Exam 1 Study Guide - Human Body and Orientation | BSCI 201, Study notes of Physiology

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BSCI 201 – Study Guide 1 HUMAN BODY AND ORIENTATION Anatomy - the study of the parts of the body and how they relate to each other Anatomical Position  Body erect  Feet slightly apart  Palms face forward  Thumbs point away from body 3 Planes and Sections  Frontal (Coronal) Plane – a vertical cut that divides the body in anterior and posterior parts  Sagittal Plane – a vertical cut that divides the body into right and left parts o Midsagittal plane – a sagittal cut exactly on the midline that divides the body into EQUAL right and left parts o Parasagittal Plane- a sagittal cut not on the midline that divides the body into UNEQUAL right and left parts  Transverse or cross sectional plane – a horizontal cut that divides the body into superior and inferior parts Body Cavity  Dorsal Body Cavity o Superior cranial cavity (brain) o Inferior vertebral cavity (spinal cord) o Brain and spinal cord are surrounded by serous membrane called meninges  Ventral Body Cavity – large ventral body cavity subdivided by a skeletal muscle -> diaphragm o Superior Thoracic Cavity  Lungs, heart, esophagus, and trachea o Inferior Abdominopelvic Cavity  Most of digestive organs, urinary organs, and reproductive organs o Each organ surrounded by membrane called serous membrane  Serous membrane surrounding heart -> pericardial sac  Serous membrane surrounding lungs -> pleural sac  Organs in Abdominopelvic cavity -> peritoneal sac  Functions  Isolate organs  Prevent interference from neighboring organs  Prevent spread of infection from organs  Hold organs in anatomical position  Protect against trauma Surface Anatomy  Axial – Relating to head, neck, and trunk, the axis of the body  Appendicular – Relating to limbs and their attachments to the axis Physiology – the study of the function (biochemical reactions occurring inside cells in human body) of the body’s parts  Principle of complementarity of structure and function – structure defines function Anterior Body Landmarks  Abdominal – Pertaining to the anterior body trunk region inferior to the ribs o Organ systems consist of different organs that work together closely  Organismal Level o The human organism is made up of organ systems CHEMICAL LEVEL  Lowest level, basis of biochemical reactions in human body  Matter – anything that occupies space and has mass. Composed of elements.  Each atom composed of 3 subatomic particles o Protons – positively charged subatomic particles located in center of atom  Nucleus positively charged  Number of protons – refers to atomic protons in nucleus o Neutrons - Uncharged subatomic particles  Overall charge of atomic nucleus is positive o Electrons - Negatively charged subatomic particles located on orbits surrounding nucleus  First shell can accommodate 2 electrons  Second shell can accommodate 8 electrons  Third shell can accommodate 18 electrons, atom can achieve stability at 8 electrons  Outermost shell called valence shell and electrons on shell called valence electrons.  Overall charge of atom is zero. Atom electrically neutral  Reactive atoms have valence shells that are incomplete -> form chemical bonds to achieve stability  Negative charged electrons -> anions  Positively charged electrons -> cations  Covalent Bonds – atoms share electrons to achieve stability o Nonpolar – electrons shared equally o Polar – unequal sharing of electrons  One atom pulls the shared electrons closer to itself and is referred to as electronegative atom. Other referred to as electropositive atom  Ionic Bonds – involve in complete transfer of electron from one atom to other resulting in charged particles -> ions  Hydrogen bonds – weak bonds that form between Hydrogen atoms and electronegative ions Important Compounds  Inorganic Compounds – do not contain Carbon chains o Water, Acids, Bases, and Salts  Organic Compounds – contain Carbons that are covalently- bonded o Carbohydrates, lipids, proteins, and nucleic acids. Inorganic Compounds Water  Most abundant compound in body (70% of body)  Known as universal solvent – involved in all biochemical reactions  High heat capacity – absorbs body heat o Blood- 90% water, warmer than body temp, necessary for enzymatic reactions, promote biochemical reactions. 38 degree C  High heat vaporization – water evaporates from using large amount of heat - sweating  Cushioning around organs Acids and Bases  Acids – substances that release Hydrogen ions (H+) = protons o Proton donors o Negative log of the H+ concentration = pH o The H+ concentration is inversely proportional to the pH. The higher the H+ the lower the pH. o Blood pH is strictly maintained between 7.35 – 7.45  Under 7.35 -> acidosis  Above 7.45 -> alkadosis  Changes in blood pH prevented by actions of chemicals required to be buffers.  Bases – substances that accept H+ o Proton acceptors  Acid-base balance is regulated by buffers  Chemicals that resist abrupt changes in pH by binding H+ when the pH falls and by releasing H+ when the pH rises. Salts  Salts are ionic compounds that dissociate in water to give cations and anions  Ions in solutions referred to as electrolytes, mediate many physiological processes. Organic Compounds  Carbohydrates – hydrated carbons o Monosaccharides – building blocks  (CH2O) - general formula  Hexose  Glucose  Fructose  Galactose  Pentose  Deoxyribose  Ribose o Disaccharides  Composed of 2 hexose sugars  Maltose – Glucose + Glucose  Sucrose – Glucose + Fructose  Lactose – Glucose + Galactose o Polysaccharides  Composed of long chains of glucose  Storage form of glucose o Function  1-2% of cell composed of carbs  Glucose is primary cellular fuel for energy o Cells catabolize glucose via glycolysis to produce energy o Pentose -> forms backbone of nucleic acids o Glucose attached to lipids -> glycolipids o Glucose attached to proteins -> glycoproteins o Glycolipid + glycoprotein ->glycocalyx (changes in glycocalyx => cancerous cells)  Lipids o Hydrophobic substances insoluble in water o 4 types:  Neutral fats – composed of a glycerol backbone and 3 fatty acid chains attached o Most abundant form in human diet o Known as FAT when solid and OILS when liquid o Saturated  Single covalent bonds exist between all carbons in the chain  Solid at room temperature  Increase Low Density Lipoproteins (LDL) o Unsaturated  At least one double covalent bond in the carbon chain  Liquid at room temperature  Trans Fat – Unsaturated fats + H+ = Saturated fats  Lipoproteins – lipid protein combination o In aqueous environment lipids are transported as lipoprotein - > lipids surrounded by proteins  Named based on lipid-protein ratio  Very Low Density Lipoprotein (vLDL)  Low Density Lipoprotein (LDL)  Bad cholesterol  High Density Lipoproteins (HDL)  Good cholesterol  High level protein compared to lipid  Transport cholesterol to the liver for breakdown and elimination from the body  Triglycerides o Transported by LDLs to adipose cells in adipose tissues for storage o Most concentrated form of energy o No limit on storage by adipose cells like glygogen  Adipose tissue provide protection against trauma to organs in the body and holds them in anatomical position  Adipose capsule -> surrounds kidneys to hold in right position  Cholesterol o Inserts in the lipid bilayer of plasma membrane to stabilize the membrane. o Required for synthesis of all steroid hormones o Increase of LDL in blood will result in formation of atherosclerotic plague in the internal surface of the blood vessels  Atherosclerotic plague -> decrease lumen of the blood vessels, decrease blood flow through blood vessel causes increase in blood pressure -> hypertension  Untreated hypertension will result in heart pumping harder. Increase in size to compensate  Tight Junctions – fusion of integral proteins in plasma membrane of adjacent forming an impermeable junction  Desmosome – linker proteins extending from plaques on the cytoplasmic surface of the plasma membrane of adjacent cells interdigiate to hold the cells together and prevent their separation also known as anchoring junction  Gap Junctions – formed by hollow cylinder called connexons. Allows for the rapid transfer for ions between cells known as communication junctions  Microvilli  Minute fingerlike projections of the plasma membrane on the apical surface of cells  Function: microvilli increase the surface area of cells -> increase surface area available for absorption  Microvilli are abundant on the apical surface of cells in the small intestine where absorption of nutrients occurs  Membrane Transport  Passive Processes – substances cross the plasma membrane without any energy input o Diffusion – movement of substances from area of higher concentration to area of lower concentration; substances move down their concentration gradient  Simple Diffusion – nonpolar/hydrophobic/lipid-soluble substances diffuse through the plasma membrane  Facilitated Diffusion – transport of large/polar substance mediated by carrier proteins embedded in the plasma membrane  Substances that are polar, hydrophobic or charged can not transverse the lipid bilayer of plasma membrane  Osmosis – movement of water from area of lower solute concentration to area of higher solute concentration through semi-permeable membrane  Water moves through specific channels called aquaporins o Filtration – movement of solution from area of higher pressure to area of lower pressure; down a pressure gradient  Occurs in capillary walls and in kidneys  Active Processes – cell provides energy required to move substances across the plasma membrane o Active Transport – movement of solutes/ions from area of lower solute concentration to area of higher solute concentration; mediated by carrier proteins. Active transport exhibits saturation and specificity. Movement against concentration o Vesicular Transport  Exocytosis – movement of substances out of the cell enclosed in vesicles which fuse with membrane.  Endocytosis – movement of substances into the cell  Phagocytosis – movement of solid particles from the exterior into the cell; solid particles are enclosed in vesicles called phagosomes. Lysosomes fuse with the phagosomes to digest the phagosomes with its contents. Cells that preform phagocytosis are called phagocytes.  Pinocytosis – movement of solution into cells by enclosing the solution in vesicles  Receptor-mediated endocytosis – substances bind to specific receptors on the surface of the cell; clathrin appear where the substances are bound; coated pits form to transport substances into the cell.  Tonicity – movement of water in and out of cells can change the shape or tone of cells  Isotonic solution – concentration of solution inside and outside of the cells is the same; the same amount of water moves in/out of the cells remain uncharged  Hypertonic solution – cells placed in solution with a higher concentration than solution inside cells; water moves via osmosis from the cells; cells shrink  Hypotonic solution – cells placed in a solution with a lower concentration than solution inside cells; water moves via osmosis into cells – cells swell and eventually burst  Transcytosis – movements of substances enclosed in caveolae into a cell, across the cell and released on the opposite side of the cell.  Vesicular trafficking – intracellular movement of substances in coatmercoated vesicles from organelle to organelle within the cell  Resting Membrane Potential (RMP)  Established by the partial/selective permeability of the plasma membrane to potassium ion diffusion over sodium ion diffusion  K+ concentration is higher inside the cell than outside the cell – K+ diffuses out of the cell down its electrochemical gradient  Na+ concentration is higher outside of the cell than inside the cell – Na+ diffuses into the cell down its electrochemical gradient o Cytoplasm – the interior of the cell between the plasma membrane and the nucleus; contains the cytoplasmic organelles. Composed of cytosol, cytoplasmic organelles, and inclusions.  Cytosol – the viscous, semitransparent fluid  Cytoplasmic organelles – specialized subcellular compartments with specific functions  Mitochondria o Threadlike membranous organelles constantly changing their shapes o Contain own DNA and are self-replicating o Composed of 2 membranes enclosing a fluid matrix  Inner and outer o Resident enzymes of the cristae and the matrix breakdown food in the presence of oxygen to release energy o Number of mitochondria in cell reflects energy demands of cell. o One molecule of glucose, aerobically = 36 ATP  Ribosomes o Each ribosome composed of 2 globular subunits  Small ribosomal subunit  Large ribosomal subunit o Each subunit consists of protein and rRNA o 2 types  Free ribosomes – float freely in the cytosol and synthesize proteins that stay in the cell  Bound ribosomes – bound to the surface or rough ER and synthesize proteins that are transported to the plasma membrane or for export out of the cell  Endoplasmic reticulum (ER) o Composed of meandering membranous channels enclosing fluid-filled cavities called cisternae o 2 types  Rough ER – external surface is studded with ribosomes (bound). These ribosomes synthesize the plasma protein and secretory proteins.  Membrane factory – synthesis of integral proteins and phospholipids in plasma membranes is associated with the rough ER  Smooth ER – devoid of ribosomes. Membrane bound enzymes catalyze  Synthesis of fats – cholesterol and steroid hormones  Fat absorption, transport, and metabolism  Glycogenolysis which results in energy production  Detoxification of drugs and carcinogens o Liver and kidney cells have abundant smooth ER  Golgi apparatus – composed of stacked/flattened membranous sacs o Receives proteins and lipids from the rough ER o Traffic Director - Golgi modifies, packages, and tags proteins and lipids to their specific destinations. o 3 types of vesicles  secretory vesicles which contain proteins released via exocytosis  vesicles that contain integral proteins and lipids destined for the plasma membrane to incorporated into the plasma membrane  vesicles containing powerful digestive enzymes that remain in cells = lysosomes  Lysosomes – spherical membranous organelles- contain powerful digestive enzymes that digest vesicles and biological molecules o Functions – demolition crew  Digest phagosomes hence, lysosomes are abundant in phagocytes  Digest worn-out organelles  Stimulate glycogenolysis  Involved in bone reabsorption to release calcium  Peroxisomes – membranous sacs that contain powerful enzymes that neutralize harmful free radicals o 2 kinds of enzymes  Oxidases  Catalases  Cytoskeleton – non membranous rod-like structures that support other cytoplasmic organelles and allow for movements in cells o 3 types