Histology collection videos 2021

2023-04-25 08:39:02 A 23-year-old, previously healthy man was involved in a motor vehicle collision. He lost consciousness at the scene but recovered by the time emergency medical services arrived. The patient was alert and awake in the ambulance but lost consciousness again soon after arriving at the emergency department. His breath smells of alcohol. Blood pressure is 130/90 mm Hg, pulse is 68/min, and respirations are 12/min. A bruise is noted over the left temple area. The left pupil is mildly dilated. Open / Comment

2023-04-24 20:03:48 USMLE Step 1 resources to aid success.

Save this list for a rainy day Open / Comment

2023-04-24 18:39:02 Educational objective: Brain herniation causes abnormal posturing due to disruption of descending motor tracts (eg, rubrospinal, vestibulospinal). Damage above the level of the red nucleus (eg, cerebral hemispheres, internal capsule) typically results in decorticate (flexor) posturing. Damage at or below the red nucleus (eg, midbrain to pons) typically results in decerebrate (extensor) posturing. Open / Comment

2023-04-24 08:38:02 A 45-year-old man is brought to the emergency department after sustaining a traumatic head injury in a motor vehicle collision. The patient was found unresponsive and had several generalized tonic-clonic seizures during transport. Medical history includes hypertension as well as alcohol and cocaine misuse. Temperature is 36.7 C (98.1 F), blood pressure is 170/96 mm Hg, pulse is 50/min, and respirations are 10/min. Pulse oximetry shows 98% on mechanical ventilation with 50% oxygen. On examination, the patient is comatose with midpositioned and fixed pupils and rigid extension of the upper and lower extremities. Noncontrast CT scan of the head is shown in the image below: Open / Comment

2023-04-23 18:11:02 Educational objective: The primary somatosensory cortex (postcentral gyrus) is responsible for processing all somatic sensory input from the contralateral side of the body. A focal onset seizure originating in this region of the cerebral cortex often results in contralateral sensory disturbance (eg, numbness, paresthesia). Open / Comment

2023-04-23 08:10:03 A 55-year-old right-handed man comes to the emergency department due to persistent right arm tingling and numbness for the past several hours. The patient has no headache, muscle weakness, slurred speech, or difficulty ambulating. He has a history of hypertension, paroxysmal atrial fibrillation, and ischemic stroke without residual symptoms. Anticoagulation was discontinued 2 months ago after he developed a gastrointestinal hemorrhage. Blood pressure is 150/90 mm Hg, and pulse is 92/min and regular. While the patient is being evaluated, his right arm paresthesia spreads to the entire right side of the body and he develops right-sided convulsions, followed by a bilateral tonic-clonic seizure. Open / Comment

2023-04-22 18:09:02 Educational objective: The autonomic nervous system utilizes three types of signal pathways: cAMP, IP3, and ion channels. Nicotinic receptors are ligand-gated ion channels that open after binding acetylcholine. This results in an immediate influx of Na+ and Ca2• into the cell and an outflux of K+ from the cell. Open / Comment

2023-04-22 13:37:20 USMLE Step 1 resources to aid success.

Save this list for a rainy day Open / Comment

2023-04-22 08:08:02 A medical research center is studying therapeutic options for the treatment of neuromuscular disorders. During experimentation, scientists develop a new drug that seems to have partial agonist/antagonist activity against receptor X. When the experimental drug is applied to cells expressing receptor X, there is an immediate change in transmembrane calcium, sodium, and potassium flow secondary to the opening of the receptor channel. Open / Comment

2023-04-21 18:08:02 Educational objective: Cervical spine trauma can cause dissection of the vertebral artery, resulting in ischemic manifestations due to occlusion of the vertebral artery and/or its branches. Posterior inferior cerebellar artery occlusion causes lateral medullary (Wallenberg) syndrome, characterized by vertigo/nystagmus, ipsilateral cerebellar signs, loss of pain/temperature sensation in the ipsilateral face and contralateral body, bulbar weakness, and ipsilateral Horner syndrome. Open / Comment