Anatomy and Cell Biology 3309 Lecture Notes - Lecture 25: Pancreas, Pineal Gland, Bronchiole
2 May 2018
School
Department
Professor
Histology Lecture 13 – Semester 2
Pineal Gland and Endocrine Pancreas
- Circadian rhythms and behavioural activities – food consumption and usage – is under hormonal
control
QUESTIONS
Alveoli are present in the wall of:
A. Trachea
B. Respiratory bronchioles
o This is what defines the respiratory bronchioles
▪ No cartilage, alveoli are coming off the wall!
C. Terminal bronchioles
D. Secondary bronchi
E. Primary bronchi
A pheochromocytoma is a rare tumor of the adrenal medulla resulting in excessive hormone production.
Which of the following symptoms would most likely be observed in the presence of this tumor?
A. Excretion of excessive amounts of dilute urine
B. Galactorrhea (excessive milk production), amenorrhea (lack of ovulation or menstrual cycle), and
loss of libido
C. Hypercalcemia, decalcification of bones, and kidney stones
D. Weight gain, constipation, fatigue, and lethargy
E. Weight loss, anxiety, elevated heart rate and blood pressure, and headaches
- Tumor of endocrine cells often profuse more hormones, because you have a larger mass of tissue
- Think about the hormones the adrenal medulla produces – and if you had more of this, what would
happen to you
o Adrenal or noradrenaline – activates your circulatory system, etc.
Learning Objectives
- Describe the location and histological appearance of an Islet of Langerhans
- Name 3 cell types in the islets and their secretory products
- List the functions of 3 Islet hormones
- Explain the location and origin of the pineal gland
o Pineal gland is important in a lot of mammals (not as much us) but a lot of farm animals
(sheep, cows, etc.)
▪ Their behavior and reproductive cycle is regulated by the pineal gland
- Name two cell types in the pineal gland and state their function
- Discuss the regulation of melatonin secretion.
find more resources at oneclass.com
find more resources at oneclass.com
Location of Endocrine Cells
- Underneath the stomach, we have the pancreas
- Wedged between pancreas and the duodenum, which comes off the pancreas and forms C shaped
structure
- Epithelial lined tube = small intestine
- Large blue staining mass of tissue = pancreas
o CT separations within it
o Note: within the red box, there are whiter spots (areas that are not stained as brightly)
- Dark stained mass at the bottom right corner = spleen
o Organ that has a lot of dark stained nuclei bunched together
o Looks like lymphatic tissue
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find more resources at oneclass.com
Endocrine Pancreas
- Exocrine pancreas made up of secretory acini that have nuclei in the centre (centroacinar cells)
o Red staining = enzymes, proteins, secreted
- Endocrine pancreas: Islets of langerhans
o Globular arrangements of cells that stain light
o There is NO structural organization you can identify EXCEPT there are red channels going
through (capillaries)
o Produce variety of different products
o Large, pale staining areas scattered throughout the pancreas
o Supported by reticular tissues
o Irregular, anastomosing cords and clumps of cells separated by capillaries
1. Insulin: decreases blood glucose levels
o Act on liver and other parts of the body
2. Glucagon: increases blood glucose levels
o By directly measuring glucose content
- Insulin and glucagon act on the body in an antagonistic function
Pancreatic Vascular Components
- Each Islets of Langerhans receives blood through an insuloacinar portal system forming a network of
fenestrated capillaries
- The exocrine pancreas receives blood:
o 1. From the islet capillaries
o 2. From an independent acinar vascular system
- Pancreas is organized, in terms of circulation, that the exocrine pancreas has dual blood supply
- EACH acinus is supplied by:
o Capillary network that arises from arterioles and carry blood away = acinar vascular system
o Receive blood that first profuses the Islets of Langerhans = Insuloacinar portal system
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Circadian rhythms and behavioural activities food consumption and usage is under hormonal control. Alveoli are present in the wall of: trachea, respiratory bronchioles, this is what defines the respiratory bronchioles, no cartilage, alveoli are coming off the wall, terminal bronchioles, secondary bronchi, primary bronchi. A pheochromocytoma is a rare tumor of the adrenal medulla resulting in excessive hormone production. Which of the following symptoms would most likely be observed in the presence of this tumor: excretion of excessive amounts of dilute urine, galactorrhea (excessive milk production), amenorrhea (lack of ovulation or menstrual cycle), and loss of libido. Think about the hormones the adrenal medulla produces and if you had more of this, what would: adrenal or noradrenaline activates your circulatory system, etc. happen to you. Describe the location and histological appearance of an islet of langerhans. Name 3 cell types in the islets and their secretory products. Name two cell types in the pineal gland and state their function.
