Untitled Quiz

Cochlea and Hearing

• Hair cells within the cochlea are responsible for transducing sound vibrations into electrical signals that the brain can interpret.
• The middle ear bones (malleus, incus, and stapes) amplify sound vibrations as they pass through the ear.
• Frequency Theory in hearing states that the frequency of a sound is encoded by the rate of firing of auditory neurons.
• Interaural time difference (ITD) and interaural intensity difference (IID) allow for the localization of sound sources.
• Tinnitus is characterized by frequent ringing in the ears.
• Endolymph, a fluid high in potassium, stimulates hair cells in the vestibular system.
• Damage to the cochlea or hair cells can result in hearing loss.

Pain and Sensory Receptors

• The auditory cortex, located in the temporal lobe, processes auditory information.
• Glutamate is the neurotransmitter primarily associated with mild pain, but other neurotransmitters like Substance P contribute to pain signaling.
• The anterior cingulate cortex (ACC) plays a crucial role in the emotional response to pain.
• Morphine and endorphins reduce pain by binding to opioid receptors, inhibiting the release of neurotransmitters involved in pain signaling, and activating descending pain pathways.
• Pacinian corpuscles are touch receptors responsive to vibrations and sudden touch.
• The prefrontal cortex is involved in evaluating the context and meaning of pain, as well as in planning and executing pain-relieving behaviors.
• Axons carrying pain signals are slower than those carrying motor responses due to their thinner diameter and lack of myelin sheath, allowing the brain to process pain information and react accordingly.
• Hair follicle receptors are touch receptors that respond specifically to the movement of hair.

Tickling and Touch

• The ability to tickle oneself is difficult because of the predictability of the stimulus and the integration of sensory and motor information in the brain.
• The brain anticipates the touch and reduces the sensation of surprise, which is a key component of tickling.

Muscle Movement and Motor Control

• Golgi tendon organs sense the tension within muscles and protect them from excessive force.
• The cerebellum coordinates balance, timing, and precision of movements.
• Dopamine pills are ineffective for treating Parkinson's disease because the disease involves not only a deficiency in dopamine but also neuron death in the substantia nigra, rendering dopamine replacement therapy insufficient.
• Early symptoms of Huntington's disease include involuntary movements (chorea), cognitive decline, and mood changes.
• The prefrontal cortex plays a role in planning and initiating complex movements.
• A high number of C-A-G repeats in the gene associated with Huntington's disease indicates a higher risk and earlier onset of the disease.
• Tremors at rest are a prominent symptom of Parkinson's disease.

Movement and Readiness Potential

• "Readiness potential" refers to the electrical activity in the brain that precedes voluntary movement, indicating a preparatory state for action.
• The supplementary motor cortex plays a crucial role in planning and sequencing movements, especially complex movements that require coordination.

Sleep and Circadian Rhythms

• The suprachiasmatic nucleus (SCN) located in the hypothalamus acts as the body's internal clock, regulating circadian rhythms.
• Melatonin, a hormone involved in regulating sleep-wake cycles, is produced by the pineal gland.
• Rapid eye movements (REM) sleep is characterized by vivid dreams, muscle paralysis, and brain activity similar to wakefulness.
• Zeitgebers, such as light and temperature, influence circadian rhythms by synchronizing the internal clock with the external environment.
• Narcolepsy is characterized by sudden sleep attacks and excessive daytime sleepiness.

Dreams and Sleep Theories

• The activation-synthesis theory describes dreams as a way for the brain to make sense of random activity during sleep.
• Histamine is a neurotransmitter involved in promoting wakefulness and arousal.
• The endopiriform cortex plays a crucial role in combining taste and smell information, creating a sense of flavor.

Taste and Smell

• Humans have an innate aversion to bitter substances because they are often associated with toxins.
• Olfaction is the only sense that is directly connected to the limbic system, making it strongly associated with emotions and memories.

Muscles and Muscle Movement

• Slow-twitch muscles are resistant to fatigue and are essential for sustained activities like endurance.
• Cardiac muscle is unique in its ability to contract spontaneously and rhythmically, controlled by specialized pacemaker cells.
• The neuromuscular junction is the synapse between a motor neuron and a muscle fiber, where acetylcholine is released to stimulate muscle contraction.
• A higher ratio of motor neurons to muscle fibers indicates greater muscle precision and fine control.
• Synesthesia is a neurological phenomenon where stimulation of one sense leads to an automatic, involuntary experience in a second sense.