Lecture 10 - Glands (2) Flashcards
What are the 2 hormones released from the posterior pituitary gland?
- Vasopressin (ADH) & Oxytocin
Where is the pituitary gland in relation to the hypothalamus and thalamus?
What connects the hypothalamus to pituitary gland?
What is the role of the hypothalamus? What does it produce?
- Hypothalamus sits inferior to thalamus. Pituitary gland sits inferior to the hypothalamus.
- The pituitary stalk
- It regulates homeostasis, releases ADH + Oxytocin to the posterior pituitary (hypophysis) via nerves and 6 hormones to the anterior pituitary via the hypophyseal portal system.
What is a portal system?
Where are the 2 portal systems in the body?
- A vascular arrangement in which blood from the capillaries of one organ is transported to the capillaries of another organ by a connecting vein or veins.
- Head & Abdomen (hypothalamic-hypophyseal & hepatoportal)
What are the 6 hormones released from the anterior pituitary gland?
What type of secretion are these hormones subject to?
- Adrenocortitropic hormone (ACTH)
- Thyroid-stimulating hormone (TSH)
- Follicle-stimulating hormone (FSH)
- Luteinising hormone (LH)
- Growth hormone (GH)
- Melanocyte-stimulating hormone (MSH)
- Both constitutive and regulated secretion
Describe the location of the thyroid gland.
What does it release?
What autoimmune diseases are associated with thyroid gland?
- In the neck, anterior to trachea, inferior to larynx
- T3/T4 in response to TSH
- Hashimoto’s (high TSH, Low T3/4)
- Grave’s (low TSH, High T3/4)
- Hyperthyroid (Low TSH, High T3/4)
- Primary hyperthyroid (High TSH, Low T3/4)
What is the role of parafollicular (C-cells) in the thyroid gland?
- Produce peptide hormone calcitonin
- Monitors Ca2+ levels and decreases it (opposing PTH) by inhibited osteoclast activity (increasing Ca2+ by degradation of bone) & inhibiting Ca2+ reabsorption in the kidney.
Where are the parathyroid glands?
What is the role of the parathyroid gland?
Where do symptoms occur if there is an overproduction of PTH?
- On the posterior aspect of the thyroid gland
- Senses when Ca2+ is low, released PTH, which increases release of Ca2+ from bone and increases Ca2+ absorption in GIT
- Head, muscles and bones - as Ca2+ plays vital role of many processes here.
Where is the adrenal gland and what are its 2 sections?
What is released from the inner section and from what cells?
What is released from each of the 3 outer (cortex) layers?
- Superior to the kidney (suprarenal) - cortex + medulla
- Chromaffin cells in medulla secrete AD & NA in response to sympathetic nerve fibre stimulation
- Zona glomeruloa (outer) produces aldosterone which regulates BP
- Zona fasciculata produces glucocorticoids such as cortisol which metabolises proteins, carbs, fats.
- Zona reticularis produces androgen precursors.
What response are the hormones released from the cortex of the adrenal gland involved in?
Describe the process of how stress hormones (glucocorticoids e.g.: cortisol & mineralocorticoids, e.g.: aldosterone) are released from the cortex of the adrenal gland.
- Fight or Flight - stress response.
- Signal received by hypothalamus, releases CRH. CRH hormone travels down portal system to anterior pituitary where ACTH is released. ACTH binds to receptors on adrenal gland cortex causing release of stress hormones.
Why is the pancreas an exocrine gland?
What are the 3 main cells of the islets of langerhans and what do they secrete?
What are the functions of these secretions?
- Because secretions from the pancreas and gall bladder pass into the duodenum via the pancreatic duct.
- alpha cells = glucagon, beta cells == insulin, delta cells = somatostatin
- Glucagon = catabolises glycogen into glucose
- Insulin = Uptake and storage of glucose into cells
- Somatostatin = Inhibits insulin and glucagon secretion
Can you pick out which of the 4 stained slides are which glands on page 4 of your lecture 10 document? - You need to be able to do this.
Kk
Which organs display both exocrine and endocrine function
Both the liver and pancreas display both these functions - as they both release secretions into a duct (bile & pancreatic duct) and also release hormones directly into the blood stream.
