Adrenal gland diagram

Learning Objectives By the end of this section, you will be able to: • Distinguish the types of intercellular communication, their importance, mechanisms, and effects • Identify the major organs and tissues of the endocrine system and their location in the body Communication is a process in which a sender transmits signals to one or more receivers to control and coordinate actions. In the human body, two major organ systems participate in relatively “long distance” communication: the nervous system and the endocrine system. Together, these two systems are primarily responsible for maintaining homeostasis in the body. Neural and Endocrine Signaling The nervous system uses two types of intercellular communication—electrical and chemical signaling—either by the direct action of an electrical potential, or in the latter case, through the action of chemical neurotransmitters such as serotonin or norepinephrine. Neurotransmitters act locally and rapidly. When an electrical signal in the form of an action potential arrives at the synaptic terminal, they diffuse across the synaptic cleft (the gap between a sending neuron and a receiving neuron or muscle cell). Once the neurotransmitters interact (bind) with receptors on the receiving (post-synaptic) cell, the receptor stimulation is transduced into a response such as continued electrical signaling or modification of cellular response. The target cell responds within milliseconds of receiving the chemical “message”; thi...

Overview What are adrenal disorders? There are many conditions that can lead to problems with the adrenal gland function. The adrenal glands are small and shaped liked triangles and are located just above each kidney. They are sometimes called suprarenal glands. Their job is to make hormones that you need to keep your metabolism, blood pressure, immune system and stress response in balance. Adrenal disorders are the result of your glands making too much or not enough of certain hormones. Hormones produced by the adrenals include hydrocortisone (also called cortisol), adrenaline and aldosterone. You can think of dominoes and how one movement by one domino sets off a chain reaction, making the next domino in line fall down. If something happens and the next domino doesn’t get the message, the effect is ruined. What are common types of adrenal disorders? There are different conditions related to your adrenal glands. Some of the most common include: • • • • Adrenal gland suppression. This is a type of adrenal insufficiency that is related to outside sources of cortisol or related synthetic hormones such as prednisone or dexamethasone. • • Virilization. This condition happens when your body produces too much of the male sex hormones and is only apparent in females or boys before puberty. There are also conditions of the adrenal glands related to growths (tumors). These include: • Adrenal gland tumors. Tumors can disrupt hormone output, but are usually noncancerous. • • Pheochro...

Learning Objectives By the end of this section, you will be able to: • Describe the location and structure of the adrenal glands • Identify the hormones produced by the adrenal cortex and adrenal medulla, and summarize their target cells and effects The adrenal glands are glandular and neuroendocrine tissue adhering to the top of the kidneys by a fibrous capsule ( Figure 17.6.1 – Adrenal Glands: Both adrenal glands sit atop the kidneys and are composed of an outer cortex and an inner medulla, all surrounded by a connective tissue capsule. The cortex can be subdivided into additional zones, all of which produce different types of hormones. LM × 204. (Micrograph provided by the Regents of University of Michigan Medical School © 2012) External Website View the University of Michigan WebScope at The adrenal gland consists of an outer cortex of glandular tissue and an inner medulla of nervous tissue. The cortex itself is divided into three zones: the zona glomerulosa, the zona fasciculata, and the zona reticularis. Each region secretes its own set of hormones. The adrenal cortex, as a component of the hypothalamic-pituitary-adrenal (HPA) axis, secretes steroid hormones important for the regulation of the long-term stress response, blood pressure and blood volume, nutrient uptake and storage, fluid and electrolyte balance, and inflammation. The HPA axis involves the hypothalamus stimulating the release of adrenocorticotropic hormone (ACTH) from the pituitary. ACTH then stimulate...

Adrenal glands Located on top of each kidney, the adrenal glands make hormones that help regulate metabolism, the immune system, blood pressure and other important functions. Although small, these glands control much of what happens in the body. Adrenal cancer is a rare cancer that begins in one or both of the small, triangular glands (adrenal glands) located on top of your kidneys. Adrenal glands produce hormones that give instructions to virtually every organ and tissue in your body. Adrenal cancer, also called adrenocortical cancer, can occur at any age. But it's most likely to affect children younger than 5 and adults in their 40s and 50s. When adrenal cancer is found early, there is a chance for cure. But if the cancer has spread to areas beyond the adrenal glands, cure becomes less likely. Treatment can be used to delay progression or recurrence. Most growths that form in the adrenal glands are noncancerous (benign). Benign adrenal tumors, such as adenoma or pheochromocytoma, also can develop in the adrenal glands. Symptoms Signs and symptoms of adrenal cancer include: • Weight gain • Muscle weakness • Pink or purple stretch marks on the skin • Hormone changes in women that might cause excess facial hair, hair loss on the head and irregular periods • Hormone changes in men that might cause enlarged breast tissue and shrinking testicles • Nausea • Vomiting • Abdominal bloating • Back pain • Fever • Loss of appetite • Loss of weight without trying Causes It's not clear...

• Identify the functional anatomy and zones of the adrenal glands and the principal hormones secreted from each zone. • Describe and contrast the regulation of synthesis and release of the adrenal steroid hormones (glucocorticoids, mineralocorticoids, and androgens) and the consequences of abnormalities in their biosynthetic pathways. • Understand the cellular mechanism of action of adrenal cortical hormones and identify their major physiologic actions, particularly during injury and stress. • Identify the major mineralocorticoids, their biologic actions, and their target organs or tissues. • Describe the regulation of mineralocorticoid secretion and relate this to the regulation of sodium and potassium excretion. • Identify the causes and consequences of oversecretion and undersecretion of glucocorticoids, mineralocorticoids, and adrenal androgens. • Identify the chemical nature of catecholamines and their biosynthesis and metabolic fate. • Describe the biologic consequences of sympatho-adrenal medulla activation and identify the target organs or tissues for catecholamine effects along with the receptor types that mediate their actions. • Describe and integrate the interactions of adrenal medullary and cortical hormones in response to stress. • Identify diseases caused by oversecretion of adrenal catecholamines. The adrenal glands are important components of the endocrine system. They contribute significantly to maintaining homeostasis particularly through their role in t...

Adrenal glands Located on top of each kidney, the adrenal glands make hormones that help regulate metabolism, the immune system, blood pressure and other important functions. Although small, these glands control much of what happens in the body. Benign adrenal tumors are noncancerous masses that form in the adrenal glands. As part of the endocrine system, the adrenal glands produce hormones that give instructions to nearly every organ and tissue in the body. You have two adrenal glands, one located above each kidney. Each gland contains two tissue types: the cortex and the medulla. Benign adrenal tumors that develop in the cortex are also called adrenal adenomas. Those that develop in the medulla are also called pheochromocytomas (fee-o-kroe-moe-sy-TOE-muhs). Most benign adrenal tumors cause no symptoms and don't need treatment. But sometimes these tumors secrete high levels of certain hormones that can cause complications. The most common hormones that can be over-secreted are aldosterone and cortisol from the cortex and adrenalin hormones from the medulla. In these cases, benign adrenal tumor treatment may include surgery or medications. • Adenoma of the adrenal gland. Genetics and Rare Diseases Information Center. https://rarediseases.info.nih.gov/diseases/5745/adenoma-of-the-adrenal-gland. Dec. 16, 2019. • AskMayoExpert. Pheochromocytoma. Mayo Clinic; 2019. • Lacroix A. Clinical presentation and evaluation of adrenocortical tumors. https://www.uptodate.com/contents/sea...