Lecture 22: Endocrine System - Thyroid and Parathyroid Glands

Question 1

What does thyroid dysfunction (hypothyroidism/hyperthyroidism) cause?

Answer 1

Cretinism, myxedema, Graves’ disease, and other pathologies

Question 2

What does parathyroid dysfunction (hyperparathyroidism/hypoparathyroidism) cause?

Answer 2

Overexcitement of muscle and nervous systems, bone demineralization, high calcium levels, duodenal ulcers, kidney stones, and behavioral disorders.

Question 3

Thyroid gland functions

Answer 3

Regulation of intensity and rate of metabolic/chemical reactions

Question 4

What are the right and left lobes of the thyroid gland connected by?

Answer 4

The isthmus

Question 5

What is the thyroid gland mostly made of?

Answer 5

Follicles that are made of two types of cells that they produce: thyroxine/tetraiodothyronine/T4 and triiodothyronine T3

Question 6

What do the parafollicular cells (C cells) make?

Answer 6

Calcitonin

Question 7

What does the thyroid need eaten?

Answer 7

Iodine, since its chemistry is iodine based. If it doesn’t get enough, the thyroid swells, causing Benign goiter.

Question 8

What are nodules

Answer 8

Cancerous thyroid tumors that are caused by people having their face irradiated.

Question 9

Where are hormones stored in the thyroid?

Answer 9

In the follicles and will last three months.

Question 10

Amino acids and iodine are synthesized into what?

Answer 10

Thyroglobulin; they are stored in the follicles as colloid.

Question 11

What do thyroid hormones manage?

Answer 11

Oxygen uptake; gross basal metabolic rate; body temperature regulation; protein synthesis; lipid and cholesterol breakdown; body growth rate and NS development; effects of catecholamines.

Question 12

What are the effects of catecholamines in hyperthyroid patients?

Answer 12

High blood pressure, nervousness, sweating, and fast heart rate.

Question 13

Process of iodine in follicular cells

Answer 13

1. Follicular cells search them out and attract them
2. Taken in through capillaries and are trapped in the endoplasmic reticulum
3. Follicles synthesize thyroglobulin
4. Small transport veins (vesicles) take iodine deeper into the follicles
5. There it is combined with thyroglobulin to make amino acid tyrosine

Question 14

What is cretinism

Answer 14

Hypothyroidism during fetal development. It causes mental retardation, physical deformities, and dwarfism

Question 15

What is myxedema

Answer 15

Hypothyroidism during adult life; causes edema, slow heart rate, low blood pressure, lethargy, sensitivity to cold, low body temperature, muscle weakness, hair loss, and obesity

Question 16

What is myxedema madness?

Answer 16

Psychotic episodes that are caused by myxedema

Question 17

What does hyperthyroidism cause?

Answer 17

Increased heart rate and blood pressure; high body temperature and sweating, nervousness, diarrhea, heat intolerance, and weight loss

Question 18

What is Graves’ disease?

Answer 18

Autoimmune disorder; antibodies are not controlled and imitate TSH effects. Results in goiter, thyroid enlargement, and exophthalmos.

Question 19

What do the four parathyroid glands do?

Answer 19

Regulates calcium and potassium levels in the blood. The chief cells (principal cells) produce parathormone (PTH) and oxyphil cells.

Question 20

Define “parathyroid”

Answer 20

“beside the thyroid”

Question 21

Name the four parathyroid glands

Answer 21

1. left inferior
2. right inferior
3. left superior
4. right superior

Question 22

Effects of PTH

Answer 22

Raise levels of phosphorus and serum calcium; increases osteoclasts (bone cells) for reabsorption of calcium, calcium urinary reabsorption in the kidneys, phosphorus excretion in the kidneys.

Question 23

What does potassium cause the kidneys to do?

Answer 23

Form calcitriol (hormone made from vitamin D) that increases calcium absorption from the GI tract.

Question 24

What does calcitonin from the thyroid gland do?

Answer 24

Is involved in forcing calcium back into bones because of the negative feedback system

Question 25

What causes hyperparathyroidism?

Answer 25

PTH is increased in production, normally because of a parathyroid adenoma. Calcium from the kidneys, stomach, and bones is reabsorbed into the blood. It causes kidney stones, osteoporosis, duodenal ulcers, and psychosis

Question 26

What is parathyroid adenoma

Answer 26

A benign tumor in one or more of the parathyroid glands.

Question 27

Results of hypoparathyroidism

Answer 27

Elevated nerve and muscle excitement, low serum calcium levels, and when extreme, convulsions and death

Question 28

What is exophthalmos?

Answer 28

Bulging eyeballs because of fat deposited behind the eye