It is possible to distinguish histologically between the stomach and the duodenum because of the presence of
A)
Stomach:
- simple columnar
- rugae- folds in stomach that accomodate expansion
- produces chyme
4 types of cells located throughout the mucosa, but not submucosa
1.mucous cells
2. chief cells- pepsinogen
3. parietal cells- HCl and intrinsic factor
4. enteroendocrine cells (APUD) cells- gastrin
In a dry-heat oven, which of the following temperatures is aufficient for achieving sterilization in 1-2 hours?
A)
Dry Heat
160 degrees C (320 degrees F) for 2 hours
OR 170 degrees for 1 hour
- denatures proteins
Pros:
- doesn't corrode/dull instruments
Cons:
- ruins heat-sensitive materials; instruments must be DRY bc water interes w/ sterilization
The MOST important viral cause of gastroenteritis in children less than 2 old is
E) Rotavirus
"Repeat-o-virus"; a REOVIRUS= dsRNA
ROTA= Right Out of The Anus
*** MOST imp global cause of infantile gastroenteritis
- acute diarrhea, esp in day-care centers, kindergartens during winter
Rubella and toxoplasmosis are similar in that both
A) are prevented by vaccinations.
B) are potentially teratogenic.
C) can not be treated with antibiotics.
D) primarily affect the elderly.
E) have non-human animal reservoirs
Maternal Infection Teratogens:
TORCH complex
1. Toxoplasmosis- parasitic disease caused by protozoan Toxoplasma gondii
- primary host is cat
- usually from infected meat or eating infected cat feces
- rarely causes symptoms in healthy people--> many enter latent phase
- acute phase- flu-like
- immunocompromised: encephalitis, neurologic, heart and liver problems
- Most infants who are infected while in the womb have no symptoms at birth but may develop symptoms later in life
2. other agents
3. Rubella
4. CMV
5. HSV
The apical cytoplasm of active serous glandular cells is typically filled with which of the following?
C) abundance of zymogen granules
- basal processes (closest to lumen) are rich w/ MITOCHONDRIA- provide E for ion transport
What is the composition of saliva?
- hypotonic
- enzymes: 1) amylase 2) lysozyme (antibacterial
- antibodies (IgA mostly)
- inorganic ions
- serous cells secrete fluid ISOTONIC w/ plasma
Which of the following BEST characterizes the alveolar mucous membrane?
D)
The majority of cases of pharyngitis are caused by
A)
A fungus that causes systemic disease, most commonly of the lungs, and is characterized by its production of tuberculate chlamydospores in culture is
A)
4 Systemic Mycoses:
- dimorphic fungi (mold in soil, yeast in tissue) except coccidiodomycosis
- Mold= cold; Heat=yeast
- all can cause PNEUMONIA and DISSEMINATE
- SYSTEMIC MYCOSES mimics TB (granulomas)
Tx: fluconazole or ketoconazole
1. Histoplasmosis- causes pneumonia
- Mississippi and Ohio R. Valleys
- bird or bat droppings
- intracellular (tiny yeast inside macrophages)
*** "Histo"="histiocyte" tissue macrophage
2. Blastomycosis= Big, Broad, Budding
3. Coccidiomycosis- California
- pneumonia and meningitis
- SPHERULE filled w/ endospores
- valley fever
Each of the following is a risk factor in atherosclerosis EXCEPT one. Which one is this EXCEPTION?
D) Alcoholism
Risks for atherosclerosis:
1. Smoking
2. Men and postmenopausal women (low estrogen)
3. HTN
4. heredity
5. nephrosclerosis (secondary HTN)
6. Diabetes
7. Hyperlipidemia (higher LDL= bad)
- most common sites:
- CAD (heart)
- abdominal aorta
Cementum differs from dentin in that cementum
B)
B is incorrect because dentin is 70% inorganic and enamel is 55% inorganic (mineralized)
Excessive deposits of copper in liver cells, degenerative changes in the brain, and a greenish-brown ring at the outer margin of the cornea characterize which of the following?
A) Diabetes mellitus
B) Tay-Sachs disease
C) Phenylketonuria
D) Wilson's disease
E) Galactosemia
Wilson's Disease
- autosomal recessive- mutations in wilson disease protein
- Cu accumulates in tissues
- hepatolenticular degeneration
- liver disease
- neurological symptoms
-Cu in LIVER and BRAIN
Which of the following represents the major pathway for metabolism of excessive intraneuronal free norepinephrine?
D)
A subject consumes 250 ml of oxygen per minute with a tidal volume of 400 ml and a respiratory rate of 18 per minute. Which of the following represents this subject's respiratory minute volume in liters?
A) 5.4
B) 7.2
C) 10.0
D) 1.8
E) 4.5
B. 7.2
respiratory minute volume= 0.4 L x 18 breaths/min= 7.2
Which of the following types of tissues can be demonstrated on the posterior slope of the articular eminence?A) Fibrocartilage
B) Fibrous connective tissue
C) Elastic cartilage
D) Hyaline cartilage
E) Articular cartilage
B) fibrous connective tissue
MOST fluid reabsorption by the kidney occurs in which of the following?
C) Proximal Tubule
A hemorrhagic tendency is seldom seen in which of the following conditions?
A) Hepatic insufficiency
B) Secondary thrombocytopenia
C) Acute leukemia
D) Renal insufficiency
E) Scurvy
A) hepatic insufficiency- bc it makes clotting factors
B) low platelets= increase bleeding time
C) acute leukemia= pancytopenia; low platelets increase bleeding time
E) Scurvy- Vit C deficiency; get bleeding esp gums
The finding of yeast cells and chlamydospores in the oral mucosa suggest which of the following?
D) Candida Albicans
- chlamydospore- thick-walled big resting spore of several kinds of fungi. It is the life-stage which survives in unfavourable conditions, such as dry or hot seasons.
Streptococcus pyogenes, group A, is subdivided into specific antigenic types principally on the basis of immunologic differences in its
C) M Protein
Which of the following are MOST antigenic?
E) Proteins
Hapten- "half an antigen"- a small molecule that can elicit immune response only when attached to a larger carrier (like a protein)
Which of the following represents a DNA gyrase inhibitor with a broad spectrum of activity?
B) Ciprofloxacin/Ofloxacin
- 2nd gen Fluoroquinolone class
- It kills bacteria by interfering with the enzymes that cause DNA to rewind after being copied, which stops DNA and protein synthesis (DNA gyrase/topoisomerase)
- Bactericidal
- AEROBIC/facultative gram + and - and mycobacteria; NOT ANAEROBES
A 6-year-old boy has minute white specks on the oral mucosa adjacent to his first molars. A bluish-red ring surrounds these spots. He appears to have a cold and his eyes are red and runny. There is a blotchy reddish rash behind his ears and on his face. This child has which of the following?
A) MeaslesB) ChickenpoxC) Scarlet feverD) Eczema
A) Measles/Rubeola- a Paramyxovirus
- Koplik spots- red spots with white centers on buccal mucosa
- rash
3 C's of Measles:
1. cough
2. coryza- inflammation of mucous membranes
3. conjunctivitis
What condylar movement is performed as the mandible moves from a pure protrusive movement from maximum intercuspal position to a maximum protruded position?
C) Translation
The absolute refractory period of a nerve action potential is determined by the duration of which of the following?
B)
3 phases of Na+ gate:
- deactivated (closed)- blocked on their intracellular side by an "activation gate", which is removed in response to stimulation that opens the channel.
- activated (open)
- inactivated (closed)
- local anesthesia favors activated and inactivated states--> rapidly firing
In an ideal intercuspal relation, the oblique ridge of the maxillary first molar opposes which structure of the mandibular molar?
C)
In anemia resulting from drug-induced bone marrow suppression, the peripheral blood smear shows erythrocytes to be
E)
In protrusive movement, the mandibular canines in a Class II occlusal relationship articulate with which of the following maxillary teeth?
C) Canines and lateral incisors
In an ideal intercuspal relation, the mesiofacial cusps of the mandibular second molars contact the maxillary molars in (on) the
E)
The growth rate in the cartilage of the epiphyseal plate of a long bone is markedly retarded when there is a lack of hormone from which of the following?
D) hypophysis= pituitary gland!
- adenohypophysis= anterior pituitary
-->B-FLAT (basophophils) and GH, Prolactin, endorphins (acidophils)
- neurohypophysis= posterior pituitary
--> oxytocin and ADH/vasopressin
Regulation of each of the following mechanisms is associated with the hypothalamus EXCEPT one. Which one is this EXCEPTION?
B)
Which of the following is an antimicrobial agent that primarily inactivates cellular DNA
D) Ethylene oxide gas
- sterilization method
- sterilization is slow 10-16 hours
- inactivates DNA and proteins
Pros:
- used mostly in HOSPITALS for heat-sensitive materials
Cons:
- long time
- VERY TOXIC and flammable; need good ventilation
A. chlorhexidine- inhibits plaque gingivitis (most potent inhibitor)
- Peridec, Perioguard
- stains teeth, alters taste perception
B. Glutaraldehyde (2%)- sterilization
- alkylates nucleic acids and proteins
- takes 10 hours--> used for respiratory equipment
- most potent CHEMICAL germicide
- associated w/ HYPERSENSITIVITY
Which of the following BEST describes the Curve of Spee?
B)
Which of the following has a high affinity for binding calcium and collagen in the calcifying matrix?
E) Osteonectin
- glycoprotein in bone that binds calcium and has high affinity for collagen
- secreted by osteoblasts during bone formation
- vital in bone mineralization, cell matrix interactions, collagen binding
- increases activity of matrix metalloproteinases (imp for invading cancer cells in bone)
- overexpressed in many cancers (e.g. breast, prostate, colon)
In a Class II occlusal relationship, the tip of the facial cusp of a mandibular first premolar lies directly below the contacting area between which maxillary teeth?
D)
Which of the following represents a striated muscle that contains transverse tubules, a slow rate of calcium sequestration, and is inhibited by acetylcholine?
B)
T-tubules are less developed
- slow rate of Ca2+ sequestration to ensure ventricles can fill up
- Ach parasympathetics decrease its activity
- sympathetics (Epinephrine) increases activity
Which of the following causes activation of the pyloric pump, relaxation of the pylorus, and contraction of the lower esophageal sphincter?
