17.2 Endocrine Glands

Nervous stimulation

- Example, release of epinephrine and norepinephrine by adrenal medulla in response to sympathetic nervous stimulation

oxyphil cell

- Function Unknown - Although these cells are associated with a rare form of cancer called oxyphil cell adenoma.

Endocrine glands

- It composed of secretory endocrine cells derived from an epithelium that is supported by a connective tissue framework. - Secretory endocrine cells - Derived from epithelium with connective tissue framework - Have extensive blood supply *facilitates rapid uptake of hormones - It has two organizations or are organized in two general ways: * either as a single organ with only endocrine function or as cells housed in small clusters within organs that have some other primary function

Humoral stimulation

- Respond to changing level of nutrients or ions. - Act on target cells to offset further loss or eliminate excess.

Endocrine Cells Within Other Organs (heading)

- Some endocrine cells are housed in tissue clusters within specific organs. - These cells secrete one or more hormones, but the organs have some other primary function as well. - These organs include the hypothalamus, skin, thymus, heart, liver, stomach, pancreas, small intestine, kidneys, and gonads (testes and ovaries)

Hormonal stimulation

- The stimulus for the release of many hormones from its endocrine gland is stimulation by another hormone. *ex. Thyroid stimulating hormone released from anterior pituitary.

Endocrine Reflexes

- What term that regulated secretion of a hormone from an endocrine gland is controlled through a reflex. - reflex is a preprogrammed response that occurs when activated by certain stimuli - ______ are initiated by one of three types of stimulation: hormonal stimulation, humoral stimulation, or nervous stimulation.

Parathyroid glands

- are located on the posterior surface of the thyroid gland - It also have four small nodules - It has two diffrent types of cells *Chief cells and Oxphil cells

chief cells

- are the source of parathyroid hormone (PTH) that is released in response to decreased blood calcium to return blood calcium to within normal homeostatic levels - A.k.A Principal cells

Endocrine Organs

- is a single organ that is entirely endocrine in function. ________ include the pituitary gland, pineal gland, thyroid gland, parathyroid glands, and adrenal glands. - Single organ that is entirely endocrine in function - Which includes *pituitary gland *pineal gland *thyroid gland *parathyroid glands *adrenal glands

pineal gland

- is also called the pineal body. It is a small, cone-shaped structure forming the posterior region of the epithalamus, which decreases in size as we age. - It is composed primarily of pinealocytes, which secrete melatonin - Melatonin makes us drowsy, and its production tends to be cyclic; it increases at night and decreases during the day, with the lowest levels around lunchtime - Melatonin also appears to affect the synthesis of a hypothalamic hormone *the hypothalamic hormone is responsible for regulating synthesis of two hormones from the anterior pituitary, *which in turn regulate the reproductive system

hormonal stimulation, humoral stimulation, or nervous stimulation

The 3 types of stimulation of endocrine reflexes called ______