Welcome to this lesson today on the hypothalamus and pituitary gland. Today, you are going to be learning about the role of the hypothalamus and pituitary gland in the endocrine system. Specifically, you will learn about:
The hypothalamus and pituitary gland interact in order to control activities of various body organs and to help regulate homeostasis of the body. The hypothalamus and pituitary gland regulate homeostasis by producing, storing, and secreting various hormones. The hypothalamus and pituitary gland can be found in the brain.
The pituitary gland consists of two separate lobes, each of which secretes different hormones. The anterior lobe of the pituitary gland makes and releases hormones while the posterior lobe stores and releases hormones from the hypothalamus.
Within the hypothalamus you have neurons that synthesize antidiuretic hormone (ADH) and oxytocin. These hormones will move down the axons of neurons and build up in their axon endings, which are located in the posterior lobe. When an action potential triggers a hormone release, the hormones will enter capillaries and then travel through the bloodstream to their target cell.
Oxytocin is one of the hormones produced within the hypothalamus and stored in the axon endings of neurons within the posterior lobe. Oxytocin plays a couple of different roles. One of its targets are mammary glands, which causes milk to move into the ducts during breastfeeding.
Oxytocin also acts on muscles within uterine walls causing contractions during childbirth. Essentially, oxytocin levels rise when a woman needs to give birth and is what causes labor contractions and pains. In sumary, oxytocin acts on mammary glands in order to move milk into ducts and to help with contractions during childbirth.
Antidiuretic hormone, also abbreviated ADH, is another produced in the hypothalamus and stored in axon endings within the posterior lobe. Antidiuretic hormone plays a role in kidney nephrons. Antidiuretic hormone causes water to be conserved within kidney nephrons, lowering someone's urine output.
If we take a look at our anterior lobe, hormone secretion works little bit differently. Neurons within the hypothalamus will secrete certain hormones into capillaries at the base of the hypothalamus. From there blood will flow from capillaries on the hypothalamus to the more capillaries on the anterior lobe. The hormones from the hypothalamus will the enter the anterior pituitary and coordinate which hormones to secrete. The hormones secreted from the anterior pituitary will then enter the bloodstream and circulate to their targets.
So this lesson has been an overview on the role of the hypothalamus and pituitary gland in the endocrine system. Specifically, the lesson focused on the posterior lobe, oxytocin, antidiuretic hormones, the anterior lobe, and .
Keep up the learning and have a great day!
Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND
Also called the adenohypophysis, the anterior lobe of the pituitary gland started developing in the nasopharynx and migrated up into the skull to join with the posterior lobe of the pituitary gland. Since the anterior pituitary didn’t originate in the brain there are no direct neural connections to it. The anterior pituitary gland secretes six hormones: growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH), prolactin, luteinizing hormone (LH), and follicle stimulating hormone (FSH).
A part of the forebrain that works closely with the pituitary gland to monitor the body's organs and their functioning.
Called the “master gland” because of its effects on other glands; endocrine hormones increase activity/secretion of many major glands of the endocrine system.
Also called the neurohypophysis, the posterior lobe of the pituitary gland developed from brain tissue during embryonic development and therefore is directly innervated by the hypothalamus. The two hormones the posterior pituitary secretes are anitdiuretic hormone (ADH) and oxytocin.