T1 L3 Nuts and bolts of the endocrine system

Question 1

What are the roles of the endocrine system?

Answer 1

Normal growth and development
Adaption to internal and external environment
Contribute to process of sexual reproduction

Question 2

Describe the structure of endocrine glands

Answer 2

Functional unit consisting of cuboidal secretory cells with a lumen at the centre
Secretory cells supported by myoepithelial cells
Not all functional units have a lumen

Question 3

What factors influence the effect a hormone will have on a cell’s metabolism?

Answer 3

Number of molecules available
Number of receptors available
Affinity hormone - receptor

Question 4

What are the classifications of hormones?

Answer 4

Steroid

Protein / peptide

Question 5

What does endocrine mean?

Answer 5

Action of a hormone on a target organ away from the secreting cell

Question 6

What does autocrine mean?

Answer 6

Action of the hormone on the secreting cell

Question 7

What does paracrine mean?

Answer 7

Action of the hormone on the adjacent cell

Question 8

What does neuroendocrine mean?

Answer 8

Neural stimulation of endocrine cells to secrete hormones e.g. medulla of the adrenal gland

Question 9

Where is the hypophysis located?

Answer 9

In sella turcica in sphenoid bone

Question 10

What is the blood supply to the hypophysis?

Answer 10

2 blood vessels branching from internal carotid
Superior hypophyseal
Inferior hypophyseal

Question 11

What does the superior hypophyseal supply?

Answer 11

Median eminence and upper park of stalk

Question 12

What does the inferior hypophyseal supply?

Answer 12

Neurohypophysis and lower part of stalk

Question 13

Describe the pathway of blood flow through the hypophyseal

Answer 13

1) Capillary plexus in median eminence and stalk ending
2) Portal vein
3) Anterior lobe of pituitary
4) Secondary capillary plexus

Question 14

Describe the size and shape of the thyroid gland

Answer 14

Bilobed gland in the neck
4 x 2cms, 30g
2 lateral lobes connected by isthmus

Question 15

Where are para-follicular cells or clear (C) cells found?

Answer 15

Between follicles of thyroid tissue

Question 16

What do C cells do?

Answer 16

Secrete calcitonin which promotes reduction of calcium concentration in the blood

Question 17

What is the thyroid gland derived from?

Answer 17

Endoderm

Develops as a growth from floor of pharynx near base of tongue

Question 18

What is the role of the thyroid?

Answer 18

Regulate tissue metabolism
Growth
Development

Question 19

What is the blood supply to the thyroid gland?

Answer 19

Superior thyroid from external carotid

Inferior thyroid from subclavian

Question 20

What is the blood drainage from the thyroid?

Answer 20

External plexus into internal jugular vein and brachiocephalic vein

Question 21

Describe the parathyroid glands

Answer 21

2 superior and 2 inferior embedded in capsule of thyroid

Question 22

Describe the development of the parathyroid glands

Answer 22

From cells originating from 3/4th pharyngeal pouches
Migrate caudally with thymus
Inferior parathyroids travel further to lie lower compared to superior parathyroids

Question 23

What is the role of the parathyroid glands?

Answer 23

Secrete parathyroid hormone to regulate calcium and phosphate levels within homeostasis

Question 24

What happens if the parathyroid glands are removed?

Answer 24

1) Fall in blood calcium levels
2) Muscles (including respiratory and laryngeal) go into titanic contraction
3) Death

Question 25

What is the blood supply to the parathyroid glands?

Answer 25

Inferior thyroid | Superior thyroid

Question 26

What is the blood drainage from the parathyroid glands?

Answer 26

Superior thyroid Middle thyroid Inferior thyroid

Question 27

What is the nervous supply to the parathyroid glands?

Answer 27

Middle cervical ganglions | Inferior cervical ganglions

Question 28

Where are the adrenal glands located?

Answer 28

Superior pole of kidneys | Retroperitoneal

Question 29

What is the structure of the adrenal glands?

Answer 29

Outer capsule Cortex Medulla Pyramidal and semilunar

Question 30

What does the cortex of the adrenal glands stem from?

Answer 30

Mesoderm

Question 31

What does the medulla of the adrenal glands stem from?

Answer 31

Neural crest cells

Question 32

In the adrenal glands, what do the cells subadjacent to the capsule do?

Answer 32

Secrete mineralocorticoids e.g. aldosterone | Function to maintain electrolyte balance

Question 33

In the adrenal glands, what do the cells in the deeper part of the cortex do?

Answer 33

Secrete glucocorticoids e.g. hydrocortisone | Affect metabolism and electrolyte balance

Question 34

What are the 3 distinct zones in the cortex of the adrenal glands?

Answer 34

Zona glomerulose Zona fasciculata Zona reticularis

Question 35

What does the zona glomerulosa secrete?

Answer 35

Mineralocorticoids Aldosterone Absorption of sodium

Question 36

What does the zona fasciculate secrete?

Answer 36

Glucocorticoids Cortisol and corticosterone Sex hormones

Question 37

What does the zona reticularis secrete?

Answer 37

17 ketosteroids | Sex hormones

Question 38

What are chromaffin cells?

Answer 38

Secretory cells | Develop from same embryonic tissue as sympathetic ganglia

Question 39

What do the compact cells in the medulla secrete?

Answer 39

Adrenaline | Noradrenaline

Question 40

What is the blood supply to the adrenal glands?

Answer 40

Superior suprarenal arteries Middle suprarenal arteries Inferior suprarenal arteries

Question 41

Where do the superior suprarenal arteries come from?

Answer 41

Inferior phrenic artery

Question 42

Where do the middle suprarenal arteries come from?

Answer 42

Aorta

Question 43

Where do the inferior suprarenal arteries come from?

Answer 43

Renal artery

Question 44

What is the venous drainage of the right adrenal gland?

Answer 44

Right adrenal vein into the IVC

Question 45

What is the venous drainage of the left adrenal gland?

Answer 45

Left adrenal vein into renal vein

Question 46

What do acidophils do?

Answer 46

Take up acidic dyes

Question 47

What do basophils do?

Answer 47

Take up basic dyes

Question 48

What hormones do somatotrophy cells produce?

Answer 48

Growth hormone that is taken up by bone

Question 49

What hormones do lactotroph cells produce?

Answer 49

Prolactin which targets breasts

Question 50

What hormones do corticotrophy cells produce?

Answer 50

ACTH which targets the adrenal glands

Question 51

What hormones do gonadotroph cells produce?

Answer 51

FSH which targets the ovary and testis

Question 52

What hormones do thydrotoph cells produce?

Answer 52

TSH which target the thyroid gland

Question 53

Describe the pathology of pituitary adenomas

Answer 53

Benign tumours Arise from anterior lobe Functional or non-functional 10% of intra-cranial neoplasms

Question 54

What symptoms are caused by the space occupying effect of adenomas?

Answer 54

``` Headaches Vomiting Nausea Diplopia Impaired vision ```

Question 55

What impact does a lack of iodine have on the thyroid gland

Answer 55

Enlarges (goitre) to absorb the maximum concentration of iodine

Question 56

Describe Grave's disease

Answer 56

``` Hyperthyroid Auto-antibodies stimulate TSH receptors Hyperplasia of thyroid cells leads to diffuse enlargement of thyroid gland Infiltrative opthalmopathy Infiltrative dermopathy ```

Question 57

What is infiltrative opthalmopathy?

Answer 57

Accumulation of soft tissue and inflammatory cells behind the eye leading to proptosis

Question 58

What is infiltrative dermopathy?

Answer 58

Thickening and induration of skin on anterior shin leading to pre-tibial myxoedema

Question 59

Describe Hashimoto's disease

Answer 59

Hypothyroid Autoimmune disease Progressive depletion of thyroid cells by inflammation leading it to be replaced by fibrosis

Question 60

What are the results of clinical tests in Hashimoto's disease?

Answer 60

Decreased T3/T4 | Increased TSH

Question 61

What is the pathologic evidence of Hashimoto's disease?

Answer 61

Irregular with solid cut surface | Prominent lymphocytic infiltrate

Question 62

What is a follicular adenoma?

Answer 62

Benign tumour of thyroid follicular cells

Question 63

What can cause adrenocortical hyperactivity?

Answer 63

Hyperplasia, adenoma or cancer Cushing's syndrome - excess cortisol Conn's syndrome - excess aldosterone Adrenogenital syndrome - excess androgens

Question 64

What can cause adrenocortical insufficiency?

Answer 64

Addison's disease

Question 65

What is phaechromocytoma?

Answer 65

Tumour of adrenal medulla | Caused by high levels of catecholamines

Question 66

What are the consequences of phaechromocytoma?

Answer 66

``` Increased BP Tachycardia Palpitations Headache Sweating Tremor ```

Question 67

What are the consequences of increased BP?

Answer 67

Congestive heart failure Ischaemic heart disease Cardiac arrhythmias Cerebrovascular accident

Question 68

What is Cushing's syndrome?

Answer 68

Excess cortisol

Question 69

What is Conn's syndrome?

Answer 69

Excess aldosterone

Question 70

What is Adrenogenital syndrome?

Answer 70

Excess androgens