Lecture 14: Adrenal Medulla Hormones

How are Epi and Norepi produced/secreted?

There are Braches of the Sympathetic Nervous System that extend out into the Adrenal Medulla. And when these branches secrete neurotransmitters, those neurotransmitters bind to those Chromaffin cells in the Adrenal Medulla and that stimulates them to produce Epi and Norepi.

Which type of hormones (steroid/amino acid-based) are released during short term stress and which endocrine gland secretes them? What are the effects?

The Sympathetic Nervous System acts on short term stress; it stimulates the Adrenal medulla to release/secrete amino acid based hormones (catecholamines, epi and norepi). the effects are: 1. Heart rate increases 2. blood pressure increases 3. bronchioles dilate 4. liver converts glycogen to glucose and release glucose to the bloodstream 5. blood flow changes, reducing digestive system activity and urine output 6. metabolic rate increases

Which type of hormones (steroid/amino acid-based) are released during prolonged stress and which endocrine gland secretes them?

After an action potential is sent, the adrenal cortex eventually receives a signal to release their hormones; the adrenal cortex released steroid hormones, Mineralocorticoids and Glucocorticoids

Why do we overheat after exercise?

Because when we exercise, our metabolism increases. We need more cellular fuel to keep on exercising, so this increase in metabolism also increases cellular respiration. A byproduct of cellular respiration is heat. So our bodies overheat and then we sweat to cool down.

Which hormones do the Adrenal Medulla make?

Catecholamines

What are Catecholamines? Which adrenal medulla cells secrete these?

Epinephrine and Norepinephrine; the medullary Chromaffin cells synthesize Catecholamines.

What is a result of hypersecretion of Catecholamines?

Hyperglycemia, increased metabolic rate, rapid heartbeat and palpitations, hypertension, intense nervousness, and sweating

Why does heart rate go up as a response to a stressful situation?

You've gotta keep the blood pumping faster and faster to your tissue to make sure they get the bloodflow they need.

What are heart palpitations?

a feeling that your heart is beating too hard or too fast, skipping a beat, or fluttering.

Why does Epi and Norepi increase blood pressure?

because they enhance vasoconstriction, which causes the blood vessels to constrict/narrow (which is almost like when you squeeze a hose pipe and the water starts to run out harder or skeet everywhere)

1. Stress is detected and sent to the hypothalamus 2. Nerve impulses are sent 3. Nerve impulse reaches the spinal cord 4. Preganglionic sympathetic fibers receive the impulse and send it to the: 5. Adrenal medulla (secreted amino acid-based hormones) 6. Catecholamines are secreted (epi and norepi) Is this the short term stress response pattern or the long term stress response pattern?

short term (Sympathetic Nervous System)

When we get an Adrenaline rush, where does it come from?

the Sympathetic Nervous System but also from the Adrenal Medulla

Because ___ ___ delivers oxygen, gas, and nutrients to your tissues; it carries away waste; if you increase this, what will happen to the oxygen, gas, and nutrients?

Because blood pressure delivers oxygen, gas, and nutrients to your tissues; it carries away waste; if you increase your Blood pressure, these things will happen more quickly and the blood will flow more quickly throughout the body.

If you're in a fight or flight situation, your cells have to metabolize more quickly to help you get through it. So you need increased __ __ to deliver more oxygen, gas, and nutrients. These cells are more metabolically active so they'll produce more waste from their metabolism. Wastes have to be carded away otherwise they would build up and become toxic.

If you're in a fight or flight situation, your cells have to metabolize more quickly to help you get through it. So you need increased BLOOD FLOW to deliver more oxygen, gas, and nutrients. These cells are more metabolically active so they'll produce more waste from their metabolism. Wastes have to be carded away otherwise they would build up and become toxic.

After prolonged stress, which effects are produced by the high and constant levels of Mineralocorticoids (Aldosterone) and Glucocorticoids (Cortisol) from the Adrenal cortex in your bloodstream?

Mineralocorticoids (Aldosterone): 1. kidneys retain Na+ and water 2. blood volume and blood pressure rise Glucocorticoids (Cortisol) 1. Proteins and fats converted to glucose or broken down for energy 2. Blood glucose increases 3. Immune system suppressed 4. Fatty levels stay too high

When the bronchioles are dilated (opened wider to help you breathe), what is being released or taken in?

O2 in CO2 out

What is Hyperglycemia?

high blood sugar/glucose

Why do we need to increase blood pressure?

Because blood pressure delivers oxygen, gas, and nutrients to your tissues; it carries away waste; if you increase your Blood pressure, these things will happen more quickly and the blood will flow more quickly throughout the body.

Mineralocorticoids (Aldosterone): 1. kidneys retain Na+ and water 2. blood volume and blood pressure rise Glucocorticoids (Cortisol) 1. Proteins and fats converted to glucose or broken down for energy 2. Blood glucose increases 3. Immune system suppressed 4. Fatty levels stay too high Why are these the effects of high and constant levels of Aldosterone and Cortisol in the bloodstream?

1. Aldosterone helps the kidneys regulate our water/salt (ion) balance, which helps regulate blood pressure./volume. High levels of Aldosterone mean you're holding onto too much water, which is because you're holding onto too much salt. If you're holding onto too much water, this means your blood volume will be too high, which will lead to a rise in blood pressure. 2. Cortisol helps with gluconeogenesis, meaning your body will start using fatty acids and amino acids to make glucose for cellular respiration. So high levels of cortisol means too much gluconeogenesis is occurring, which means too many of your fats and proteins are being converted to glucose or broken down for energy. Blood glucose increases because of gluconeogenesis Immune system is suppressed because high levels of cortisol lead to you being sick more often. Stress = more likely to be sick. Fatty levels stay too high because with gluconeogenesis, your body uses fatty acids and amino acids to convert to glucose for cellular respiration. This will not only increase glucose levels, but will increase fatty acid and protein levels in the blood. Proteins are great for us, but too much fatty acid in the body could lead to other health issue = blockages, heart disease, etc.

Why does hypersecretion of Catecholamines (Epi and Norepi) lead to hyperglycemia, increased metabolic rate, rapid heartbeat and palpitations, hypertension, intense nervousness, and sweating?

1. It causes hyperglycemia (high blood glucose) because (they are responders of stress) so, if you are stressed a lot, your sympathetic system will ignite the fight or flight response, and when you're in the fight or flight response, your body needs more glucose to give energy to the cells who are working harder than normal) ... And also because when you are stressed, cortisol levels increase, which stimulates gluconeogenesis, so your body is constantly making new glucose and there will be high levels in the blood. 2. It causes increased metabolic rate because when your body is in the fight or flight response, our cells need a lot more glucose to use for energy to make ATP in order for them to function. So if you're stressed, your catacholamines will be released and your cortisol levels will be high which causes gluconeogenesis, so you make enough glucose plus more, so your cells are getting more glucose than they need, so they will probably become overactive and your metabolism will be extremely high (which can't be good) 3. Rapid heart beat and palpitations probably because when our body knows we are stressed or anxious our heart beats much faster than normal (Our chemical reactions start happening faster, the body is just fully charged...). This is because catecholamines are released (we have an adrenaline rush) to help us to be able to deal with the stress. 4. It causes hypertension because one of the effects of Catecholamine release is vasoconstriction (which constricts the blood vessels, puts pressure on them, and raise blood pressure).. So if you are producing more catecholamines, your vasoconstriction also increases, and thus your BP will keep rising. 5. Intense nervousness, probably because your body and your metabolism is overcharged 6. We sweat to cool down. Which means that your body overheated to cause the sweating. Heat is a byproduct of cellular respiration. So when you have an increase in catecholamines, that also increases metabolism, which then increases cellular respiration, so you will probably have hot flashes and sweat more often.

What do the Catecholamines do/lead to?

1. Vasoconstriction (which leads to a rise in blood pressure) 2. Increased heart rate 3. Increased blood glucose levels (which make sense because the catecholamines respond to stress by the fight or flight response or relaxing you, and if you're in a fight or flight response, your cells need more glucose for cellular fuel) 4. Blood diverted to the brain, heart, and skeletal muscles (because you need more blood at more vital organs so you can fight or flight) 5. Bronchial dilation (makes wider, so you can breathe better)

What are some effects of hyposecretion of catecholamines?

It is not problematic; Adrenal catecholamines are not essential to life. Even if the adrenal medulla stops making them, they are still secreted by the Sympathetic Nervous System.

All your tissues need help when you're in the fight or flight response, but which are the two most important and need a lot of oxygen, gas, and glucose? Why?

Skeletal muscles, so they can help you run faster, etc

1. Heart rate increases 2. blood pressure increases 3. bronchioles dilate 4. liver converts glycogen to glucose and release glucose to the bloodstream 5. blood flow changes, reducing digestive system activity and urine output 6. metabolic rate increases These happen because of what system and as a response to what?

Sympathetic Nervous System; short term stress

What is the difference between the catecholamines released by the Sympathetic Nervous System vs the Adrenal Medulla?

The Sympathetic Nervous System = norepi is secreted quickly due to you being in a fight or flight stage (stressful scenario) The Adrenal medulla takes longer to make these chemicals but it produces them in greater amounts and they get into the bloodstream and last much longer. Also, The Sympathetic Nervous System (short term) -- neurotransmitters secrete things locally out of synaptic knobs across to other synapses. The Adrenal medulla releases chemicals throughout the whole body