2 Phase: Preparation for mitosis. Mitosis: Division of the cell nucleus. o Prophase: Chromatin condenses into chromosomes; nuclear envelope breaks down. o Metaphase: Chromosomes align in the center of the cell. o Anaphase: Sister chromatids separate and move to opposite poles. o Telophase: Nuclear membranes form around each set of chromosomes, chromosomes decondense. Cytokinesis: Division of the cytoplasm, resulting in two daughter cells. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Examples: Mitosis in Skin Cells: Continuous replacement of skin cells to maintain a protective barrier. Cell Cycle Regulation: Involvement of cyclins and cyclin-dependent kinases to ensure proper cell division and prevent uncontrolled growth, which can lead to cancer. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 III. TISSUE PHYSIOLOGY 1. Tissue Types Overview: The human body is composed of four primary tissue types: epithelial, connective, muscle, and nervous tissues. Each type has distinct characteristics and functions. Epithelial Tissue Characteristics: Closely packed cells with minimal extracellular material, avascular (lacking blood vessels), high regenerative capacity. Functions: Protection, absorption, filtration, secretion. Examples: o Simple Squamous Epithelium: Single layer of flat cells, found in the alveoli of lungs, allowing for gas exchange. o Stratified Squamous Epithelium: Multiple layers of cells, found in the skin, providing protection against abrasion. o Simple Cuboidal Epithelium: Single layer of cube-shaped cells, found in the kidney tubules, involved in secretion and absorption. o Simple Columnar Epithelium: Single layer of tall, column-like cells, found in the digestive tract, aiding in absorption and secretion. Connective Tissue Characteristics: Diverse group of tissues with varying functions, abundant extracellular matrix, vascular (except for cartilage). Functions: Support, protection, insulation, transportation of substances. Examples: o Loose Connective Tissue (Areolar): Gel-like matrix with collagen and elastic fibers, found under epithelia, wraps and cushions organs. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 o Adipose Tissue: Fat-storing tissue, provides insulation and energy storage. o Dense Connective Tissue: Contains densely packed collagen fibers, found in tendons and ligaments, providing strong attachment. o Cartilage: Firm but flexible matrix with collagen fibers, found in joints, providing support and flexibility. o Bone: Hard matrix of calcium salts and collagen fibers, providing structural support. o Blood: Fluid matrix (plasma) with cells (red and white blood cells), involved in transportation of nutrients and waste. Muscle Tissue Characteristics: Cells specialized for contraction, highly vascularized. Functions: Movement, maintenance of posture, heat production. Examples: o Skeletal Muscle: Long, cylindrical, multinucleated cells with striations, voluntary control, found attached to bones. o Cardiac Muscle: Branched, striated cells with intercalated discs, involuntary control, found in the heart. o Smooth Muscle: Spindle-shaped, non-striated cells, involuntary control, found in walls of hollow organs (e.g., intestines, blood vessels). Nervous Tissue Characteristics: Neurons and supporting cells (neuroglia), highly specialized for communication. Functions: Transmission of electrical signals, processing information, control of body functions. Examples: o Neurons: Nerve cells that generate and conduct nerve impulses, found in the brain, spinal cord, and nerves. o Neuroglia: Supporting cells that provide structural and metabolic support for neurons. 2. Tissue Membranes Overview: Tissue membranes are thin layers of cells that cover surfaces, line cavities, and divide spaces or organs. There are four main types of membranes: Mucous Membranes (Mucosa): Line body cavities that open to the exterior, such as the digestive and respiratory tracts, secrete mucus for lubrication and protection. Serous Membranes (Serosa): Line closed body cavities (e.g., thoracic and abdominal cavities), secrete serous fluid to reduce friction between organs. o Examples: Pleura (lungs), pericardium (heart), peritoneum (abdominal organs). Cutaneous Membrane: The skin, covering the body surface, provides protection against external environment. Synovial Membranes: Line joint cavities, produce synovial fluid for lubrication. 3. Damage, Inflammation, and Repair Overview: Tissue damage triggers an inflammatory response and subsequent repair processes to restore normal function. A.BARRUGA, PTRP  MC 1: ANATOMY AND PHYSIOLOGY UNIT 1 Inflammation Characteristics: Initial response to tissue damage, characterized by redness, heat, swelling, pain, and loss of function. Process: o Vasodilation: Increased blood flow to the affected area, causing redness and heat. o Increased Vascular Permeability: Fluid and immune cells leave the blood vessels and enter the tissue, causing swelling and pain. o Phagocytosis: Immune cells (e.g., macrophages) engulf and remove pathogens and debris. Repair Regeneration: Replacement of damaged tissue with the same type of cells, restoring normal function. o Examples: Skin, liver, and epithelial tissues have high regenerative capacity. Fibrosis: Replacement of damaged tissue with scar tissue (dense connective tissue), which may not restore original function. o Examples: Severe wounds, heart tissue after myocardial infarction. A.BARRUGA, PTRP