RAD 105 EXAM 1 2025

Microorganisms that cause infectious diseases can be classified as: a. lytic. b. endogenous. c. pathogenic. d. nosocomial - Correct Answer-c. pathogenic. The best method of preventing the spread of aerosol infections is by: a. the patient wearing a mask. b. the health care worker wearing a gown. c. hand washing. d. all of the above - Correct Answer-a. the patient wearing a mask. All of the following are types of indirect transmission EXCEPT: a. fomite. b. vector. c. aerosol. d. touching. - Correct Answer-touching. The common cold is an example of an infection by a: a. bacterium. b. virus. c. fungus. d. protozoan - Correct Answer-b. virus The term that best describes the absolute removal of all life forms is: a. antisepsis b. medical asepsis c. disinfection d. sterilization - Correct Answer-d. sterilization A person is bitten by a mosquito and develops an infection. This type of transmission is known as a. vector b. fomite c. nosocomial d. iatrogenic - Correct Answer-a. vector A health care worker is accidentally punctured with a contaminated needle. This type of transmission is known as: a. vector b. fomite c. nosocomial d. iatrogenic - Correct Answer-b. fomite An outpatient develops a staphylococcal infection after a surgical procedure. This type of transmission is known as: a. vector b. fomite c. nosocomial d. more than one of the above, but not all - Correct Answer-d. more than one of the above, but not all An infectious microbe can gain entrance into the human body by: a. ingression b. penetration c. both a and b d. neither a nor b - Correct Answer-c. both a and b (ingression & penetration) Hand washing uses which of the following methods of infection control? a. chemical b. physical c. sterile d. a and b - Correct Answer-d. a and b (chemical & physical) Infection - Correct Answer-Establishment and growth of a microorganism on or in a host, resulting in injury to the host Caused by pathogenic organisms RAD105 RAD105 Pathogens have three functions Pathogens have three functions - Correct Answer-They can multiply in large numbers can cause an obstruction Cause tissue damage Secrete organic substances called Exotoxins Exotoxins cause side effects - Correct Answer-High body temp (Fever) Nausea Vomiting Shock Types of Pathogens - Correct Answer-Bacteria Viruses Fungi Parasitic protozoa Bacteria - Correct Answer-Microscopic, single celled organisms Prokaryotes—lack nuclei and membrane bound organelles Reside in host as a group or cluster called a colony Classified into three morphologies: cocci or spheres, bacilli or rods, and spirals Gram staining—staining technique to classify bacteria Contains both DNA and RNA Produce endospores: Internal Metabolically dormant and highly resistant to external environment Possess extreme resistance to chemical and physical agents Remain viable for many years and germinate in response to specific requirements Viruses - Correct Answer-Microscopic, single cells Cannot live outside a living cell—lack components for own survival Carry their own DNA or RNA but never both A protein coat called a capsid surrounds the viral DNA or RNA Viral Infection caused by a viral particle (virion) attaches to host cell, inserts its own genetic information, and then redirects host cell to produce new viruses. Not affected by antibiotics Size of a virus may vary from 20 to 250 nm. Direct observation of a virus is possible only through an electron microscope. May lie dormant for extended periods of time and then manifest in illness. Fungi - Correct Answer-Eukaryotic (has nucleus and membrane bound organelles) Size much larger than bacteria Medically important fungi are called dimorphic. Two forms: yeast and molds Diseases caused by fungi can be of four different classifications: Superficial RAD105 RAD105 Cutaneous Subcutaneous Systemic Parasitic Protozoa - Correct Answer-Unicellular organisms are neither plant nor animal. Larger than bacteria Eukaryotic Classified by their motility Live on or in other organisms at expense of host Usually have motile functionality Can ingest food particles, and some are equipped with digestive systems Establishment of Infectious Disease - Correct Answer-Categorized into 6 steps: Encounter Entry Spread Multiplication Damage Outcome Encounter - Correct Answer-Involves the infectious organism coming in contact with the host Each encounter varies according to the host and microorganism. Entry - Correct Answer-Access to the organism through a portal of entry Entry may be one of two types: ingression or penetration. Spread - Correct Answer-The propagation of the infectious organism Requires overcoming body's immune defenses Degree of spreading is a function of the logistics of both the host and the microbe. Multiplication - Correct Answer-The growth in microbe numbers as a function of mitosis Many infectious agents undergo great multiplication before their impact is recognized by the host. Incubation period Damage - Correct Answer-Damage can be either direct or indirect. A microbe can induce a host response that also causes tissue and cell death through activation of the host's inflammatory and immune responses. Outcome - Correct Answer-Results in any of three outcomes Host gains control of the infectious agent and eliminates it Infectious agent overcomes host's immunities to cause disease Host and infectious agent compromise and live in a sort of symbiotic state Chain of Infection - Correct Answer-Hos