Anatomy and Physiology Preliminary Exam Reviewer PDF

Anatomy and Physiology Themes of Anatomy and Physiology Preliminary Exam Reviewer Structure and Function Structure and function are closely related 1st Semester...

Anatomy and Physiology Themes of Anatomy and Physiology Preliminary Exam Reviewer Structure and Function Structure and function are closely related 1st Semester Structure determines function Chapter 2: Introduction To The Human Body Changes in protein shape can change Overview of Anatomy and Physiology their function Anatomy Human pelvis evolved to support abdominal and thoracic organs The study of the body’s structure Branching structures in living organisms Gross anatomy (larger structures) increase surface area for molecular absorption Microscopic anatomy (smaller structures) and exchange Subcategories Phosphorylation Causes Changes in Protein Regional anatomy, systemic anatomy, Shape histology, cytology, and others This illustrates how form is related to function Anatomical Structures in a Variety of Imaging Techniques Adding a phosphate group to a protein changes the shape of the protein Gross anatomy of the brain compared to microscopic anatomy of the brain Common form of molecular regulation Functional MRI (fMRI) of the brain and Branching Structures in Nature ultrasound imagining of fetal brain Branching maximizes surface area X-rays can be used to show hard structures like E.g., Respiratory tubes increase surface bone area available for gas exchange CT scans can be used to show soft tissues Branching increases speed of molecular Physiology transport The study of function of the human body Evolution and Human Variation Helps to understand the chemistry and Evolution physics of the anatomical structures of the body Caused by random changes in gene and how they work expression that occur from generation Categories of physiology to generation - Leads to variation among a species Neurophysiology Cardiovascular physiology Becomes more frequent when the variation Renal physiology offers an advantage Variation less likely to be seen in traits that affect the ability to reproduce  Anatomical variation occurs more frequently than represented in most texts Does not affect the function For example, the number of pulmonary veins and lumbar vertebrae can vary from person to person Physiological Variation More diverse and widespread than anatomical variation Homeostasis Affects function of an organ, organ system, or organism The dynamic stability of the body’s internal environment Physiological variation can be based on age or gender The body’s parameters, or variables, are kept near a normal setpoint Necessitates diversity when health studies are - pH, temperature, blood pressure, oxygen conducted levels, nutrient levels, and electrolyte levels are Flow constantly monitored Receptors monitor and send information to The movement of a substance or molecule a control center Dependent on a gradient Control center determines if changes are necessary Examples of gradients in nature Changes made by effectors keep - Electrical, pressure, and concentration parameters, or variables, near setpoint gradients For example, body temperature homeostasis: Flow is directly proportional to size of a gradient Sensors in the skin detect increase in Resistance opposes or stops flow temperature Control center receives Flow is inversely proportional to resistance sensory information to maintain body - An increase in resistance will decrease temperature setpoint (37°C) flow Control center communicates with effector to change body temperature (e.g., sweating) Anatomy of Flow Physiological Variables Maintained by Gradients determine the direction of flow Homeostasis Molecules flow down their concentration gradients Pressure gradients move food, blood, and air through the body Feedback Loops The method of control for many variables of the human body Most variables are controlled through negative feedback The body’s response is to decrease the original stimulus Positive feedback occurs when the original stimulus is enhanced or increased Structural Organization of the Human Body Control of Blood Sugar Levels The Levels of Organization Negative feedback loop to control blood sugar The human body has several levels of levels: organization A decrease in blood sugar levels leads to From the simplest to the most complex these release of glucagon from the pancreas include: Glucagon will then promote an increase in Chemical, Cell, Tissue, Organ, Organ System, blood sugar levels Organism Maintaining Blood Sugar Levels Near a Setpoint Levels of Organization of the Human Body Physiological processes help maintain blood sugar levels near a setpoint Eating increases blood sugar levels and insulin is secreted to lower them Fasting decreases blood sugar levels and glucagon is secreted to increase them Positive Feedback Loop Involved in Childbirth Childbirth involves a positive feedback loop Stretching of the cervix leads to release of oxytocin Oxytocin strengthens contractions of the uterus Cervix stretches more as labor continues Organ Systems of the Human Body 9. Digestive System - Breaks down food and 1. Integumentary System absorbs nutrients into the - Creates a barrier that protects the body body from pathogens and fluid 10. Urinary System loss - Contributes to blood pressure and - Sensory reception pH homeostasis 2. Skeletal System - Removes waste products from the - Supports and body protects the body 3. Muscular System 11. Reproductive System - Creates the movement of the body - Produce and - Contibutes to body temperature exchange gametes homeostasis - House the fetus until 4. Nervous System birth - Acts as the sensor for homeostasis - Lactation - Connects the brain to every part of the body Anatomical Terminology 5. Endocrine System Anatomical Position - Secretes the hormones that The body is standing upright regulate many Feet are parallel and shoulder-width bodily processes apart 6. Cardiovascular System - Delivers oxygen, nutrients, Toes pointed forward hormones, and waste products Upper limbs are held out to each throughout the body side with palms facing forward 7. Lymphatic System - Regulates fluid Anterior and Posterior Regional Terms balance in the body - Houses some of the immune cells that defend the body from pathogens 8. Respiratory System - Exchanges air with the atmosphere - Provides surface area for the diffusion of oxygen and carbon dioxide with the blood Directional Terms Sagittal Frontal (coronal) Superior Transverse Anterior Anatomical Planes Medial A sagittal plane divides the person in anatomical position into right and left halves. Midsagittal Cranial passes through the midline, while parasagittal is Proximal off to one side. Inferior A frontal or coronal plane divides the standing Posterior body into front and back. Lateral A transverse or cross-sectional plane divides the body into top and body sections, perpendicular Caudal to the long axis. Distal Two Dimensional Planes Planes and sections can illustrate the same structures, but from Sections and Planes different perspectives Sections through the It is important to human body can be understand the plane or used to investigate section being presented internal anatomy This information can be A plane is an used to build a 3-D imaginary section understanding of body structures through the body: Midsagittal Section (pelvis) Subdivisions of the Posterior and Anterior Cavities Frontal Section (thorax) Posterior Body Cavity and Subdivisions Transverse Section (head) Posterior, or dorsal, body cavity Cranial cavity - Brain Spinal (or vertebral) cavity - Spinal cord, beginning of spinal nerves Anterior Body Cavity and Subdivisions Organization and Compartmentalization of the Thoracic cavity Human Body Pleural cavity Internal compartments organize the body’s - Lungs internal space Mediastinum Separated by membranes Thymus Referred to as cavities Esophagus Posterior, or dorsal, body cavity Trachea Pericardial cavity Consists of cranial and spinal (or vertebral) - Heart cavities Abdominopelvic cavity Anterior body cavity Abdominal cavity Consists of thoracic and abdominopelvic - Stomach cavities - Spleen - Liver - Small intestine Pelvic cavity Urinary bladder Ovaries Abdominal Regions and Quadrants Right iliac- large intestine, cecum Left iliac- large intestine Serous Membranes of the Anterior Body Cavity Serous membranes are sheets of tissue that cover organs in the anterior body cavity reduce rubbing and friction as internal organs move Abdominopelvic Quadrants Serous membranes have two layers Right Upper Quadrant (RUQ): parietal layer lines the wall of the body Right lobe of liver, gallbladder, right kidney, cavity portions of stomach, small and large intestine visceral layer lies directly on the surface of the organ Left Upper Quadrant (LUQ): cavity between the layers contains serous Left lobe of liver, stomach, pancreas, left kidney, fluid spleen, portions of large intestine Layers of a Serous Membrane Right Lower Quadrant (RLQ): Serous membrane layers Cecum, vermiform appendix, portions of small develop as the organ develops intestine, reproductive organs (right ovary in into the membrane female and right spermatic cord in male), right This is similar to the way that ureter an underinflated balloon forms Left Lower Quadrant (LLQ) two separate layers around a fist Most os small intestine, portions of large intestine, left ureter, reproductive organs (left ovary in female and left spermatic in male) Medical Imaging Abdominopelvic Regions X-Rays Hypogastric- large intestine, sm intestine, Medical imaging bladder provides an internal view Umbilical- sm and lg intestine of the human body Epigastric- stomach, liver, spleen, pancreas Aids in diagnosing disease Right hypochondriac- liver X-rays are best used to Left hypochondriac- stomach, liver, spleen, view teeth and bone pancreas Right lumbar- large and small intestine Left lumbar- large and small intestine Computed Tomography Mass is the same regardless of where the object is Uses computers and a series of x- rays to Weight can vary because it depends on visualize internal gravity structures in planes Elements and Compounds Provides more detail Elements—pure substances that are made of a than x-rays alone single type of atom Magnetic Resonance Imaging (MRI) Atom—smallest unit of an element that Uses radio signals retains properties of that element emitted by internal Molecule—two or structures to provide more atoms very precise details chemically bound Expensive together Compound—two or more elements Other Forms of Medical Imaging joined by chemical Positron Emission Tomography (PET) bonds Uses small amounts of radiation to detect Atoms and Subatomic Particles metabolic activity Subatomic particles make up atoms Useful in diagnosing cancers, heart disease, and strokes Proton—positively Ultrasonography charged Neutron—no charge Uses sound waves to yield a real time image (neutral) of internal anatomy Electron—negatively Used in sensitive situations like pregnancy charged The Periodic Table of Chapter 3: The Chemical Level of Organization Elements Elements and Atoms: The Building Blocks of Elements are organized in the periodic table Matter Each element has its own box with its atomic Matter number, atomic weight, element name, and Matter—anything that occupies space and has symbol mass Mass—the amount of matter contained in an object Mass is not the same as weight Atomic Number, Mass Number, and Isotopes Cation—positively charged ion Anion—negatively charged ion The Behavior of Electrons Electron shells Regions around an atom’s nucleus that contain electrons Atomic number—number of protons within an Can hold from two to eight electrons atom Valence shell Atomic weight—equals number of protons, The outermost electron shell of an atom neutrons, and small amount of weight from Atoms react in a manner to completely fill their electrons valence shell Mass number—roughly equal to the number of They may share, accept or donate electrons protons and neutrons in the atom to do so Isotopes—the different forms of an element Electron Shells Differ in the number of neutrons and atomic The first electron weight shell can hold up to 2 electrons Isotopes of Hydrogen The second electron Isotopes differ in their number of neutrons shell can hold up to 8 Number of protons remains the same electrons Protium – 1 proton, 1 electron, 0 neutrons Atoms with more than 10 electrons require additional electron shells Deuterium – 1 proton, 1 electron, 1 neutron Forming Bonds and Ions Tritium – 1 proton, 1 electron, 2 neutrons Atoms react with other atoms to try and fill Radioactive isotopes are unstable and shed their valence shell subatomic particles Ex. potassium is likely to donate its single electron in its valence shell to become a stable ion (positive) Ions Ex. fluorine is likely Ion—an atom with an electrical charge to gain an additional Can be positive or negative electron to achieve Ions are formed when atoms donate or stability in its valence accept electrons shell (negative) Determining Valence Electrons Benefits both atoms by stabilizing the valence shell Elements in each column of the periodic table share the same number of electrons in their Polar covalent bonds valence shells Electrons are more attracted to certain atoms, leading to unequal sharing Nonpolar covalent bonds Electrons are shared equally Nonpolar Covalent Bonds Occur when electrons are equally shared between atoms Atoms form nonpolar molecules where no Chemical Bonds region is more positive or negative (i.e., neutral) Types of Bonds Atoms can share multiple electrons Bond—an electrical attraction that holds Multiple atoms can form single, double, or atoms together triple covalent bonds The number of electrons in the valence shell Polar Covalent Bonds determines the likelihood that an atom will Occur when electrons are not shared equally form a chemical bond Electrons are attracted to one atom more than Three types of bonds are important within the the human body: other(s) 1. Ionic bonds In water, the electrons are attracted more to 2. Covalent bonds oxygen than hydrogen 3. Hydrogen bonds Atoms form polar molecules where one end is 1. Ionic Bonds more negative and the other more positive Formed between ions with opposite charges 3. Hydrogen Bonds Think “opposites attract” Occur when molecules are attracted to one Table salt (sodium chloride, NaCl) is a common another example Commonly occur between water molecules The cation is sodium (Na+) and the anion is Negatively charged region of a water chloride (Cl−) molecule is attracted to the positively charged 2. Covalent Bonds region of another water molecule Formed when electrons are shared by atoms This creates surface tension between water molecules Forming Solutions Characteristics of Chemical Reactions Water molecules are attracted to other water Reactants or substrates—the substances that molecules and polar molecules enter into the reaction Polar molecules and charged molecules Products—the substances produced by the dissolve to form solutions reaction Water molecules repel nonpolar molecules like Three types of reactions lipids, fats, and oils 1. Synthesis reaction—atoms, molecules, or Chemical Reactions ions combine to form new molecules 2. Decomposition reaction—larger molecules The Role of Energy in Chemical Reactions are broken down into smaller atoms, ion, or Energy is the ability to do work molecules 3. Exchange reaction—the combination of Potential energy—stored energy that can be both synthesis and decomposition reactions released Types of Chemical Kinetic energy—the energy of motion Reactions Chemical energy—potential energy that is stored in bonds Synthesis reactions Exergonic reactions—release energy join monomers (or reactants) that were Endergonic reactions—absorb energy previously separated Energy can be converted from one form to An endergonic another through chemical reactions reaction Forms of Energy Decomposition Potential energy is stored energy breaks molecules down into their Kinetic energy is the energy of motion constituent parts Chemical energy is the energy stored in An exergonic reaction chemical bonds Exchange reactions involve both synthesis and Endergonic and Exergonic Reactions decomposition reactions Energy can be stored in chemical bonds Both endergonic and exergonic reactions ATP is a common form of cellular energy Factors Influencing the Rate of Chemical Reactions Endergonic reactions require energy and store it in bonds Properties of reactants—atomic weight, phase Exergonic reactions release energy by breaking of the reactants (solid, liquid, or gas) chemical bonds Temperature—reactions occur faster at higher temperatures  Concentration and pressure—higher Water concentration of reactants and higher pressure increase rate of reaction Enzymes and other catalysts—increase the rate of reactions by lowering activation energy Activation energy = the minimal energy required for the reaction to occur Enzymes and Activation Energy 50–70% of an adult body Enzymes lower activation energy to increase Functions of water in the body include: rate of reactions 1. Provides lubrication for joints Reactants are held together close enough 2. Provides cushioning for cells and tissues and long enough by enzymes during synthesis 3. Aids in temperature regulation reactions 4. Is a solvent for ions and nutrients needed Enzymes are unchanged by reactions by cells 5. Involved in dehydration synthesis and Inorganic Compounds Essential to Human hydrolysis reactions Functioning Solutions Inorganic versus Organic Compounds The nutrients required by cells within the body Inorganic compounds are typically dissolved in water. Substances that do not contain both carbon A nutrient dissolved in water makes up a and hydrogen Water, salts, acids and bases, solution: carbon dioxide Solution—a mixture where one substance is Organic compounds dissolved in another Solvent—the substance that dissolves Substances that contain both carbon and another substance in a solution hydrogen Solutes—the substances dissolved in the Carbohydrates, lipids, proteins, nucleic solvent acids Water as a Solvent Common Chemical Formulas in A&P Solution consists of solvent and solute Common chemical compounds important in Solvent is the substance that dissolves A&P Solute is the substance that is dissolved Water is the universal solvent because many Inorganic compounds do not contain both molecules dissolve in water carbon and hydrogen Because of polarity of molecules Organic compounds contain both carbon and hydrogen Concentrations of Solutes Capable of allowing the body to conduct electrical currents Solute concentration refers to the number of the solute particles in a specific matter (e.g., air, Important in nerve impulses and muscle water, etc.) contraction It can be expressed in a variety of ways: Acids and Bases Oxygen is 21% of atmospheric air Acids release hydrogen Blood glucose is expressed in mg/dL ions (H+) when dissolved Molarity is moles of the molecule per L in solution. Different Types of Solutions Bases release hydroxyl Colloid = a mixture that is a heavy solution ions (OH−) when dissolved in solution or Solute molecules make mixture opaque bind hydrogen ions in Examples = milk and cream solution. Suspension = a liquid mixture in which heavier substance is suspended temporarily and settles pH and Buffers out over time pH scale from 0 to 14 indicates the acidity or Sedimentation = separation of particles alkalinity of a solution Occurs if blood is left in the air for a period pH of 7 is neutral of time The closer to 0, the more acidic the solution Role of Water in Chemical Reactions The closer to 14, the more alkaline the Dehydration synthesis forms new molecules solution while creating water at the same time Buffers are used to prevent rapid changes in Hydrolysis the pH of a solution reactions break covalent bonds using water Salts Organic Compounds Essential to Human Functioning Formed when ions bond through ionic bonding Organic Biological Macromolecules Dissolve into separate ions when placed in water Organic biological macromolecules contain carbon atoms that generally bond to hydrogen The ions cannot be hydrogen ions (H+) or atoms hydroxide ions (OH−) Oxygen and other elements may be These ions are referred to as electrolytes incorporated as well  Four major organic macromolecules are 3. Proteins—amino acids important within the human body: 4. Nucleic acids—nucleotides 1. Carbohydrates Carbohydrates 2. Lipids Made up of carbon, hydrogen, and oxygen 3. Proteins 4. Nucleic acids Ratio of hydrogen to oxygen is usually 2:1 The Chemistry of Carbon Monosaccharides—simple individual sugar Organic molecules contain carbon bonded to molecules like glucose hydrogen atoms Disaccharides—sugars like lactose that are They can form chains or ring structures made of two monosaccharides Carbon is represented by the symbol C or by Polysaccharides—multiple monosaccharides using lines and angles in diagrams bound together to form large, more complex carbohydrates Functional Groups Main source of chemical energy in the human Carbon atoms body can bind to functional groups Important Monosaccharides A functional Monosaccharides can be used to form group is a group disaccharides or polysaccharides of atoms linked by Monosaccharides include: covalent bonds that function as a Glucose unit Fructose Galactose They can have predictable behaviors in Ribose chemical reactions Deoxyribose Hydroxyl, carboxyl, amino, phosphate, and Important Polysaccharides methyl functional groups are important in human Polysaccharides contain from a few to physiology thousands of monosaccharides Monomers Important polysaccharides include: Monomers Starches – glucose storage in plants Individual units that make up organic Glycogen – glucose storage in animals molecules Monomers bond together to form polymers Monomers of major organic molecules 1. Carbohydrates—monosaccharides 2. Lipids—fatty acids and glycerol  Cellulose – cell walls of plants Each fatty acid is a long chain of hydrocarbons Fatty Acid Shapes Saturated fats = Lipids that have the maximal number of hydrogen atoms bound to carbon Solid or semisolid at room temperature Important Disaccharides Unsaturated fats = lipids that contain double Disaccharides are bonds common in the human diet Fatty acid tails zig zag as a result Sucrose – table sugar Liquid at room temperature Lactose – milk sugar Maltose – malt sugar Other Types of Lipids Functions of Carbohydrates Phospholipids Primary source of cellular energy Important in cellular membranes Used to produce ATP Cholesterol Help maintain cellular structure Precursor used to make several hormones and provides stability to the cell Component of plant cells walls membrane Can bond with lipids and proteins to form Prostaglandins glycolipids or glycoproteins Play a role in inflammation Help form cell membrane and aid in cell Phospholipids, Sterols, and Prostaglandins signaling Phospholipids contain a phosphorus “head” Lipids Sterols contain hydrocarbons in a ring structure Made mostly of hydrocarbons Prostaglandins are derived from unsaturated Are nonpolar, hydrophobic molecules fatty acids Triglyceride is the most common form of lipid in Proteins our diet Composed of amino acids linked together by Major energy source for cells peptide bonds Provides insulation Function to provide cellular structure, transport Triglycerides substances, and catalyze reactions Most common lipid in human diet The shape of proteins: Contain a 3-carbon glycerol molecule 1. Primary structure—the sequence of amino acids 3 fatty acids are attached to the glycerol  2. Secondary structure—folding of amino acid Amino Acid Interactions Determine Protein chains into alpha-helix or beta-pleated sheet Shape 3. Tertiary structure—additional folding that Interactions occurs between different regions of the same between amino amino acid chain acids determine 4. Quaternary structure—interactions shape of protein between 2+ proteins, each with its own tertiary structure Amino acids Structure of Amino Acids may form hydrogen bonds Amino acids are the monomers of proteins Hydrophobic amino acids may huddle together while hydrophilic amino acids surround them 20 amino acids in total Enzymes Each consists of an amino group, Biological catalysts speed up the rate of carboxyl group, and an R group chemical reactions Amino acids are linked by peptide bonds to Reduce the energy of activation to increase the form proteins speed of a reaction Peptide Bonds Most enzymes are proteins Peptide bonds link amino acids Highly specific for substrate due to active site Formed through dehydration synthesis Active site = the location on the enzyme Carboxyl and amine groups of neighboring where the substrate binds amino acids react Shape of the active site depends on the structure of the protein Enzymes increase the reaction rate by lowering activation energy Steps of an Enzymatic Reaction Substrates bind to enzyme at the active site The Shape of Proteins The active site for each enzyme is specific The shape of proteins: for a particular substrate 1. Primary structure Forms enzyme-substrate complex 2. Secondary Enzyme catalyzes the reaction, forming the structure product 3. Tertiary structure The enzyme is unchanged by reaction and can 4. Quaternary be reused structure Denaturation is a change in the shape and will no longer carry out the function Nucleic Acids Adenosine Triphosphate (ATP) Two types of nucleic acids: A modified nucleotide Deoxyribonucleic acid (DNA) - Monomer bases = adenine, cytosine, Energy currency guanine, thymine of the cell Ribonucleic acid (RNA) Covalent bonds - Monomer bases = adenine, cytosine, between guanine, uracil phosphate groups store energy DNA contains the sugar deoxyribose; RNA contains the sugar ribose Energy is released when bonds are broken Store the genetic code of the cells (DNA) and participate in protein synthesis (RNA) Chapter 4: The Cellular Level of Organization The Nucleotides of DNA and RNA The Cell Membrane and Its Involvement in Nucleotides are Transport composed of one Structure of the Cell Membrane or more phosphate groups, a sugar, Separates the cell’s internal environment from and a nitrogen base the external environment Adenine and Regulates the movement of materials into and guanine are purines out of the cell Cytosine, Composed of phospholipids, cholesterol, thymine, and uracil are pyrimidines carbohydrates, and proteins DNA versus RNA Flexible, dynamic structure DNA is a Phospholipids double-stranded, Major structural component of the cell helical molecule membrane RNA is a single Amphipathic molecules stranded molecule Hydrophilic (“water-loving”) phosphate heads Hydrophobic (“water-fearing”) fatty acid tails Arranged into a bilayer (two layers) Phosphate heads face internal and external environments Fatty acid tails create hydrophobic region within bilayer Phospholipid Structure Glycoproteins = proteins that have carbohydrate molecules attached Amphipathic molecule Aid in cell recognition Hydrophilic head contains a phosphate Glycocalyx is formed by numerous group and is attracted to glycoproteins water Only present in some cells Hydrophobic tails Can serve as receptors for hormones and a are nonpolar and means to bind to other cells repelled by water Helps break down nutrients Organized into a bilayer to form biological Transport Across the Cell Membrane membranes Cell membrane is selectively permeable Cell Membrane Allows only small, nonpolar molecules to Structure pass freely Molecules able to pass will flow across the Selectively membrane if there is a gradient permeable barrier Flow occurs from high to low concentration unless prevented by resistance Composed mainly of phospholipid Passive Transport bilayer Movement does not require energy Intracellular fluid (ICF) inside of cell Requires a concentration gradient Also called cytosol Two forms: Extracellular fluid (ECF) outside of cell 1. Simple diffusion: molecules move from Proteins also associate with cell membrane higher to lower concentration without the Membrane Proteins use of membrane proteins 2. Facilitated diffusion: molecules move from Proteins associated with cell membrane add higher to lower concentration through functionality membrane proteins Serve as channel proteins, receptors, Simple Diffusion Across a Cell Membrane enzymes, and in cell–cell recognition Small, nonpolar molecules can pass through Transmembrane, or integral, proteins the cell membrane Span the entire width of the cell membrane Diffusion continues until a net equilibrium is Peripheral proteins reached Do not span the membrane Diffusion occurs faster at higher temperatures Attached to the interior or exterior of the membrane Facilitated Diffusion Across a Cell Membrane A hypoosmotic solution contains less solute by comparison Requires assistance of transmembrane proteins Tonicity describes the osmolarity of the ECF compared to the cytosol of the cell Molecules still move down concentration gradient Effect of Tonicity on Cells Used for molecules that cannot diffuse through An isotonic solution has equal water the cell membrane concentration across the cell membrane Such as polar or ionic molecules Cell functions normally Osmosis A hypertonic solution contains more The movement of water across the cell solutes in the environment membrane Cell shrinks Water moves from areas of lower solute to A hypotonic solution contains fewer solutes in higher solute concentration the environment Hypotonic solution—less solute outside of cell Cell swells and may burst Water enters cells when they are in Active Transport hypotonic solutions Hypertonic solution—more solute outside of Requires energy to move molecules against cell their concentration gradient Water will leave cells in hypertonic solutions From areas of lower concentration to areas Water Molecule Concentration of higher concentration Osmosis depends on the ratio of solute Primary active transport—uses ATP as energy molecules to water source Water will move from areas of lower solute Secondary active transport—uses concentration to areas of higher solute electrochemical gradient as energy source concentration Symporters—move two molecules in the Osmosis Across a Membrane same direction Water moves across a semipermeable Antiporters—move two molecules in membrane toward the area with a higher solute opposite directions concentration (i.e., lower water concentration) Sodium-Potassium Pump Solution Comparisons Common example of primary active transport Uses ATP to move 3 sodium ions out of the cell Isosmotic solutions have equal and 2 potassium ions concentrations of solute into the cell, against A hyperosmotic solution contains more their concentration solute by comparison gradients Endocytosis The Cytoplasm and Cellular Organelles A form of active transport Internal Components of Cells Uses the cell membrane to engulf materials Major components of the inside of cells include: Cell membrane pinches off to form a vesicle and material enters cell Cytoplasm—the fluid-like interior of cells including its compartments and Three forms of endocytosis: organelles 1. Phagocytosis Organelles—membrane-bound structures 2. Pinocytosis that perform specific functions 3. Receptor-mediated endocytosis Cytosol – the gel-like substance within the Forms of Endocytosis cytoplasm Contains organelles and molecules 1. Phagocytosis: needed by cell extends the cell membrane to A Model Human Cell bring in large molecules 2. Pinocytosis: membrane invagination brings in small amounts of fluid containing dissolved substances 3. Receptor-mediated endocytosis: more selective Ligand binds to membrane receptor for cellular entry Exocytosis The process of a cell exporting material, or cell secretion Endoplasmic Reticulum Vesicle fuses with cell membrane Endoplasmic Contents are Reticulum released from cell (ER)—series of Hormones and channels digestive enzymes continuous secreted this way with the nuclear membrane; provides passages for synthesis, transportation and storage Rough ER—contains ribosomes Involved in protein synthesis  Smooth ER—lacks ribosomes The Cytoskeleton Involved in lipid synthesis Helps maintain the structure of the cell Golgi Apparatus Organizes cytoplasm The Golgi Apparatus—series of flattened sacs Aids in separation during cellular division Sorts and modifies products from rough ER for transport Composed of protein filaments that provide support Cis-face receives products for 1. Microtubules—made modification of tubulin 2. Intermediate Trans-face releases filaments—made of keratin products after 3. Microfilaments— modification made of actin Membranous Dynamic Nature of the Cytoskeleton Organelles for Detoxification and Energy Cytoskeleton is not fixed Production Cytoskeletal components Lysosomes—membrane-bound vesicles that form and can contain digestive enzymes move depending on needs Used to break down wastes within cell of the cell Helps move molecules Peroxisomes—contain enzymes used to and structures around produce hydrogen peroxide interior of cellynamic Used for detoxification and lipid metabolism Cell Surface Specializations Mitochondria—site of aerobic respiration Microvilli help increase surface area of the cell Responsible for nutrient breakdown and ATP Cilia aid in movement of the cell or movement production across the surface of the cell Mitochondria Flagella are long appendages used for “Energy transformer” of the cell movement Lined by 2 bilayers Outer membrane Inner membrane is folded into cristae More numerous in muscle and nerves The Nucleus and DNA Adenine forms a double bond with Organization of the Nucleus thymine. Nucleus houses the Cytosine forms a triple DNA of the cell bond with guanine. Most human cells have a single nucleus. Organization of DNA Nucleus is surrounded by a nuclear envelope. DNA strands are wrapped around histone Nuclear pores allow small molecules to proteins for organization move into and out of nucleus. Chromatin is the loose Nucleolus within nucleus is involved in form of DNA ribosome production. Chromatin is packaged Nucleic Acids Found in Human Cells during replication to form chromosomes Nucleic acids found in a healthy human cell Protein Synthesis include DNA, mRNA, tRNA, and rRNA Protein Synthesis within the Cell DNA is storage form of DNA contains the genetic code of the cell genome Genetic code provides the instructions to mRNA is produce cellular proteins used in translation of Protein production begins in the nucleus and proteins ends in the cytoplasm tRNA moves Genes are transcribed into messenger RNA amino acids (mRNA) during translation rRNA is structural component of ribosomes Gene is a segment of DNA that codes for a protein Nucleotide Bases of DNA mRNA is then translated into proteins DNA has a double-helix structure formed by Making Proteins from DNA hydrogen bonds between nucleotide bases. Proteome is a cell’s full complement of The four nucleotide bases of DNA are: proteins 1. Adenine (A) Genes contain 2. Thymine (T) information 3. Cytosine (C) and necessary to 4. Guanine (G) make proteins  DNA is transcribed to mRNA Translation mRNA is then translated to proteins Process of creating a protein from a mRNA template Transcription Occurs in the cytoplasm of the cell Process of creating a strand of messenger RNA (mRNA) from a DNA template Carried out by ribosomes Ribosomal RNA (rRNA)—component of Occurs within the ribosomes nucleus of the cell Each three nucleotide sequences of mRNA is Complementary mRNA is a codon. made from a Ribosomes read codons. Transfer RNA (tRNA) brings amino acids to gene of one strand of DNA ribosomes. mRNA will leave the nucleus for translation tRNA contains anticodons that match The Process of Transcription specific mRNA codons. Three stages of transcription: Amino acids are linked by peptide bonds to form proteins. 1. Initiation – DNA strands are separated and RNA polymerase begins to synthesize The Process of Translation complementary RNA molecule Initiation – ribosome subunits 2. Elongation – RNA polymerase continues to attach to start codon of mRNA add nucleotides to growing strand transcript 3. Termination – RNA polymerase reaches end of gene and mRNA transcript is released Elongation – tRNA molecules are attracted to the ribosome and deliver the corresponding amino Creating a Mature mRNA Transcript acids to the growing polypeptide Before leaving nucleus, mRNA transcript is Termination – translation modified continues until ribosome reaches a DNA contains regions that do not code for “stop” codon that ends the process amino acids Called introns Cell Replication Regions that code for amino acids are The Cell Cycle called exons Introns must be removed before mRNA leaves nucleus Three phases: Interphase, mitosis, and cytokinesis The cell spends most of its time in interphase Interphase is split into:  1. G1 phase—cell grows, makes proteins, and Sister chromatids are attached at a centromere carries out cellular functions Chromatids separate during mitosis 2. S phase—cell replicates its DNA 3. G2 phase—cell prepares for mitosis Makes sure each daughter cell has a complete copy of DNA Cellular Replication Phases of Nucleic Acid Processes Cellular replication occurs as the parent cell divides to form two daughter cells Transcription, translation, and replication are each divided into 3 steps: Mitosis occurs in somatic cells Daughter cells are identical to parent cell Initiation Cells contain 46 chromosomes or the Elongation diploid number Meiosis occurs for reproductive cells Termination Resulting cells have half the amount of Mitosis genetic material from one parent and half from the other parent Cell replication consists of four major phases, Cells contain 23 chromosomes or the followed by cytokinesis: haploid number Prophase: Chromatin DNA condenses into Replication chromosomes and the centrioles The process of migrate to copying DNA opposite sides of the Occurs during cell. the S phase of the cell cycle Metaphase: Chromatids align in the middle of the cell. Three phases: Anaphase: Chromatids separate and move 1. Initiation: the DNA strands are toward the opposite sides of the cell. separated by helicase Telophase: Nucleoli and nuclear membranes 2. Elongation: the DNA polymerase start to form, and chromosomes return to synthesizes a new strand chromatin form 3. Termination: the DNA replication stops Cytokinesis: Cleavage furrow divides cell into two distinct cells. Chromatin—the linear form of DNA Condensed into chromosomes during replication Replicated copy is called a sister chromatid Factors That Chapter 5: The Tissue Level of Organization Regulate Cell Types and Components of Tissues Division Levels of Organization Cellular division is regulated by: Tissues are groups of cells that function together in the body Growth factors like hormones Histology = microscopic study of the Contact inhibition appearance, function, and organization of If cell is surrounded, it won’t divide tissues Increasing efficiency Pathology = study of changes that occur with Larger cells are less efficient disease Tissues Cellular Differentiation A tissue is a group of cells that performs a specific function. Cellular Differentiation Histology is the study of tissue structure, The cells of the human body develop from a organization, and function. single cell. Four main types of tissue make up the human Cells become specialized for a specific body. function through differentiation. Pathology is the study of changes associated Stem cells are undifferentiated yet can become with disease of tissues. required cell types. Tissue Types The four types of tissue in the body are: Epithelial tissue—form coverings, linings, and glands Connective tissue—protection and support Muscle tissue—provides movement Stem Cells Nervous tissue—allows communication Stem cells can differentiate into specific cell types. Specific genes are turned on during differentiation. Transcription factors turn on necessary genes. Turning specific genes on in stem cells produces certain proteins needed for the differentiated cell’s function. General Features of Tissues Preparing Tissues for Examination Extracellular matrix (ECM)—material found Tissues must be carefully prepared for outside of a tissue examination Major components: Multiple factors influence the appearance of a tissue Collagen—tough, protective protein fibers Plane of section Proteoglycans—negatively charged Stain used during preparation protein/carbohydrate molecules Planes Influence Appearance Cellular connections—attachments between cells Same structure may appear differently depending Tight junctions—allow no movement of on the plane of the section substances between cells Sagittal plane Desmosomes—flexible connections that Transverse plane allow some movement of substances between cells Oblique plane Gap junctions—passageways that allow Cutting Tissues for Examination movement of certain substances between the Special blade is used to cut tissues cells Cut into thin slices for examination Cellular Connections Tissues Placed on Slides Cells can be connected by: Thin slices of tissue are placed on slides Tight junctions – fuse membranes of Tissues are Stained for Examination adjacent cells Many tissues are stained prior to examination Desmosomes – Results of Various Stains provide strong, Tissues may have different appearances and flexible connections colors depending on the stain used between cells Hemidesmosomes connect cells to ECM Epithelial Tissue Gap junctions – allow for intercellular passageways between cells Characteristics of Epithelia Form coverings, linings, and glands Basement membrane anchors epithelia to ECM (extracellular matrix) Two surfaces of epithelia:  Basal surface—attached to basement Epithelia That Defy Naming Convention membrane Pseudostratified columnar epithelium Apical surface—exposed to external environment or internal space May appear stratified Avascular All cells touch basement membrane because there is only a single layer Highly regenerative Transitional epithelium Anatomy of Epithelia Stratified tissue Epithelia are: Cells stretch and change shape Goblet Highly cellular Cells Polar (apical and basal surface) Common Avascular feature of Innervated simple and pseudostratified epithelia Bound to Secrete mucus basement membrane Stratified Epithelia The Epithelial Cell Contain more than one layer of cells Apical and basal membranes may have Cells of basal layer are stem cells that different functions regenerate cells into apical layers Apical surface Basal layer cells may be different in shape from modifications apical layer cells Cilia – move materials across surface Tissue is named based on shape of cells in Microvilli – increase surface area apical layer Simple Squamous Epithelium Cells of Epithelia Consists of a single layer of flat cells Epithelial tissue is named after its shape and Found in the air sacs of lungs, the lining of the number of layers of cells on the apical surface heart, blood vessels, and lymphatic vessels Based on shape: Allows materials to pass through by diffusion and filtration Squamous—flat cells Secretes lubricating substances Cuboidal—box-shaped cells Columnar—column-like cells Based on number of layers: Simple—one layer of cells Stratified—two or more layers of cells Pseudostratified—one layer of cells that appears like more Simple Cuboidal, Simple Columnar, Transitional Epithelium Pseudostratified Columnar Epithelia Transitional epithelium Simple cuboidal epithelium Lines bladder, urethra, and ureters Lines kidney tubules Allows urinary organs to expand and stretch Secretes and absorbs substances (Na+, K+, glucose, etc.) Simple columnar epithelium Lines digestive and reproductive tracts Secretes and absorbs various Glands of Epithelia materials Endocrine glands secrete hormones into the Pseudostratified blood columnar epithelium Examples: Thymus, pituitary gland, adrenal Lines trachea glands and respiratory tract Are ductless Exocrine glands secrete substances locally Secretes and through a duct moves mucus Examples: Sweat glands and glands of Stratified digestive system Squamous, Stratified Cuboidal, and Stratified Secrete mucus, sweat, saliva, and Columnar Epithelia breastmilk Stratified squamous Exocrine Gland Structure epithelium Unicellular – single cells Lines Multicellular – single layer of cells that esophagus, mouth, vagina fold into surrounding tissue Protects Tubular glands form tubes against abrasion Acinar glands form pockets Stratified cuboidal epithelium Simple glands have one duct Found in sweat glands, salivary glands Compound Secretes and protects glands Stratified columnar epithelium combine Found in male urethra formats Secretes and protects Exocrine Secretions Fluid connective tissue Blood and lymph Merocrine secretion: Cells and Fibers of Connective Tissues accomplished by exocytosis Fibroblasts produce fibers in the ECM Apocrine secretion: material accumulates near Collagen—strongest fibers apical surface of gland Elastic—provide elasticity Reticular—branching fibers that support Holocrine secretion: involves rupture and internal organs destruction of entire gland cell Adipocytes—store energy and provide Serous glands produce watery secretions cushioning Mucous glands produce watery to thick White blood cells—provide immune function secretions Red blood cells—carry gases such as oxygen Connective Tissue and carbon dioxide Anatomy of Connective Tissue Connective Tissue Types Connective Connective tissue proper tissue Loose connective tissue consists of - Areolar cells and the - Reticular extracellular matrix (ECM) Supportive connective tissue Cells rarely touch each other Hyaline cartilage Fibrocartilage ECM consists of ground substance and Elastic cartilage Fibers Fluid connective tissue Ground substance is between fibers Blood Vascularized Connective tissue proper Classification of Connective Tissues Dense regular connective tissue Twelve types of connective tissues are Dense irregular connective tissue separated into three categories: Adipose tissue Connective tissue proper Supportive connective - Areolar, adipose, reticular, dense regular, tissue and dense irregular connective tissue Bone Supportive connective tissue Hyaline cartilage, fibrocartilage, elastic Fluid connective tissue cartilage, compact bone, spongy bone Lymph Loose Connective Tissues Cartilage Areolar connective tissue Hyaline cartilage Subcutaneous layer Located within joints, ribs Supports nearby Most abundant tissues cartilage Adipose tissue Fibrocartilage Subcutaneous layer Located in intervertebral discs Energy storage, Strongest cartilage cushioning Elastic cartilage Loose Connective Tissues Located in external ear Reticular Most flexible type of cartilage connective tissue Application: The Framework of Ribcage internal organs The ribcage Lymphatic tissues, spleen, liver merges two supporting Dense Irregular Connective Tissue connective tissue Contains a high types number of collagen Bone makes up most of the ribcage fibers Protects lungs and heart Fibers oriented in Cartilage allows for expansion during every direction breathing Allows tissue to withstand force in any plane The Perichondrium Found in the dermis of the skin Made of dense irregular connective tissue Dense Regular Connective Tissue Encapsulates Contains a high number of collagen fibers cartilage within the body Collagen fibers oriented parallel to each other Allows tissue to withstand force in the direction of the orientation of the fibers Found in ligaments and tendons Bone Muscle Tissue The most rigid of the Anatomy of Muscle Tissue connective tissues Muscle tissue is responsible for movement Provides protection and Shortens to generate pulling force support for internal organs Cells are tightly packed Compact bone Differs in location and manner of control Solid with greater strength than spongy bone Skeletal muscle, cardiac muscle, smooth muscle Spongy bone Empty spaces contain red bone marrow Fluid Connective Tissues Blood and lymph Transport molecules and cells throughout the body Blood contains cells: Erythrocytes, leukocytes, and platelets Characteristics of Muscle Tissue Lymph is primarily acellular The major function of muscle tissue is Lymph movement Lymph is a fluid Contracts in response to stimuli connective tissue Voluntary muscle—conscious control Unlike blood, Skeletal muscle lymph is mainly acellular Involuntary muscle—unconscious control Cardiac and smooth muscle Skeletal Muscle Neurons and Nervous Tissue Attached to bone Neurons generate Allows body movement and maintains posture action potentials Contains striations—alternating light and dark Anatomical structure bands under light microscope of neurons: Voluntarily controlled Dendrites—short Cells are multinucleated branches that receive signals Cell body—houses nucleus and organelles Cardiac Muscle Axon—long projection used to send action Found in the walls of the heart potentials Synapse—gap between neuron and its target Contains striations cell Involuntarily controlled Glial Cells Cells attached by intercalated discs There are various types of glial cells associated Smooth Muscle with nervous tissue Found within internal organs Many perform support functions for neurons Associated with digestive, respiratory, Some form myelin that insulates axons urinary, and reproductive systems Allows for faster movement of action Lacks striations potentials Involuntarily controlled Membranes Nervous Tissue Tissue Membranes Anatomy of Nervous Tissue Mucous membranes Nervous tissue makes up the brain, spinal line body cavities that are cord, and peripheral nerves open to the outside Neurons conduct action potentials to Serous membranes line communicate with other cells body cavities and surround some organs Glial cells support Cutaneous membrane neuronal is the skin and covers the functioning body Synovial membranes line joints Mucous Membranes Tissue Growth and Healing Line body cavities that are exposed to the Inflammation external environment The body’s initial response to Usually contain goblet cells that secrete injury mucus Limits extent of injury and Associated with: begins the repair 1. Digestive tract process 2. Respiratory tract Acute inflammation is short- 3. Urinary tract term 4. Reproductive tract Chronic inflammation Serous Membranes persists for long periods of time Cover and line internal organs Tissue Healing Reduce friction created as organs move Begins with removal of debris and toxins Examples include: Clotting stops the bleeding Pericardium of the heart Granulation tissue forms to allow epithelial Pleura of the lungs cells to regenerate lost tissue Peritoneum of the abdominal cavity Scar tissue may form due to rapid repair and Cutaneous Membrane replacement of collagen fibers Essentially the skin Protects body from desiccation and pathogens Made of stratified squamous epithelium and connective tissue Keratin provides a thick barrier for protection against pathogens Synovial Membrane Tissue and Aging Found inside freely moveable joints like the Tissue changes as the body ages elbow, hip, and knee Rate of mitosis slows down Cells secrete synovial fluid Leads to slower tissue healing Helps lubricate and nourish the cartilage at the joint Number of elastic fibers decreases Reduces friction as bones move Structures are less elastic Contributes to wrinkles, joint stiffness, and high blood pressure Tissues and Cancer Mutations may alter the regulatory signals cell receives Altered signals lead to uncontrolled replication of cells Mass of cells is a tumor - Malignant tumors are cancerous, cause disease, and can spread to other areas of the body - Benign tumors do not cause disease in the body or metastasize (spread to other areas of the body) Tumor Growth Tumor growth is typically limited by physiological constraints Tumors that grow “trick” tissues into supporting their growth Breast Density and Breast Cancer Increased collagen density is correlated with increased breast cancer risk