Endocrine System | 17.6 & 17.7

What glands are paired, pyramid-shaped and are wedges of glandular and neuroendocrine tissue adhering to the top of the kidneys by a fibrous capsule?

Adrenal Glands

What is the location of the Adrenal glands?

• Retroperitoneal (Retro = behind) (Peritoneal = serous membrane)

• Suprarenal (Above = Kidney) (Arenal = Kidneys)

How many regions does the Adrenal Glands have?

Two

• Cortex (Has three layers)

• Medulla

What are the three layers of the adrenal cortex?

• Zona Glomerulosa

• Zona Fasciculata

• Zona Reticularis

The Adrenal Cortex are stimulated by what hormone?

Adrenocorticotropic hormone (ACTH)

Adrenal Cortex is made of what tissue?

Glandular Tissue

Adrenal Medulla is made of what tissue?

Nervous Tissue

• Neuroendocrine Tissue

• Postganglionic sympathetic nervous system (SNS) neurons.

What is the hypothalamic-pituitary-adrenal (HPA) axis?

A hormonal pathway in which the hypothalamus stimulates the pituitary to release adrenocorticotropic hormone (ACTH), and ACTH then stimulates the adrenal cortex to produce cortisol.

What does the hypothalamic-pituitary-adrenal (HPA) axis help regulate?

The long-term stress response, blood pressure, and blood volume, nutrient uptake and storage, fluid and electrolyte balance, and inflammation.

The Adrenal Medulla is really an extension of?

The autonomic nervous system

• regulates homeostasis in the body.

The sympathomedullary (SAM) pathway involves the?

Stimulation of the medulla by impulses from the hypothalamus via neurons from the thoracic spinal cord.

One of the major functions of the adrenal gland is to respond to?

Stress

• Physical Stress

• Psychological Stress

What is general adaptation syndrome (GAS)?

The pattern the body follows when responding in different ways to short-term and long-term stress.

• Has three stages

What is the Alarm Reaction?

• Stage one of GAS

• Short-term stress

• The fight-or-flight response

• Mediated by the hormones epinephrine and norepinephrine from the adrenal medulla via the SAM pathway.

What is the function of Alarm Reaction?

Prepare the body for extreme physical exertion.

What is Stage of resistence?

• Stage two of GAS

• Occurs when stress is not relieved, the body adapts to stress in the second stage

• Ex: A person is starving for example, the body may send signals to the gastrointestinal tract to maximize the absorption of nutrients from food.

What is the Stage of Exhaustion?

• Stage three of GAS

• Individuals may begin to suffer depression, the suppression of their immune response, severe fatigue, or even a fatal heart attack.

Zona Fasciculata releases what kind of hormones?

Glucocorticoids

• Regulate glucose metabolism

Zona Reticularis releases what kind of hormones?

Androgens

• Stimulate masculinization

Zona Glomerulosa releases what kind of hormones?

Mineralcorticoids

• Regulate mineral balance

Adrenal Medulla release what kind of homones?

Stress hormones

• Stimulate Sympathetic automatic nervous system

• Catecholamines

Mineralcorticoids example and what does it do?

Aldosterone

• Increases Na levels

• Decreases Potassium Levels

• Controls Minerals

Glucocorticoids example and what does it do?

Cortisol

Corticosterone

Cortisone

• Increases blood glucose levels

• Anti-inflammatory function

• Immunosuppression

• Controls glucose

Androgens example and what does it do?

Dehydroepiandrosterone

• Used to boost low levels, increase libido, improve mood, and aid with conditions like adrenal insufficiency.

Stress hormones example and what does it do?

Epinephrine

Norepinephrine

• Stimulates fight or flight response

What is released in response to elevated blood K⁺, low blood Na⁺, low blood pressure, or low blood volume?

Aldosterone

What is the renin-angiotensin-aldosterone system (RAAS)?

Specialized cells of the kidneys secrete the enzyme renin in response to low blood volume or low blood pressure.

The adrenal medulla is stimulated by the?

The Sympathetic Nervous System

During puberty and most of adulthood, androgens are produced in the?

Gonads (Ovaries and Testes)

Gonads are produced in response to ACTH from the anterior pituitary and are converted in the tissues to?

Testosterone or estrogens

What are the unique postganglionic SNS neurons that are large, irregularly shaped, and shaped, and produce the neurotransmitters epinephrine (also called adrenaline) and norepinephrine (or noradrenaline)?

Chromaffin cells,

Conn’s syndrome is caused by?

Hyperaldosteronism

• Overproduction of aldosterone

Cushing’s disease is caused by?

Hyperadrenocorticism

• Overproduction of cortisol

• The accumulation of lipid deposits on the face and neck.

• High blood glucose levels

Hypocorticism is caused by?

Addison’s Disease

• a rare disorder that causes low blood glucose levels and low blood sodium levels. The

Goiter is caused by?

• iodine deficiency

• Hashimoto’s Disease

• Grave’s disease

• Thyroid nodules

• Thyroid Cancer

• Pregnancy

• Inflammation

What is Hashimoto’s disease?

An autoimmune disorder where the immune system mistakenly attacks the thyroid gland, leading to its damage and reduced hormone production

• causes goiter

When is cortisol highest in our body?

When we wake up in the morning

What gland is Inferior but somewhat posterior to the thalamus and attached to the 3rd ventricle of the brain?

The Pineal Gland

The pineal gland is made up of what kind of cells?

Pinealocyte cells

The pineal gland is known to produce and secrete the hormone?

Melatonin

• Derived from serotonin

The secretion of melatonin varies according to the?

Level of light received from the environment

• The more light = the less melatonin = more awake

• Less light = more melatonin = less awake

The secretion of melatonin may influence the body’s?

Circadian rhythms, the dark-light fluctuations that affect not only sleepiness and wakefulness, but also appetite and body temperature.

Who have higher melatonin levels, children or adults?

Children

• Prevent the release of gonadotropins from the anterior pituitary, thereby inhibiting the onset of puberty.

What is the function of melatonin?

Regulates biological clock

What is melatonin linked too?

• Seasonal affective disorder (SAD)

• Jet lag

What are Catecholamines?

Group of hormones

• Norepinephrine

• Epinephrine

• Dopamine