PCOS is polycystic ovary syndrome, which is a chronic hormonal disorder that can cause enlarged ovaries with multiple small cysts on the outer edges. The cause is unknown, but the disorder can be managed via lifestyle changes, hormonal birth control methods, and surgery. If left untreated, it can cause infertility, high cholesterol problems, mental health issues, and is a risk factor for cancer and diabetes. 

Chlamydia is a sexually transmitted disease that can present in multiple ways. The most common symptoms are burning sensation during urination and abnormal discharge, but chlamydia infection is also asymptomatic in some cases. It can be treated with antibiotics. 

Gonorrhea, Chlamydia, and Syphilis are common sexually transmitted infections (STI's or STD's). They are caused by viruses that are most often transmitted during sexual activity. They can be found in areas other than the genitals, including the mouth or rectum. 

BV is also known as bacterial vaginosis. It is caused by a proliferation of bacteria in the vagina and is the most common vaginal infection in women between the ages of 15-44. It can be treated via antibiotics or will occasionally go away on its own.  

"Orchitis" refers to inflammation of either one or both of the testicles. It is marked by pain, swelling, and a feeling of heaviness in the testes. It can be caused by bacterial infection and is also commonly associated with the mumps virus. In contrast, "otitis" refers to inflammation of the outer, middle, or inner ear; it is commonly associated with infection. "Oophoritis" refers to inflammation of the ovary and is often seen with salpingitis, which is inflammation of the fallopian tubes. Lastly, osteoarthritis refers to a joint disease which results from the breakdown of joint cartilage and bone.

Calcitonin inhibits osteoclasts and can be used therapeutically for treatment of osteoporosis and hyperparathyroidism. Osteoclasts are responsible for removing "old bone". Osteoporosis may occur when the removal of "old bone" is greater than the creation of "new bone". By inhibiting osteoclasts, the bone is able to create "new bone" at a faster rate. Similarly, hyperparathyroidism is likely to cause hypercalcemia, which is in part due to the activation of osteoclasts. Thus, calcitonin may be used to take blood calcium levels back down to baseline.

The four palpable landmarks for identifying the borders of the perineum are the pubic symphysis, coccyx, and the ischial tuberosities (one in each side). These landmarks are found in both males and females, although the perineum area is larger in women due to the wider pelvic opening. 

Posterior superior and inferior iliac spines lie beyond the area of the perineum, and therefore are not used as landmarks for this identification purpose. 

A man's ejaculate contains seminal fluid. Seminal vesicles produce the alkaline portion of seminal fluid, which contains fructose and choline. Thus, the presence of fructose on or inside the female patient would provide forensic evidence of rape.

Neurotransmitters will never enter the postsynaptic neuron. They will attach to receptors on the membrane of the postsynaptic neuron, release, and then be dealt with while in the synaptic cleft. In some instances, the neurotransmitter simply diffuses away from the synapse, but in most cases synaptic proteins help to recycle the molecules. Some enzymes will break the neurotransmitter into parts, which then reenter the presynaptic neuron and are reassembled. Acetylcholinesterase is a common example of this type of enzyme. Other neurons use membrane pumps to retrieve neurotransmitter from the synaptic cleft.

Once an action potential has reached the end of the presynaptic neuron, voltage-gated calcium channels are stimulated, allowing calcium to enter the neuron. This influx of calcium stimulates the release of neurotransmitters into the synaptic cleft.

The neurotransmitters then bind to receptors on the surface of the postsynaptic neuron to generate small electrical stimuli. The sum of these stimuli must reach threshold in order for an action potential to be generated.

GABA and acetylcholine are two common neurotransmitters. GABA generally inhibits the postsynaptic neuron, while acetylcholine generally excites/stimulates the postsynaptic neuron.