Human Physiology

The two labia minora meet at the clitoris, a small, sensitive protrusion that is comparable to the penis in males. The clitoris is covered by a fold of skin, called the prepuce, which is similar to the foreskin at the end of the penis. It is an external structure of the female reproductive system.

The corpus luteum secretes the hormone progesterone. Progesterone prepares the uterus for a fertilized egg to implant.

The prostate is a walnut-shaped gland that surrounds the urethra. Along with the seminal vesicles it produces the fluid secretions that support and nourish the sperm. Without this fluid to dilute them, the sperm cannot move easily. After the age of 40 years,  the prostate enlarges and can press on the urethra. An enlarged prostate is often the cause of urinary problems in older men.

The scrotum is a sac that hangs under the penis and holds the testes. It is divided internally into two halves by a membrane; each half containing a testis. It has an outer layer of thin, wrinkled skin over a layer of tissue which contains muscle.

As estrogen levels rise, like a switch, it turns off the production of follicle-stimulating hormone. This careful balance of hormones allows the body to limit the number of follicles that mature.

Vagina is a canal that joins the cervix (the lower part of uterus) to the outside of the body. It  is also known as the birth canal. It is an internal reproductive organ in the female .

Perimenopause is the term used to describe the menopause transition years. In women who have a uterus, perimenopause describes the years before and after the final period (although it is only possible to determine in retrospect which episode of flow was indeed the final period).

It stores and concentrates bile, and then releases it into the duodenum to help absorb and digest fats.

The stomach is a hollow organ, or container, that holds food while it is being mixed with enzymes that continue the process of breaking down food into a usable form. Cells in the lining of the stomach secrete a strong acid and powerful enzymes that are responsible for the breakdown process. When the contents of the stomach are sufficiently processed, they are released into the small intestine.

As the follicular phase progresses, one follicle in one ovary becomes dominant and continues to mature. This dominant follicle suppresses all of the other follicles in the group. As a result, they stop growing and die. The dominant follicle continues to produce estrogen.

Large intestine is divided into three parts. The first organ of the large intestine is the cecum. The cecum is attached to the appendix and is also the connecting pouch between the small and the large intestines. The colon comes after the cecum and is responsible for the abrogation of water and salts from the digested foods. The third part of the large intestine is the rectum, which acts as the connection between the intestines and anus.It is an organ of lower gastrointestinal tract .

Gall bladder is a pouch-shaped organ which lies near the liver. It accepts bile from the liver, and stores it. When food is digested, the gall bladder releases bile into the small intestine where it is able to help dissolve fats. It is not an accessory organ of the alimentary canal .

Kupffer cells, are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system.

Von Ebner's glands are glands found in circumvallate papillae of the tongue. They secrete a serous fluid that begin lipid hydrolysis. They facilitate the perception of taste.

Amenorrhoea simply means an absence of your periods. Doctors usually classify amenorrhoea into primary or secondary amenorrhoea. Girls who haven't started their periods by the time they're 16 years old or 3 years after they've shown the first signs of puberty have primary amenorrhea, which is usually caused by a genetic abnormality, a hormone imbalance, or a structural problem.

Salivary amylase (ptyalin) is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion.

Fallopian tubes are about 10 cm long and begin as funnel-shaped passages next to the ovary. These have a number of finger-like projections known as fimbriae on the end near the ovary. When an egg is released by the ovary it is 'caught' by one of the fimbriae and transported along the fallopian tube to the uterus. The egg is moved along the fallopian tube by the wafting action of cilia .

Chyme is the semifluid mass of partly digested food expelled by the stomach into the duodenum. In other words, chyme is partially digested food.

The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible (or elastic) organ, the bladder sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra.

The intermediate part of male urethra (membranous portion) is the shortest, the least dilatable, and with the exception of the external orifice, the narrowest part of the canal. It extends downward and forward, with a slight anterior concavity, between the apex of the prostate and the bulb of the urethra, perforating the urogenital diaphragm about 2.5 cm. below and behind the pubic symphysis.

Secretin is in the duodenum and signals the secretion of sodium bicarbonate in the pancreas and it stimulates the bile secretion in the liver. This hormone responds to the acidity of the chyme.

Having a baby does not cure endometriosis. It is suppressed during pregnancy, but the symptoms may recur.

A surge of luteinising hormone occurs roughly just before day 14 in a 28-day cycle. This surge stimulates the mature follicle in one of the ovaries to release its egg (ovulation) 16 to 32 hours later. The other follicles over-ripen and break down. Oestrogen also peaks during this surge. Some women can feel a pain on one side of the abdomen around the time the egg is released.

The space of Disse (or perisinusoidal space) is a location in the liver between a hepatocyte and a sinusoid. It contains the blood plasma. Microvilli of hepatocytes extend into this space, allowing proteins and other plasma components from the sinusoids to be absorbed by the hepatocytes.

The cystic duct is the short duct that joins the gall bladder to the common bile duct. It usually lies next to the cystic artery. It is of variable length. It contains a 'spiral valve', which does not provide much resistance to the flow of bile.