Cells and Neural Signals
This organelle produces most of a cell’s ATP.
What is the mitochondrion?
This neurotransmitter carries the motor neuron’s signal to skeletal muscle at the neuromuscular junction.
What is acetylcholine?
Every autonomic preganglionic neuron releases this neurotransmitter.
What is acetylcholine?
These thinly myelinated fibers transmit fast, sharp, well-localized pain.
What are Aδ fibers?
These retinal photoreceptors are especially important for vision in dim light.
What are rods?
This ATP-dependent pump moves three sodium ions out of a cell and two potassium ions into it.
What is the Na⁺/K⁺ ATPase?
This brain region integrates temperature, hunger, thirst, and autonomic regulation.
What is the hypothalamus?
Activation of this adrenergic receptor increases heart rate and cardiac contractility.
What is the β₁ receptor?
A light brush against the skin causes pain even though that stimulus is normally painless. This sensory abnormality is present.
What is allodynia?
This cranial nerve carries taste from the posterior one-third of the tongue.
What is the glossopharyngeal nerve, CN IX?
Glucose enters an intestinal epithelial cell by using the sodium gradient rather than directly using ATP. This transport mechanism is involved.
What is secondary active transport?
Degeneration of dopamine-producing neurons in the substantia nigra is characteristic of this movement disorder.
What is Parkinson disease?
Activation of this adrenergic receptor relaxes bronchial smooth muscle.
What is the β₂ receptor?
Repeated nociceptive input increases the responsiveness of CNS neurons, contributing to persistent pain.
What is central sensitization?
A pituitary mass compresses the center of the optic chiasm, producing this visual-field defect.
What is bitemporal hemianopia?
Immediately after a neuronal action potential begins, a second stimulus fails to produce another spike because these channels are inactivated and must recover before reopening.
What are voltage-gated sodium channels?
After brain injury, a patient remembers childhood events but cannot form new long-term declarative memories. Damage to this structure best explains the deficit.
What is the hippocampus?
During exercise, sympathetic nerves stimulate sweating by releasing acetylcholine onto this receptor type on eccrine sweat glands.
What are muscarinic receptors?
A patient cannot detect vibration or identify the position of the great toe with the eyes closed, but pain and temperature sensation remain intact. This ascending sensory pathway is most likely damaged.
What is the dorsal column–medial lemniscus (DCML) pathway?
When a person turns the head to look over the shoulder, these vestibular structures detect the rotational acceleration.
What are the semicircular canals?
A toxin blocks calcium entry into a presynaptic terminal. The action potential arrives normally, but this process that releases neurotransmitter fails.
What is synaptic vesicle exocytosis?
An ischemic stroke produces predominantly right-sided face and arm weakness. This cerebral artery on the left is most likely affected.
What is the left middle cerebral artery?
A patient taking an α₁ blocker becomes dizzy upon standing because compensatory vasoconstriction is impaired. This condition explains the symptoms.
What is orthostatic hypotension?
A vibrating tuning fork is placed against the skin. These rapidly adapting, encapsulated receptors are especially sensitive to high-frequency vibration and deep pressure.
What are Pacinian corpuscles?
While a person turns the head to the right, the eyes move to the left to keep a stationary object in focus. This vestibular reflex stabilizes the image on the retina.
What is the vestibulo-ocular reflex (VOR)?