ENDOCRINE SYSTEM

CRS101 HUMAN ANATOMY | CRS102 HUMAN PHYSIOLOGY

Autocrine

A cell targets itself

Signaling across gap junctions

A cell targets a cell connected by gap junctions

Paracrine

A cell targets a nearby cell

Endocrine

A cell targets a distant cell through the bloodstream

Neurotransmitter

Produced by neurons; secreted into a synaptic cleft by presynaptic nerve terminals; travels short distances; influences postsynaptic cells

Endocrine chemical messenger

Secreted into the blood by specialized cells; travels some distance to target tissues; results in coordinated regulation of cell function

Hypothalamus

Small region located at the base of the brain, above the brainstem, and below the thalamus, regulating secretory activity and essential physiological/behavioral functions

Pituitary gland

Situated at the base of the brain below the hypothalamus within the sella turcica, often referred to as the master gland because it secretes hormones controlling other endocrine glands

Thyroid gland

Located in the neck, just below the larynx and in front of the trachea, consisting of two lobes connected by an isthmus, producing metabolism-regulating hormones and calcitonin

Parathyroid glands

Usually four small glands located on the posterior surface of the thyroid gland, typically the size of a grain of rice, producing parathyroid hormone to regulate calcium and phosphate levels

Adrenal gland

Situated on top of each kidney, having an outer cortex and an inner medulla that produce mineralocorticoids, glucocorticoids, adrenal androgens, epinephrine, and norepinephrine

Pancreas

Located behind the stomach near the small intestine with both endocrine and exocrine functions, producing insulin and glucagon to regulate blood sugar levels

Pineal gland

A small, pinecone-shaped structure located deep within the brain near the center that primarily produces melatonin to help regulate the sleep-wake cycle and circadian rhythms

Testes

Located in the scrotum outside the abdominal cavity, acting as male reproductive organs responsible for producing sperm and releasing testosterone

Ova/Ovaries

Located in the lower abdomen one on each side, serving as female reproductive organs responsible for producing eggs and releasing estrogen and progesterone