Set 3 Flashcards
In performing a lumbar puncture to obtain a sample of CSF, what structures are pierced, starting with the most exterior?
Skin Superficial fascia/subQ fat Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural space Dura mater Arachnoid mater Subarachnoid space (CSF) *Pia is not Pierced
At what level is a lumbar puncture done? What is a clinical marker?
To keep the cord alive, keep the spinal needle between L3 and L5! SC extends to L1-L2, subarachnoid space (CSF) extends to lower border of S2. Lumbar puncture usually performed between L3-L4 or L4-L5 (level of cauda equina)
*illiac crest clinical marker
In which phase of meiosis is a primary oocyte arrested until just prior to ovulation? In which phase of meiosis is an oocyte arrested until fertilization?
Meiosis I is arrested in prOphase I for years until Ovulation (primary oocytes)
Meiosis II is arrested in METaphase II until fertilization (secondary oocytes)… an egg MET a sperm
Does the notochord become the neural tube?
No - the notochord is derived from mesoderm and neural tissue comes from ectoderm. It is important though because the notochord induces overlying ectoderm to become the neural plate which gives rise to -> neural tube and NCC
Notochord induces overlying ectoderm to differentiate into neuroectoderm and form the neural plate.
Neural plate gives rise to the neural tube and neural crest cells.
Notochord becomes nucleus pulposus (inner core) of the intervertebral disc in adults.
A 65-year-old woman with COPD is in severe respiratory distress, and she has cyanosis and signs of right-sided heart failure. What medications are used in the treatment of pulmonary hypertension? What are their mechanisms of action?
Four classes
Endothelin-1 receptor antagonists: bosentan, ambrisentan
Prostaglandins: Iloprost, epoprostenol (all have prost in their name)
Phosphodiesterase inhibitors: Tadalafil, sildenafil
Dihyropyridine CCBS: Nifedipine
All result in vasodilation
A 35-year-old man develops hallucinations just before sleep, episodes of excessive sleepiness, and cataplexy during times of laughter and sadness. Narcoleptic sleep episodes begin with what stage of sleep? What are the different stages of normal sleep? How do they differ from one another?
Narcoleptic episodes occur with REM sleep
Awake (eyes open) Beta (highest freq, lowest amp)
Awake (eyes closed) Alpha
Non-REM
N1 (5%) light sleep, Theta waves
N2 (45%) deeper sleep, when bruxism occurs, Sleep spindles and K complexes
N3 (25%) deepest non-REM sleep (slow wave); when sleepwalking, night terrors and bedwetting occurs, Delta (lowest freq, highest amp)
REM (25%) loss of motor tone, increased brain oxygen use, increased variable pulse and blood pressure; when dreaming and penile/clitoral tumescence occur; may serve a memory processing function, Beta
At night, BATS Drink Blood
From where does the amygdala receive inputs? To where does it send output?
Input:
Limbic cortex
Neocortex (parietal, temporal, occipital lobes)
Output: Cortical areas from which it received inputs Hippocampus Septum Thalamus Hypothalamus
What are some of the reasons a woman might have primary amenorrhea?
Turner syndrome Imperforate hymen Androgen insensitivity syndrome Mullerian duct agenesis Delayed puberty
The body uses both the cell-mediated and the humoral immune responses to fight infection. Which T cell type regulates the humoral response?
CD4+ T-cells - Th2 specifically
Th2 cells (stim by IL-4, inhibited by IFN-y) Augment humoral immune response by generating IL-4 and IL5 that promote the growth and differentiation of B cells
Th1 vs. Th2 (inhibits, promotes, fn)
Th2 cells (stim by IL-4, inhibited by IFN-y)
Augment humoral immune response by generating IL-4 and IL5 that promote the growth and differentiation of B cells
Also releases IL-6 and IL-13
Recruits eosinophils for parasite defense and promotes IgE production by B cells
Th1 cells (stim by IL-12, inhibited by IL-4 and IL-10)
Augment cell-mediated response by generating IL-2 and IFN-y
Activates macrophages and cytotoxic T lymphocytes
Coal miners are at an increased risk for skin cancer because of their exposure to arsenic. Which type of skin cancer is associated with this exposure?
Squamous cell carcinoma
What is actinic keratosis? Keratoacanthoma?
Actinic keratosis is a scaly plaque precursor to squamous cell carcinoma
Keratoacanthoma is a variant of squamous cell carcinoma that grows rapidly (4-6 wks) and may regress spontaneously over months
Squamous cell carcinoma. Associated with? Appears where? Spreads? Histopathology?
Second most common skin cancer. Associated with excessive exposure to sunlight, immunosuppression, and occasionally arsenic exposure. Commonly appears on face, lower lip, ear and hands. Locally invasive, but may spread to lymph nodes and will rarely metastasize. Ulcerative red lesions with frequent scale. Associated with chronic draining sinuses. Histopathology: keratin pearls
Palisading nuclei associated with what?
Basal cell carcinoma
Melanom is associated with what tumor marker? What mutation is it often driven by?
S-100
BRAF Kinase activating mutation, metastatic or unresectable melanoma in patients with BRAF V600E mutation may benefit from vemurafenib, a BRAF kinase inhibitor
