Endocrine, Kidney, and Calcium Regulation

Question 1

Physiology of the adrenal gland

Answer 1

2 divisions- Inner medulla and outer cortex.

The cortex can be divided further into the inner zona recticularis, middle zona fasciculata, and outer zona glomerulus.

Question 2

What does the medulla and cortex of the adrenal gland release?

Answer 2

The medulla releases epinephrine and norepinephrine.

The cortex can be divided into 3 layers from inner to outer:

1. Zona reticularis releases androgens and cortisol
2. Zona fasciculata releases cortisol and androgens
3. Zona glomerulosa releases aldosterone (can be released by itself or stimulated to release by RAAS system)

Question 3

Adrenal gland insufficiency

1. Caused by what?
2. How does it affect other systems?
3. May lead to

Answer 3

1. Caused primarily by autoimmune attack.
2. Without the release of aldosterone, there will be less Na+ reabsorption and K+ excretion. (imbalance)
3. Imbalance may lead to hypotension since aldosterone works to increase BP when it is low.

Question 4

Primary adrenal insufficiency is known as

Answer 4

Addison’s Disease. Any type of disfunction of the zona glomerulosa.

Question 5

Vasopressin/ADH is released from the posterior pituitary and packaged into secretory vesicles with a carrier protein called

Answer 5

Neurophysin.

Question 6

The posterior pituitary receives axons from which nuclei in the hypothalamus?

Answer 6

Receives axons from the supraoptic nuclei and the paraventricular nuclei.

Question 7

The most common disease of humans and mammals related to antidiuretic hormone is

Answer 7

Diabetes inspidus.

Question 8

Diabetes inspipidus can arise from 2 situations

Answer 8

1. Hypothalamic (central) diabetes. Results from deficiency in secretion of ADH from the posterior pituitary. Could be due to head trauma, or infection.
2. Nephrogenic Diabetes. Occurs when the kidney is unable to respond to ADH. Usually due to renal disease, or mutations in the ADH receptor. Usually associated with AQP2 not functioning properly.

Question 9

Main sign of either type of diabetes insipidus

Answer 9

Excessive urine production.

Question 10

Nephrogenic Diabetes Insipidus occurs due to the loss of function of which aquaporin?

Answer 10

Kidney is unable to respond properly to ADH. usually due to loss of function of AQP2.

Question 11

2 hormone that originate in the Kidney

Answer 11

1. Epo. Causes RBC production in the bone marrow.

2. Calcetrol (D3)

Question 12

If visiting Denver, how long will it take for EPO to turn on/adjust?

Answer 12

2 weeks.

Question 13

When is Epo secreted

Answer 13

In response to hypoxia. Stimulates RBC production.

Produced by fibroblasts in the kidney associated with the proximal convoluted tubule and peritubular capillaries.

Question 14

Activated vitamin D is called

Answer 14

Calciferol. Fat soluble essential vitamin that helps to prevent skeletal disease by maintaining normal levels of calcium and phosphorous in the blood.

Question 15

There are forms of activated and inactivated vitamin D. The kidney and GI tract can respond to which types?

Answer 15

Kidney can respond to all forms of Vitamin D. The GI tract can only respond to activated Vitamin D

Question 16

Where is vitamin D’s receptor on a cell?

Answer 16

It is inside the cell on the nucleus. It is a lipid so it can travel through the membrane.

Majority of receptors are found in the cells of the small intestine.

Vit D binds to nuclear receptor, initiates mRNA to be produced to make calcium channels and put them on the cell membrane.

Allows calcium to enter the cell and be escorted by a calcium binding protein.

Question 17

Hyperparathyroidism

Answer 17

Release of too much parathyroid hormone. Can cause hypoglycemia or hypertension.

Question 18

Hyperglycemia

Answer 18

Secondary effect of hyperparathyroidism. Too much calcium in the blood

Question 19

Parathyroid hormone affects calcium levels how?

Answer 19

Increases levels of calcium in the blood. Causes reabsorption from kidneys and bones.

Question 20

Hypoparathyroidism

Answer 20

Not enough parathyroid hormone release. Low levels of calcium in the blood. Easy fix- take calcium supplement.

Question 21

Cells of the parathyroid gland (2)

Answer 21

1. Chief cells: Make the parathyroid hormone

2. Oxyphil cells. No clue.

Question 22

How does vitamin D affect calcium levels

Answer 22

Vit D promotes bone reabsorption back into the body, but also helps in remineralization of bone by osteoblasts as well.

Question 23

Where are osteoblasts, osteocytes, and osteoclasts located at in the bone

Answer 23

Osteoblasts surround bone that is being made. They secrete it.

Osteocytes are found in the center of the bone being made. They are isolated, but connected by cannaliculi.

Osteoclasts chew up bone and release calcium. Creates a pit called Howship Lacunae.

Question 24

PTH. In addition to stimulating bone reabsorption, it also produces ___, which helps stimulate osteoblasts to remineralize the bone

Answer 24

Growth Factor

Question 25

Thyroid gland contains which types of cells

Answer 25

Has cuboidal follicle cells. In between, are "C" cells. They make 3 proteins

Question 26

What 3 peptides do C cells make of the thyroid?

Answer 26

Procalcitonin and calcitonin-gene related peptide or CGRP (alpha and beta)

Question 27

CGRP is a peptide created by C cells of the thyroid. Now in a new drug that is treating

Answer 27

Migraines.

Question 28

How is calcitonin derived?

Answer 28

C cells of the thyroid make precursor called procalcitonin. Then calcitonin is derived from this. It is a 32 amino acid peptide.

Question 29

Action of calcitonin?

Answer 29

Inhibition of bone reabsorption. Osteoclasts have receptors for calcitonin, causing them to stop. Antagonist of parathyroid hormone.

Question 30

What stimulates calcitonin to be released?

Answer 30

Elevated serum levels of calcium or GI levels such as gastrin.

Question 31

Which organs clear the serum of calcitonin once calcium levels are restored?

Answer 31

Kidney, liver, and bone clear the serum of calcitonin through a G protein receptor.

Question 32

Paget's disease.

Answer 32

Excessive bone reabsorption and bone formation.

Question 33

Which two hormones that are highly active during puberty favor bone growth?

Answer 33

Estrogen and androgens. As people age, these hormones decrease, causing a decline in calcium. They favor bone growth by inhibiting hormones that cause reabsorption.

Question 34

Lack of vitamin D is linked to which diseases?

Answer 34

``` AMD Cardiovascular disease Diabetes Obesity Leukemia ```

Question 35

What is vitamin D dependent rickets type II

Answer 35

Impaired calcium absorption. Generally the receptor that doesn't work is in the intestinal epithelium.

Question 36

Risk factors for osteoperosis

Answer 36

Older than 50 Female Dark skin that cannot absorb Vitamin D from the sun as easily Poor skin integrity due to non healthy epithelial cells obesity malabsorption