Development, Gross Anatomy and Functional Histology of the Suprarenal Gland

Question 1

Where are the suprarenal glands located?

Answer 1

In the superior pole of the kidneys, there are two glands: one left and one right.

They lie between the superomedial aspect of the kidney and the diaphragm

Question 2

What are the fascial relations of the kidney?

Answer 2

Fibrous capsule
Perirenal fat
Renal fascia
Pararenal fat

Question 3

What separates the suprarenal gland from the kidney?

Answer 3

The perirenal fat

Question 4

What is the shape of the right suprarenal galnd?

Answer 4

Pyramidal in shape

Question 5

What is the shape of the left suprarenal gland?

Answer 5

Crescentic in shape

Question 6

What are the relations of the right suprarenal gland?

Answer 6

Anterior: Liver and IVC
Posteriorly: Right crus of the diaphragm

Question 7

What are the relations of the left suprarenal gland?

Answer 7

Anterior: Stomach, pancreas and spleen
Posterior: Left crus of the diaphragm

Question 8

What are the the cruses of the diaphragm?

Answer 8

Part of the origin of the diaphgram

Question 9

What is the cavity between the stomach and the adrenal gland?

Answer 9

The lesser sac

Question 10

What are the parts of the suprarenal gland?

Answer 10

Medulla and the cortex

Question 11

What are the layers of the cortex of the suprarenal gland?

Answer 11

Zona glomerulosa
Zona fasciculata
Zona reticularis

Question 12

What are the embryological origins of the medulla and the cortex?

Answer 12

Medulla: ectoderm (neural crest cells)
Cortex: mesoderm

Question 13

What is the developmental process of the formation of the fetal cortex?

Answer 13

1. Mesenchymal cells on each side of the embryo
2. Located between the root of the dorsal mesentery and the urogenital ridge
3. Formation of the fetal cortex from the aggregate of these mesenchymal cells

Question 14

What is the fetal cortex?

Answer 14

The first stage of the process of the cortex development

Question 15

What occurs with the formation of the fetal cortex?

Answer 15

Neural crest cells arrive

Question 16

Where are neural crest cells derived from?

Answer 16

Neural tube

Question 17

What kind of cells do neural crest cells give rise to?

Answer 17

Neurons
Glia
Melanocytes

Question 18

What happens following the arrival of the neural crest cells?

Answer 18

The neural crest cells form a mass on the medial side of the fetal cortex; cells differentiate into secretory cells of the medulla

Question 19

What are chromaffin cells?

Answer 19

They are cells that stain positive with the chromaffin stain

Question 20

Where are medullary chromaffin cells derived from?

Answer 20

Neural crest cells

Question 21

What happens after the differentiation of medullary chromaffin cells into the medulla?

Answer 21

1. A 2nd wave of mesothelial cells penetrates the underlying mesenchyme
2. Aggregate of cells surround the fetal cortex and form the definitive cortex

Question 22

Where do the different zone develop from?

Answer 22

Zona glomerulosa: Definitive cortex
Zona fasciculata: Definitive cortex
Zone reticularis: fetal cortex regression

Question 23

What is the different theory regarding the development of the layers of the cortex?

Answer 23

A second theory claims that all zones are derived from the definitive cortex and the fetal cortex is simply degraded

Question 24

What are the cells of the adrenal cortex like?

Answer 24

Typical ultrastructure of steroid-secreting cells
They do not store their secretory products in granules

Question 25

Why are there lipids in the cells of the adrenal cortex?

Answer 25

They are part of the synthesis of the steroid hormones

Question 26

Why is SER so abundant in adrenal cortex cells?

Answer 26

It is involved in the synthesis of steroid hormones

Question 27

What is the difference between RER and SER?

Answer 27

RER has ribosomes and is usually associated with peptide-hormone secretion

Question 28

What kind of cells does zona glomerulosa consist of?

Answer 28

Rounded clusters of columnar/pyramidal cells

Question 29

What do the cells of the zona glomerulosa secrete?

Answer 29

Mineralocorticoids

Question 30

What is an example of mineralocorticoids?

Answer 30

Aldosterone --> balances potassium and sodium

Question 31

What % of the cortex does zona glomerulosa make up?

Answer 31

15% of cortex

Question 32

What cells does zona fasciculata consist of?

Answer 32

Long cords of large polyhedral cells which form bundles

Question 33

What are the cells of the zona fasciculata also called?

Answer 33

Spongycytes because they contain a great number of lipid droplets in their cytoplasm

Question 34

What do the cells of the zona fasciculata secrete?

Answer 34

Glucocorticoids and small amounts of sex hormones

Question 35

What is an examples of glucocorticoids?

Answer 35

Cortisol

Question 36

What % of the cortex does the zona fasciculata account for?

Answer 36

65 to 80%

Question 37

What kind of cells does the zona reticularis consist of?

Answer 37

Smaller cells, heavily stained

Question 38

Why are the cells of the zona reticularis heavily stained?

Answer 38

They contain less lipid droplets

Question 39

What do the cells of the zona reticularis form?

Answer 39

Network of irregular cords, interspersed with wide capillaries

Question 40

WHat do the cell of the zona reticularis secrete?

Answer 40

Mainly sex hormones and cortisol

Question 41

What is an example of sex hormone secreted by the zona reticularis?

Answer 41

DHEA --> helps produce other hormones such as testosterone and estrogen

Question 42

What % of the cortex does the zona reticularis make up?

Answer 42

10% of the cortex

Question 43

What are the cells of the adrenal medulla like?

Answer 43

Large polyhedral cells arranged in cords or clumps

Question 44

What is the most abundant cell in the adrenal medulla?

Answer 44

Chromaffin cells from the neural crest cells

Question 45

What other structures does the adrenal medulla contain? (2)

Answer 45

1. Single or groups of sympathetic ganglions and preganglionic sympathetic nerve bundles --> thus the adrenal medulla has a close relation to the sympathetic nervous system 2. Presence of sinusoidal capillaries

Question 46

What hormones does the adrenal medulla secrete?

Answer 46

Adrenaline/epinephrine (80%) Noradrenaline/norepinephrine (20%)

Question 47

What are the cells of the suprarenal gland medulla like?

Answer 47

Medullary cells have abundant membrane-limited electron-dense secretory cells These granules contain one or the other of the catecholamine (epinephrine or norepinephrine)

Question 48

What is the difference in appearance between NE and E secretory cells?

Answer 48

NE cells are larger and more electron-dense compared to E cells

Question 49

What is the arterial supply of the suprarenal gland like?

Answer 49

Superior suprarenal artery Middle suprarenal artery Inferior suprarenal artery

Question 50

What is the root of the superior suprarenal artery?

Answer 50

Inferior phrenic artery

Question 51

What is the root of the middle suprarenal artery?

Answer 51

Abdominal aorta

Question 52

What is the root of the inferior suprarenal artery?

Answer 52

Renal artery

Question 53

Why does the suprarenal gland have three different sources of blood supply?

Answer 53

Cortisol is such a crucial hormone, and since it is secreted by the suprarenal gland, it is important for the gland to have an efficient enough blood supply to provide it even in the case that anything happens

Question 54

Why is there no hilum in the suprarenal gland?

Answer 54

So that there is continuous supply of blood to the gland at different points

Question 56

What is the medullary artery?

Answer 56

It is one of the two supplies of blood for the medulla of the suprarenal gland, it penetrates the cortex and goes straight into the medulla

Question 57

How many blood supplies does the medulla have?

Answer 57

2: Medullary artery Capillaries of the plexus

Question 58

Why are the capillaries of the plexus not enough to supply the medulla of the suprarenal gland?

Answer 58

They have to pass and supply the cortex with oxygenated blood as well so by the time they would have reached the medulla there would be insufficient blood to provide

Question 59

What is the venous drainage of the suprarenal gland?

Answer 59

Right suprarenal vein --> Inferior vena cava Left suprarenal vein --> Left renal vein --> Inferior vena cava

Question 60

Which suprarenal vein is closer to the IVC?

Answer 60

The right suprarenal vein is closer to the IVC and thus drains directly into it

Question 61

Why does the left suprarenal vein not drain directly into the IVC?

Answer 61

It is further away from the IVC, and because of the anterior structures and the fragile nature of the vein, it drains into the renal vein first, and then that one drains into the IVC

Question 62

Which artery is closer to the IVC?

Answer 62

Left suprarenal side of the arteries

Question 63

What is the lymphatic drainage of the suprarenal gland like?

Answer 63

Lumbar aortic nodes and paraaortic nodes

Question 64

What is the parasympathetic system known as?

Answer 64

Craniosacral

Question 65

What is the sympathetic system known as?

Answer 65

Thoracolumbar

Question 66

Where do the sympathetic nerves originate from?

Answer 66

Lateral horn, and then they move to the gray ramus, where they either synapse or bypass the sympathetic trunk

Question 67

Which are the pre-ganglionic sympathetic neurons?

Answer 67

T5 to T8 --> greater thoracic splanchnic nerves

Question 68

What happens to the pre-ganglionic sympathetic neurons if they bypass the sympathetic trunk without synapse?

Answer 68

They initiate an alternative route, where they stay as preganglionic and they target the modified cells of the medulla to secrete NE or E

Question 69

What happens to the pre-ganglionic sympathetic neurons that synapse at the sympathetic trunk?

Answer 69

They are not involved in the secretion of NE or E in the medulla but instead they regulate dilation of the blood vessels