Adrenal Glands Flashcards
1
Q
What are the 2 parts of the adrenal gland?
A
- Cortex
2. Medulla
2
Q
What does the cortex develop from?
A
Mesoderm
3
Q
What does the medulla develop from?
A
Develops in the neural crest cells (neuroectoderm)
4
Q
Which develops first, cortex or medulla?
A
Cortex
5
Q
What occurs at 6 weeks gestation of the cortex?
A
- Proliferation of the mesoderm from the posterior abdominal wall
- Mesoderm penetrates the retroperitoneum and becomes the primitive adrenal cortex
6
Q
What occurs at 8 weeks gestation of the cortex?
A
Structure separates from the posterior peritoneal surface and is surrounded by retroperitoneal connective tissue
7
Q
After birth, what happens to the primitive cortex?
A
Involutes and disappears by 1 year of age
8
Q
At what age does the permanent adrenal cortex differentiates into 3 zones?
A
Age 3
9
Q
What are the 3 zones of the permanent adrenal cortex?
A
- Glomerulosa
- Fasciculata
- Reticularis
10
Q
When does the medulla form?
A
7th week gestation
11
Q
What occurs at the 7th week gestation of the medulla?
A
- Neural crest cells migrate and invade the medial side of the cortex
- The cells differentiate into the CHROMAFFIN CELLS
12
Q
Where are the paired adrenal glands located?
A
Retroperitoneal cavity
13
Q
What is another name for the adrenal glands?
A
Suprarenal glands
14
Q
Where are the adrenal glands positioned in comparison to the kidneys?
A
Anterior, medial and superior
15
Q
What tissue surrounds the adrenal glands?
A
Perinephric fat and Gerota’s fascia
16
Q
Do the adrenal glands have a capsule?
A
Yes
17
Q
Do the adrenal glands move with the kidneys?
A
No, they are surrounded by their own fascial supports
18
Q
What phase of breathing do the kidneys separate from the adrenals?
A
Inspiration
Or in upright position
19
Q
What word can be used to describe the adrenals surface?
A
Nodular
20
Q
What are the adrenals composed of?
A
Anteromedial ridge and a medial and lateral wing
21
Q
What is the size of adults adrenal glands?
A
L 4-6cm
W 2-3cm
AP .3-.6cm
22
Q
What is the size of an adrenal gland compared to an adult kidney?
A
1/13th the size
23
Q
What is the size of a newborns adrenal gland?
A
L .9-3.6
W .2-.5
24
Q
What is the size of newborns adrenals compared to the kidneys?
A
Proportionately larger
1/3 the size of the kidney
25
What is the shape of the adrenals?
Pyramid, semi-lunar, V, Y, Z configuration
26
What is the common shape of the RT adrenal?
Pyramidal shaped
27
What is the common shape of the LT adrenal?
Semilunar or crescent shaped and usually slightly larger then the RT
28
What is the RT gland posterior and lateral to?
IVC
29
What is the RT gland superior to?
Right kidney
30
What is the RT gland posterior and medial to?
Liver
31
What is the RT gland lateral to?
Crus of the diaphragm
32
What is the RT gland posterior to?
Duodenum
33
What is the relation of the LT gland to the LT kidney?
Superoprmedial- lower border can reach the renal hilum
34
How is the LT adrenal positioned in relation to the stomach and lesser sac?
Posterior
35
Is the LT gland posterior or anterior to the crus of the diaphragm?
Posterior
36
What structures is the inferior portion of the LT gland posterior to?
Pancreas and splenic vessels
37
How is the LT adrenal positioned compared to the aorta?
Posterolateral to the aorta
38
Are the adrenal glands vascular organs?
Yes
39
How many arteries are there in each gland?
3
40
Describe the 3 arteries that supply blood to the adrenal glands
1. Superior suprarenal arteries from the inferior phrenic arteries
2. Middle suprarenal arteries from the aorta
3. Inferior suprarenal arteries from the renal artery
41
What vein drains the adrenal gland?
Suprarenal veins
42
What does the right adrenal gland drain into?
IVC
43
What does the left adrenal gland drain into?
Left renal vein
44
How does the adrenal gland maintain homeostasis?
Through hormone secretion
45
Are the adrenal glands double endocrine or exocrine glands?
Double endocrine glands
46
What % of the gland is made of the cortex?
90% cortex
47
What steroid hormones does the cortex secrete? (3)
1. Mineral corticoids
2. Glucocorticoids
3. Gonadal hormones
48
Is the cortex of the adrenal essential?
Essential for life
49
What is the release of hormones form the cortex controlled by?
Negative feedback system b/w the hypothalamus, anterior pituitary and adrenal gland
50
What does the hypothalamus secrete?
ACTHRF- adrenocorticotropic hormone releasing factor
51
What does the secretion of ACTHRF cause the anterior pituitary to secrete?
ACTH- adrenocorticotropic hormone
52
What does the release of ACTH from the anterior pituitary cause the adrenal gland to do?
Secrete hormones
53
What are the 3 layers of the cortex? What is the volume of each layer?
1. Zone glomerulosa- 15%
2. Zona fasciculate- 75%
3. Zona reticulate- 10%
54
What is the most outer layer of the cortex?
Zona glomerulosa
55
What does the zona glomerulosa secrete?
Mineralocorticoids- Aldosterone
56
What does aldosterone act on?
Renal-tubules- sodium retension
57
What is the middle layer of the cortex?
Zona fasciculate
58
What does the zona fasciculate secrete?
Glucocorticoids- Cortisone and hydrocortisone
59
What are the releases of cortisone and hydrocortisone cause? (3)
1. Fat, protein and carbohydrate metabolism
2. Suppresses immune response (anti-inflammatory)
3. Helps resist mental and physical stress
60
What is the inner most zone of the cortex?
Zona reticularis
61
What does the zona reticular secrete?
Sex hormones- estrogen and progesterone
62
What does the secretion of estrogen and progesterone cause?
Promote normal development of the reproductive organs and bones
63
When is the release of sex hormones present?
4th year of life
64
What is the medulla?
Center portion of adrenal gland
65
What system is related to the medulla?
sympathetic nervous system
66
What is the medulla derived from?
Ectoderm
67
Is the medulla essential for life?
No
68
What portion of the adrenal gland is responsible for the fight or flight response?
Medulla
69
What hormones does the medulla secrete?
Catecholamine hormones- epinephrine (adrenalin) and norepinephrine
70
What is epinephrine responsible for?
Dilating coronary vessels
| Constricts skin and renal vessels
71
What is norepinephrine responsible for?
Constricts all arteries except coronary vessels
72
What is the body's response to accelerated HR?
Vessels constrict and theres increased BP
73
What is the body's response to accelerated respiration?
Dilation of respiratory passage
74
What does a decreased rate of digestion allow for?
Allows for more blood to the muscles
75
What are blood tests used to measure?
Cortical function
76
What are urine tests used to measure?
Medulla function
77
What are the 4 lab tests used to monitor adrenal gland function?
1. ACTH
2. Aldosterone
3. Cortisol
4. Catecholamines
78
How is ACTH measured?
Through blood test
79
What does ACTH stimulate the cortex to secrete?
Cortisol, androgens and aldosterone
80
What can cause elevated levels of ACTH?
Cushing's dx and primary adrenal hypofunction
81
How is aldosterone measured?
Serum and urine tests
82
When are levels of aldosterone increased?
Adenoma, adrenal carcinoma and adrenocorticohyperplasia
83
When are levels of aldosterone decreased?
Hypo-functioning adrenal
84
How is cortisol measured?
Serum and urine tests
85
When are levels of cortisol increased?
Hyperthyroidism, stress, obesity and hyperfunction
86
When are levels of cortisol decreased?
Adrenal hypofunction and hypothyroidism
87
How are levels of catecholamines measures?
Urine test more reliable then blood test
88
What can cause increased levels of catecholamines?
Strenuous activity, malignant neuroblastoma and pheochromocytoma
89
What is the pt prep?
Overnight fast
90
What are the factors that affect visualization of the adrenal gland? (7)
```
Age
Size
Amount of perirenal fat
Presence of bowel gas
Ability to change pt position
Sonographers experience
Equipment
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91
What is the appearance of the adrenal gland in an adult?
```
Rarely visualized (visualized to rule out pathology)
Homogeneous, hypoechoic structure
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92
What is the adult adrenal gland surrounded by?
Perirenal fat
93
What is the appearance of the adrenal gland in newborns?
Easily identified- very little perirenal fat to obscure
Medulla- echogenic
Cortex- less echogenic rim
94
What structures can mimic the adrenal structure?
Crus, pancreatic tail, lymphadenopathy and gastric fundus
95
How is the right adrenal best visualized?
Intercostally using liver or kidney as a window
Supine or LLD
Scan beam directed towards the IVC
Scanned from level of the renal hilum to liver
96
How is the left adrenal best visualized?
Intercostally using liver or kidney as a window
Supine or LLD
Scan from the epigastrium
Difficult to visualize
Alternate- LPO and scan through IVC and aorta
