Human Anatomy and Physiology Lecture Prelims PDF

HUMAN ANATOMY AND PHYSIOLOGY ANATOMY - A Greek word derived from the prefix ana- which means “or or upon” and the suffix –tomy from the adverb temno which means to “to cut apart” - Studies the structure of body parts and their relationships to one another PHYSIOLOGY - Studies the functio...

HUMAN ANATOMY AND PHYSIOLOGY ANATOMY - A Greek word derived from the prefix ana- which means “or or upon” and the suffix –tomy from the adverb temno which means to “to cut apart” - Studies the structure of body parts and their relationships to one another PHYSIOLOGY - Studies the function of the body, how the body parts work and carry out their life-sustaining activities - Focuses on events at the cellular or molecular level BRANCHES OF PHYSIOLOGY Renal physiology Neurophysiology Cardiovascular physiology Anatomy and Physiology is inseparable - Function always reflects with structure Principle of complementarity of structure and function LEVELS OF STRUCTURAL ORGANIZATION LEVELS OF STRUCTURAL ORGANIZATION 1. CHEMICAL LEVEL - Atoms combine to form molecules 2. CELLULAR LEVEL - Molecules form organelles of the cell 3. TISSUE LEVEL - Groups of similar cells that have a common function form the tissue - Epithelial, muscle, connective, and nervous tissue 4. ORGAN LEVEL - Tissues form the body organs 5. ORGAN SYSTEM LEVEL - Organs work together to form an organ system 6. ORGANISMAL LEVEL - The highest level of organization – the human being - Represents the sum total of all structural levels LIFE PROCESSES AND HOMEOSTASIS HOMEOSTASIS - Walter Cannon, an American physiologist who coined the term “homeostasis” - A.K.A. dynamic state of equilibrium - The ability to maintain stable internal conditions even though the world changes continuously. HOMEOSTATIC CONTROL - Communication within the body for homeostasis - Accomplished by the nervous and endocrine system COMPONENTS OF HOMEOSTATIC CONTROL SYSTEM COMPONENTS OF HOMEOSTATIC CONTROL SYSTEM 1. RECEPTOR 2. CONTROL SYSTEM 3. EFFECTOR RECEPTOR - Monitors the environment, and responds to stimuli Temperature change - Sends information (input) to the control center CONTROL CENTER - The set point - Analyze the input it receives and determines the appropriate response - Nervous system (hypothalamus) or endocrine gland AFFERENT WAY - Approached the control center EFFERENT PATHWAY - Exits the control center EFFECTOR - The structure that brings about change to alter the stimulus FEEDBACK - Responses made after change has been detected HOMEOSTATIC CONTROL 1. NEGATIVE FEEDBACK MECHANISMS - Original stimulus reversed - Information (output) shuts off the original effect of the stimulus or reduces its intensity - Used for conditions that need frequent adjustment, returning to its “ideal” value - e.g. Thermoregulation, blood pressure, increase in blood glucose 2. POSITIVE FEEDBACK MECHANISMS - Original stimulus intensified - Results proceed from the direction as the initial change, causing the variable to deviate further and further from its original range - e.g. Childbirth, blood clotting, breastfeeding, fruit-ripening  THE LANGUAGE OF ANATOMY ANATOMICAL POSITION - The anatomical reference point is a standard body position - It resembles “standing at attention” - The body is erect with feet slightly apart - Most directional terms refer to the body as if it were in this position, regardless of its actual position DIRECTIONAL TERMS - Explain where one body structure is in relation to another Term used: The ears are located on each both side of the head to the right and left of the nose Anatomical terminologies: The ears are lateral to the nose. REGIONAL TERMS TWO FUNDAMENTAL DIVISIONS OF OUR BODY 1. AXIAL - Makes up the main axis of our body Head Neck Trunk 2. APPENDICULAR - Attached to the body’s axis Appendages Limbs  BODY PLANES, SECTIONS, AND BODY CAVITIES PLANE - A flat surface where the body is cut or sectioned SAGITTAL PLANE - A vertical plane that divides the body into right and left parts Midline – Median plane or midsagittal Offset from midline – Parasagittal FRONTAL PLANE - A.K.A. Coronal plane - Divides the body into anterior and posterior parts TRANVERSE PLANE - A.K.A. cross section - Divides the body into superior and inferior parts BODY CAVITIES TWO SETS OF INTERNAL BODY CAVITIES 1. DORSAL BODY CAVITY - Protects the fragile nervous system organs CRANIAL CAVITY - Encases the brain VERTEBRAL OR SPINAL CAVITY - Encloses the delicate spinal cord 2. VENTRAL BODY CAVITY - More anterior and larger of the closed body cavities THORACIC CAVITY - Ribs, muscles of the chest, lungs, heart, esophagus, trachea, etc. ABDOMINOPELVIC CAVITY - Stomach, intestines, spleen, liver, bony pelvis, urinary bladder, rectum, etc. CELLULAR BASIS OF LIFE AND BODY TISSUES CELLULAR BASIS OF LIFE BREIF HISTORY 1600’s - Robert Hooke, an English scientist, first observed plant cell with a crude microscope 1830’s - German scientists, Matthias Schleiden and Theodor Schwann proposed that all living things are composed of cells - Rudolf Virchow, a German pathologist extended this idea by contending that cells arise only from other cells 1800’s - Cell research became prevalent THE CELL - The basic structural and functional units of all living organisms - The human body has 50 to 100 trillions of cells - It contains all the parts necessary to survive THREE MAIN PARTS 1. PLASMA MEMBRANE The outer boundary which acts as a selectively permeable barrier 2. CYTOPLASM The intracellular fluid where organelles float 3. NUCLEUS Controls cellular activities ANATOMY AND CELL PHYSIOLOGY PLASMA MEMBRANE - A semi-permeable phospholipid bilayer that monitors what comes in and out of the cell FUNCTIONS: 1. Separates two of the body’s fluid compartment 2. Selective permeable: Regulates which substances enter and exit the cells 3. Helps maintain homeostasis 4. Allows cell-to-cell communication 5. Cell signaling PLASMA MEMBRANE – Membrane Transport 1. PASSIVE TRANSPORT - No energy (ATP) required DIFFUSION - The movement of small non-polar molecules FACILITATED DIFFUSION - Requires the help of carrier and channel proteins OSMOSIS - The movement of water through the cell membrane  2. ACTIVE TRANSPORT - Energy (ATP) is required Endocytosis - Cells engulf or internalize molecules or substances from the external environment - Phagocytosis, Pinocytosis, and Receptor-Mediated Exocytosis - Active release of substances from intracellular vesicles into the extracellular environment CYTOPLASM - The cellular material between the plasma membrane and the nucleus - The site of most cellular activities Cytosol – Where the organelles float MITOCHONDRIA - The powerhouse of a cell, providing most if its ATP supply - The density of mitochondria in a particular cell reflects the cell’s energy requirements, and mitochondria generally cluster where the action is RIBOSOMES - Dense particles consisting of two subunits, each composed of ribosomal RNA and protein - Attached to RER - The sites of protein synthesis ENDOPLASMIC RETICULUM - Consists of SER and RER SMOOTH ENDOPLASMIC RETICULUM - Site of lipid and steroid synthesis, lipid metabolism, and drug detoxification ROUGH ENDOPLASMIC RETICULUM - Synthesizes phospholipids GOLGI APPARATUS Packages, modified and segregates proteins for secretion from the cell Incorporation into the plasma membrane NUCLEUS The control center of the cell It contains the instructions needed to Build nearly all the body’s proteins It dictates the kinds and amounts of proteins to be synthesized NUCLEAR ENVELOPE - Covers the nucleus from the external environment NUCLEAR PORE - Transport channel and regulating entry and exit of molecules CHROMATIN - Composed of the DNA, our genetic material. INTEGUMENTARY SYSTEM INTEGUMENT - “Covering” - It functions go well beyond serving as a bag for body contents SKIN - Its derivatives (sweat and oil glands, hairs, and nails) make up a complex set of organs that serves several functions, mostly for protection FUNCTIONS OF THE INTEGUMENTARY SYSTEM 1. Regulates body temperature 2. Stores blood 3. Protects body from the external environment 4. Detects cutaneous sensations 5. Excretion of substances from the body 6. Synthesizes vitamin D CONSIST OF TWO LAYERS 1. EPIDERMIS - Composed of epithelial cells, and is the outermost protective shield of the body - It is a keratinized stratified squamous epithelium CELLS OF THE EPIDERMIS a. KERATINOCYTE - Produces keratin, the fibrous protein that helps give the epidermis its protective properties - Most epidermal cells - Arise in the deepest part of the epidermis called stratum basale - Millions of dead keratinocytes are rub off every day, giving us a totally new epidermis every 25 to 45 days b. MELANOCYTE - Synthesize the pigment melanin - Found in the deepest layer of the epidermis MELANOSOMES - As melanin is made, it accumulates this membrane-bound granule c. DENDRITIC CELLS - A.K.A. Langerhans cells - Arise from bone marrow and migrate to the epidermis - They ingest foreign substances and are key activators of our immune system d. TACTILE CELLS - A.K.A. Merkel cells - Present at the epidermal junction - Functions as a sensory receptor for touch LAYERS OF THE EPIDERMIS a. STRATUM BASALE - The deepest epidermal layer - Attached to dermis - Represents the youngest keratinocytes - 10-25% are melanocytes Stratum minativum → “Germinating layer” b. STRATUM SPINOSUM - “Prickly layer” - The keratinocytes of this layer appear to have spines causing them to be called prickle cells c. STRATUM GRANOLOSUM - “Granular layer” KERATINIZATION - Keratinocyte appearance changes drastically d. STRATUM LUCIDUM - “Clear layer” - Visible only in thick skin, is a thin translucent band just above the stratum granulosum - It is consists of two or three rows of clear, flat, and dead keratinocyte e. STRATUM CORNEUM - “Horny layer” - The outermost epidermal layer - Protect the skin against abrasion and penetration - Provides a durable “overcoat” for the body  2. DERMIS - Making up the bulk of the skin - It is a tough, leathery layer composed mostly of dense connective tissue - Vascularized - The major portions of hair follicles, as well as oil and sweat glands, derive from epidermal tissues but reside in the dermis LAYERS OF THE DERMIS a. PAPILARY LAYER FRICTION RIDGES - Assumed to enhance the gripping ability of the fingers and feet b. RETICULAR LAYER - The deeper reticular layer, accounting for about 80% of the thickness of the dermis, is coarse, dense irregular connective figure. HYPODERMIS - A.K.A. superficial fascia - The subcutaneous tissue that is deep to the skin - It is NOT a part of the skin FUNCTIONS: Stores fat Anchors the skin to muscles Shock absorber and insulator that reduces heat THE SKIN AND IT’S DERIVATIVES 1. SKIN - Melanin is a pigment that determine skin color - Freckles and moles are local accumulations of melanin - Tanning occurs when exposed to UV, speeding up the synthesis of melanin 2. HAIR - Distributed in all parts of the body except palms, soles, lips, nipples, and the penis’ head FUNCTIONS: Keep humans warm Sense insects on the skin before they sting Hair in the scalp guards the head from heat loss Eyelashes shields the eye Nose filters dirt 3. NAILS - Forms a protective covering on a finger or toe 4. SUDORIFEROUS OR SWEAT GLANDS - Distributed over the entire skin surface except nipples and parts of genitalia Eccrine Sweat Glands Apocrine Sweat Glands 5. SEBACEOUS OR OIL GLANDS - Found all over the body except in the thick skin in our palms - Secrete sebum SKIN DISORDERS 1. SKIN CANCER Risk factor: Too much exposure to the UV radiation of the sun There is not such thing as “healthy tan” THREE MAJOR FORMS OF SKIN CANCER: 1. BASAL CELL CARCINOMA - Least malignant and most common, accounts for nearly 80% of cases - Occur on sun-exposed areas - Slow-growing and metastasis - Cure: Surgical excision 2. SQUAMOUS CELL CARCINOMA - Second most common skin cancer - Arises most often on the scalp, ears, lower lip, and hands - Grow rapidly and metastasize if not removed - Cure: Surgically or by radiation therapy 3. MELANOMA - Cancer of melanocytes - The most dangerous skin cancer - Occur wherever there is pigment - Cure: Early detection, surgical excision, and immunotherapy 2. BURNS a. FIRST-DEGREE BURNS - Only the epidermis is damaged - Signs and Symptoms: Redness, swelling, and pain - Cure: Heal in 2-3 days without special treatment b. SECOND-DEGREE BURNS - Injure the epidermis and upper region of dermis - Signs and Symptoms: Same with 1st degree, but blisters appear - Cure: Regeneration occurs with little or no scarring within 3-4 weeks c. THIRD-DEGREE BURNS - Full-thickness burns - Signs and Symptoms: Appears gray-white, cherry red, or blackened - Cure: Regeneration occurs but in a long run, skin grafting