3/29 - UW 32 Flashcards
What sensory receptors detect muscle tension? Where?
Golgi tendon organs (GTO) at the junction of muscle and tendon
What sort of change is detected by Golgi tendon organs? What nerves innervate them?
Increases in tension, transmitted by group 1b sensory axons
What purpose does the Golgi tendon organ serve?
Negative feedback to the alpha motor neurons, turning off muscles when tension is too high, preventing damage
What are the fast and slow mechanoreceptors that mediate touch, proprioception, and vibration? What type of fibers innervate them?
Fast: Pacinian corpuscles
Slow: Ruffini’s end organs
Innervated by myelinated A-beta fibers
What is the condition that has decreased ability to repair DNA following UV damage? Its inheritance?
Xeroderma Pigmentosum (“dry, pigmented skin”), AR
How does retinoblastoma (Rb) gene suppress tumors?
Arrests cell cycle in G1, defect leads to retinoblastoma and osteosarcoma
How does ras protein suppress tumors?
G-protein that regulates signal transduction, cell division, apoptosis, cell adhesion
What type of DNA repair is impaired in Hereditary Nonpolyposis Colorectal Cancer (HNPCC or Lynch syndrome)?
DNA mismatch repair
CD14 is a surface marker for what cells?
Monocyte-macrophage lineage
What are the two factors that enhance diuresis by loop diuretics?
- Blocks Na-K-2Cl symporters, preventing reabsorption of Na, Cl, and water in the loop
- Stimulates renal prostaglandin release, which are vasodilatory, increasing RBF and GFR
What are the foregut structures? What vessel supplies them?
From esophagus to UPPER duodenum, including liver, gallbladder, and pancreas. Supplied by Celiac Trunk.
What are the embryologic midgut structures? What vessel supplies them?
From the LOWER duodenum to the PROXIMAL 2/3 of the transverse colon. Supplied by the SMA.
What are the hindgut structures? What vessel supplies them?
DISTAL 1/3 of transverse colon to the sigmoid colon. Supplied by the IMA
During which weeks of fetal development are the midgut structures outside the abdomen?
6th - 10th weeks
What is the toxin found in poisonous mushrooms? MOA?
Amatoxins are concentrated in hepatocytes, where they bind RNA polymerase II (mRNA synthesis)
What lung pathology is seen in Goodpasture syndrome?
Focal necrosis of alveolar walls and intra-alveolar hemorrhages, with hemoptysis
Does Churg-Strauss cause restrictive or obstructive pulmonary pathology?
Obstructive: severe asthma with bronchial wall thickening and eosinophilic infiltrates
What is the only RNA that contains thymidine? What is on its 3’ end?
tRNA, with CCA on the 3’ end
What are two causes of diastolic heart failure?
Impaired myocardial relaxation (eg from ischemia)
Increased intrinsic ventricular wall stiffness (eg from amyloid deposition)
Which branchial arch regresses completely?
5th
What are the structures derived from the 1st branchial arch?
(Associated with CN V)
Neural crest (bones): maxilla, zygoma, mandible, vomer, palatine, incus, malleus
Mesoderm (muscles): muscles of mastication, anterior digastric, mylohyoid, tensor tympani, tensor veli palatini
Muscular elements derived from any branchial arch are from what layer? Bony elements are from what cells?
Muscle: mesoderm
Bones: neural crest cells that migrate in
What are the structures derived from the 2nd branchial arch?
(Associated with CN VII)
Neural crest (bone): styloid, lesser horn of hyoid, stapes
Mesoderm (muscles): muscles of facial expression, stylohyoid, stapedius, posterior digastric
Which branchial arches form the cartilaginous structures of the larynx?
4th and 6th (5th arch regresses completely)
