MLS 1104 Anatomy and Physiology with Pathophysiology PDF

HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 1.1 ANATOMY AND PHYSIOLOGY ANATOMY “ana” - up ; “tomy” - process of cutting investigates body structure a science of body structures...

HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 1.1 ANATOMY AND PHYSIOLOGY ANATOMY “ana” - up ; “tomy” - process of cutting investigates body structure a science of body structures and the relationships among them was first studied by dissection PHYSIOLOGY “physio” - natury ; “logy” - study of investigates processes and functions a science of body functions - how the body parts works human physiology - studies human organism SYSTEMIC PHYSIOLOGY studies body organ-systems Figure 1.1 Levels for the organization of the human body structure of specific systems of the body such as the nervous or respiratory systems 1.2 STRUCTURAL AND FUNCTIONAL ORGANIZATION CELLULAR PHYSIOLOGY Six levels of structural and functional organization studies body cells (from chemical to organism) cellular structure and functions CHEMICAL IMPORTANCE OF ANATOMY AND PHYSIOLOGY smallest level Atoms, chemical bonds, and molecules are Understands how the body: fundamental units of matter, essential for life. Atoms responds to stimuli like carbon, hydrogen, oxygen, nitrogen, phosphorus, environmental changes calcium, and sulfur are vital. DNA and glucose are environmental cues common molecules in the body. diseases (caused by pathogens) injury TYPES OF ANATOMY SYSTEMATIC studies body organ-systems structure of specific systems of the body such as nervous or respiratory systems REGIONAL studies body regions CELLULAR specific regions of the body such as head or chest cells: basic units of life SURFACE compartments and organelles studies external features e.g. bone projections examples are mitochondria, nucleus Surface markings of the body to understand internal Molecules combine to form cells, the basic structural anatomy through visualization and palpation (gentle and functional units of an organism that are composed of touch) chemicals. ANATOMICAL IMAGING uses technology (x-rays, ultrasounds, MRI) Internal body structures that can be visualized with techniques such as x-rays, MRI, CT scans, and othe technologies for clinical analysis and medical intervention ALBASON, E.R. 1 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 STRUCTURAL AND FUNCTIONAL ORGANIZATION STRUCTURAL AND FUNCTIONAL ORGANIZATION TISSUES ORGAN-SYSTEM group of cells with similar structure and function plus group of organs contributing to some function extracellular substances they release for example, digestive system, reproductive system four broad types: Epithelial, Connective, Muscular, A system consists of related organs with a common Nervous function. An example of the system level, also called the organ-system level, is the digestive system, which breaks down and absorbs food. Its organs include the mouth, salivary glands, pharynx (throat), esophagus (food tube), stomach, small intestine, large intestine, liver, gallbladder, and pancreas. Sometimes an organ is part of more than one system. 1. Epithelial tissue - a type of body tissue that forms the covering on all internal and external surfaces of your body, lines body cavities and hollow organs and is the major tissue in glands. 2. Connective tissue - tissue that connects, supports, binds, or separates other tissues or organs. 3. Muscular tissue - composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts. 4. Nervous tissue - responsible for coordinating and controlling many body activities. ORGANISM all organ systems working together includes associated microorganisms such as intestinal bacteria ORGANS two or more tissue types acting together to perform function(s) Examples: stomach, heart, liver, ovary, bladder, kidney organs are structures that are composed of two or more different types of tissues; they have specific functions and usually have recognizable shapes. ALBASON, E.R. 2 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 ORGAN SYSTEMS OF THE BODY SKELETAL SYSTEM Provides protection and support, allows body movements, produces blood cells, and stores minerals and adipose. Consists of bones, associated cartilages, ligaments, and joints. Figure 1.2 Major Organs of the Body ORGAN SYSTEMS OF THE BODY INTEGUMENTARY SYSTEM NERVOUS SYSTEM Provides protection, regulates temperature, prevents A major regulatory system that detects sensations and water loss, and helps produce vitamin D. Consists of skin, controls movements, physiological processes, and hair, nails, and sweat glands. intellectual functions. Consists of the brain, spinal cord, nerves, and sensory receptors. MUSCULAR SYSTEM Produces body movements, maintains posture, and produces body heat. Consists of muscles attached to the ENDOCRINE SYSTEM skeletons by tendons. A major regulatory system that influences metabolism, growth, reproduction, and many other functions. Consists of glands, such as the pituitary, that secrete hormones. ALBASON, E.R. 3 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 ORGAN SYSTEMS OF THE BODY ORGAN SYSTEMS OF THE BODY CARDIOVASCULAR SYSTEM DIGESTIVE SYSTEM Transports nutrients, waste products, gases, and Performs the mechanical and chemical processes of hormones throughout the body; plays a role in the immune digestion, absorption of nutrients, and elimination of response and the regulation of body temperature. wastes. Consists of the mouth, esophagus, stomach, Consists of the heart, blood vessels, and blood. intestines, and accessory organs. URINARY SYSTEM LYMPHATIC SYSTEM Removes waste products from the blood and regulates Removes foreign substances from the blood and lymph, blood pH, ion balance, and water balance. Consists of the combats disease, maintains tissue fluid balance, and kidneys, urinary bladder, and ducts that carry urine. absorbs dietary fats from the digestive tract. Consists of the lymphatic vessels, lymph nodes, and other lymphatic organs. FEMALE REPRODUCTIVE SYSTEM Produces oocytes and is the site of fertilization and fetal development; produces milk for the newborn; produces RESPIRATORY SYSTEM hormones that influence sexual function and behaviors. Exchanges oxygen and carbon dioxide between the blood Consists of the ovaries, uterine tubes, uterus, vagina, and air and regulates blood pH. Consists of the lungs and mammary glands, and associated structures. respiratory passages. MALE REPRODUCTIVE SYSTEM Produces and transfers sperm cells to the female and produces hormones that influence sexual functions and behaviors. Consists of the testes, accessory structures, ducts, and penis. ALBASON, E.R. 4 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 1.3 CHARACTERISTICS OF LIFE HOMEOSTASIS ORGANIZATION functional interrelationships between parts SET POINT normal, or average value of a variable over time, body specific relationship of the many individual parts of an temperature fluctuates around a set point. organism, from cell, organelles to organs, interacting and working together. Set points for some variables can be temporarily adjusted depending on body activities, as needed: METABOLISM sum of all chemical and physical changes sustaining an COMMON CAUSE OF EXAMPLES CHANGES organism ability to acquire and use energy in support of these changes. body temperature fever Catabolism - breakdown of complex chemical substances heart rate, blood exercise into simpler components. pressure, respiratory Anabolism - the building up of complex chemical rate substances from smaller, simpler components. RESPONSIVENESS ability to sense and respond to environmental changes includes both internal and external environment NEGATIVE FEEDBACK the main mechanism used homeostatic regulation. GROWTH A negative feedback response involves: detection: of can increase in size deviation away from set point and correction: reversal size of cells, groups of cells, extracellular materials of deviation toward set point and normal range DEVELOPMENT THE COMPONENTS OF FEEDBACK changes in form and size changes in cell structure and function. from generalized to RECEPTOR specialized—differentiation detects changes in variable Such precursor cells, which can divide and give rise to a body structure that monitors changes in a controlled cells that undergo differentiation, are known as stem cells. condition and sends input to a control center. REPRODUCTION This pathway is called an afferent pathway formation of new cells or new organisms CONTROL CENTER generation of new individuals receives receptor signal tissue repair establishes set point sends signal to effector 1.4 HOMEOSTASIS Output from the control center typically occurs as nerve impulses, or hormones or other chemical signals. This “homeo” - the same ; “statis” - to stop pathway is called an efferent pathway. maintenance of constant internal environment despite fluctuations in the external or internal environment EFFECTOR directly causes change in variable VARIABLES body structure that receives output from the control center measures of body properties that may change in value and produces a response or effect that changes the Examples: controlled condition. body temperature, heart rate, blood pressure, blood glucose level, blood cell counts, respiratory rate normal range of homeostasis is normal extent of increase or decrease around a set point ALBASON, E.R. 5 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 1.5 TERMINOLOGY AND THE BODY PLAN ANATOMICAL POSITION person standing erect with face and palms forward all relational descriptions based on the anatomical position, regardless of body orientation DIRECTIONAL TERMS Superior: above Inferior: below Anterior: front (also: ventral) Posterior: back (also: dorsal) Note: In four-legged animals, the terms ventral (belly) and dorsal POSITIVE FEEDBACK (back) correspond to anterior and posterior in humans occur when the initial stimulus further stimulates the response system response causes progressive deviation away Medial: close to midline from Lateral: away from midline set point, outside of normal range Proximal: close to point of not directly used for homeostasis attachment some positive feedback occurs under normal Distal: far from point of conditions attachment Example: childbirth Superficial: structure close to generally associated with injury, disease the surface negative feedback mechanisms unable to maintain Deep: structure toward the homeostasis interior of the body NEGATIVE VS. POSITIVE FEEDBACK BODY PLANES Sagittal plane: separates the body into right and left parts Median plane: a sagittal plane along the midline that divides body into equal left and right halves Transverse plane: a horizontal plane that separates the body into superior and inferior parts. Frontal plane: a vertical plane that separates the body into anterior and posterior parts. ALBASON, E.R. 6 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 BODY REGIONS Upper limbs: upper arm, forearm, wrist, hand Lower limbs: thigh, lower leg, ankle, foot Central region: head, neck, trunk DIRECTIONAL TERMS Superior: above Inferior: below Anterior: front (also: ventral) Posterior: back (also: dorsal) Note: In four-legged animals, the terms ventral (belly) and dorsal (back) correspond to anterior and posterior in humans PLANES OF SECTION THROUGH AN ORGAN Medial: close to midline Lateral: away from midline Proximal: close to point of attachment Distal: far from point of attachment Superficial: structure close to the surface Deep: structure toward the interior of the body BODY PLANES Sagittal plane: separates the body into right and left parts Median plane: a sagittal plane along the midline that divides body into equal left and right halves Transverse plane: a horizontal plane that separates the body into superior and inferior parts. Frontal plane: a vertical plane that separates the body into anterior and posterior parts. ALBASON, E.R. 7 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 BODY REGIONS BODY CAVITIES Thoracic cavity: space within chest wall and diaphragm contains heart, lungs, thymus gland, esophagus, trachea Mediastinum: space between lungs contains heart, thymus gland, esophagus, trachea Abdominal cavity: space between diaphragm and pelvis contains stomach, intestines, liver, spleen, pancreas, kidneys Pelvic cavity: space within pelvis contains urinary bladder, reproductive organs, part of large intestine SEROUS MEMBRANES Line trunk cavities, cover organs Structure: visceral serous membrane covers organs parietal serous membrane is the outer membrane cavity - a fluid-filled space between the membranes SUBDIVISIONS OF THE ABDOMEN Three sets of serous membranes and cavities: ALBASON, E.R. 8 HUMAN ORGANISM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 PERICARDIUM PERICARDIUM ANDAND PERICARDIAL PERICARDIAL CAVITY CAVITY PERITONEUM AND PERITONEAL CAVITY Peritoneum visceral peritoneum Pericardium covers, anchors organs visceral pericardium covers heart double layers called mesenteries parietal pericardium thick, fibrous parietal peritoneum lines inner wall of abdominopelvic cavity pericardial cavity reduces friction peritoneal cavity reduces friction PLEURA AND PLEURAL CAVITY Pleura visceral pleura covers lungs parietal pleura lines inner wall of thorax pleural cavity reduces friction adheres lungs to thoracic wall ALBASON, E.R. 9 CHEMICAL BASIS OF LIFE Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 BASIC CHEMISTRY CHEMICAL BONDS Matter: anything that occupies space and has mass (solid, liquid, or gas) Mass: amount of matter in an object Weight: gravitational force acting on object ELEMENTS AND ATOMS Element: simplest form of matter Example: C, H, O, N, Ca, K, Na, Cl Atom: smallest particle of an element contains protons, electrons, and neutrons COVALENT BOND Covalent bonding occurs when atoms share one or more pairs of electrons Example: hydrogen molecule Polar covalent bonds form when there is an unequal sharing of electrons Example: water (H2O) Polar molecules have an asymmetrical electrical charge Nonpolar molecules have a symmetrical electrical charge SUBATOMIC PARTICLES Proton: positive charged particle located inside the nucleus Neutron: neutral charged particle located inside the nucleus Electron: negative charged particle located outside the nucleus ATOMIC NUMBER AND ATOMIC MASS Atomic number: the number of protons in each atom Mass number: the number of protons and neutrons in each HYDROGEN BOND atom Polar molecules, like water, have a positive end and a negative end. CHEMICAL BONDS A hydrogen bond forms when the positive end of one polar molecule is weakly attracted to the negative end of another Chemical bonds occur when outermost electrons (valence shell polar molecule. electrons) are transferred or shared between atoms The hydrogen bond is a weaker bond than the ionic or Types of chemical bonds covalent bonds. Ionic Covalent Hydrogen ION AND IONIC BOND Ion: a charged atom formed because of a donation or gain of an electron(s) Example: Na+ Ionic bonding occurs when there is an attraction between two oppositely charged ions Example: NaCl ALBASON, E.R. 1 CHEMICAL BASIS OF LIFE Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 MOLECULES AND COMPOUNDS ENERGY Molecule Energy is the capacity to do work. 2 or more atoms chemically combine Work is the moving of matter. Example: water (H2O) Kinetic energy is energy in motion Compound Potential energy is stored energy chemical combination of 2 or more different types of atoms Example: NaCl CHEMICAL ENERGY Chemical energy is a form of potential energy stored in CHEMICAL REACTIONS chemical bonds Food molecules such as glucose contain potential energy Chemical reactions occur when there is a formation or An example of a reaction that releases energy is the breaking of chemical bonds between atoms, ions, molecules, breakdown of ATP (adenosine triphosphate) to ADP or compounds. (adenosine diphosphate) and a phosphate group Reactants: substances that enter into the reaction ATP → ADP + P Products: substances that result from the reaction RATE OF CHEMICAL REACTIONS The rate at which a chemical reaction proceeds is influenced Types of Chemical Reactions by several factors: 1. Synthesis reaction: concentration of the reactants build a new molecule temperature energy-requiring catalyst Example: ADP + P → ATP Concentration of the reactants: within limits the higher the 2. Decomposition reaction: concentration of reactants the faster the rate break down molecule energy-releasing Temperature: within limits, the higher the temperature the Example: ATP → ADP + P faster the rate Catalyst: increases the rate of a reaction without itself being permanently changed or depleted. ACIDS AND BASES Acid: a proton H+ donor pH below 7 Example: HCl (hydrochloric acid) Base: a proton H+ acceptor pH above 7 Example: NaOH (sodium hydroxide) pH scale 3. Exchange reaction: combination of synthesis and decomposition reactions Example: AB + CD → AC + BD Example: HCl + NaOH → NaCl + H2O 4. Reversible reaction: Reversible reactions occur when the reaction can run in the opposite direction, so that the products are converted back to the original reactants. CO + H20 = Н+ НСОз Equilibrium: when the rate of product formation equals the rate of reactant formation ALBASON, E.R. 2 CHEMICAL BASIS OF LIFE Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 ORGANIC VS. INORGANIC CHEMISTRY LIPIDS Inorganic chemistry deals with those substances that do not FUNCTIONS OF LIPIDS contain carbon. Long term energy storage Organic chemistry is the study of carbon-containing Insulates against heat loss substances Protective cushion for organs Exception: some carbon containing compounds are not Cholesterol is part of the cell membrane structure organic in that they do not also contain hydrogen, such as CO2 TYPES OF LIPIDS (carbon dioxide) Saturated: single covalent bonds between carbon atoms ORGANIC MOLECULES Examples: beef, pork, whole milk, cheese, eggs Carbon’s ability to form covalent bonds with other atoms makes Unsaturated: it possible the formation of large, diverse, complicated one or more double covalent bonds between carbons molecules for life. The four major groups of organic molecules Examples: olive oil, fish oil, sunflower oil essential to living organisms are carbohydrates, lipids, proteins, and nucleic acids. CARBOHYDRATES CHARACTERISTICS OF CARBOHYDRATES Contain C, H, O H:O is a 2:1 ratio Example: C6H12O6 Monosaccharides are the building blocks. Monosaccharide: simple sugar (1 sugar) Examples: glucose and fructose Disaccharide: 2 sugars Example: glucose + fructose = sucrose Example: glucose + galactose = lactose Polysaccharide: many sugars Example: starch, grain, vegetables, glycogen FUNCTIONS OF CARBOHYDRATES Short-term energy storage Converted to glucose quickly Glucose is used to make ATP (energy) Brain cells require glucose LIPIDS CHARACTERISTICS OF LIPIDS Contain C, H, O Contain a lower proportion of oxygen to carbon than do carbohydrates Insoluble in water Examples: fats, oils, cholesterol, triglycerides, phospholipids ALBASON, E.R. 3 CHEMICAL BASIS OF LIFE Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 PROTEINS PROTEIN DENATURATION Protein denaturation occurs when the hydrogen bonds CHARACTERISTICS OF PROTEINS that maintain shape of a protein are broken and the protein Contains C, H, O, N becomes nonfunctional. Amino acids are the building blocks 20 different naturally Factors that can cause denaturation are: high occurring amino acids temperatures and/or improper pH Amino acids contain an amine (NH2) group and carboxyl group ENZYMES Amino acids are not stored, so a daily supply is required Enzymes are organic catalysts that increase the rate at which biochemical reactions proceed without the enzyme being permanently changed. Enzymes work by lowering the energy of activation. FUNCTIONS OF PROTEIN Used to make skin, hair, nails, muscles Part of the hemoglobin molecule Act as enzymes Immune system functions Muscle contractions (actin and myosin) Part of the cell membrane ALBASON, E.R. 4 CHEMICAL BASIS OF LIFE Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 NUCLEIC ACIDS Composed of C, H, O, N, P Examples: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) Nucleotides are the building blocks Nucleotides are composed of a nitrogen base, phosphate, and 5-carbon sugar NUCLEIC ACIDS ATP is an especially important organic molecule found in all living organisms. It consists of adenosine (the sugar ribose with the organic base adenine) and three phosphate groups. ATP is often called the energy currency of cells because it is capable of both storing and providing energy ALBASON, E.R. 5 CELL STRUCTURE AND ITS FUNCTIONS Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 GENERALIZED CELL MOVEMENT THROUGH THE CELL MEMBRANE Passive Transport No energy expenditure required Rely on concentration gradients. Diffusion is the process by which substances move from an area of higher concentration to an area of lower concentration, influenced by the concentration gradient. Example: Oxygen moving into cells while carbon dioxide moves out. Osmosis specifically refers to the diffusion of water across a selectively permeable membrane. Factors affecting osmosis. Osmotic Pressure: The pressure required to prevent water movement across a membrane. Solutions can be hypotonic, isotonic, or hypertonic depending on solute concentration relative to the cell. CELL STRUCTURE Hypotonic solution: Lower solute concentration and higher water concentration relative to cell cytoplasm. ; has less osmotic pressure than cell. ; Cell swells due Organelles are specialized structures within cells that perform to water movement, potentially leading to lysis. distinct functions essential for cellular operation. Examples of Isotonic solution: Same solute concentrations inside and outside cell. organelles are mitochondria, nucleus, ribosomes. Hypertonic solution: Higher solute concentration and lower water Organelles perform specific functions essential for survival. concentration ; Osmosis causes cell shrinkage or crenation. Cytoplasm is a jelly-like substance filling the cell, holding Facilitated Diffusion uses specific proteins to help organelles in place, and serving as the site for various transport molecules like glucose across the cell metabolic processes. membrane without energy input. (carrier-mediated The cytoplasm is crucial for metabolic processes. transport) Cell membrane or the plasma membrane, encloses the Active Transport cytoplasm and forms a selective barrier between the Requires energy (ATP) to move substances against a intracellular and extracellular environments. concentration gradient. The cell membrane's structure supports selective permeability. Crucial for cellular functions requiring higher concentrations of CELL FUNCTIONS specific ions or molecules. Sodium-Potassium Pump: Moves Na⁺ out and K⁺ into Smallest units of life Communication cells. Cell metabolism and energy use Reproduction and DIFFUSION THROUGH THE LEAK AND GATED Synthesis of molecules inheritance CELL MEMBRANE MEMBRANE CHANNELS CELL MEMBRANE STRUCTURE The fluid-mosaic model describes the cell membrane, noting its composition: Phospholipids: Form a bilayer with hydrophilic (polar) heads facing the aqueous environment and hydrophobic (nonpolar) tails opposing them. Proteins: Embedded within the phospholipid bilayer, these proteins assist with transport and communication. Cholesterol and Carbohydrates: Contribute to membrane FACILITATED DIFFUSION Na-K PUMP fluidity and cell recognition, respectively. The fluid-mosaic model illustrates the dynamic nature of the cell membrane. Phospholipids are fundamental to membrane integrity and function. ALBASON, E.R. 1 CELL STRUCTURE AND ITS FUNCTIONS Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 ENDOCYTOSIS VS. EXOCYTOSIS ORGANELLES Endocytosis and exocytosis are vital for cellular communication and material exchange. Endocytosis This process involves the uptake of materials into the cell via vesicles. Types include: Phagocytosis: Engulfing solid particles. Pinocytosis: Ingesting liquids. RIBOSOMES Produced in nucleolus. Exocytosis Organelles for protein production. Exocytosis entails exporting materials out of the cell via secretory Can be attached to endoplasmic reticulum. vesicles, crucial for processes like hormone and enzyme release. Free ribosomes unattached to other organelles. ORGANELLES CELL NUCLEUS Large organelle located near cell center. Bounded by a nuclear envelope with outer and inner membranes. ENDOPLASMIC RETICULUM Nuclear membrane contains nuclear pores for material Membranes forming sacs and tubules extend from outer passage. nuclear membrane to cytoplasm. Human cells contain 23 pairs of chromosomes, primarily Rough ER involved in protein synthesis due to attached chromatin. ribosomes. Chromosomes become tightly coiled during cell division. Smooth ER stores calcium ions in skeletal muscle cells. Nucleoli, diffuse bodies with no surrounding membrane, found within the nucleus. Nucleolus contains subunits of ribosomes, exiting the nucleus through nuclear pores. ALBASON, E.R. 2 CELL STRUCTURE AND ITS FUNCTIONS Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 ORGANELLES GOLGI APPARATUS / GOLGI COMPLEX CYTOSKELETON Comprises tightly packed, membrane-bound sacs. Provides internal framework to cells. Collects, modifies, packages, and distributes proteins and Comprises protein structures like microtubules, lipids. microfilaments, and intermediate filaments. Forms vesicles, including secretory, lysosome, and other Microtubules: Hollow structures supporting cell types. cytoplasm, aiding in cell division, and forming organelle components. Microfilaments: Small fibrils supporting cytoplasm, determining cell shape. Some involved in cell movement. Intermediate Filaments: Fibrils smaller than microtubules but larger than microfilaments, providing mechanical support. A specific type of intermediate filament is keratin, a protein associated with skin cells LYSOSOMES Membrane-bound vesicles from Golgi apparatus. Enzymes function as intracellular digestive systems. Endocytosis-formed vesicles can fuse with lysosomes. Ex: White blood cells phagocytize bacteria. CENTRIOLE The centrosome is a specialized area of cytoplasm close to the nucleus for microtubule formation. Consists of two perpendicular centrioles. Each centriole is a small, cylindrical organelle composed of microtubules. Centrioles are involved in mitosis process. PEROXISOMES Small, membrane-bound vesicles with enzymes for breaking down fatty acids, amino acids, and hydrogen peroxide. Hydrogen peroxide, a by-product of fatty and amino acid breakdown, can be toxic to cells. Enzymes in peroxisomes break down hydrogen. MITOCHONDRIA CILIA Small organelles producing significant ATP through aerobic cylindrical structures projecting from cell surfaces, metabolism. responsible for material movement. Composed of Inner and outer membranes separated by space. microtubules. Inner membranes have numerous folds called cristae. FLAGELLA Inner membrane contains mitochondrial matrix, enzymes, Similar to cilia but longer, typically one per cell. Each sperm and mtDNA. cell has one flagellum. Large energy-required cells have more mitochondria. MICROVILLI Specialized extensions of cell membrane, supported by microfilaments. They increase cell surface area and are abundant in areas with important absorption functions. ALBASON, E.R. 3 CELL STRUCTURE AND ITS FUNCTIONS Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 WHOLE CELL ACTIVITY PROTEIN SYNTHESIS AND GENETIC CONTROL TRANSLATION A cell’s characteristics are determined by the type of After transcription, the mRNA exits the nucleus through proteins it produces. nuclear pores and enters the cytoplasm. The proteins are produced based on the genetic mRNA attaches to a ribosome, where the process of information stored in the nucleus. translation occurs. DNA contains the code that guides cellular processes by During translation, transfer RNA (tRNA) reads the codons directing the production of proteins in a process called (sequences of three nucleotide bases) on the mRNA using gene expression. anticodons that match the mRNA codon. tRNA carries specific amino acids to the ribosome, and STRUCTURE OF DNA these amino acids are joined together to form a polypeptide DNA is composed of nucleotides, which are made of three chain (protein). components: a 5-carbon sugar, a phosphate group, and a This process continues until the entire protein is nitrogenous base. synthesized. The DNA molecule consists of two strands of nucleotides, Summary of Pairing: twisted to form a double helix. DNA’s thymine (T) pairs with RNA’s adenine (A). Each nucleotide on one strand pairs specifically with a DNA’s adenine (A) pairs with RNA’s uracil (U). nucleotide on the opposite strand: DNA’s cytosine (C) pairs with RNA’s guanine (G). Adenine (A) pairs with Thymine (T) DNA’s guanine (G) pairs with RNA’s cytosine (C). Cytosine (C) pairs with Guanine (G) Genes and Protein Production: A gene is a sequence of nucleotides that provides instructions for making a specific protein. Gene expression is the process of protein synthesis, consisting of two main steps: transcription and translation. TRANSCRIPTION Transcription occurs in the nucleus. It involves copying the DNA code into messenger RNA (mRNA). During transcription, the DNA strands separate, and RNA nucleotides pair with their complementary DNA bases: DNA’s thymine pairs with RNA’s adenine. DNA’s adenine pairs with RNA’s uracil (since RNA uses uracil instead of thymine). DNA’s cytosine pairs with RNA’s guanine. DNA’s guanine pairs with RNA’s cytosine. OVERVIEW OF GENE EXPRESSION ALBASON, E.R. 4 CELL STRUCTURE AND ITS FUNCTIONS Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 THE CELL CYCLE PROCESS MITOSIS DNA template strands pair with new nucleotides. Telophase: Enzymes join these nucleotides to form a new strand. The chromosomes reach the poles and begin to DNA template sequence determines new strand sequence. decondense back into chromatin. DNA replication creates two identical chromatids, forming The nuclear membrane reforms around each set of one chromosome. chromosomes, creating two distinct nuclei. DNA REPLICATION Cytokinesis follows, dividing the cytoplasm and resulting in two separate daughter cells. CELL GENETIC CONTENT Each cell has 23 pairs of chromosomes, totaling 46. DIFFERENTIATION Sperm and egg contain 23 chromosomes. Sperm cell and oocyte unite to form a single cell. Sex chromosomes: two X chromosomes for females, X and Numerous mitotic divisions occur for trillions of cells. Y for males. Differentiation process involves specialized structures and MITOSIS functions. Mitosis is the process of cell division that results in two Differentiation affects active and inactive DNA portions. daughter cells from a single parent cell. It is divided into DIVERSITY OF CELL TYPES four distinct phases: Prophase: Chromatin condenses into visible chromosomes. Spindle fibers, made of microtubules, form and begin to attach to the centromeres of chromosomes. The nuclear membrane disintegrates, allowing the spindle fibers to interact with the chromosomes. Metaphase: APOPTOSIS Chromosomes align at the cell's equatorial plane, Programed cell death that adjusts tissue cell numbers. also known as the metaphase plate. In developing fetus, removes extra tissue. Spindle fibers ensure proper alignment and In adult tissues, eliminates excess cells to maintain attachment to the centromeres. constant tissue cell count. Anaphase: CELLULAR ASPECTS OF AGING The chromatids are pulled apart by the spindle Existence of cellular clock. Formation of free radicals. fibers, each becoming an independent Presence of death genes. Mitochondrial damage. chromosome. DNA damage. The separated chromosomes move toward TUMORS opposite poles of the cell, ensuring that each Abnormal Cell Proliferations malignant (cancerous) daughter cell will have an identical set of Caused by cell cycle issues. Malignant tumors spread via chromosomes. benign metastasis. ALBASON, E.R. 5 TISSUES Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 EPITHELIAL TISSUE A tissue is a group of cells with similar structure and Simple Columnar Epithelium: function, plus extracellular matrix. Single layer of tall, thin cells. Large size allows complex functions like secretion. Histology is the study of tissues. Produces and secretes mucus and digestive enzymes. Four types of tissues: Pseudostratified Columnar Epithelium: Epithelial: Covers surfaces and forms glands. Secrets mucus covering free surface. Connective: Supports and connects other tissues. Airway cilia move mucus and debris to throat for Muscle: Responsible for movement. swallowing. Nervous: Conducts electrical impulses for communication. Stratified Squamous Epithelium: Forms thick epithelium with multiple cell layers. Epithelium, or epithelial tissue, covers and protects surfaces, both Deepest cells are cuboidal or columnar, capable of cell outside and inside the body. division and production. Characteristics Named based on surface cell shape. 1. Mostly composed of cells 5. Cell and matrix connections Types: Keratinized and Nonkeratinized stratified 2. Covers body surfaces 6. Nonvascular squamous epithelia. 3. Distinct cell surfaces 7. Capable of regeneration Keratinized Stratified Squamous Epithelium: Functions Contains keratin, making the skin waterproof. 1. Protection 4. Secretion Nonkeratinized Stratified Squamous Epithelium: 2. Barrier 5. Absorption Found in moist environments like the mouth and 3. Permits passage of esophagus. substances Classification Stratified Cuboidal Epithelium: classified primarily according to the number of cell Comprises multiple cuboidal epithelial layers. layers and the shape of the superficial cells. Rare, found in sweat gland ducts, ovarian follicular cells, salivary glands. Based on cell layer Functions in absorption, secretion, and protection. Simple epithelium (single layer) for absorption/secretion Stratified Columnar Epithelium: (e.g., lungs, kidneys). Comprises multiple layers of epithelial cells. Stratified epithelium (multiple layers) for protection (e.g., Surface cells are columnar, deeper cells are irregular or skin, mouth). cuboidal. Pseudostratified (e.g., respiratory tract), Transitional(e.g., Rarely found in mammary gland ducts, larynx, and male bladder) urethra. Based on idealized shapes of the epithelial cells Carries out secretion, protection, and some absorption. Squamous: Thin, flat cells (e.g., lining of blood vessels). Transitional Epithelium: Cuboidal: Cube-shaped cells (e.g., in glands). Special type of stratified epithelium that can be stretched. Columnar: Tall, narrow cells (e.g., lining of intestines). Changes cell shape with stretching. Transitional: Cells change shape as they stretch (e.g., in the Lines cavities expanding cavities like urinary bladder. bladder). Protects underlying structures from urine caustic effects. Specialized Classification Free Cell Surfaces Simple Squamous Epithelium: Most epithelia have a free surface, away from tissues. Single layer of thin, flat cells. Surface characteristics reflect functions. Allows certain substances to pass easily. Can be smooth or lined with microvilli or cilia. Facilitates gas exchange in the lungs. Cilia move materials, microvilli increase surface area. Helps filter wastes from blood while maintaining blood Cell Connections cells within blood vessels. Simple Cuboidal Epithelium: Cells have structures that bind cells together, form Single layer of cube-like cells. permeability barriers, and facilitate intercellular Carry out active transport, diffusion, secretion. communication. Greater secretory capacity than simple squamous Desmosomes are mechanical links that bind cells epithelial cells. together. Hemidesmosomes anchor cells to the basement membrane. Tight junctions surround each cell, preventing material passage. ALBASON, E.R. 6 TISSUES Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 EPITHELIAL TISSUE GLANDS Classification of glands according to how products Cell Connections leave the cell Gap junctions allow small molecules and ions to pass from one cell to another. merocrine: secretion involves the release of secretory Most epithelial cells are connected by gap junctions, products by exocytosis. ex: sweat glands acting as communication signals to coordinate cell apocrine: secretion involves the release of secretory activities. products as pinched-off fragments of gland cells. ex: sweat, mammary glands holocrine: secretion involves shedding of entire cells. ex: sebaceous glands CONNECTIVE TISSUES Connective tissue is a diverse primary tissue type that makes up part of every organ in the body. General Characteristics: Diverse: Found in all parts of the body and includes bones, cartilage, fat, and blood. Composed of cells and an extracellular matrix: The matrix contains protein fibers (collagen, elastic, reticular) and ground substance (fluid, proteins). Functions: a. Enclosing and separating tissues (e.g., the fascia around muscles). GLANDS b. Connecting tissues: Tendons (connect muscle to bone) and ligaments (connect bone to bone). Glands are secretory organs that secrete substances into c. Supporting and moving: Bones provide support, while the bloodstream. cartilage enables movement at joints. Composed primarily of epithelium with a supporting d. Storing energy: Fat (adipose tissue) stores energy and network of connective tissue. provides insulation. Exocrine glands have ducts and are lined with epithelium. e. Cushioning and protecting: Cartilage and fat protect Endocrine glands are ductless glands secreting hormones organs. into the bloodstream. f. Transporting substances: Blood transports oxygen, Most exocrine glands are multicellular, some are single nutrients, and waste. cells secreting mucus. g. Protecting against infection: Immune cells in connective Classification of glands based on duct structure and tissue defend against pathogens. secretory regions Connective Tissue Cells Simple glands have a single, non-branched duct,some have The specialized cells of the various connective tissues branched ducts. produce the extracellular matrix. Compound exocrine glands have multiple, branched ducts. The name of the cell identifies the cell functions. Tubular glands are glands with secretory regions shaped as Osteoblasts form bone, osteocytes maintain it, tubules (small tubes), whereas those shaped in saclike osteoclasts break it down. structures are called acinar or alveolar. Fibroblasts form fibrous connective tissue, fibrocytes Tubular glands can be straight or coiled. maintain it. Glands with a combination of the two are called tubuloacinar Chondroblasts form cartilage, chondrocytes maintain it. or tubuloalveolar. Connective tissue contains immune-associated cells like white blood cells. Macrophages can move and ingest foreign substances, including microorganisms. Mast cells release chemicals like histamine, promoting inflammation ALBASON, E.R. 7 TISSUES Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 CONNECTIVE TISSUE Bone: Composed of osteocytes, providing rigid support and Extracellular Matrix of Connective Tissue protection. Composed of three main components: protein fibers, ground Spongy Bone: Contains trabeculae and marrow. substance, and fluid. Ground substance is non-fibrous protein and other Compact Bone: Dense, organized into osteons. molecules. Blood: Contains plasma and formed elements Its structure determines the functional characteristics of (erythrocytes, leukocytes, platelets), functions in transport connective tissues. and immunity. MUSCLE TISSUE Matrix Protein Fibers Main Function: Contraction, enabling movement. Collagen, reticular, and elastic fibers form most connective Types: tissues. Skeletal Muscle Collagen fibers are flexible but resist stretching. Attaches to skeleton for movement. Reticular fibers branch to form a supporting network. Cells are striated due to contractile protein Elastic fibers return to original shape after compression or arrangement. deformation. Cardiac Muscle Cardiac or Heart muscle responsible for blood Matrix Ground Substance pumping. Non-fibrous, shapeless, composed of proteoglycans. Cylindrical, shorter than skeletal muscle cells. Proteoglycans trap water between polysaccharides. Strained, one nucleus per cell. Often branched, connected by intercalated disks. Types of Connective Tissue Smooth Muscle Main Types Forms hollow organ walls. embryonic and adult connective tissue Found in skin and eyes. By eight weeks of development, most of the Moves food through digestive tract. embryonic connective tissue has become Empties urinary bladder. specialized to form the types of connective tissue Tapered at ends, single nucleus. seen in adults. Loose Connective Tissue: NERVOUS TISSUE Areolar: Composed of collagen and elastic fibers, found Nervous tissue forms the brain, spinal cord, and nerves. under the skin and around organs. Function: Conducts electrical impulses. Adipose: Stores fat, providing insulation and energy Components: storage. a. Neurons: Nerve cells responsible for transmitting Reticular: Forms the framework of lymphatic organs impulses. such as the spleen. Cell Body: Contains the nucleus. Dense Connective Tissue: Dendrites: Receive signals. Dense Regular: Collagen fibers aligned in one direction Axon: Sends signals. (e.g., tendons, ligaments). b. Glial Cells: Support and protect neurons. Dense Irregular: Collagen fibers arranged in multiple directions (e.g., dermis of skin). TISSUE MEMBRANE Elastic Connective Tissue: Contains elastic fibers, Tissue membranes are thin sheets or layers of tissue covering allowing tissues to stretch and recoil (e.g., in the walls of structures or cavities. arteries). Most membranes consist of epithelium and connective tissue. Cartilage: Four types of tissue membranes: cutaneous, mucous, serous, and Hyaline Cartilage: Most abundant, found in joints, synovial. respiratory system, and fetal skeleton. Coughty membrane: Covers the skin. Fibrocartilage: Strong, found in intervertebral discs. Mucous membranes: Line cavities open to the outside of the body. Elastic Cartilage: Provides flexibility, found in the ear Serous membranes: Line cavities not open to the exterior. and epiglottis. Synovial membranes: Line cavities of freely moveable joints. Synovial fluid: Produces synovial fluid, making the joint slippery. ALBASON, E.R. 8 TISSUES Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 TISSUE MEMBRANE TISSUE REPAIR Involves replacing dead cells with viable ones. Can be facilitated by regeneration or fibrosis. Regeneration restores normal function by replacing destroyed cells with new ones. Fibrosis develops a new tissue type, leading to scar production and function loss. Regeneration can repair tissues like skin and intestine mucous membrane, primarily by stem cells. Repair process involves sequential steps. TISSUE INFLAMMATION Inflammation is beneficial when tissues are damaged. Common cold symptoms are produced when viruses infect upper respiratory tract epithelial cells. Inflammation occurs in stages, mobilizing body's defenses and destroying microorganisms and damaged cells. Major symptoms include redness, heat, swelling, pain, and function disturbance. ALBASON, E.R. 9 INTEGUMENARY SYSTEM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 THE INTEGUMENTARY SYSTEM SKIN STRUCTURE Consists of the skin, hair, nails, and glands. EPIDERMIS It provides protection, regulates body temperature, enables Prevents water loss and resists abrasion. sensation, and synthesizes vitamin D. Composed of strata, including the stratum corneum. Integument = covering The stratum corneum is composed of dead squamous appearance can indicate physiological imbalances of the cells filled with keratin. body. Keratin gives the stratum corneum its structural strength. Friction increases stratum corneum layers, forming a thickened area called a callus. Over a bony prominence, the stratum corneum can thicken to form a cone-shaped structure called a corn. The melanocytes are cells that produce melanin, responsible for skin pigmentation and UV protection. Excessive sloughing from the stratum corneum is called dandruff. FUNCTIONS DERMIS 1. Protection: Prevents mechanical injury, pathogen entry, Composed of dense collagenous connective tissue. and UV damage. Extends into nerves, hair follicles, smooth muscles, 2. Sensation: Detects external stimuli (touch, temperature, glands, and lymphatic vessels. pressure, pain). Structural strength and resistance to stretch attributed to 3. Thermoregulation/Temperature Regulation: Maintains collagen fibers and elastic fibers. body temperature via sweating and Certain collagen fibers form cleavage lines, or tension vasodilation/vasoconstriction. lines, in the skin, are more resistant to stretch. 4. Vitamin D Production: Converts a cholesterol derivative Parallel incisions reduce scar tissue production. to vitamin D under UV light, essential for calcium Overstretched skin can cause damage, leaving absorption. 5. Excretion: Removes waste products (urea, salts) via stretch marks. sweat. Dermal Papillae Projections towards epidermis in upper dermis. SKIN STRUCTURE Contains numerous blood vessels. Comprises two major tissue layers: epidermis and dermis. Arranged parallel in palms, feet, and digit tips. Epidermis: Most superficial layer of skin, composed of Shape overlying epidermis into fingerprints and epithelial tissue. footprints. Dermis: Dense connective tissue layer. Skin rests on subcutaneous tissue, a connective tissue layer not part of the skin. SUBCUTANEOUS TISSUE Not part of the skin, also known as hypodermis. Attaches skin to underlying bone and muscle, providing blood vessels and nerves. Loose connective tissue, including adipose tissue, contains about half the body's stored lipids. Adipose tissue functions as padding and insulation. Subcutaneous tissue can estimate total body fat. Acceptable body fat percentages 21%-30% for females 13%-25% for males. ALBASON, E.R. 1 INTEGUMENARY SYSTEM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 SKIN COLOR HAIR Factors include skin pigments, blood circulation, and Hair is found on all skin except palms, soles, lips, nipples, stratum corneum thickness that determines color. parts of the genitalia, and distal segments of the fingers Primary pigments are melanin and carotene. and toes. Melanin is responsible for skin, hair, and eye color. Each hair originates from a hair follicle, an invagination Most melanin molecules are brown to black, some of the epidermis that extends deep into the dermis. yellowish or reddish. Hair has a hard cortex surrounded by a softer center, the Melanin provides UV protection. medulla, covered by the cuticle. Produced by melanocytes, packaged into Hair is produced in the hair bulb, which rests on the hair melanosomes. papilla, an extension of the dermis that contains blood Epithelial cells acquire melanosomes through vessels. phagocytization. Hair is produced in cycles: Melanin forms freckles or moles in certain skin growth stage (mitosis of epithelial cells within the hair regions. bulb) Production is influenced by genetic factors, light resting stage (growth stops and hair is held in the hair exposure, and hormones. follicle) Racial variations in skin color are influenced by the new growth stage (new hair is formed and old hair amount, type, and distribution of melanin. falls out). Exposure to ultraviolet light stimulates The duration of each stage depends on the individual hair. melanocytes, resulting in a suntan. Hair color is determined by varying amounts and A single mutation can prevent melanin production, types of melanin, which can decrease with age or causing albinism. become white. Carotene is a yellow pigment found in plants. Each hair follicle is attached to smooth muscle cells called Carotene is lipid-soluble and accumulates in the arrector pili muscle, which can contract and cause stratum corneum lipids and dermis adipocytes. the hair to become perpendicular to the skin’s surface. Consumption of large amounts can cause skin to turn yellowish. HAIR FOLLICLE Dermis blood color influences skin color. Shock-induced decrease in blood flow can make skin pale. Decrease in blood O2 content results in cyanosis, a blueish skin color. ALBASON, E.R. 2 INTEGUMENARY SYSTEM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 GLANDS NAILS Two major glands of the skin: sebaceous and sweat glands Sebaceous Glands: Simple, branched acinar glands connected by ducts to hair follicles. Produce sebum, an oily, white substance rich in lipids. Released by holocrine secretion, lubricates hair and skin surface. INTEGUMENTARY SYSTEM PROTECTION Reduces body water loss. Sweat Glands: Acts as a barrier against foreign substances. Eccrine sweat glands: Protects underlying structures against abrasion. simple, coiled, tubular glands. Melanin absorbs ultraviolet light, protecting underlying Release sweat by merocrine secretion. structures. Most abundant in palms and soles. Produce a secretion mostly water with a few Hair Protection salts. Acts as a heat insulator. Used for thermal regulation and emotional Prevents sweat from the eyes. stress release. Prevents entry of dust and other materials. Apocrine Glands: Nails protect fingers and toes from damage. Simple, coiled, tubular glands. Produce a thick secretion rich in organic substances. SENSORY RECEPTORS Active at puberty due to sex hormones. Associated with the skin, detecting pain, heat, cold, and Generally odorless but breaks down quickly, pressure. giving body odor. Sensory receptors around the hair follicle can detect hair movement. VITAMIN D PRODUCTION UV light causes skin to produce a precursor molecule of vitamin D. Vitamin D stimulates the small intestine to absorb calcium and phosphate. TEMPERATURE REGULATION Important for maintaining homeostasis. Blood vessels in the dermis dilate and allow more blood to flow within the skin. Sweat assists in heat loss through evaporative cooling. If body temperature drops below normal, heat can be conserved by the constriction of dermal blood vessels. NAILS Nail is a thin plate composed of dead stratum corneum cells containing hard keratin. The visible part is the nail body, while the skin-covered part is the nail root. The cuticle extends onto the nail body, while the nail root extends distally from the nail matrix. The nail also attaches to the underlying nail bed, which is epithelial tissue with a stratum basale. The lunula, a small part of the nail matrix, is visible at the base. Continuous cell production within the nail matrix drives growth. ALBASON, E.R. 3 INTEGUMENARY SYSTEM Human Anatomy and Physiology with Pathophysiology | LEC MLS 1104 | Stub 1411 | BSMLS-1A | PAREDES | 1st SEM 2024 EXCRETION AND DIAGNOSTIC AID Excretion Skin Cancer The integumentary system plays a minor role in waste Most common skin cancer caused by UV light exposure. removal from the body. Preventable by limiting sun exposure and using Sweat contains small amounts of waste products like