Human Anatomy for Medical Scientists Lecture 1 - PDF

Human Anatomy for Medical Scientists - Lecture 1 Introduction to the Human Body Anatomy and physiology are subdivisions of the science of biology. Human anatomy relates to body structure and the relationships between body structures. Human physiology concerns the...

Human Anatomy for Medical Scientists - Lecture 1 Introduction to the Human Body Anatomy and physiology are subdivisions of the science of biology. Human anatomy relates to body structure and the relationships between body structures. Human physiology concerns the functions of the body parts. In general, function is determined by structure. The Body’s Organization Levels Chemical: Atoms, Molecules, Macromolecules compose the cellular organelles, which perform cell functions. Cellular: Cells are the basic unit of life. Tissue: Made of similar cells that perform a specific function. Organs: Several types of tissues that perform a specific function. Organ Systems: Several organs that work together to perform related functions. Organism: All systems interact to make the whole organism. The Subspecialties of Human Anatomy Gross anatomy: Study of structures observed with the unaided eye. Microscopic anatomy: Study of structures observed with the aid of a microscope. Developmental anatomy: Study of structural changes from conception to birth. Pathological anatomy (pathology): Study of structural changes caused by disease. Introduction to Anatomical Terms Describe: Location of body parts, Regions of the body, Imaginary planes used to section the body. Anatomical Position Standard anatomical position: Erect, Feet parallel and flat on the floor, Eyes directed forward, Arms at the sides with palms forward, Fingers pointing downward. Directional Terms Anterior (ventral): Toward the front Example: The navel is on the anterior side. Posterior (dorsal): Toward the back Example: The kidneys are posterior to the intestines. Superior: Toward the top; toward the head Example: The thorax is superior to the abdomen. Inferior: Away from the head; toward the bottom Example: The legs are inferior to the trunk. Medial: Towards the midline of the body Example: The heart is medial to the lungs. Lateral: Toward the side of the body Example: The ears are lateral to the head. Proximal: Toward the main mass of the body Example: The knee is proximal to the foot. Distal: Away from the main mass of the body Example: The hand is distal to the elbow. Superficial (External): Toward the surface of the body Example: The skin is external to the muscles. Deep (Internal): Away from the surface of the body  Example: The brain is internal to the cranium. Visceral: Related to internal organs Example: The lungs are covered by the visceral pleura. Parietal: Related to the body walls Example: The parietal pleura is the inside lining of the thoracic cavity. Ipsilateral: Refers to the same side of the body. Contralateral: Refers to opposite sides of the body. Supine: Lying on the back. Prone: Lying face downward. Anatomical Planes and Sections Sagittal plane: Divides the body into right and left portions. Midsagittal plane: Exactly through the midline. Parasagittal plane: Parallel to the sagittal plane dividing the body into left and right portions. Coronal (frontal) plane: Divides the body into anterior and posterior portions. Transverse (horizontal) plane: Divides the body into superior and inferior portions. Planes Through an Organ 1. Longitudinal section: Cut along the length of an organ. 2. Transverse (Cross) section: Cut at a right angle to the length of the organ. 3. Oblique: Cut at any angle but a right angle. Body Parts and Regions Divided into main regions: 1. Head, 2. Neck, 3. Trunk, 4. Upper limb (extremity), 5. Lower limb (extremity).  The trunk (torso) is frequently divided into the thorax and abdomen. Body Parts and Regions (Illustrated) Region Parts Head Frontal, Orbital, Nasal, Oral, Mental Neck Cervical Trunk (a) Pectoral, Sternal, Mammary, Abdominal, etc. Upper Limb Brachial, Carpal, Palmar, Digital, etc. Lower Limb Femoral, Patellar, Crural, Digital, etc. Trunk (b) Dorsal, Lumbar, Sacral, Gluteal, etc. Body Cavities and Membranes Posterior (Dorsal) Body Cavity Cranial cavity: Contains the brain. Vertebral canal: Contains the spinal cord. Meninges: Membranous layers lining the dorsal body cavity, containing cerebrospinal fluid supporting the brain and spinal cord. Anterior (Ventral) Body Cavity Thoracic cavity and abdominopelvic cavity: Separated by the diaphragm muscle. Serous membranes: Line these cavities and secrete serous fluid to reduce friction. Thoracic Cavity Medial Portion (Mediastinum): Contains the heart, thymus gland, trachea, esophagus, and other structures. Right and Left Portions (Pleural Cavities): Contain the lungs. Abdominopelvic Cavity Superior Portion (Abdominal Cavity): Contains the stomach, liver, spleen, gallbladder, and most intestines. Inferior Portion (Pelvic Cavity): Contains the rectum, urinary bladder, internal reproductive organs, and the rest of the intestines. Illustrations Detailed diagrams available through McGraw-Hill Education and other specialized academic resources. Terms of Movements Flexion/Extension Abduction/Adduction Rotation/Circumduction Pronation/Supination Inversion/Eversion Specific Movements Flexion: Decreasing angle between bones in a sagittal plane. Extension: Increasing angle between bones to straighten the joint. Abduction: Moving a limb away from the body midline in a coronal plane. Adduction: Moving a limb towards the body in a coronal plane. Rotation: Moving a body part around its long axis. Circumduction: Moving a body part to create a cone shape. Pronation: Medial rotation of the forearm so the palm faces posteriorly. Supination: Lateral rotation of the forearm from the pronated position so the palm faces anteriorly. Inversion: Moving the foot so the sole faces medially. Eversion: Moving the foot so the sole faces laterally. Disease State of Human Body Disease: When homeostasis fails and a body part doesn’t function properly. Local Disease: Restricted to a specific body part (e.g., skin inflammation). Systemic Disease: Affects several organs or the entire body (e.g., bacteremia). Acute Disease: Occurs suddenly and lasts a short time (e.g., liver failure). Chronic Disease: Develops slowly and is long-term (e.g., cancer). Sources Primary References: Mader’s Understanding Human Anatomy & Physiology, Seeley's Anatomy & Physiology.  Supplemental Images and Research: TeachMeAnatomy.info and academic journals such as Aquaculture. Human Anatomy: Body Tissue and Membrane Introduction Tissues are composed of specialized cells with similar structures and perform common functions. Four major types of tissue (4C): Epithelial (Cover) Connective (Connect) Muscular (Contract) Nervous (Communicate) Organs are typically composed of all four types of tissue. Epithelial Tissue ➡ Characteristics Also known as epithelium. Covers body surfaces and organs. Lines body cavities and hollow organs. Cells are tightly packed. Avascular (lack blood supply). Has a free surface and a basement membrane. Classified by: Cell shape: Squamous, Cuboidal, Columnar. Number of cell layers: Simple, Stratified, Pseudostratified. Functions Physical protection: Protects external and internal surfaces. Resistant to dehydration, abrasion, destruction. Secretions: Some cells specialized to secrete substances.  Sensations: Contains nerve endings. Supplies information about touch, pressure, temperature, pain. Neuroepithelium houses cells responsible for sight, taste, smell, hearing, equilibrium. Types of Epithelial Tissue Simple Squamous Epithelium Structure: Single layer of flat cells. Locations: Alveoli of lungs, blood and lymphatic vessels, certain kidney tubules. Functions: Diffusion, filtration, secretion, absorption. Stratified Squamous Epithelium Structure: Many layers; cells flattened at surface. Types: Keratinized: Epidermis (protection from injury, drying out). Non-keratinized: Lines mouth, esophagus, vagina (protection from drying out). Simple Cuboidal Epithelium Structure: Single layer of cube-shaped cells; some with microvilli or cilia. Locations: Kidney tubules, glands, bronchioles, ovaries. Functions: Secretion, absorption. Stratified Cuboidal Epithelium Structure: Multiple layers of cube-shaped cells. Locations: Sweat gland ducts, ovarian follicles, salivary glands. Functions: Secretion, absorption, protection against infections. Simple Columnar Epithelium Structure: Single layer of elongated cells; may have microvilli or goblet cells. Locations: Digestive organs, uterine tubes. Functions: Protection, secretion, absorption. Stratified Columnar Epithelium  Structure: Two or more layers of elongated cells. Locations: Parts of the pharynx, male urethra. Functions: Protection, secretion. Pseudostratified Columnar Epithelium Structure: Appears stratified but is one layer; all cells touch basement membrane. Types: Ciliated: Respiratory tract; moves mucus. Non-ciliated: Male urethra, epididymis. Transitional Epithelium Structure: Variable appearance; stretches. Locations: Urinary bladder, ureters, superior urethra. Functions: Protection against the caustic effects of urine. Connective Tissue ➡ Characteristics Binds structures, provides support and protection. Fills spaces, produces blood cells, stores fat. Cells are separated by an extracellular matrix containing fibers (collagen, elastic, reticular). Types of Connective Tissue Fibrous Connective Tissue 1. Loose Connective Tissue: Structure: Collagenous and elastic fibers, fibroblasts. Function: Binds tissues and organs. Locations: Beneath skin, around organs. 2. Dense Connective Tissue: Regular: Parallel collagen fibers (tendons, ligaments, aponeuroses). Irregular: Nonparallel fibers (dermis, joint capsules). 3. Reticular Connective Tissue:  Structure: Reticular fibers, reticular cells. Function: Supportive framework. Locations: Lymphatic system organs (nodes, spleen, thymus, bone marrow). Muscular Tissue ➡ Characteristics Contracts/shortens with force. Moves entire body parts, pumps blood. Types of Muscular Tissue Skeletal Muscle Appearance: Striated, multinucleated, cylindrical. Control: Voluntary. Function: Moves body parts. Location: Attached to bones or skin. Smooth Muscle Appearance: Non-striated, spindle-shaped. Control: Involuntary. Function: Moves substances through organs. Location: Walls of hollow organs (intestines, bladder, blood vessels). Cardiac Muscle Appearance: Striated, branched, single nucleus. Control: Involuntary. Function: Pumps blood. Location: Heart. Extracellular Junctions Tight Junction: Plasma membrane proteins join, forming an impermeable barrier. Gap Junction: Plasma membrane channels join, allowing substance passage between cells. Adhesion Junction: Adjacent plasma membranes held together by extracellular filaments. Summary Tables Epithelial Tissue Type of Tissue Description Location Simple squamous One layer of flattened cells Blood capillaries, alveoli of lungs Stratified squamous Many layers; cells flattened at free surface Skin, body orifices Simple cuboidal One layer of cube-shaped cells Secreting glands, ovaries, kidney tubules Stratified cuboidal Two or more layers of cube-shaped cells Salivary and mammary gland ducts Simple columnar One layer of elongated cells Digestive organs, uterine tubes Stratified columnar Two or more layers of elongated cells Pharynx, male urethra Pseudostratified columnar One layer of elongated cells, appear stratified Respiratory system Transitional Many layers; stretches Urinary bladder, ureters, urethra Connective Tissue Type Structure of Matrix Types of Cells Example of Location Loose connective tissue (Areolar) Collagen, elastin, reticular fibers Fibroblasts, white blood cells Between tissues and organs Adipose Fibroblasts, store fat Fibroblasts Beneath skin, around organs Dense connective tissue (Regular) Parallel collagen fibers Fibroblasts Tendons, ligaments, aponeuroses Dense connective tissue (Irregular) Nonparallel collagen fibers Fibroblasts Dermis, joint capsules Reticular connective tissue Reticular fibers Fibroblasts, many white blood cells Lymphatic organs, liver Muscular Tissue Type Fiber Appearance Location Control Skeletal Striated, cylindrical Attached to skeleton or skin Voluntary Smooth Non-striated, spindle-shaped Walls of hollow organs Involuntary Cardiac Striated, cylindrical, and branched Heart Involuntary Human Anatomy for Medical Scientist — Lecture 3: Integumentary S Prepared by: Louis TONG Revised by: Wing LI Content in this Lecture 1. Structure of the skin 2. Function of the Integumentary system 3. Epidermis 4. Dermis 5. Hypodermis 6. Glands 7. Function of skin 8. Disorder of skin 9. Skin cancer 10. Burns 11. Homeostasis Structure of the Skin Skin is also called the cutaneous membrane (皮膚膜) or the integument (外皮). Covers the entire surface of the body. Largest organ in the body: 1.8 m². Comprised of all 4 tissue types. Two regions: epidermis (表皮) and dermis (真皮). Hypodermis (皮下組織) or subcutaneous tissue (皮下組織) attaches the skin to underlying tissue. Functions of the Integumentary System Structures that are Part of the Integument Skin Hair Nails  Glands Overview of Functions Protection Sensation Temperature regulation Vitamin D production Excretion Skin 1. Epidermis Superficial layer of epithelial tissue. 2. Dermis Deep layer of connective tissue. Provides structural strength. 3. Subcutaneous Tissue Not part of skin. Loose connective tissue connects skin to underlying structures. Properties of Epidermis 1. Avascular (無血管); nourished by diffusion from capillaries of the papillary layer of the dermis. 2. Composed of cells arranged into layers. 3. Separated from dermis by basement membrane. Layers of Epidermis Stratum basale/basal layer Stratum spinosum/spinous layer Stratum granulosum/granular layer Stratum lucidum Stratum corneum/cornified layer Stratum Basale Superficial to dermis. Cells constantly dividing; new cells pushed to the surface and die when far from blood supply. Cell types: Keratinocytes: Produce keratin (角蛋白), a waterproof protein. Langerhans cells: Macrophages (巨噬細胞). Merkel cells: Sensory mechanoreceptors, light touch sensation. Melanocytes: Produce melanin (黑色素), skin color, and UV protection. Albinism Genetic disease affecting melanin production. Characteristics: white or very light blonde hair, pale skin that burns easily. Stratum Spinosum Cells divide in this layer. Spiny appearance due to keratin fibers. Stratum Granulosum Flattened cells with keratin and dark-staining pigment granules. Stratum Lucidum Found only in thick skin. Provides protection from constant friction (摩擦). Stratum Corneum Tough, uppermost layer. Cells are keratinized (hardened) and dead. Keratin prevents water loss and water gain. Serves as a mechanical barrier against microbes. Dermis Thicker than epidermis.  Made of dense, irregular connective tissue. Dermal papillae in the most superficial layer. Collagenous fibers prevent skin tearing. Elastic fibers allow movement of muscles and joints. Vascularization supplies oxygen and nutrients to cells and causes temporary skin color changes. Numerous sensory nerve fibers. Hypodermis Located below the dermis. Subcutaneous injections (皮下注射) are given here. Composed of loose connective tissue. Contains adipose tissue (fat) for energy storage, insulation, and protective padding. Glands (腺) Types of Glands in the Skin 1. Sweat Glands (汗腺) Apocrine glands (大汗腺) Open into hair follicles in the anal region. Begin secretion at puberty (青春期). Eccrine sweat glands (外分泌汗腺) Open onto the surface of the skin. Active when body heats up; helps lower body temperature. Sweat primarily water, also excretes wastes. Modified sweat glands produce cerumen (earwax) (耳垢). 2. Sebaceous Glands (皮脂腺) Associated with a hair follicle. Secrete an oily substance called sebum (皮脂): Lubricates and waterproofs hair and skin.  Weakens or kills bacteria. If sebum collects, whiteheads or blackheads form. 3. Mammary Glands Modified apocrine sweat glands; produce milk after childbirth.