The thyroid, parathyroid and adrenal glands

Question 1

what is the location of the thyroid gland?

Answer 1

the thyroid is a butterfly shaped endocrine gland in the front of the neck.

->located either side of the trachea and is two lateral lobes connected by isthmus in front of trachea.

Question 2

What form does the thyroid store hormones in?

Answer 2

stores hormones in the form of colloids

Question 3

3 functions of the thyroid

Answer 3

1. Regulates BMR
2. Influences growth and maturation of the nervous tissue
3. Regulates blood ca level in conjunction with the parathyroid hormone.

Question 4

what is the thyroid covered by

Answer 4

dense irregular connective tissue capsule

Question 5

what kind of septa

Answer 5

thin collagenous

Question 6

where does the septa extend from

Answer 6

capsule into the gland dividing it into lobules

Question 7

what does the septa carry

Answer 7

blood vessels with lymphatic and nerves

Question 8

what are lobules made up of?

Answer 8

spherical masses called follicles (40-60) per lobule.

the thyroid follicle is the structural unit of the thyroid.

Question 9

What is each follicle lined by?

Answer 9

follicular cells

Question 10

what are follicular cells?

Answer 10

normally cuboidal
have a cavity filled with homogenous material called colloid

Question 11

what do follicular cells secrete?

Answer 11

They secrete two hormones that influence the rate of metabolism[23]: T3 (tri-iodothyronine) and. T4 (tetra-iodothyronine or thyroxine)

Question 12

how do follicular cells vary depending on activity?

Answer 12

Inactive follicular lumina are larger; colloid is abundant and appears solid.

In contrast, active follicular lumina are smaller and there is little to no colloid present.

Question 13

what are the spaces between follicles made up of?

Answer 13

connective tissue with numerous capillaries and lymphatics

Question 14

where are parafollicular cells located?

Answer 14

They are located adjacent to the thyroid follicles and reside in the connective tissue.

Question 15

what are parafollicalar cells also called and what do they secrete?

Answer 15

also called C cells, are neuroendocrine cells in the thyroid. The primary function of these cells is to secrete calcitonin.

Question 16

hormones of the thyroid:

Answer 16

T3 (tri-iodothyronine) and

T4 (tetra-iodothyronine or thyroxine)

Question 17

What is T4 secreted to in the vernal circulation

Answer 17

T3

Question 18

is t3 more potent than t4

Answer 18

yes

Question 19

what do thyroid hormones do?

Answer 19

regulate BMR and influence maturation of nervous tissue

Question 20

what are thyroid hormones regulated by?

Answer 20

TSH of the pituitary which is regulated by TRH of the hypothalamus

Question 21

what is goitre?

Answer 21

enlarged thyroid gland. A goiter may be associated with no change in thyroid function or with an increase or decrease in thyroid hormones.

Question 21

what is calcitonin and what cells secrete it?

Answer 21

parafollicular cells secrete calcitonin. which regulate blood ca levels in cojunction with parathyroid hormone. under control of blood ca level.

reduces bone resorption, hence decreases blood ca level.

Question 22

hypothyroidism

Answer 22

An underactive thyroid (hypothyroidism) is when your thyroid gland does not produce enough of the hormone thyroxine (also called T4).

symtoms
tiredness
weight gain
depression
being sensitive to the cold
dry skin and hair
muscle aches

Question 23

hyperthyroidism

Answer 23

An overactive thyroid, also known as hyperthyroidism or thyrotoxicosis, is where the thyroid gland produces too much of the thyroid hormones.

symtoms
nervousness, anxiety and irritability.
mood swings.
difficulty sleeping.
persistent tiredness and weakness.
sensitivity to heat.
swelling in your neck from an enlarged thyroid gland (goitre)
an irregular and/or unusually fast heart rate (palpitations)
twitching or trembling.

Question 24

what is graves disease?

Answer 24

Graves’ disease is an autoimmune condition where your immune system produces antibodies that cause the thyroid to produce too much thyroid hormone. The cause of Graves’ disease is unknown, but it mostly affects young or middle-aged women and often runs in families.

Question 25

what is thyroiditis?

Answer 25

Thyroiditis is a general term that refers to “inflammation of the thyroid gland”. Thyroiditis includes a group of individual disorders causing thyroidal inflammation but presenting in different ways.

For example, Hashimoto’s thyroiditis is the most common cause of hypothyroidism in the United States.

Question 26

what is hashimotos?

Answer 26

Hashimoto’s thyroiditis is an autoimmune disorder. Normally, your autoimmune system protects your body by attacking bacteria and viruses. But with this disease, your immune system attacks your thyroid gland by mistake. Your thyroid then can’t make enough thyroid hormone, so your body can’t work as well.

Question 27

cells of the parathyroid

Answer 27

chief and oxyphil cells

Question 28

what do chief cells secrete?

Answer 28

secrete parathyroid hormone which increases serum calcium concentration through its effects on bone, kidney, and intestine.

Question 29

effect of parathyroid hormone on the bone

Answer 29

PTH stimulates the release of calcium in an indirect process through osteoclasts which ultimately leads to the resorption of the bones.

Question 30

effect of parathyroid on the kidney

Answer 30

Circulating parathyroid hormone targets the distal convoluted tubule and collecting duct, directly increasing calcium reabsorption.

Parathyroid hormone decreases phosphate reabsorption at the proximal convoluted tubule.

Question 31

effect of parathyroid in the gut

Answer 31

parathyroid hormone indirectly increases calcium absorption from food in the intestine, via its effects on vitamin D metabolism.

Question 32

hyperparathyroidism

Answer 32

Complications of hyperparathyroidism are mainly related to the long-term effect of too little calcium in your bones and too much calcium in your bloodstream. Common complications include: Osteoporosis. The loss of calcium from bones often results in weak, brittle bones that break easily (osteoporosis).

Question 33

what controls the release of Thyroid hormone?

Answer 33

thyroid stimulating hormone TSH which is produced in the anterior pituitary

Question 34

where are the adrenal glands located?

Answer 34

Adrenal glands are embedded in peri- renal adipose near the superior poles of each kidney.

Question 35

how many layers does the adrenal cortex have?

Answer 35

3

Question 36

what does the adrenal cortex secrete?

Answer 36

corticosteroid hormones.

Question 37

The adrenal medulla secretes?

Answer 37

adrenaline and noradrenaline

Question 38

function of the outer fibrous adrenal capsule

Answer 38

The outer fibrous adrenal capsule provides protection.

Question 39

The zona glomerulosa (outer cortex) produces what?

Answer 39

produces mineralocorticoids such as aldosterone.

Question 40

The zona fasciculata (outer cortex) produces what?

Answer 40

produces glucocorticoids such as cortisol.

Question 41

The zona reticularis produces what?

Answer 41

produces weak androgens.

Question 42

what are corticosteroid hormones

Answer 42

Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response, regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior.

Question 43

Mineralocorticoids function

Answer 43

Mineralocorticoids: aldosterone regulates Na+ uptake by renal tubules.

Question 44

Gonadocorticoids are

Answer 44

weak androgens. androgen hormones and estrogen. Androgens produced include testosterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate, which are present in both men and women.

Question 45

Catecholamines

Answer 45

hormones made by your adrenal glands, two small glands located above your kidneys. These hormones are released into the body in response to physical or emotional stress. The main types of catecholamines are dopamine, norepinephrine, and epinephrine.