Endocrine Introduction

Question 1

What types of epithelial do glands have?

Answer 1

Glands are comprised of cuboidal or columnar epithelial cells surrounded by a basement

Question 2

Exocrine Gland

Answer 2

Maintain contact with tissue surface; secrete products into ducts.

Question 3

Endocrine glands

Answer 3

Lose contact with surface; secretions enter/exit the blood stream via fenestrated capillaries to affect tissues usually far from the site of secretion.

Question 4

Glycoproteins examples

Answer 4

FSH and LH

Question 5

Peptides hormones

Answer 5

Oxytocin, Vasopressin, hypothalamic hormones, Calcitonin

Question 6

Modified amino acids

Answer 6

Noradrenaline, adrenaline, thyroxine

Question 7

What kind of receptors do protein/peptide hormones bind to? What about steriods?

Answer 7

Protein/peptides bind to cell surface receptors while steroids bind to intracellular/cytoplasmic receptors.

Question 8

Protein/peptide hormones are hydrophilic or hydrophobic?

Answer 8

Hydrophilic

Question 9

Other names of anterior lobe of pituitary

Answer 9

Pars distalis or adenohypophysis

Question 10

other names of posterior lobe of pituitary

Answer 10

Pars nervosa

Question 11

What is anterior pituitary embryologically derived from?

Answer 11

Rathke’s pouch (oral ectoderm)

Question 12

Posterior pituitary embryological origin

Answer 12

Infundibulum (neural ectoderm)

Question 13

What is the primary Plexus?

Answer 13

Collection of blood vessels at the base of hypothalamus called median eminence.

It allows collection of secretory products from the hypothalamus into portal veins.

Question 14

What is the secondary plexus?

Answer 14

Capillary bed that baths the cells of adenohypophysis. Joined to the primary capillary plexus by portal veins.

Question 15

Three types of cells in the anterior pituitary

Answer 15

1. Basophilic
2. Acidophilic
3. Chromophobic

Question 16

Basophilic cells

Answer 16

Stain blue/light pink because they contain glycoproteins that bind basophil dyes.

Contains FSH, LH, POMC and ACTH

Question 17

Acidophilic cells

Answer 17

Stain dark pink and contain growth and prolactin hormones.

Question 18

List the 7 hormones, common names, target and effect

Answer 18

Question 19

Where are the cell bodies of neurons secreting oxytocin?

Answer 19

Ventromedial nuclei of the hypothalamus

Question 20

Where are the cell bodies of the neurons secreting vasopressin?

Answer 20

Supraoptic nuclei of hypothalamus

Question 21

What are the 3 cell types of posterior pituitary?

Answer 21

1. Pituicytes- astrocytes
2. Herring bodies
3. Endothelial cells

Question 22

Herring bodies

Answer 22

terminal portions of the axonal processes that contain stored hormones.

Question 23

How are oxytocin and vasopressin transported?

Answer 23

They are transported through the axon as prepro-oxytocin and prepro-vasopressin attached to carrier proteins called neurophysins.

Question 24

Parafollicular cells

Answer 24

Neural crest derived cells in the thyroid that secrete calcitonin.

Question 25

Thyroid follicle

Answer 25

Spherical structures comprised of cuboidal epithelial cell called follicular cells. Follicular cells produce and secrete thyroglobulin, the precursor to thyroxine which is then stored as Colloid.

Question 26

Production of thyroid hormones

Answer 26

TSH binds to the follicular cell, thyroglobulin is endocytosed, delivered to lysosomes and proteolyzed to produce active T3 and T4.

Question 27

Difference between T3 and T4

Answer 27

T4 is more stable but T3 is more bioactive

Question 28

What happens if TH is too during development

Answer 28

Cretinism Short stature, cognitive deficits.

Question 29

What can cause hypothyroidism? (3 things)

Answer 29

1. Iodine deficiency 2. Iodine uptake or oxidation impaired 3. Autoimmune destruction of thyroglobulin or thyroid peroxidase (Hashimoto's syndrome)

Question 30

What happens in Iodine deficiency

Answer 30

Lower TH, increase in TSH due to lack of negative feedback. Increased TSH leads to hypertrophy of follicular cells to make more TH (goiter)

Question 31

Grave's disease

Answer 31

hyperthyroid condition in which antibodies constitutively activate the TSH receptor. Thus, thyroglobulin and TH are enhanced but TSH is lowered. Symptoms: bulging of the eyes, increased appetite but weight loss

Question 32

How are Ca2+ and PO4 stored in the bone matrix?

Answer 32

As hydroxyapatite

Question 33

What are the two cell types of parathyroid?

Answer 33

1. Principle or chief cells 2. Oxyphilic cells

Question 34

Chief cells

Answer 34

small lightly stained cells with large centrally located nuclei. Release PTH in response to low Ca++.

Question 35

What does PTH do for Ca++ in bone?

Answer 35

Stimulate the differentiation of osteoclasts to increase Ca++

Question 36

Too much PTH leads to...

Answer 36

Kidney stones

Question 37

Too little PTH leads to

Answer 37

Harmful effect on nerve, muscle function

Question 38

Oxyphil cells

Answer 38

larger, appear in clusters, eosinophilic

Question 39

How does Calcitonin regulate Ca and PO4

Answer 39

inhibit bone resorption through its ability to inhibit osteoclast function. Increase Ca++ excretion in the urine.

Question 40

What is the adrenal cortex derived from?

Answer 40

Mesoderm

Question 41

Adrenal medulla derived from

Answer 41

Neural crest

Question 42

Different between norepinephrine containing chromaffin cells and epinephrine containing chromaffin cells

Answer 42

Norepinphrine: More densely stained core Epinephrine: less dense stained core

Question 43

What is the biggest layer of the adrenal cortex?

Answer 43

Zona Fasciculata

Question 44

Zona glomerulosa

Answer 44

Round cells in clusters, separated by CT and lipid droplets. Secretes Aldosterone

Question 45

Zona Fasciculata

Answer 45

Arranged as cords, one cell layer separated by CT+ capillaries. Round nuclei Vacuolated cytoplasm indicates high lipid-spongiocyte Secretes Glucocorticoids

Question 46

Zona Reticularis

Answer 46

Small cells, irregular network, surrounded by blood vessels and CT Secretes androgen precursors

Question 47

What would hypophysectomy lead to?

Answer 47

Hypophysectomy is surgical removal of pituitary and it will lead to adrenal corticol atrophy