The ejaculatory duct in males is formed by a union of the ampulla of the ductus deferens and the duct of the seminal vesicle. This duct receives secretions from the seminal vesicle and prostate gland and penetrates the prostate gland where it empties into the urethra.

These are pea-sized structures located on the sides of the urethra . These glands produce transparent, slippery fluid which serves to lubricate the urethra and to neutralize the acidity present due to the drops of urine in the urethra.

These glands are located beside the vaginal opening and produce a fluid secretion. It is one of the important parts among the main external structures of the female reproductive system.

The cerebral cortex is the portion of the brain that provides remarkable distinctions between humans and other animals. It enables humans not only to receive and interpret all kinds of sensory information, such as colour, odor, taste, and sound, but also to remember, analyze, interpret, make decisions, and perform a host of other higher brain functions.

The epithalamus is a dorsal part of the diencephalon and connects the limbic system to other parts of the brain.

Although the administration of drugs to enhance acetyl coenzyme A, production is not effective in elevating acetylcholine neurotransmission, cholinergic neurons increase their coenzyme A production as a means of increasing acetylcholine availability for neurotransmission.

Glutamine synthase is a glial enzyme that metabolizes glutamate into glutamine. Because glutamine is relatively small and uncharged, it can diffuse across the glial and neuronal membranes and once in the neurons glutaminase converts glutamine into glutamate trapping it in the neuron, it can then be packaged into vesicles for release.

The cochlea is the most complex part of the ear. It collects the physical vibrations caused by the sound wave and translates them into electrical information the brain can recognize as distinct sound.

Movement of the cilia opens potassium channels. The influx of potassium causes a subsequent influx of calcium and a receptor potential that can cause an action potential in the afferent dendrites.

The superior temporal gyrus contains the primary auditory cortex, which is responsible for processing sounds. It is involved in auditory processing, including language.

Neuropeptides are neuronal signaling molecules. They are synthesized in the cell body and are processed in vesicles that are transported to axon terminals along microtubules via fast axonal transport.

The lateral lemniscus is a tract of axons in the brainstem transferring the information about sound from the cochlear nucleus to the contralateral inferior colliculus of the midbrain.

It is a part of the metathalamus consisting of a small oval tubercle situated between the pulvinar, colliculi, and cerebral peduncle. It is fourth in the sequence. All sensory afferents, except olfactory, synapse in the thalamus.

The hilum of the lung is a triangular part which allows the other structures forming the root of the lung to enter and exit. It permits arteries, veins, nerves, bronchi and other structures to enter and exit.

The lateral vestibular nuclei, although not contained within the cerebellum, are considered to be functionally analogous to the deep cerebellar nuclei because of their functional connectivity with the cerebellum.