Problem Sets and Quizzes Flashcards
What is the correct sequence reflecting the pathway of recycling RBC heme to bilirubin?
a) RBC > liver > spleen > kidney > intestine > blood stream
b) RBC > spleen > liver > biliary system > intestine > blood stream
c) RBC > liver > biliary system > spleen > intestine > blood stream
d) RBC > spleen > kidney > intestine > blood stream
b) RBC > spleen > liver > biliary system > intestine > blood stream
The liver produces all of the following except:
- bile
- clotting factors
- albumin
- erythropoietin (hormone that stimulates RBC production)
- cholesterol
- Synthesizes all of the above
-Synthesizes all of the above
Bile contains all of the following except:
- bile salts
- cholesterol
- heme metabolism products
- drug metabolites
- contains all of the above
Contains all of the above
The pancreas develops from fusion of dorsal and ventral pancreatic buds during development. The main pancreatic duct merges with which of the following, followed by exit through the Ampulla of Vater?
- cystic duct
- hepatic duct
- common bile duct
- Sphinchter of Oddi
Common bile duct
Which are common reasons for physiologic neonatal jaundice? More than one answer may be correct.
- Immaturity of the liver UGT enzyme involved in heme metabolism
- Increased RBC breakdown from the trauma of birthing process
- Increased RBC turnover due to shorter fetal RBC lifespan
- Breast feeding jaundice
- hereditary spherocytosis
- Immaturity of the liver UGT enzyme involved in heme metabolism
- Increased RBC turnover due to shorter fetal RBC lifespan
All of the following are true about the red blood cell EXCEPT:
- Normally, RBCs are biconcave
- In hereditary spherocytosis, the surface area of RBCs is increased
- the average lifespan of RBCs is ~100 to 120 days
- RBC quality is assessed and discriminated in the spleen where the reticuloendothelial cells like splenic macrophages ingest the least deformable RBCs
In hereditary spherocytosis, the surface area of RBCs is increased
Most gallstones on x-ray are radio-lucent (black) but in hereditary spherocytosis, the excessive bilirubin complexes with a substance to produce radio-opaque (white) signal on a plain x-ray. What substance?
- Bile
- Intrinsic factor
- Calcium
- Drug metabolites
- Erythropoietin
Calcium
This vessel, the _______ emerges from the spleen to merge with the ____________ which drains the hindgut-derved organs and the _________ which drains the foregut and midgut-derived organs like the duodenum ileum and jejunum to form the _________
splenic vein; inferior mesenteric vein; superior mesenteric vein; portal vein
Which of the following is not a consequence of untreated jaundice?
- acute bilirubin encephalopathy
- hearing loss
- diarrhea
- cerebral palsy
Diarrhea
Which of the following is not a function of bicarbonate secreted by the pancreas?
- Neutralization of gastric acid arriving at the duodenum
- Provide ideal pH for pancreatic enzymes
- Inhibit the activity of pepsin
- Stimulate the secretion of CCK
Stimulate the secretion of CCK
On which trimester is the major period of neurogenesis?
First trimester
Development of human brain cortex involves which of the following? More than one may be correct.
- Radial glial cells are neuronal stem cells
- Asymmetric division of radial glial next to the ventricular zone generates neurons and glia
- Migration of neurons along radial glial cells towards distal signals emanating from the meningeal layer
- The youngest layer of cortical neurons is next to the ventricular zone
- All of the above
- Radial glial cells are neuronal stem cells
- Asymmetric division of radial glial next to the ventricular zone generates neurons and glia
- Migration of neurons along radial glial cells towards distal signals emanating from the meningeal layer
In rare genetic forms of microcephaly, culprit genes like CENPJ and ASPM are connected to which category of gene function?
- Cell migration
- Cell division
- Cell specialization
- Neuron survival
Cell division
Which of the following viruses covered in the presentation is known to cause malformation of the CNS? More than one answer may be correct.
- Influenza virus
- Zika virus
- Rubella virus
- Cytomegalovirus (CMV)
- None of the above
- Zika virus
- Rubella virus
- Cytomegalovirus (CMV)
Zika virus is thought to infect what cells in the CNS?
Radial glial cells
Recent work by several groups demonstrates that cells infected by zika virus in the placenta, eye and developing brain express the receptor encoded by the AXL gene. The conclusion that AXL-expressing cells are susceptible to zika infection from this evidence is based on which feature? (correlation, necessity, sufficiency, both correlation and sufficiency)
Correlation
If an AXL-knock out cell line is created and Zika infection does not occur in the cell line upon exposure, what concept does this demonstrate? (N, S, N and S, and C)
Necessity
Signaling from the meninges direct migration of neurons along radially-oriented glial cells. One such signal is:
- Prostaglandin D3
- Semaphorin
- Ptx3
- Somatostatin
Semaphorin
Shepard’s criteria is principally based on which concept?
Correlation
AXL encodes one of several suspected zika virus receptors. What functional class of protein is encoded by AXL?
Tyrosine kinase
The value of experimental models of organ development from isolated cells is demonstrated from studies of zika virus infection in human organoids. Compared to the native developing human cortex as the standard, which features are reconstituted in organoids? More than one answer is possible.
- Presence of key cell subsets including neural stem cells, neurons and glia
- Reconstitution of meningeal and cortical layering
- Infection of radial glial cells that express AXL, like in native developing cortex
- Reduction of growth accompanied by cell death after zika virus infection
- All of the above
- Presence of key cell subsets including neural stem cells, neurons and glia
- Infection of radial glial cells that express AXL, like in native developing cortex
- Reduction of growth accompanied by cell death after zika virus infection
The ‘Philadelphia’ chromosome in chronic myelogenous leukemia represents a fusion that brings together which two genes that are normally not adjacent to each other?
Bcr and abl
You are an investigator studying cancer therapeutics and you notice that dramatic regression and shrinkage of tumors occurs in patients with mutations in the kinase domain of a membrane receptor.
These mutations produce alleles of the receptor that are_______
Activating
You are an investigator studying cancer therapeutics and you notice that dramatic regression and shrinkage of tumors occurs in patients with mutations in the kinase domain of a membrane receptor.
Thus, you hypothesize that your compound has which effect on the mutant receptor?
Inhibits activity
You are an investigator studying cancer therapeutics and you notice that dramatic regression and shrinkage of tumors occurs in patients with mutations in the kinase domain of a membrane receptor.
You have generated cell lines with the kind of mutation you observe from patients who respond to the compound. What manipulation would retard growth of the cell line?
- Inhibition of the RNA encoding the tyrosine kinase by RNAi to prevent protein production
- Increased expression of the mutant tyrosine kinase
- Neither A nor B
- Increased cell death
-Inhibition of the RNA encoding the tyrosine kinase by RNAi to prevent protein production
You are an investigator studying cancer therapeutics and you notice that dramatic regression and shrinkage of tumors occurs in patients with mutations in the kinase domain of a membrane receptor.
For those cell lines from unresponsive patients, what effect on growth will RNAi-based inhibition of the RNA encoding the tyrosine kinase likely have?
No effect on growth
Which of these is correct regarding the interstitial cells of Cajal?
- Represent primordial gut cells that herniate outside the fetal body in week 6 of development and completely regress by week 10
- Are precursor cells to gastrointestinal stromal tumors that can be treated by targeting Bcr-abl
- May fail to migrate to their appropriate location in the GI tract during development, leading to the classic symptoms of Hirschprung disease
- Are regulated by c-kit, a kinase receptor for kit-ligand, in which activating mutations of c-kit lead to gastrointestinal stromal tumors
Are regulated by c-kit, a kinase receptor for kit-ligand, in which activating mutations of c-kit lead to gastrointestinal stromal tumors
Gleevec (imatinib) targets the tyrosine kinase gene fusion in chronic myoelogenous leukemia encoded by the Philadelphia chromosome
True or False:
Gleevec has activity against other tyrosine kinase receptors including the c-kit and PDGF receptor.
True
True or False:
The effect of Gleevec is sustained leading typically to decased or longer remission in CML
False
What is one mechanism for the possible resistance that patients may develop to Gleevec after initial response?
Second mutation
Which of the following factors can be passed from maternal to fetal circulation?
- Insulin
- Glucose
- C-peptide
Glucose
Poorly controlled diabetes in the mother is a major cause of fetal malformation or abnormal metabolism. What is one example of such malformation?
Macrosomia
All of the following are consistent with a diagnosis of congenital hypothyroidism, except:
- Weight less than 10th percentile for age
- Protruding tongue
- Radiographic evidence of thyroid tissue under the tongue
- Reduced TSH levels
Reduced TSH levels
In a mother with gestational diabetes, what is the relative level of insulin in the fetus compared to one in a diabetic mother?
Increased
A six-week old male presents with lethargy and hypotonia. On physical exam he is slightly jaundiced and has an umbilical hernia and a large protruding tongue. Which of the following may have contributed to his condition?
- Annular pancreas
- Iodine overload
- Maternal diabetes
- Thyroid disgenesis
- Hirschprung disease
Thyroid dysgenesis
A newborn baby weighing 10 pounds and 13 ounces is irritable and displays poor feeding, and seems to be breathing quickly. On a physical exam the baby is also slightly jaundiced. Which of the following may have contributed to this condition?
- Hirschprung disease
- Iodine overload
- Maternal diabetes
- Thyroid dysgenesis
- Hepatitis A infection
Maternal diabetes
The following factor can be passed from maternal to fetal circulation:
- TSH
- T3
- T4
- Iodine
Iodine
Iodine is added to T3 and T4 to produce bioactive thyroid hormone. This ‘organification’ is stimulated by:
- Chemial association of iodine with T3 and T4
- Thyroid enzymes
- Low TSH
- Low glucose
Thyroid enzymes
Mandatory newborn screening involves blood tests for all except:
- Inborn errors of metabolism
- Hemoglobin defects like sickle cell disease
- HIV infection
- Hyperthyroidism
HIV infection
Thyroid function is regulated by feed back loops involving input from the pituitary. The following states reflect this normal regulation, except:
- Low TSH, high T3 and T4
- Normal TSH, Normal T3 and T4
- Hight TSH, low T3 and T4
- High TSH, high T3 and T4
High TSH, high T3 and T4
Which stage serves as the major point that divides preembryonic and embryonic development?
Gastrulation
Mesoderm gives rise to:
- lens of the eyes
- epidermis of the skin
- neural tube
- bone
- lung endothelium
Bone
By which week does the developing embryo have a distinct human appearance?
Week 8
What is the name of the stage when embryonic and extra-embryonic cells are present?
Blastocyst
True or False:
Both the node and anterior visceral endoderm (AVE) are in tissues that will be incorporated by the embryo
False
Which structure is is essential for establishing proper L-R asymmetry in gastrulation?
Node
The intervillous space is filled with what?
Maternal blood
True or False:
Oxygen-rich maternal blood is carried from the placenta to the fetus by the umbilical arteries while oxygen-depleted fetal blood is carried from the fetus to the placenta by the umbilical vein
False
If the zona reaction fails to exclude multiple sperm from entering the egg, and overtake the maternal pronucleus, which of the following would be suggestive of this?
- Lower than normal levels of hCG
- Higher than normal levels of hCG
- Lower than normal levels of progesterone
- Absence of markers of pregnancy
Higher than normal levels of hCG
Which of the following would NOT be a key feature in a patient who has pre-eclampsia?
- Breakdown of the normal maternal endometrial smooth muscle
- Hypertension in a pregnant woman who was previously normotensive
- Weight gain
- “Foamy urine” from proteinuria
Breakdown of the normal maternal endometrial smooth muscle
The notochord and ______ produce Sonic hedgehog (Shh) to establish the Dorsal-Ventral (DV) axis in the spinal cord during ______
floor plate; neurulation
Which of the following describes steroid signaling? More than one may apply
- Often localized to the cell nuclei
- Unique to mammalian species
- Enter cells through passive diffusion of cell surface receptors
- Includes sex hormones, bilirubin, and cholesterol
- Typically relies on several second messengers
- Often localized to the cell nuclei
- Enter cells through passive diffusion of cell surface receptors
You see a young, deaf patient with brilliantly blue eyes. This patient mostly likely has:
- Ehlers-Danlos Syndrome
- A mutation in the PAX3 gene
- Prader-Willi Syndrome
- A mutation in the MDR3 gene
- Blue-Eye Paramyxovirus
A mutation in the PAX3 gene
A baby has a mutation in EDN3. The newborn’s abdomen appears swollen, and upon performing a DRE (digital rectal exam) you notice that the rectal vault is empty. What is the most likely cause?
- Several small hamartomatous polyps
- Hypertrophy of the colonic muscularis propria
- Normal, healthy bowel tissue in all biopsy samples
- Sections of aganglionic bowel
- Patchy epithelial dysplasia
Sections of aganglionic bowel
Which germ layer do melanocytes arise from?
neural crest
Which germ layer does the enamel of teeth arise from?
ectoderm
Which germ layer do vascular endothelial cells (lining of blood vessels) arise from?
Mesoderm
Which germ layer do respiratory epithelial cells (in the lungs) arise from?
Endoderm
In neural development Hox genes regulate patterning along which axis?
Anterior-posterior
What macromolecule do Hox proteins bind and regulate?
DNA
Fertilization is followed by __________
inner cell mass development
Inner cell mass development is preceded by ________ and followed by _________
fertilization; implantation
implantation is preceded by _________ and followed by ____________
inner cell mass development; gastrulation
Gastrulation is preceded by ________ and followed by _________
implantation; neurulation
Which one occurs first: heart development or limb development?
heart development
True or False:
The radius and ulna develop before the humerus in limb development
False
Differentiation of the stylopod, zeugopod, and autopod requires signaling primarily from which structure?
Apical ectodermal ridge
Which of the following is the best match for: Wnt7A signal
- dorsal limb ectoderm
- interzone
- achondroplasia
- nail patella syndrome
- cleidocranial dysplasia
- ZPA
Dorsal limb ectoderm
Which of the following is the best match for: Programmed cell death
- dorsal limb ectoderm
- interzone
- achondroplasia
- nail patella syndrome
- cleidocranial dysplasia
- ZPA
Interzone
Which of the following is the best match for: Activating mutation in FGFR3
- dorsal limb ectoderm
- interzone
- achondroplasia
- nail patella syndrome
- cleidocranial dysplasia
- ZPA
Achondroplasia
Which of the following is the best match for: LMX1b mutation
- dorsal limb ectoderm
- interzone
- achondroplasia
- nail patella syndrome
- cleidocranial dysplasia
- ZPA
Nail Patella Syndrome
Which of the following is the best match for: Intramembranous bone defect
- dorsal limb ectoderm
- interzone
- achondroplasia
- nail patella syndrome
- cleidocranial dysplasia
- ZPA
cleidocranial dysplasia
Which of the following is the best match for: Sonic hedgehog signal
- dorsal limb ectoderm
- interzone
- achondroplasia
- nail patella syndrome
- cleidocranial dysplasia
- ZPA
ZPA
The anterior pituitary forms the _________ and secretes___________ and develops from _______
adenohypophysis; ACTH; Rathke’s pouch
Hypothalamic signals to the pituitary transit by which mechanism?
Portal system
Which structure carries blood from the aorta away from the lungs in fetal life, then closes upon the first moments of birth?
Ductus arteriosus
Absence of a limb
amelia
Fewer than normal digits
oligodactyly
