Grade 12 biology - Endocrine system

Protein hormone

A hormone composed of chains of amino acids that is water soluble; usually acts on cell membrane receptors

Steroid hormone

A hormone composed of cholesterol that is not very water soluble; usually passed through the cell membrane and acts on receptors inside the cell

Glucagon

A hormone produced by alpha cells in the pancreas that raises the blood glucose level by promoting the breakdown of glycogen in the liver

Hypothalamus

The region of the brain that releases hormones to control the pituitary gland, which, in turn, controls other endocrine glands

Neurohormone

A hormone produced by neurons, such as in the hypothalamus, that controls the production of other hormones in the pituitary gland

Pituitary gland

A two-lobed gland within the cranial cavity that produces hormones that control the other endocrine glands

Thyroid gland

An endocrine gland located in the throat that is regulated by the hypothalamus-pituitary system

Parathyroid hormone

A hormone secreted by the parathyroid glands that controls calcium and phosphate levels in the blood

Pineal gland

An endocrine gland located in or on the brain of vertebrates that secreted the hormone melatonin to regulate biological rhythms

Islets of langerhans

Endocrine cell clusters inside the pancreas that produce insulin and glucagon

Testerone

The main male sex hormone, which stimulates and controls the development of male secondary sexual characteristics

Estrogens

Predominantly female sex hormones, including estradiol, that trigger sexual development

Progestins

Predominantly female sex hormones, including progesterone, that control the menstrual cycle

Synthetic hormone

A hormone created by humans that behaves like a natural hormone

Gonads

Glands responsible for the production of sex hormones, as well as the egg and sperm cells; called testes in males and ovaries in females

Androgens

Predominantly male sex hormones, including testosterone, that control sexual development and reproduction

Gonadotropin-releasing hormone (GnRH)

A hormone released by the hypothalamus that controls the release of LH and FSH from the anterior pituitary, which, in turn, controls the synthesis and release of the male or female sex hormones in the gonads

Oogenesis

The production of eggs, or ova, from oocytes in the ovaries by two meiotic divisions

Menopause

The end of a females reproductive capability, after which menstruation ceases and female hormone levels drop

Menstrual cycle

The monthly cycle of events in a sexually mature female that prepares the uterus for the implantation of a fertilized egg

Spermatogenesis

The production and development of sperm cells in the testes