mid session exam Flashcards
define anatomy
the scientific discipline that investigates the body’s structure
define physciology
scientific investigation of the processes or functions of living things
define the body’s levels of organisation
chemical level: interaction of atoms
cell level: functional unit of life
tissue level: group of similar cells and the materials surrounding them
organ level: one or more tissues functioning together
organ system level: group of organs functioning together
list the organs systems and give a brief description of their functions
cell physiology: examines processes in cells
systemic physiology: function of organ systems
neurophysiology: focuses on the nervous system
cardiovascular: the heart and blood vessels
define homeostasis and explain its importance, as well a variable and set point
homeostasis: the existence and maintenance of a relatively constant environment within the body
importance: maintains optimal conditions for enzyme action throughout the body and all cell functions.
values/variables fluctuate around the set point to establish a normal range of values
set point: the ideal normal value of a variable
in the context of homeostasis, explain negative and positive feedback
negative feedback: any deviation from the set point is made smaller (resisted), e.g. regulation of blood pressure, body temperature, blood sugar levels
positive feedback: when a deviation occurs, the response is to make the deviation greater, e.g. childbirth
describe the anatomical position and use correct anatomical terminology to describe body directions, regions, sections/planes, body cavities and associated membranes
anatomical position: body erect, face forward, feet together, palms face forward
supine: lying face upward
prone: lying face downward
directional terms:
- superior (cephalic) vs inferior (caudal)
- medial vs lateral relative to the midline
- proximal vs distal used to describe linear structures
- superficial vs deep relative to the surface of the body
- anterior (ventral) vs posterior (dorsal), anterior is forward and posterior is toward the back
body planes:
- median (through the midline) and sagittal (same plane, but to the left or right of median)
- frontal or coronal divides the body into anterior and posterior sections
transverse/cross divides body into superior and inferior sections
- oblique: other than at a right angle
planes of section through an organ:
- longitudinal: cut along the length of an organ
- cross/transverse: cut at right angle to length of the organ
- oblique: cut at any but a right angle
trunk cavities:
- diaphragm: divides the body cavity into thoracic and abdominopelvic cavities
- mediastinum: contains all structures of the thoracic cavity except the lungs
serous membrane:
- cover the organs of trunk cavities and line the cavity
- fist represents an organ
- inner balloon wall represents visceral serous membrane
- outer balloon wall represents parietal serous membrane
- cavity between two membranes filled with lubricating serous fluid that is produced by the membranes
- pericardium refers to the heart
- pleura refers to lungs and thoracic cavity
- peritoneum refers to abdominopelvic cavity
define matter, mass, element and atom
matter: anything that occupies space and has mass
mass: the amount of matter in an object
element: the simplest type of matter with unique chemical properties; composed of atoms of only one kind
atom: smallest particle of an element that has chemical characteristics of that element
describe atomic structure in terms of the three main subatomic particles and determine atomic number and mass number
atoms composed of subatomic particles
- neutrons no electrical charge
- protons one positive charge
electrons one negative charge
atomic number: equal to number of protons in each atom, which is equal to the number of electrons
mass number: number of protons plus number of neutrons
define isotope, atomic mass, describe Avogadros number and define mole and molar mass
isotope: two or more forms of same element with same number of protons and electrons but different neutron number
atomic mass: average mass of naturally occurring isotopes
Avogadros number: displays number of units in one mole solution, 6.022 x 10^23
mole: Avogadros number of atoms, ions, molecules
molar mass: mass of one mole of a substance in grams, which is equal to its atomic mass units
describe ionic and covalent bonding and hydrogen bonds
ionic bonding: atoms exchange electrons, are formed when a valence outer shell electron is transferred from one atom to another - much weaker
covalent bonding: two or more atoms share electron pairs, is stronger because the 2 atoms involved share 2 or more outer shell electrons
hydrogen bonds: occur when the positively charged H of one molecule is attracted to the negatively charged O, N or F of another molecule.
distinguish between the different types of chemical reactions and the formulae used to describe them
synthetic reactions: two or more reactants chemically combine to form a new and larger product - anabolism
decomposition reactions: a large reactant is broken down to form smaller products - catabolism
reversible reactions: chemical reactions in which the reaction can proceed with from reactants to products or from products to reactants
describe what enzymes are and how the body uses enzymes to regulate chemical reactions
enzymes (biological catalysts) proteinaceous catalysts that increase the rate of chemical reactions by lowering the activation energy necessary for reaction to begin
regulated through: temperature, concentration, catalysts
define anabolism, catabolism and metabolism
anabolism: the constructive part of metabolism concerned especially with macromolecular synthesis
catabolism: molecules break down in the body for use as energy
metabolism: a chemical reaction that occurs in the body’s cells to change food to energy
distinguish between a mixture and a solution
mixture: substances physically but not chemically combined (suspension - materials separate unless stirred, colloid - dispersal of tiny particles through a medium)
solution: mixture of liquids, gasses, or solids that are uniformly distributed and chemically combined (solvent: that which dissolved the solute, solute: that which dissolves the solvent)
explain the different ways in which solution concentration can be expressed
percent: weight of a solute in a given volume of solvent
equivalents: a measure of the concentration of an ionised substance
molarity: number of moles of solute dissolved in 1 litre of solvent
osmolarity/osmolality: molarity x number of particles into which the solute dissociates
briefly describe the role of electrolytes in the body
molecules or ions with an electrical charge
obtained by ingestion/diet
removed by kidneys, liver, skin, lungs
regulated by homeostatic mechanisms
help the body to regulate fluids and maintain the balance between fluids inside and outside cells
describe what acids, bases and buffers are, and how pH effects the human body
acid: a proton donor or any substance that releases hydrogen ions
base: a proton acceptor or any substance that binds to or accepts hydrogen ions
buffer: a solution of a conjugate acid-base pair in which acid and base components occur in similar concentrations
pH can disrupt the body’s balance, which can lead to the development of bacteria, viruses, fungi, yeasts and parasites.
describe the structure of proteins and nucleic acids and explain why they are important in the human body
proteins: composed of carbon, hydrogen, oxygen, nitrogen, sometimes iodine. functions: regulate processes, aid transport, protection, muscle contraction, structure, energy
nucleic acids: composed of carbon, hydrogen, oxygen, nitrogen, phosphorus
importance: carry the genetic blueprint of a cell and carry instructions for the functioning of the cell
describe glycolysis
anaerobic respiration, breaking down glucose into 2 ATP molecules
describe the major steps in lactic acid fermentation
where glucose is converted into cellular energy and the metabolic lactate
describe the major steps in aerobic respiration
includes citric acid cycle and electron transport chain
creates 38 ATP molecules
define glycogenesis, lipogenesis, glycogenolysis and gluconeogenesis
glycogenesis: excess glucose used to form glycogen
lipogenesis: when glycogen stores filled, glucose and amino acids used to synthesise lipids
glycogenolysis: breakdown of glycogen to glucose
gluconeogenesis: formation of glucose from amino acids and glycerol
differentiate between the absorptive and post absorptive metabolic states
absorptive state: (storage) period immediately after eating when nutrients absorbed through intestinal wall into circulatory and lymphatic systems
postabsorptive state: (breakdown) occurs late morning, afternoon, night after absorptive state concluded, blood glucose levels maintained by conversion of other molecules to glucose
define the term microbiology
is the study of microbes, either living organisms or non-living entities that cannot be seen with the naked eye
discuss some of the applications of microbiology as well as the present and future challenges in medical microbiology
applications: - food production - bioremediation - use organisms to degrade environmental waste - synthesis of numerous products - genetic engineering - introduces genes of one organism into an unrelated organism to confer new properties on the organism future challenges: - infectious disease - COVID-19 pandemic - emerging diseases - resurgence of old diseases
define the living organisms that exist in the microbial world
prokaryotes are unicellular, simple cells, dont have a nucleus
eukaryotes are multicellular, contain organelles, have a membrane-bound nucleus
name the three domains of all living organism and the properties that distinguish them from one another
three domains: organisms in each domain share certain disgusting properties
- bacteria
- archaea
- eucarya
describe the classification and structure of the algae, protozoa and fungi
algae: a diverse group of eukaryotic organisms, use light to convert carbon dioxide and water to carbohydrates, includes both microscopic unicellular and macroscopic multicellular organisms
protozoa: microscopic unicellular organisms, lack photosynthetic capability, usually motile, usually transmitted by ingesting contaminated food or water, can be difficult to treat
fungi: eukaryotes with a cell wall, yeast - unicellular, moulds - multicellular, cells organised into string, some fungi can exist as yeast or mould
define taxonomy and describe how microorganisms are classified
is the science of naming, describing and classifying organisms
identification: process of characterising in order to group them -microscopy, culture characteristics and other tests
classification: arranging organisms into smaller or related groups
nomenclature: system of assigning names
describe the 3 types of infectious agents
vector: a living organism that transmits an infectious agent
direct: spread when disease-causing microorganisms pass from the infected person to healthy person via direct physical contact
indirect: spread when an infected person sneezes or coughs, sending infectious droplets in the air
distinguish between viruses, viroid and prions and discuss the reasons why they are not organisms
viruses: non-living entities that can infect organisms of every domain. commonly referred to by organism they infect
prions: are non-cellular infectious particles, appear to consist of miss-folded protein
viroids: are infectious pieces of nucleic acid that infect plants
not living entities
what does the term ‘normal flora’ mean?
defined as populations of microorganisms routinely found growing on the body of healthy individual
describe the types of relationships that exist between microorganisms and their hosts
mutualism: association in which both partners benefit
commensalism: association in which one partner benefits and other is unharmed
parasitism: association in which the microbe benefits at expense of the host
explain the difference between resident flora and temporary flora
resident flora: typically inhabits body sites for extended periods
temporary flora: transient, they form associations for a short time and are replaced
describe the functions of normal flora and how they are influenced
protection against potentially harmful organisms - normal flora competitively excludes pathogens through covering binding sites used for pathogenic attachment, consume available nutrients, produce toxic compounds such as antibodies
stimulate immune system: response mounted against normal flora that breaches bodys anatomical barriers, may cross-react with pathogen encountered later
list the locations of the body where you would find high populations of normal flora
GI tract
Genitourinary system
respiratory system
skin
what are pathogens and opportunistic pathogens?
pathogens are organisms that can cause disease in otherwise healthy people
opportunistic pathogens are microbes that cause disease when the bodys defences are down
define virulence and infectious dose
virulence is a quantitative term referring to a pathogen disease-causing the ability
infectious dose is the number of organisms required to establish infection
describe the course of infectious disease
incubation: the time between the introduction of an organism to the onset of symptoms, the incubation period depends on numerous factors
illness: follows incubation, individual experiences signs and symptoms of the disease
convalescence: period of recuperation and recovery, infectious agents may still be spread
what does the suffic -anemia mean
blood
briefly describe the mechanisms of pathogenesis that microbes utilise
production of toxins that are ingested
the colonisation of the surface of the host followed by toxin production
invasion of host tissue
invasion of host tissues followed by toxin production
what are the 3 steps that are necessary for the establishment of infection?
adherence
colonisation
delivery of effector molecules to host cells