Anatomy and Physiology Midterm Notes (2) PDF

INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 aspects of the functions of specific DEFINITION OF TERMS organ systems (cardiovascular, 1....

INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 aspects of the functions of specific DEFINITION OF TERMS organ systems (cardiovascular, 1. Human anatomy – the scientific study respiratory, and reproductive of the body's structures physiology) 2. Gross/Macroscopic anatomy - the Pathologic physiology - the study of study of the larger structures of the the effects of diseases on organ or body, those visible without the aid of system functions magnification 7. Homoeostasis - the state of steady Regional anatomy - helps us internal conditions maintained by appreciate the interrelationships of living things; refers to the body’s ability body structures, such as how to maintain a stable internal muscles, nerves, blood vessels, and environment (regulating hormones, other structures work together to body temperature, water balance, etc.) serve a particular body region Systemic anatomy - the study of the LEVELS OF ORGANIZATION OF THE structures that make up a discrete HUMAN BODY body system—a group of structures that work together to perform a The human body is the sum of its parts unique body function and these parts can be studied at a variety Surface anatomy - the study of the of levels of organization: landmarks on the body surface of the different visceral organs 3. Embryology - the study of the development of the human body from fertilization of the ovum up to the period of extrauterine life 4. Neuroanatomy - the study of the normal microscopic, gross features and development of the nervous system 5. Microscopic anatomy - the study of structures that can be observed only with the use of a microscope or other magnification devices Cytology - chemical and microscopic study of cells Histology - the study of normal tissues of the body 6. Human physiology - the scientific study of the chemistry and physics of the structures of the body and the ways in which they work together to support the functions of life; centers on the body’s tendency toward homeostasis 1. Chemicals Cell physiology - the study of the Atoms are the simplest level functions of living cells Two or more atoms comprise a Special physiology - the study of the molecule → chemical building functions of specific organs (cardiac blocks of all body structures physiology) Macromolecules are large, Systemic physiology - includes all biologically important molecules inside the cells INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 2. Cells - the basic units of structure and FUNCTIONAL CHARACTERISTICS OF function for living things HUMAN LIFE 3. Tissues - groups of cells functioning together 1. Organization 4. Organs - groups of tissues that have Consists of trillions of cells specialized functions organized in a way that maintains 5. Organ system - groups of organs distinct internal compartments → functioning together keeps body cells separated from external environmental threats and ORGAN SYSTEMS OF THE BODY keeps the cells moist and nourished Cells have a cell membrane (plasma Integumentary Protection, membrane) that keeps the Skin, hair, nails thermoregulation intracellular environment (fluids and organelles) separate from the Nervous Regulation of other extracellular environment Brain, spinal cord, body systems Blood vessels keep blood inside a nervous closed circulatory system, and Endocrine Secretion of nerves and muscles are wrapped in Hormone-secreting regulatory molecules connective tissue sheaths that glands (pituitary, called hormones separate them from surrounding thyroid, adrenals) structures Variety of internal membranes keep Skeletal Movement and major organs such as the lungs, Bones, cartilages support heart, and kidneys separate from Muscular Movements of the others Skeletal muscles skeleton The surface tissue of skin (body's largest organ system) is a barrier Circulatory Movement of blood that protects internal structures and Heart, blood vessels, and lymph fluids from potentially harmful lymphatic vessels microorganisms and other toxins Immune Defense of the body 2. Metabolism Bone marrow, against invading Sum of all anabolic and catabolic lymphoid organs pathogens reactions that take place in the body Respiratory Gas exchange Two types of reactions: Lungs, airways ○ Anabolism Smaller, simpler molecules Urinary Regulation of blood are combined into larger, more Kidneys, ureters, volume and complex substances urethra composition Combining small molecules Digestive Breakdown of food derived from the foods you eat Mouth, stomach, into molecules that Reactions are building intestine, liver, enter the body reactions, consume energy gallbladder, pancreas ○ Catabolism Larger, more complex Reproductive Continuation of the substances are broken down Gonads, external human species into smaller, simpler genitalia, associated molecules glands and ducts Reactions break materials down and release energy INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 3. Human Movement Required for many metabolic Includes not only actions at the processes joints of the body but also the Transportation of cells and body motion of individual organs and materials even individual cells Regulates body temperature Red and white blood cells are moving Makes up intracellular and throughout your body extracellular fluid compartments Muscle cells are contracting and What does water do for you? relaxing to maintain your posture ○ Forms saliva (digestion) and to focus your vision ○ Keeps mucous membranes moist Glands secrete chemicals to regulate ○ Allows body's cells to grow, body functions reproduce and survive Entire muscle groups to enable you ○ Flushes body waste (in urine) to move air into and out of your ○ Lubricates joints lungs, to push blood throughout your ○ Water is the major component of body, and to propel the food you have most body parts eaten through your digestive tract ○ Needed by the brain to manufacture hormones and 4. Development, Growth, and neurotransmitters Reproduction ○ Regulates body temperature Development (sweating and respiration) ○ All of the changes the body goes ○ Acts as a shock absorber for brain through in life and spinal cord ○ Includes the process of ○ Converts food to components differentiation → unspecialized needed for survival-digestion cells become specialized in ○ Helps deliver O2 all over the body structure and function to perform certain tasks in the body 2. Food ○ Includes the processes of growth Provides the body with needed and repair → involves cell nutrients differentiation Needed for energy, raw building Growth materials for growth and repair and ○ Increase in body size to regulate chemical reactions ○ All multicellular organisms grow by increasing the number of 3. Oxygen existing cells and the amount of Releases energy from food non-cellular material around cells (ex: mineral deposits in bone) 4. Heat Reproduction Product of metabolic reactions and ○ Formation of a new organism muscle movement that controls and from parent organisms maintains the body temperature ○ Carried out by the male and female reproductive systems 5. Pressure Force applied to something Atmospheric pressure is needed for MAINTENANCE OF LIFE breathing Life depends on the availability of: Hydrostatic (water) pressure is 1. Water needed to move blood through blood Most abundant chemical in the body vessels - our blood pressure INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 HOMEOSTASIS Both the quality and quantity of these factors are important to maintain homeostasis ○ Temperature ○ pH (acidic or basic) ○ Salinity (salt level) ○ Fluid levels State of steady internal conditions maintained by living things Refers to the body's ability to maintain a stable internal environment (regulating Positive feedback hormones, body temperature, water Intensifies a change in the body's balance, etc.) physiological condition rather than Regulated through control systems reversing it which have receptors (sensors), a set Deviation from the normal range results point, and effectors in common in more change, and the system moves ○ Receptors are of many types whose farther away from the normal range jobs is to monitor for changes Normal only when there is a definite ○ Set point is the normal value or endpoint range of values Childbirth and the body's response to ○ Effectors are muscles or glands that blood loss are two examples of positive respond to the changes to return to feedback loops that are normal but are stability activated only when needed FEEDBACK LOOPS As the body works to maintain homeostasis, any significant deviation from the normal range will be resisted and homeostasis restored through a process called a feedback loop Negative feedback A mechanism in which the effect of the response to the stimulus is to shut off the original stimulus or reduce its intensity The body's most common mechanisms used to maintain homeostasis In a negative feedback loop, a ROLES OF ORGAN SYSTEMS IN stimulus—a deviation from a set point HOMEOSTATIC REGULATION is resisted through a physiological 1. Body temperature process that returns the body to Integumentary - heat loss homeostasis. Muscular - heat production ○ A negative feedback loop has four Cardiovascular - heat distribution basic parts Nervous - coordination of blood flow, ○ Body temperature is regulated by heat production, and heat loss negative feedback INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 2. Body fluid composition ANATOMICAL POSITIONS AND Nutrient concentration PLANE OF MOTION Digestive - nutrient absorption, storage, and release Cardiovascular - nutrient distribution Anatomical position Urinary - control of nutrient loss in urine Body standing upright, feet at shoulder Skeletal - mineral storage and release width and parallel, toes forward Upper limbs are held out to each side Oxygen and carbon dioxide levels Palms of the hands face forward Respiratory - absorption of oxygen, elimination of carbon dioxide Common anatomical positions Cardiovascular - internal transport of oxygen and carbon dioxide Prone Face down orientation when lying down Levels of toxins and pathogens Lymphatic - removal, destruction, or inactivation of toxins and pathogens 3. Body fluid volume Supine Urinary - elimination or conservation of Face up orientation when lying down water from the blood Digestive - absorption of water, loss of water in feces Integumentary - loss of water through perspiration Cardiovascular, lymphatic - distribution Right lateral recumbent of water throughout body tissues Horizontal position with the right side oriented down 4. Water concentration Urinary - excretion of wastes from the blood Digestive - elimination of wastes from the liver in feces Cardiovascular - transport of waste Left lateral recumbent products to sites of excretion Horizontal position with the left side oriented down 5. Blood pressure Cardiovascular - pressure generated by the heart moves blood through blood vessels Nervous, endocrine - adjustments in Fowler’s Position heart rate and blood vessel diameter Used to avoid regurgitation and provide can raise or lower blood pressure good respiration. INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 Trendelenburg Position posterior (rear) portion ○ Often referred to as a coronal plane. Used during lower abdominal and pelvic surgeries and central venous catheter ("Corona" is Latin for "crown.") placement Transverse plane ○ Divides the body or organ horizontally into upper and lower portions ○ Produce images referred to as cross-sections Reverse Trendelenburg Position Used for gallbladder, biliary tract, and stomach laparoscopic surgeries as well as head and neck surgeries to minimize blood loss Lithotomy Used during childbirth and surgery in the pelvic area Body planes Imaginary two-dimensional surface that passes through the body Sagittal plane Directional terms ○ Divides the body or an organ vertically into right and left sides 1. Anterior (or ventral) ○ Midsagittal or median plane - a Describes the front or direction vertical plane that runs directly down toward the front of the body the middle of the body The toes are anterior to the foot. ○ Parasagittal plane or longitudinal 2. Posterior (or dorsal) section - divides the body into Describes the back or direction unequal right and left sides toward the back of the body Frontal plane The popliteus is posterior to the ○ Divides the body or an organ into an patella. anterior (front) portion and a 3. Superior (or cranial) INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 Describes a position above or higher than another part of the body proper. The orbits are superior to the iris. 4. Inferior (or caudal) Describes a position below/lower than another part of the body, near/toward the tail (coccyx-lowest part of the spinal column) The pelvis is inferior to the abdomen. 5. Lateral Describes the side or direction toward the side of the body. The thumb (pollex) is lateral to the digits. 6. Medial Describes the middle or direction toward the middle of the body. The hallux is the medial toe. 7. Proximal Describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The brachium is proximal to the antebrachium. 8. Distal 2. Abduction & Adduction Describes a position in a limb that is Abduction is the motion of a farther from the point of attachment structure away from the midline or the trunk of the body. Adduction refers to motion towards The crus are distal to the femur. the center of the body 9. Superficial Describes a position closer to the surface of the body. The skin is superficial to the bones. 10. Deep Describes a position farther from the surface of the body. The brain is deep to the skull. Body movements 1. Flexion & Extension Flexion describes a bending movement that decreases the angle between a segment and its proximal 3. Circumduction segment Conical movement of a body part, Extension describes a straightening such as a ball and socket joint or eye movement that increases the angle Combination of flexion, extension, between body parts adduction and abduction INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 4. Elevation & Depression Elevation refers to movement in a Anterior or ventral cavity superior direction 1. Thoracic cavity Depression refers to movement in More superior subdivision of the an inferior direction anterior cavity Enclosed by the rib cage 2. Abdominopelvic cavity Largest cavity in the body Two divisions: ○ Abdominal cavity houses the digestive organs ○ Pelvic cavity houses the reproductive organs 5. Dorsiflexion & Plantar Flexion (Ventral Extension) Dorsiflexion is where the toes are brought closer to the shin. Plantarflexion is the movement which decreases the angle between the sole of the foot and the back of the leg SEROUS MEMBRANE Also referred to as serosa One of the thin membranes that cover the walls and organs in the thoracic and abdominopelvic cavities ○ Parietal layers of the membranes line the walls of the body cavity (pariet refers to a cavity wall) ○ Visceral layer of the membrane covers the organs (the viscera) 6. Ipsilateral and Contralateral Three serous cavities and their Ipsilateral occurs on the same side associated membranes: ○ Pleura of the body Surrounds the lungs in the Contralateral occurs on opposite sides of the body pleural cavity ○ Pericardium Surrounds the heart in the BODY CAVITIES pericardial cavity ○ Peritoneum Posterior or dorsal cavity Surrounds several organs in the 1. Cranial cavity houses the brain abdominopelvic cavity 2. Spinal cavity or vertebral cavity encloses the spinal cord INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 cannot undergo MRI because it MEDICAL IMAGING TECHNIQUES can dislodge these implants 1. X-Rays Form of high-energy electromagnetic 4. Positron Emission Tomography (PET) radiation with a short wavelength A medical imaging technique capable of penetrating solids and involving the use of ionizing gases radiopharmaceuticals Best used to visualize hard body ○ Substances emitting radiation structures such as teeth and bones that is short-lived Capable of damaging cells and ○ Relatively safe to administer to initiating changes that can lead to the body cancer Main advantage: it can illustrate The disadvantage of irradiation to physiologic activity-including the patient and the operator is nutrient metabolism and blood flow attenuated by proper shielding and of the organ or organs being targeted limiting exposure Used to diagnose: heart disease, the spread of cancer, certain forms of 2. Computed tomography (CT) infection, brain abnormalities, bone Noninvasive disease, and thyroid disease Uses computers to analyze several cross-sectional X-rays in order to 5. Ultrasonography reveal minute details about Uses the transmission of structures in the body high-frequency sound waves into the Patient lies on a motorized platform body to generate an echo signal that while a computerized axial is converted by a computer into a tomography (CAT) scanner rotates real-time image of anatomy and 360 degrees around the patient, physiology taking X-ray images Least invasive ○ The computer combines these Used more freely in sensitive images into a 2D view of the situations such as pregnancy scanned area, or "slice." Used to study heart function, blood flow in the neck or extremities, 3. Magnetic Resonance Imaging (MRI) certain conditions (gallbladder Noninvasive disease, fetal growth and Based on a phenomenon of nuclear development) physics in which matter exposed to Main disadvantages: magnetic fields and radio waves was ○ Image quality is heavily found to emit radio signals operator-dependent Major advantage: not exposing ○ Unable to penetrate bone and gas patients to radiation Disadvantages: ○ Much higher cost RELATED MEDICAL CONDITIONS ○ Uncomfortable and impractical 1. Heat stroke for ill patients Sweat on the skin's surface is not ○ Device is noisy even with able to evaporate and internal body earplugs → patients can become temperature can get dangerously anxious or even fearful high ○ Patients with iron-containing metallic implants (internal 2. Hypothermia sutures, prosthetic devices) Clinical term for an abnormally low INTRODUCTION TO HUMAN ANATOMY AND PHYSIOLOGY MIDTERM LESSON #1 AUGUST 17, 2024 body temperature (hypo- = "below" or "under") 3. Altitude sickness Occurs in part because the atmosphere at high altitudes exerts less pressure, reducing the exchange of gases, and causing shortness of breath, confusion, headache, lethargy, and nausea. 4. Decompression sickness (DCS) A condition in which gases dissolved in the blood or in other body tissues are no longer dissolved following a reduction in pressure on the body CHEMICAL COMPOSITION OF THE BODY MIDTERM LESSON #2 AUGUST 31, 2024 between hydrogen atoms and ATOMS oxygen atoms. Smallest unit of matter with unique ○ Hydrogen bonds chemical properties Weak bonds between the Chemical units of cell structure hydrogen atom (more positive, Consist of a central nucleus with the lesser share of the electron) protons and neutrons and orbit(s) of in one polar bond and an oxygen electrons or nitrogen atom (more negative, ○ Proton carries a +1 charge greater share of the electron) in ○ Neutron has no charge another polar bond ○ Electrons carry a -1 charge and are Ex. hydrogen bonds occur attracted to the positive nucleus between water molecules, Each type of atom is called a chemical contributing to water's unique element or element properties like high boiling point ○ The most abundant of which are and surface tension oxygen (O), carbon (C), hydrogen (H) and nitrogen (N) INORGANIC COMPOUNDS ESSENTIAL TO From the foods you eat and the HUMAN FUNCTIONING air you breathe Oxygen is the most abundant in Do not contain hydrogen and carbon the body by mass Atoms form molecules when two or 1. Water more are bonded together Most common molecule in the A1-bond-A2 = Molecule: A1A2 human body (~98-99%) Both hydrogen atoms are attached to the single oxygen atom by polar CHEMICAL BONDS bonds. Forces that hold atoms together to form 2. Salts molecules and compounds When dissolved in water, dissociate Result from the interactions between into ions other than H+ or OH- the electrons of different atoms 3. Acids release H+ in solution, making it ○ Ionic bonds more acidic Bonds formed between two 4. Bases accept H+ making the solution oppositely charged ions more alkaline (caustic) Cations are ions with a net positive charge, while anions are ORGANIC COMPOUNDS ESSENTIAL TO those with a net negative HUMAN FUNCTIONING Ex. sodium chloride (NaCl) is formed when a sodium atom (Na) They contain both carbon and hydrogen donates an electron to a chlorine Carbon atoms in organic compounds atom (Cl), resulting in a bond readily share electrons with hydrogen between Na and Cl and other atoms, usually oxygen, and ○ Covalent bonds sometimes nitrogen Occur when two atoms share one Carbon atoms also may bond with one or more pairs of electrons → to or more functional groups such as attain the electron configuration carboxyls, hydroxyls, aminos, or of a noble gas achieving greater phosphates stability Monomers are single units of organic Ex. a molecule of water (H, O) is compounds. They bond by dehydration formed by covalent bonds synthesis to form polymers, which can CHEMICAL COMPOSITION OF THE BODY MIDTERM LESSON #2 AUGUST 31, 2024 in turn be broken by hydrolysis. function in protein synthesis ATP is the body's fundamental 1. Carbohydrates molecule of energy transfer Provide essential body fuel Their structural forms include ○ Monosaccharides - glucose ○ Disaccharides - lactose ○ Polysaccharides - starches (polymers of glucose), glycogen (storage form of glucose), fiber All body cells can use glucose for fuel Converted via an oxidation-reduction reaction to ATP 2. Lipids Hydrophobic compounds that provide body fuel and are important components of many biological compounds Triglycerides are the most abundant lipid in the body, and are composed of a glycerol backbone attached to three fatty acid chains Phospholipids are compounds composed of a diglyceride with a phosphate group attached at the molecule's head Steroids are lipids formed of four hydrocarbon rings Cholesterol is the most important Prostaglandins are signaling molecules derived from unsaturated fatty acids 3. Proteins Critical components of all body tissues Made up of monomers called amino acids, which contain nitrogen joined by peptide bonds Most body proteins are globular Ex. enzymes, which catalyze chemical reactions 4. Nucleotides Compounds with three building blocks: one or more phosphate groups, a pentose sugar, and a nitrogen containing base DNA and RNA are nucleic acids that CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 surface of an integral protein THE CELL Ex. act as digestive enzymes to Basic unit of structure and function in breakdown nutrients to sizes that the body can pass through the cell and Approximately 75 trillion cells in the into the bloodstream. human body Highly organized molecular factory Comes in variety of shapes and sizes Divided into 3 principal parts: ○ Plasma (cell) membrane ○ Cytoplasm and organelles ○ Nucleus CELL MEMBRANE Structure and Composition Transport across the Cell Membrane Selectively permeable plasma A membrane has selective membrane surrounds the cell permeability that allows only Gives form to the cell substances meeting certain criteria to Separates the cells internal structures pass through it unaided. from the extracellular environment Small, nonpolar materials can move Also participates in the intracellular through the lipid bilayer → oxygen and communication carbon dioxide gases, and alcohol Composed primarily of back to back Water-soluble materials-like glucose, phospholipids (a bilayer) amino acids, and electrolytes-need ○ The lipid tails are uncharged or some assistance to cross the nonpolar, and hydrophobic or water membrane fearing ○ The head is negatively charged, polar Two general methods based on whether and hydrophilic or water loving or not energy is required 2 types of proteins: 1. Passive transport is the movement of ○ Integral proteins - protein that is substances across the membrane embedded in the membrane without the expenditure of cellular Channel protein selectively energy allows particular materials, such Concentration gradient: molecules as certain ions, to pass into or (or ions) will spread/diffuse from out of the cell where they are more concentrated to Receptor is a type of recognition where they are less concentrated protein that selectively bind a until they are equally distributed in specific molecule outside of the that space. cell, and this binding induces a Facilitated diffusion is the diffusion chemical reaction within the cell. process used for substances that Ligand is the specific cannot cross the lipid bilayer due to molecule that binds to and their size, charge, and/or polarity activates a receptor. ○ Ex. glucose, sodium ions ○ Peripheral proteins Osmosis Enzymes found on the inner or ○ Diffusion of water through a outer surface of the lipid bilayer, semipermeable membrane down also in internal and external its concentration gradient CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 ○ If a membrane is permeable to Sodium-potassium pump (N+/K+ water, though not to a solute, ATPase) transports sodium out of a water will equalize its own cell while moving potassium into the concentration by diffusing to the cell to maintain an electrical side of lower water concentration gradient across their cell (the side of higher solute membranes concentration). ○ Moves 3 Na ions out of the cell and 2 K ions into the cell for each ATP molecule that is used Symporters are secondary active transporters → move two substances in the same direction ○ Ex. sodium-glucose symporter uses sodium ions to "pull" Hypertonic solution glucose molecules into the cell → ○ Has a higher concentration of cells store glucose for energy solutes than another solution Antiporters are secondary active ○ Water molecules tend to diffuse transport systems → transport into a hypertonic solution substances in opposite directions ○ Cells will shrivel/shrink as water ○ Ex. sodium-hydrogen ion leaves the cell antiporter uses the energy from Hypotonic solution the inward flood of sodium ions ○ Has a a lower concentration of to move hydrogen ions (H+) out of solutes than another solution the cell → used to maintain the ○ Water molecules tend to diffuse pH of the cell's interior. out of a hypotonic solution Endocytosis (bringing "into the cell") ○ Cells will take on too much water is the process of a cell ingesting and swell with the risk of material by enveloping it in a portion bursting (process called lysis) of its cell membrane, and then Isotonic solution pinching off that portion of ○ The concentration of water membrane molecules is the same outside Exocytosis (taking "out of the cell") and inside the cells is the process of a cell exporting ○ Water flows both in and out and material using vesicular transport → the cells maintain their normal the vesicle releases it contents into shape (and function) the interstitial fluid Other forms of active transport do not involve membrane carriers ○ Pinocytosis ("cell drinking") brings fluid containing dissolved substances into a cell through membrane vesicle ○ Phagocytosis ("cell eating") is the endocytosis of large particles 2. Active transport is the movement of (immune cells engage in substances across the membrane using phagocytosis of invading energy from adenosine triphosphate pathogens (ATP) often with the help of protein ○ Receptor-mediated endocytosis carriers, and usually against its is endocytosis by a portion of the concentration gradient CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 cell membrane that contains Provides passages throughout of the many receptors that are specific cell that function in transporting, for a certain substance synthesizing, and storing materials. Exist in two forms: ○ Rough ER (RER) Its membrane is dotted with embedded granules - organelles called ribosomes, giving the bumpy appearance. Primary job is the synthesis and modification of proteins or for export from the cell ○ Smooth ER (SER) THE CYTOPLASM AND CELLULAR Lacks these ribosomes ORGANELLES Main function is in the All living cells in multicellular synthesis of lipids → the main organisms contain an internal component of biological cytoplasmic compartment, and a membranes, as well as steroid nucleus within the cytoplasm. hormones Cytosol, the jelly-like substance within Sequesters (i.e., stores) and the cell, provides the fluid medium regulates the concentration of necessary for biochemical reactions. cellular Ca++ → trigger the An organelle ("little organ") is one of neurotransmitter release several different types of Metabolizes some membrane-enclosed bodies in the cell, carbohydrates and performs a each performing a unique function. detoxification role → breaking The organelles and cytosol, taken down certain toxins together, compose the cell's cytoplasm. The nucleus is a cell's central organelle, 2. Golgi apparatus which contains the cell's DNA. Responsible for sorting, modifying, and shipping off the products from the rough ER (like a post-office) ○ Manipulates products from the rough ER and produces new organelles called lysosomes Looks like stacked flattened discs or stacks of oddly shaped pancakes Has two distinct sides, each with a different role ○ One side of the apparatus receives products in vesicles ○ Sorted through the apparatus, and then they are released from Endomembrane System Organelles the opposite side after being 1. Endoplasmic reticulum repackaged into new vesicles A system of channels that is ○ If the product is to be exported continuous with the nuclear from the cell the vesicle migrates membrane (or "envelope") covering to the cell surface and fuses to the nucleus and composed of the the cell membrane same lipid bilayer material ○ Cargo is secreted CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 3. Lysosome/s 2. Peroxisomes Contains enzymes that break down A membrane-bound cellular and digest unneeded cellular organelle that contains mostly components such as a damaged enzymes organelle Perform a couple of different ○ Autophagy ("self-eating") is the functions: process of a cell digesting its own ○ Lipid metabolism structures. ○ Chemical detoxification Also important for breaking down The enzymes within peroxisomes foreign material serve to transfer hydrogen atoms ○ Ex. when certain immune defense from various molecules to oxygen, cells (white blood cells) producing hydrogen peroxide phagocytize bacteria → bacterial (H202) cell is transported into a ○ Neutralize poisons such as lysosome → digested by the alcohol enzymes inside Neutralize harmful toxins Perform a more grand and dire ○ Liver cells contain an function → can be triggered to open exceptionally high number of up and release their digestive peroxisomes. enzymes into the cytoplasm of the cell → killing the cell. ○ Autolysis - "self-destruct" The Cytoskeleton ○ "Apoptosis" - a process of cell Helps the cells to maintain their death structural integrity A group of fibrous proteins that provide structural support for cells Organelles for Energy Production and Also critical for cell motility, cell Detoxification reproduction, and transportation of The cell has many other important substances within the cell functions: Forms a complex thread-like network ○ Consume nutrients to provide energy throughout the cell consisting of three → cells take in nutrients which different kinds of protein-based convert to chemical energy that can filaments: microfilaments, be used to power biochemical intermediate filaments, and reactions microtubules ○ Detoxification. 1. Microtubules 1. Mitochondria Maintain cell shape and structure A mitochondrion (plural = Help resist compression of the cell mitochondria) is a membranous, The thickest structural filament bean-shaped organelle called the composed of subunits of a protein "energy transformer" of the cell called tubulin Consist of an outer lipid bilayer Has 2 types of cellular appendages membrane as well as an additional important for motion inner lipid bilayer membrane ○ Cilia ○ Inner membrane is highly folded Found on the epithelial cells into winding structures with a that line the airways of the great deal of surface area called respiratory system cristae Move rhythmically; they beat constantly, moving waste CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 materials such as dust, filaments work with myosin to mucus, and bacteria upward create a cleavage furrow that through the airways, away eventually splits the cell down from the lungs and toward the the middle, forming two new cells mouth from the original cell. Beating cilia on cells in the female fallopian tubes move THE NUCLEUS AND DNA REPLICATION egg cells from the ovary towards the uterus The Nucleus ○ Flagellum (plural = flagella) Appendage larger than a Largest and most prominent of a cell's cilium and specialized for cell organelles locomotion Considered the control center of the cell The only flagellated cell in because it stores all of the genetic humans is the sperm cell that instructions for manufacturing proteins must propel itself towards Multinucleated: contain more than one female egg cells nucleus (muscle cells) Mammalian red blood cells (RBCs) do 2. Intermediate filament not contain nuclei Intermediate in thickness between ○ RBCs eject their nuclei as they the microtubules and mature, making space for the large microfilaments numbers of hemoglobin molecules Made up of long fibrous subunits of that carry oxygen throughout the a protein called keratin → threads → body rope ○ Without nuclei, the life span of RBCs Important for maintaining cell shape is short → the body must produce and structure new ones constantly Resist tension (the forces that pull Sends "commands" to the cell via apart cells) → epithelial cells of the molecular messengers that translate skin are compressed, tugging them the information from DNA in different directions Helps anchor organelles together within a cell → also link cells to other cells by forming special cell-to-cell junctions Type of cytoskeletal filament Actin ○ A protein that forms chains is the primary component of these microfilaments ○ Actin fibers constitute a large component of muscle tissue along with the protein myosin Responsible for muscle contraction Organization of Nucleus and Its DNA ○ Note: Actin also has an important Nuclear envelope is the membrane role during cell division surrounding the nucleus When a cell is about to split in ○ Consists of two adjacent lipid half during cell division, actin CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 bilayers with a thin fluid space replication is stopped and the two Nuclear pore is a tiny passageway for new identical DNA molecules are proteins, RNA, and solutes between the complete. nucleus and the cytoplasm Nucleolus is a region of the nucleus that is responsible for manufacturing the RNA necessary for construction of ribosomes ○ A dark-staining mass often visible under a simple light microscope Within the nucleus are threads of chromatin composed of DNA and associated proteins The chromosome (condensed form of chromatin) is composed of DNA and proteins ○ Estimated that humans have almost 22,000 genes distributed on 46 chromosomes Protein Synthesis Begins with genes, a functional DNA Replication segment of DNA that provides the genetic information necessary to build a The copying of DNA that occurs before protein cell division can take place In order for an organism to grow, From DNA to RNA: Transcription develop, and maintain its health, cells Stage 1: Initiation must reproduce themselves by dividing ○ A region at the beginning of the gene to produce two new daughter cells called a promoter (a particular ○ Each with the full complement of sequence of nucleotides) triggers the DNA as found in the original cell start of transcription Four DNA bases: adenine (A), thymine Stage 2: Elongation (T), cytosine (C), and guanine (G) ○ Transcription starts when RNA Stage 1: Initiation polymerase unwinds the DNA ○ The two complementary strands are segment. separated, like unzipping a zipper ○ One strand becomes the template ○ Special enzymes, including helicase, with the genes to be coded untwist and separate the two ○ Polymerase then aligns the correct strands nucleic acid (A, C, G, or U) with its Stage 2: Elongation complementary base on the coding ○ Each strand becomes a template strand of DNA. along which a new complementary Stage 3: Termination strand is built. ○ When the polymerase has reached ○ DNA polymerase brings in the the end of the gene, one of three correct bases to complement the specific triplets (UAA, UAG, or UGA) template strand, synthesizing a new codes a "stop" signal, which triggers strand base by DNA base. the enzymes to terminate Stage 3: Termination transcription and release the mRNA ○ Once the two original strands are transcript. bound to their own, finished, complementary strands, DNA CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 From RNA to Protein: Translation The process of synthesizing a chain of CELL GROWTH AND DIVISION amino acids called a polypeptide Requires two major aids: A somatic cell is a general term for a ○ “Translator,” the molecule that will body cell, and all human cells, except for conduct the translation the cells that produce eggs and sperm ○ A substrate, on which the mRNA (which are referred to as germ cells) strand is translated into a new Somatic cells contain two copies of protein, like the translator's "desk." each of their chromosomes (one copy Transfer RNA (tRNA) is a type of RNA received from each parent) for a total of that ferries the corresponding amino 46 (23 pairs) acids to the ribosome Each copy of the chromosome is ○ Attaches each new amino acid to the referred to as a sister chromatid and is last building the polypeptide chain physically bound to the other copy one-by-one ○ Centromere: structure that attaches ○ Transfers specific amino acids from one sister chromatid to another the cytoplasm to a growing Cells in the body replace themselves polypeptide over the lifetime of a person ○ Ex. cells lining the gastrointestinal tract must be frequently replaced when constantly "worn off" by the movement of food through the gut. The cell cycle is the sequence of events in the life of the cell from the moment it is created at the end of a previous cycle of cell division until it then divides itself, generating two new cells. Cell Cycle 1. Interphase The period of the cell cycle during which the cell is not dividing Majority of cells are in interphase most of the time subdivided into: ○ G1 phase is the first growth phase in the cell cycle ○ S phase (synthesis phase) is period during which a cell CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 replicates its DNA A checkpoint is a point in the cell cycle ○ G2 phase is a second gap phase, at which the cycle can be signaled to during which the cell continues move forward or stopped to grow and makes the necessary A cyclin is one of the primary classes of preparations for mitosis cell cycle control molecules. ○ G0 phase is a resting phase of A cyclin-dependent kinase (CDK) is one the cell cycle cells that have of a group of molecules that work temporarily stopped dividing and together with cyclins to determine are resting (a common condition) progression past cell checkpoints. Duration: ○ S phase - between 8-10 hours ○ G2 phase - approximately 5 hours 2. Mitosis and Cytokinesis The mitotic phase of the cell typically takes between 1 and 2 hours Mitosis is divided into four major stages that take place after interphase and in the following order: prophase, metaphase, anaphase, and telophase. The process is then followed by cytokinesis, dividing the cytoplasm and cell body into two new cells. CELLULAR DIFFERENTIATION Process by which unspecialized cells become specialized to carry out distinct functions Stem cell - an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into specialized cells Divided according to their potential to differentiate ○ Totipotent have the potential to differentiate into any of the cells needed to enable an organism to grow and develop. Cell Cycle Control ○ Pluripotent stem cell has the The control system involves molecules potential to differentiate into any within the cell as well as external type of human tissue but cannot triggers support the full development of an ○ These internal and external control organism. triggers provide "stop" and "advance" ○ Multipotent stem cell has the signals for the cell. potential to differentiate into Precise regulation of the cell cycle is different types of cells within a given critical for maintaining the health of an cell lineage or small number of organism, and loss of cell cycle control lineages, such as a red blood cell or can lead to cancer. white blood cell. CELLULAR LEVEL OF ORGANIZATION MIDTERM LESSON #3 AUGUST 31, 2024 ○ Oligopotent stem cell is limited to There are different stem cells: becoming one of a few different cell 1. Embryonic stem cells of the embryo types. 2. Fetal stem cells of the fetus ○ Unipotent cell is fully specialized 3. Adult stem cells in the adult and can only reproduce to generate Epithelial stem cell gives rise to more of its own specific cell type. keratinocytes in multiple layers of epithelial cells in the epidermis of skin Adult bone marrow has three distinct types of stem cells: ○ Hematopoietic stem cells give rise to red blood cells ○ White blood cells ○ Platelets Endothelial stem cells give rise to the endothelial cell types that line blood and lymph vessels Mesenchymal stem cells give rise to the different types of muscle cell PRIMARY TISSUES MIDTERM LESSON #4 SEPTEMBER 7, 2024 FOUR TYPES OF TISSUES EPITHELIAL TISSUE/EPITHELIUM 1. Epithelial tissues Large sheets of cells covering all Cells that form membranes and of surfaces of the body exposed to the glands outside world and lining the inside and Refers to sheets of cells that cover covering the outside of organs the exterior surfaces of the body, Forms much of the glandular tissue of lines internal cavities and the body passageways, and forms glands Location: skin, airways, digestive tract, urinary and reproductive systems, blood 2. Connective tissues vessels and serous membranes are Cnnective tissue proper, cartilage, lined by endothelium bone, blood Epithelial tissues are nearly completely Binds the cells and organs of the avascular body together and functions in the Generalized functions: protection, support, and integration ○ Provide the body's first line of of all parts of the body protection from physical, chemical, and biological wear and tear 3. Muscle tissues ○ Act as gatekeepers of the body Skeletal (voluntary), cardiac, smooth controlling permeability and Excitable, responding to stimulation allowing selective transfer of and contraction to provide materials across a physical barrier movement ○ Capable of secretion and release mucous and chemical compounds 4. Nervous tissues onto their apical surfaces: Nerve cells (neurons), glia cells Epithelium of the small intestine (neuroglial) release digestive enzymes Excitable, allowing the propagation Cells lining the respiratory tract of electrochemical signals in the secrete mucus that traps form of nerve impulses that incoming microorganisms and communicate between different particles regions of the body Glandular epithelium contains many secretory cells Classification of Epithelial Tissues According to the shape of the cells ○ Squamous - flattened and thin ○ Cuboidal - boxy, as wide as it is tall ○ Columnar - rectangular, taller than it is wide According to the number of cell layers ○ Simple - one layer ○ Stratified - more than one layer Pseudostratified (pseudo-="false") - describes tissue with a single layer of irregularly shaped cells that give the appearance of more than one layer PRIMARY TISSUES MIDTERM LESSON #4 SEPTEMBER 7, 2024 Endocrine and Exocrine Glands Consist of groups of epithelial cells Secretions are passed outside of the epithelial membranes (and hence to the surface of the body) through ducts Examples: ○ Lacrimal glands - tears ○ Sebaceous glands - oily sebum into hair follicles ○ Eccrine/merocrine sweat glands Secrete a dilute salt solution that serves in thermoregulation Evaporation cools the skin ○ Apocrine sweat glands 1. Simple squamous epithelium Located in the axillae Have the appearance of thin scales (underarms) and pubic regions Nuclei tend to be flat, horizontal, Ssecrete a protein-rich fluid that and elliptical provide nourishment for bacteria, producing the characteristic odor 2. Simple cuboidal epithelium of this type of sweat The nucleus of the box-like cells ○ Mucous glands (digestive tract), appears round and generally located salivary glands, gastric glands, near the center of the cell simple tubular glands ○ Exocrine gland of the pancreas 3. Simple columnar epithelium Pancreatic juice contain digestive The nucleus of the tall column-like enzymes & bicarbonate → small cells tends to be elongated and intestine → pancreatic duct located in the basal end of the cells ○ Liver Produces and secretes bile (fat 4. Pseudostratified columnar emulsifier) → small intestine via epithelium gallbladder and bile duct Appears to be stratified ○ Prostate gland and seminal vesicles Consists of a single layer of - contribute to semen irregularly shaped and differently sized columnar cells CONNECTIVE TISSUES 5. Stratified squamous epithelium Cells are dispersed in a matrix Has several stacked layers of cells Two major components of the matrix ○ Ground substance - made of an Most common type of stratified epithelium in the human body organic substance (usually a protein) and an inorganic substance 6. Transitional epithelium (usually a mineral or water) ○ Protein fibers Another kind of stratified Collagen fiber epithelium Made from fibrous protein Gradual changes in the shapes of the apical cells as the bladder fills with subunits Flexible, have great tensile urine → convoluted and has cuboidal apical cells with convex, strength, resist stretching Ex. ligaments and tendons umbrella shaped PRIMARY TISSUES MIDTERM LESSON #4 SEPTEMBER 7, 2024 hold connective tissues ○ Subtypes: areolar, adipose, together even during the reticular movement of the body Dense connective tissue Elastic fiber ○ Collagenous fibers oriented Contains the protein elastin parallel to each other and densely After being stretched or packed in the matrix, leaving compressed, it returns to its room for cells and ground original shape substances Ex. elastic ligaments of the ○ Subtypes: regular elastic, vertebral column irregular elastic Reticular fiber ○ Ex. tendons connect bone to Narrow and are arrayed in a bone; ligaments connect bones branching network together at joints Found throughout the body but are most abundant in soft 2. Supportive connective tissue organs (Ex. liver and spleen) Cartilage: hyaline, fibrocartilage, Anchor and provide structural elastic support to the parenchyma Bones: compact bone, cancellous Functions: bone ○ Support and connect other tissues (from the connective tissue sheath 3. Fluid connective tissue surrounding muscle cells, to the Blood, lymph tendons that attach muscles to bones, and to the skeleton that TISSUE MEMBRANES supports the positions of the body) ○ Provide protection Thin layer or sheet of cells that covers Fibrous capsules and bones ○ Outside of the body (skin) protect delicate organs and the ○ Ogans (pericardium) skeletal system ○ Internal passageways that open to Defend the body from the exterior of body (mucosa of microorganisms that enter stomach) ○ Transport fluid, nutrients, waste, and ○ Lining of the moveable joint cavities chemical messengers (Ex. blood and Two basic types: connective tissue and lymph) epithelial membranes ○ Store surplus energy in the form of fat and contribute to the thermal insulation of the body Classification of Connective Tissues 1. Connective tissue proper Consists of protein fibers and proteinaceous, gel-like ground substance Loose connective tissue ○ Protein fiber composed of collagen (collagenous fibers) which provides space for the presence of blood vessels, nerve fibers and other structures PRIMARY TISSUES MIDTERM LESSON #4 SEPTEMBER 7, 2024 single central nucleus MUSCLE TISSUES Function: contracts to pump blood Location: heart Characterized by properties that allow movement Excitable - they respond to a stimulus Contractile - they can shorten and generate a pulling force ○ When attached between two movable objects, bones and contractions of the muscles cause 3. Smooth muscle the bones to move Histology: short, spindle-shaped, no Voluntary - it is under conscious control evident striation, single nucleus in Involuntary - they are not under each fiber conscious control (EX. contraction of Functions: your pupil in bright light) ○ Involuntary movement ○ Peristalsis: push food from the oral to the anal end of the Classification of Muscle Tissues digestive tract 1. Skeletal muscle ○ Involuntary control of respiration Attached to the bones at both ends ○ Moves secretions by means of tendons ○ Regulates flow of blood in arteries Arranged in bundles called by contraction syncytium Location: walls of major organs and Histology: long, cylindrical fiber, passageways striated, many peripherally located ○ Ex. digestive tract, blood vessels, nuclei bronchioles, and the ducts of the Functions: urinary and reproductive systems ○ Voluntary movement of the skeleton (excludes tongue, superior portion of the esophagus, anal sphincter, and diaphragm) ○ Produces heat ○ Protects organs Location: attached to bones and around entrance points to the body NERVE TISSUES ○ Ex. mouth, anus Specialized for the generation and conduction of electrical events Three parts: ○ Cell body - contains the nucleus; serves as metabolic center of the cell ○ Dendrites (branches) - highly branched cytoplasmic extensions of the cell body that receive input from 2. Cardiac muscle other neurons or from receptor cells Cells are short, branched, and ○ Axon - a single cytoplasmic immediately interconnected to form extension of the cell body that can a continuous fabric be quite long (up to a few feet in Histology: short, branched, striated, length) PRIMARY TISSUES MIDTERM LESSON #4 SEPTEMBER 7, 2024 Specialized for conducting nerve 2. GMCSF impulses from the cell body to Source: T lymphocytes, endothelial another neuron or to an effector cells, fibroblast cell (muscle or gland) Primary effects: macrophage and Neuroglial cells granulocyte activation ○ Serve to bind neurons together ○ Modify the EC environment of the 3. TNF-alpha nervous system Source: macrophages ○ Influence the nourishment and Primary effects: PG production electrical activity of neurons 4. Interferons Source: macrophages, T lymphocytes, endothelial cells Primary effects: many 5. PDGF Source: macrophages, endothelial cells, fibroblast, platelets Primary effects: fibroblast chemotaxis, proliferation THE INFLAMMATORY RESPONSE Rheumatoid Arthritis Three phases: Chronic inflammation Acute inflammation/acute phase Pain and destruction of bone and Immune response/sub-acute or delayed cartilage phase Severe disability → systemic changes → Chronic inflammation/chronic shortening of life proliferative phase An autoimmune disease → T-cell activation → IL-1 and TNF-alpha Mediators of Acute Inflammation Vasodi- Vascular Chemo- Pain lation Permeability taxis Histamine ++ ↑↑↑ - - Serotonin +/- ↑ - - Bradykinin +++ ↑ - +++ Prosta- glandin +++ ↑ +++ + Leukotriene - ↑↑↑ +++ - Mediators of Chronic Inflammation 1. Interleukins 1, 2, 3 Source: macrophage, T lymphocytes Primary effects: lymphocyte activation, PG production INTEGUMENTARY MIDTERM LESSON #5 SEPTEMBER 7, 2024 Melanocyte produces the pigment THE SKIN melanin -> gives hair and skin its color, Largest organ of the body and also helps protect the living cells of A total area of about 20 square feet the epidermis from ultraviolet radiation Has 3 layers: damage. 1. Epidermis: the outermost layer of skin. Provides a waterproof barrier and creates our skin tone. Stratum spinosum 2. Dermis: beneath the epidermis. Is composed of 8-10 layers of Contains tough connective tissue keratinocytes -> begin the synthesis of 3. Hypodermis: the deeper keratin and release water-repelling subcutaneous tissue made of fat glycolipid -> helps prevent water loss and connective tissue from the body -> making the skin Color is created by special cells called relatively waterproof melanocytes: ○ Produces the pigment melanin Stratum granulosum ○ Located in the epidermis Cells are 3-5 layers deep -> become flatter, they generate large amounts of THE EPIDERMIS protein keratin -> fibrous, and Composed of keratinized, stratified keratohyalin -> accumulates as lamellar squamous epithelium granules within the cells -> form the It is avascular stratum lucidum, the stratum corneum, Has four layers of cells, referred to as and the accessory structures of hair and “thin skin” nails ○ Deep to superficial: Stratum basale Stratum lucidum Stratum spinosum Stratum granulosum Is a smooth, translucent layer of the Stratum corneum epidermis located just above the “Thick skin” is found only on the palms stratum granulosum and below the of the hands and the soles of the feet stratum corneum ○ Fifth layer: stratum lucidum Thin layer of cells is found only in the Located between the stratum thick skin of the palms, soles, and digits corneum and the stratum Are dead and flattened -> densely granulosum packed with eleiden, a clear protein rich in lipids, derived from keratohyalin -> gives their transparent appearance Stratum basale Provides a barrier to water Aka: stratum germinativum Deepest epidermal layer, below which lie Stratum corneum the layers of the dermis Single layer of cells made of basal cells Is the most superficial layer of the -> cuboidal-shaped stem cell epidermis -> exposed to the outside Merkel cell functions as a receptor -> environment responsible for stimulating sensory Usually 15 to 30 layers of cells nerves that the brain perceives as touch Dry, dead layer helps prevent the ○ Abundant on the surfaces of hands penetration of microbes and the and feet dehydration of the underlying tissues Provides a mechanical protection INTEGUMENTARY MIDTERM LESSON #5 SEPTEMBER 7, 2024 against abrasion Retin-A creams stimulating blood Are shed periodically and are replaced flow and repair of the dermis (about 4 weeks) Cosmetic procedures, such as THE HYPODERMIS microdermabrasion -> help remove some of the dry upper layer -> aim to Also called the subcutaneous layer or keep the skin looking fresh and healthy the superficial fascia Is a layer directly below the dermis Serves to connect the skin to the THE DERMIS underlying fascia (fibrous tissue) of the Considered the “core” of the bones and muscles integumentary system (derma = skin) Consists of well vascularized, loose, Contains blood and lymph vessels, areolar connective tissue and adipose nerves and other structures, such as tissue hair follicles and sweat glands Functions as a mode of fat storage -> Made of two layers of connective tissue provides insulation and cushioning for (elastin and collagenous fibers) the integument Layers of the dermis PIGMENTATION OF THE SKIN 1. Papillary layer The color of skin is influenced by a Made of loose, areolar connective number of pigments, including melanin, tissue carotene, and hemoglobin Within the papillary layer are Melanin occurs in 2 primary forms: fibroblasts, a small number of fat ○ Eumelanin exists as black and cells (adipocytes), an abundance of brown small blood vessels, and phagocytes ○ Pheomelanin provides a red color -> help fight bacteria or other infections that have breached the skin ACCESSORY STRUCTURES OF THE SKIN Also contains lymphatic capillaries, 1. Hair nerve fibers, and touch receptors Is a keratinous filament growing out called meissner corpuscles of the epidermis Primarily made of dead, keratinized 2. Reticular layer cells Composed of dense, irregular Serves a variety of functions connective tissues ○ Protection Well vascularized and has a rich Protects skull from the sun sensory and sympathetic nerve In the nose and ears, and supply around the eyes (eyelashes) Appears reticulated (netlike) due to defends the body by trapping tight meshwork of fibers and excluding dust particles ○ Elastin fibers provide some that may contain allergens elasticity to the skin, enabling and microbes movement Eyebrow prevents sweat and ○ Collagen fibers provide structure other particles from dripping and tensile strength; binds water into the eye to keep the skin hydrated Hair grows and is eventually shed Collagen injections help restore skin and replaced by new hair, occurs in turgor three phases INTEGUMENTARY MIDTERM LESSON #5 SEPTEMBER 7, 2024 ○ Anagen phase -> cells divide hand, the soles of the feet, and rapidly at the root of the hair, the forehead pushing the hair shaft up and out ○ Coiled glands lying deep in the Length of this phase is dermis with the duct rising up to measured in year (2 to 7 years) a pore on the skin surface where Grows at.3mm per day the sweat is released by ○ Catagen phase lasts only 2 to 3 exocytosis -> hypotonic and weeks -> marks the hair follicle’s composed mostly of water with active growth some salt, antibodies, traces of ○ Telogen phase -> the hair follicle metabolic waste, and dermicidin is at rest; no new growth occurs -> antimicrobial peptide Lasts about 2 to 4 months ○ Primary component of On average, 50 hairs are lost and thermoregulation -> help replaced per day (result from the maintain homeostasis aging process, or the influence of Apocrine sweat gland hormones) ○ Associated with hair follicles in Hair color densely hairy areas such as ○ As a person ages, the melanin armpits and genital regions production decreases -> hair ○ Larger than eccrine sweat glands tends to lose its color -> becomes ○ Lie deeper in the dermis; gray and/or white sometimes reaches the hypodermis with the duct 2. Nail emptying into the hair follicle Nail bed ○ Includes water and salts, organic ○ Is a specialized structure of the compounds that make the sweat epidermis that is found at the thicker and subject to bacterial tips of our fingers and toes decomposition and subsequent ○ Protects the tips of our fingers smell -> release under both and toes nervous and hormonal control ○ Forms a back support for picking Most commercial antiperspirants up small objects with the fingers use an aluminum based compound ○ Is composed of densely packed as their primary active ingredient to dead keratinocytes stop sweat -> prevents sweat from ○ Is rich in blood vessels, making it coming out of the pore appear pink except at the base Nail cuticle also called the 4. Sebaceous gland eponychium Oil gland that is found all over the Lunula the crescent shaped region body and helps to lubricate and called the “little moon” waterproof the skin and hair Hyponychium area beneath the free Associated with hair follicles edge of the nail Generates and excretes sebum -> a ○ Consists of a thickened layer of mixture of lipids, onto the skin stratum corneum surface -> thereby naturally lubricating the dry and dead layer of 3. Sweat glands keratinized cells of the stratum Eccrine sweat gland corneum ○ Produces a hypotonic sweat for ○ Fatty acids of sebum also have thermoregulation antibacterial properties ○ Abundant on the palms of the ○ Prevent water loss from the skin INTEGUMENTARY MIDTERM LESSON #5 SEPTEMBER 7, 2024 in low-humidity environments 3. Synthesizing vitamin D ○ Secretion of sebum is stimulated Epidermal layer of human skin by hormones -> become active synthesizes vitamin D when exposed until puberty to UV radiation/sunlight -> form of vitamin D3 called cholecalciferol -> liver converts cholecalciferol to FUNCTIONS OF THE INTEGUMENTARY calcidiol, which is then converted to SYSTEM calcitriol (the active chemical form 1. Acting as a sensory organ of the vitamin) in the kidneys Acts as a sense organ because the Vitamin D is essential for normal epidermis, dermis, and the absorption of calcium and hypodermis contain specialized phosphorous, which are required for sensory nerve structures that detect healthy bones touch, surface temperature, and pain Vitamin D deficiency ○ Meissner corpuscle (tactile ○ Children: rickets ->, painful corpuscle) responds to light condition where the bones are touch misshapen due to lack of ○ Pacinian corpuscle (lamellated calcium, causing bow leggedness corpuscle) responds to vibration ○ Elderly: osteomalacia -> softening ○ Merkel cells seen scattered in of the bones the stratum basale, are also touch receptors MEDICAL AND SURGICAL CONDITIONS 2. Modulating body temperature and OF THE INTEGUMENTARY SYSTEM electrolyte balance 1. Skin Cancers At rest: approximately 500ml of Causes: sweat (insensible perspiration) are ○ Degradation of the ozone layer in secreted a day the atmosphere At high temperature or vigorous ○ Increase in exposure to UV activity: sweat glands stimulated by radiation -> damages DNA -> the sympathetic nervous system to accumulation of DNA mutations produce large amounts of sweat -> ○ Exposure to other agents, such as 0.7 to 1.5 L per hour radiation and arsenic Sweat evaporates from the skin Types: surface -> the body is cooled as the ○ Basal cell carcinoma body heat is dissipated Affects the mitotically active Arterioles in the dermis dilate -> stem cells in the stratum accounts for skin redness that many basale of the epidermis people experience when exercising Most common Reduced body temperatures -> Found on the head, neck, arterioles constrict to minimize heat arms, and back (areas that are loss -> particularly in the ends of the most susceptible to long-term digits and tip of the nose -> reduced sun exposure) circulation Respond best to treatment ○ Temperature of the skin drops too when caught early -> surgery, much (such as environmental freezing (cryosurgery) temperatures below freezing), the ○ Squamous cell carcinoma conservation of body core heat Affects keratinocytes of the can result -> frostbite stratum spinosum INTEGUMENTARY MIDTERM LESSON #5 SEPTEMBER 7, 2024 Commonly found on the scalp, 3. Acne ears and hands Is a skin disturbance that occurs on Second most common skin areas rich in sebaceous glands (face cancer and back) Two of 10 skin cancers are Most common along with the onset squamous cell carcinoma of puberty due to associated More aggressive than basal hormonal changes (androgen) -> cell carcinoma also occur in infants and adulthood Treatment: surgery and Androgens, stimulate the release of radiation sebum -> overproduction and ○ Melanoma accumulation of sebum along with Cancer characterized by the keratin can block hair follic