Practicals

Question 1

What is a key feature of endocrine cells?

Answer 1

Large cytoplasms to allow for the production of the hormones

Question 2

Describe the histopathological appearance of the adenohypophysis, the neurohypophysis and the pars intermedia relative to each other

Answer 2

• Neurohypophysis is paler than the other two portions of the pituitary gland
• Pars intermedia is blue
• Adenohypophysis is dark purple

Question 3

What is the typical trend in hormone production as a neoplasm grows?

Answer 3

The more malignant a neoplasm gets, the less of the hormone is usually found - more focus on multiplying than producing hormone

Question 4

Describe the appearance of chromophobes in the pituitary gland

Answer 4

Appear grey

Question 5

Give an example of chromophobic cells

Answer 5

Melanotropes, produce MSH

Question 6

What is secreted by acidophils/eosinophils and describe their appearance

Answer 6

• Secrete growth hormones

- Pink

Question 7

Give examples of basophils, what they produce, and describe their appearance

Answer 7

• Somatotropes: GH
• Gonadotropes: FSH, LH
• Lactotropes: PRL
• Thyrotropes: TSH
• Corticotropes: ACTH
• Blue appearance

Question 8

What is a potential consequence of a growing pituitary tumour regarding the rest of the brain?

Answer 8

• May grow upwards and destroy brain tissue above it
• INcrease in intracranial pressure
• May get destruction of thalamus, hypothalamus and ventricular system, leading to other conditions such as neurogenic diabetes insipidus

Question 9

Describe the appearance of the adrenal glands and thyroid glands in the case of a pituitary tumour leading to adrenocortical hypofunction?

Answer 9

• Both will be atrophied

- In adrenal gland will clearly see brown medulla and white cortex (white due to fat and cholesterol)

Question 10

Describe the appearance of the adrenal glands in the case of a functional pituitary adenoma

Answer 10

Massive laminar hypertrophy and hyperplasia in adrenal glands

Question 11

Compare the appearance of the endocrine and neuroedocrine cells of the adrenal gland

Answer 11

• Endocrine cells: adrenal cortex, eosinophilic, close pattern
• Neuroendocrine cells: more basophilic, paler, nuclear pattern more open

Question 12

What is produced by the neuroendocrine portion of the adrenal gland?

Answer 12

Catecholamines

Question 13

What features may be seen in an adrenocortical carcinoma?

Answer 13

• Difficult to identify cells as normal adrenal cortical cells
• Tumour cell emboli in the vasculature
• Nuclear, cellular and cytoplasmic pleomorphism visible

Question 14

What histopathological features may be seen in a pheochromocytoma?

Answer 14

• Neoplastic chromaffin cells haphazardly arranged in poorly demarcated lobules of varied sizes
• Moderate variation in cellular and nuclear size and shape
• If malignant, will be dark red brown, if cortical will be white

Question 15

Describe the appearance of normal, hyperactive and underactive follicular cells of the thyroid gland

Answer 15

• Normal: cuboidal
• Overactive: elongated
• Underactive: flattened

Question 16

Describe the appearance of the thyroid follicles in over and underactive thyroid glands

Answer 16

• Over: collapsed follicles, lumens of remaining contain pale pink colloid and have numerous endocytic vacuoles at the epithelial cell-follicular lumen interface
• Under: follicular lumens distended with dense colloid

Question 17

Explain the prognosis for a malignant endocrine tumour

Answer 17

• Poor

- Endocrine glands have close association with blood vessels, so metastases develop quickly

Question 18

Describe the normal appearance of cells in the pancreatic islets

Answer 18

Pale cytoplasm

Question 19

Describe the appearance of islet amyloid

Answer 19

• Pink, dense islets
• Irregular shape
• Amorphous pink material in cells = amylin

Question 20

Explain how islet amyloid deposition occurs

Answer 20

• Islet amyloid polypeptide (IAAP, amylin) is normal secretory product of beta-cells
• Over production of abnormal amylin (beta-pleated sheet conformation abnormal) by beta cells leads to deposition in cells as it cannot be broken down, cells degenerate = loss of function of cells

Question 21

what is the function of islet amyloid polypeptide

Answer 21

• Regulatory peptide
• Functions locally in islets by inhibiting insulin and glucagon secretion
• And also at distant targets

Question 22

Describe the sympathetic supply for the adrenal medulla (nerve, origin, pre-/post-ganglionic)

Answer 22

• Mainy greater splanchnic nerves
• These originate from sympathetic trunk
• Are pre-ganglionic, adrenal cells act as the post-ganglionic cells

Question 23

Compare the histological appearance of adrenal glands and lymph nodes

Answer 23

• In medulla of lymph nodes, will find germinal follicles due to immune responses
• These will not be found in the adrenals

Question 24

Describe the pattern of venous drainage of the pancreas

Answer 24

• Body and neck drain into splenic vein
• Head drains into the superior mesenteric and portal veins into the liver
• Some branches communicate with the superior mesenteric vein directly, creating loop of venous drainage utilising both sets of venous plexi

Question 25

Name the structures that sit in the following locations relative to the pituitary gland: - Rostrally - Caudally - Ventrally - Laterally - Dorsal

Answer 25

- Rostrally: optic chiasma - Caudally: mammillary bodies - Ventrally: sphenoid bone - Laterally: cavernous sinus - Dorsal: hypothalamus

Question 26

Describe the embryological origin of the pituitary gland

Answer 26

- Adeno: upgrwoth of roof of developing mouth, called Rathke's pouch, ectoderm - Neuro: down-growth from ectoderm of forebrain (diencephalon/future hypothalamus)

Question 27

What is produced by the epiphysis? What is it's function?

Answer 27

Melatonin, function is circadian rhythm, and control of seasonal breeding

Question 28

What brain region does the epiphysis belong to?

Answer 28

The telencephalon

Question 29

In which animals, are the right and left thyroid glands connected by a functional isthmus?

Answer 29

Pigs, humans, cattle

Question 30

What anatomical factors should be taken into consideration when performing a thyroidectomy?

Answer 30

- May be some ectopic tissue so may not remove all thyroid cells - 3rd parathyroid located near/next to or on thyroid gland but should be left in place - Care re. surrounding musculature, blood vessels, trachea, oesophagus - 4th parathyroids usually within the thyroid gland so will be removed in a thyroidectomy

Question 31

What aspects need to be addressed in every general examination of a horse?

Answer 31

- Assess horse in natural environment where possible, assess gait, breathing, demeanour etc. - Assess environment pasture (presence of plants, stocking density, fencing, faeces), individual and other stables - Other horses - Physical examination, incl. BCS

Question 32

Describe the general physical examination of the head and neck a horse

Answer 32

- Contours of head and neck - Normal position and carriage - MMs, drooling, dropping feed - Nasal discharge, assess character of any discharge, airflow from nostrils - Percuss maxillary and frontal sinus area - Assess eyes for symmetry and free of discharge, characterise discharge, erythema, cloudiness, swelling, blepharospasm etc. Palpebral response, menace response - Facial artery - Ears - symmetry - Palpation of LNs - Neck from both sides, jugular vein

Question 33

Describe the general physical examination of the thorax of a horse

Answer 33

- Auscultate heart, assess rate, rhythm, murmurs - Auscultate lung fields, check for adventitious sounds - Check for evidence of pectoral oedema

Question 34

Describe the general physical examination of the abdomen of a horse

Answer 34

- Auscultate for abdominal borborygmi in 4 quadrants - Evaluate distension in paralumbar fossa if applicable - Check for oedema, commonly in sheath area or at most dependent portion of the abdomen

Question 35

Describe the general physical examination of the perineum and genital region of a horse

Answer 35

- Check the rectal temperature, simultaneously check anal tone - Check for evidence of diarrhoea - F: Examine vulva and udder for swelling discharge, heat or pain on palpation - M: examine prepuce, sheath, testes for swelling, discharge, heat, pain on palpation - Check normal tail carriage and movement

Question 36

Describe the general physical examination of the limbs of a horse

Answer 36

- Assess symmetry, even weight bearing on all feet, heat, pain, lameness, raised digital pulses or swelling - Lift feet and examine

Question 37

Describe the general physical examination of the skin of a horse

Answer 37

- Examine for hair loss, scabs, papules, nodules , seborrhea - Evidence of ectoparasites - Scratching/rubbing, abnormal swelling, abnormal sweating