Phase 1 Topics by Chapter 2016-2018 Document Flashcards
Define prevalence
The number of cases of disease in a known population at a designated time.
Define incidence
The number of new cases of disease that occur in a known population over a designated period of time.
What muscles are involved in external hip rotation?
Internal and external obturator, gemellus, quadratus femoris are responsible for external rotation of the hip (insert at trochanteric fossa, antagonize the glutes).
The gluteal muscles (superficial, middle, deep, and piriformis) perform what motion(s) of the hip joint?
Abduction and internal rotation.
What muscles adduct the hip joint?
Those that run from the pelvis to the shaft of the femur: adductor, pectineus groups.
What is ectrodactyly?
Ectrodactyly, which is also known as split hand/foot malformation (SHFM), is a condition characterized by absence or malformation of one or more of the digits. Usually, the middle digits are affected.
What cells produce TNF-α?
Monocytes, macrophages, neutrophils, NK cells, and several others (T, B, fibroblasts). But Activated M1 macrophages are a major source of TNF-alpha.
What is stimulated by the release of TNF-α?
Production of proinflammatory cytokines (e.g., IL-6), reactive oxygen intermediates, chemotaxins, and endothelial adhesion molecules (all facilitate the recruitment of cells at the site of inflammation).
The main effect of TNF-α is stimulation of cytokines (IL-6, ROS, etc.) that facilitate cell recruitment at the site of inflammation. What are three additional effects of TNF-α?
Activation of natural killer cells, proliferation of cytotoxic T-cells, and T-cell apoptosis.
What are released from the cell surface to reduce the activity of TNF-α?
Tumor necrosis factor soluble receptors are found constitutively at low levels in the blood but are increased in inflammatory conditions such as sepsis. The solubilized receptors bind to TNF-α and effectively reduce the cytokine’s activity.
TNF-α has both beneficial and deleterious effects. Name some of each:
Beneficial - protects against mycobacterial infection, blocking it in septic patients increases mortality
Deleterious - causes all the classic signs of shock (hypotension, metabolic acidosis), causes inflammation (inflammatory diseases like Crohns).
What is TNF-α?
A membrane-bound surface protein, cleaved by metalloproteases, that is released in soluble form. It has two receptors, TNFR1 and TNFR2.
Corticosteroids and recombinant TNFR receptors (Enbrel, a treatment for RA/Crohn’s) inhibit TNF-α, which increases risk of what?
Recrudescence of pulmonary mycobacterial infections and infectious complications after orthopedic surgeries.
True or False: Activated M1 macrophages produce proinflammatory cytokines (IL-1β, IL-6, and TNF-α) and prostaglandins, enhancing the inflammatory response?
True.
True or False: M2 macrophages are activated in response to proinflammatory cytokines?
False. M2 macrophages are activated in response to anti-inflammatory cytokines (IL-4, IL-13, and IL-10). They then secrete growth factors like PDGF or TGF-β, which stimulate fibroblasts to produce collagen, aiding in wound healing and further dampening the inflammatory response.
True or False: M1 macrophages are activated by infectious agents or proinflammatory cytokines?
True. M1 macrophages are activated by infectious agents or proinflammatory cytokines (interferon-gamma [IFN-γ] or TNF-α). They then produce more proinflammatory cytokines and prostaglandins to increase inflammation.
What is something both M1 and M2 macrophages produce?
Both M1 and M2 macrophages secrete enzymes like collagenases and elastases to dissolve the extracellular matrix, facilitating phagocytosis and remodeling, respectively.
What cells produce VEGF?
Predominantly keratinocytes on the wound edge and also by macrophages, endothelial cells, fibroblasts, and platelets.
