Module 6: Endocrine Flashcards
What are the 4 hormone classes and they are all water soluble except for which one?
- Peptide hormones
- Derivatives of phenylalanine
- Derivatives of arachidonic acid
- Steroid hormones
Steroid hormones are lipid soluble
- What are the 3 steps of peptide hormone biosynthesis?
- What is the precursor for all steroid hormones?
- What are the 4 types of steroid hormones?
- Pre-prohormone, prohormone and parent hormone
- Cholesterol
- Corticoids
Progestins
Androgens
Oestrogens
- What is the difference between an exocrine gland and an endocrine gland?
- What are the 5 ways hormones can communicate?
- Exocrine: secrete into a duct
Endocrine secrete directly into blood vessels - Endocrine, intracrine, paracrine, autocrine and juxtacrine
- What are the 3 glands under the direct control of the hypothalamus and pituitary?
- What are the 3 types of effects that a hormone can have on another substance? Briefly explain them…
- Thyroids, gonads and adrenal cortex
- Permissive effect: strengthens effect
Synergistic effect: both hormones needed together
Antagonistic effect: opposite effects of two different hormones
Steroid hormones What are the following secreted by: 1. Cortisol and aldosterone 2. Oestrogen and pregesterone 3. Oestrogen and progesterone 4. Testosterone
- Adrenal cortex
- Ovaries
- Placenta
- Testes
Steroids
- What two things make all steroid hormones?
- Which enzyme helps this?
- How do steroid hormones circulate after being released?
- What converts cholesterol into pregnenalone? What kind of step is this?
- Are steroid hormones stored and what does this mean?
- Pregnenolone and progesterone
- 3 beta HSD
- Bound to protein
- Desmolase- limiting step
- Not stored (synthesised as required), therefore slower time for action
Hormone signalling methods:
- Which 3 ways do water soluble hormones signal?
- Which 2 ways do lipid soluble hormones signal?
- Cell membrane receptors, G-protein coupled receptors and tyrosine kinase coupled receptors
- Intracellular cytoplasmic or nuclear receptors
- The hypothalamus controls which 2 systems?
- What does the hypothalamus contain that has different releasing factors?
- What does the hypothalamus sit on top of?
- Autonomic nervous system and endocrine system
- Nuclei
- Pituitary gland
Pituitary gland:
- What are the two areas called and what are alternative names for it?
- What does each part secrete?
- What can be said about their embryological origins?
- Does the gland lie inside or outside the blood brain barrier?
1. Anterior = adenohypophysis Posterior = neurohypophysis 2. Anterior: secretes classic hormones Posterior: secretes neurohormones 3. Both have separate embryological origin 4. Outside the BBB
Posterior pituitary
- What is its other name?
- What is it an extension of?
- What is composed of?
- How is connected to the hypothalamus?
- Neurohypophysis
- Hypothalamus
- Axons of hypothalmic neurons
- Pituitary stalk
Anterior pituitary
- What is its other name?
- What is another name for the system its a part of?
- What distinguishing thing does it contain?
- Adenohypophysis
- Hypothalamo-hypophyseal system
- Blood vessels
Hypothalmic factors/hormones
- Where are the two places these travel to? One of these destinations is via a structure, what is it?
- Which part is responsible for storing the hormones and which one acts on specific cells?
- These hormones can be what 2 things in terms of behaviour?
- Anterior pituitary - via median eminence
Posterior pituitary - Anterior pituitary: acts on specific cells once here
Posterior pituitary: stored - Stimulating or inhibitory
Hypothalmic factors that travel to anterior pituitary Give the full name for the following acronyms: 1. TRH 2. GnRH 3. CRH 4. GHRH 5. S 6. PRH 7. PIH 8. D
- TRH: thryotrophin releasing hormone
- GnRH: gonadotropin releasing hormone
- CRH: corticotrophin releasing hormone
- GHRH: growth hormone releasing hormone
- S: somatostatin
- PRH: prolactin-releasing hormone
- PIH: prolactin inhibiting hormone
- D: dopamine
What is the effect of the following:
- TRH
- GnRH
- CRH
- GHRH
- S
- PRH
- PIH
- TRH - stimulates TSH
- GnRH - stimulates LH and FSH
- CRH - Stimulates ACTH
- GHRH - stimulates GH
- S - INHIBITS GH
- PRH - stimulates prolactin
- PIH - INHIBITS PROLACTIN
Hypothalmic factors that travel to posterior pituitary
- What two things travel to the posterior pituitary?
- One of these had an alternative name. What is it?
- Which 2 hypothalmic nuclei are they made in?
- What bodies are they stored in?
1. Vasopressin Oxytocin 2. Vasopressin = ADH 3. Supraoptic and paraventricular 4. Herring bodies
ADH = anti-diuretic hormone (posterior pituitary)
- What does it promote?
- What is the main stimulus for it?
- What is this stimulus sensed by in the hypothalamus?
- What is the other stimulus and what is it sensed by?
- What are 2 inhibitors of ADH release?
- Water conservation by the kidney
- Increased osmotic pressure
- Osmoreceptors
- Volume depletion sensed by baroreceptors
- Alcohol and alpha blockers
Oxytocin (posterior pituitary)
1. It has 2 major targets:
The myoepithelial cells of the _________
The smooth muscle cells of the ____________
2. What are the 2 main functions?
3. Explain the milk let-down reflex briefly…
- Breast
Uterus - Milk ejection reflex and uterine smooth muscle contraction
- Suckling, nipple receptors, oxytocin released from posterior pituitary, myoepithelial cells contract, milk moves and is ejected
Anterior pituitary: What type of cells secrete the following hormones? 1. ACTH 2. TSH 3. LH and FSH 4. GH 5. Prolactin
- ACTH = corticotroph
- TSH = thyrotroph
- LH and FSH = gonadotroph
- GH = somatotroph
- Prolactin = lactotroph
Anterior pituitary: What is the target of the following hormones? 1. ACTH 2. TSH 3. LH and FSH 4. GH 5. Prolactin
- ACTH: adrenal cortex
- TSH: thyroid gland
- LH and FSH: ovaries and testes
- GH: most tissues
- Prolactin: breasts and gonads
ACTH
- What is it derived from?
- What is it stimulated by?
- What cell is it secreted from?
- Where does it act?
- What does this cause the release of?
- When do the levels increase, and what does this eventually cause?
- POMC gene
- CRH
- Corticotroph
- Adrenal cortex
- Glucocorticoid/cortisol release
- Early before awakening, causing cortisol awakening response
Cortisol Complete the following sentences that describe the functions of cortisol: 1. Regulation of..... 2. Potent... 3. During fasting... 4. Metabolic adaptation...
- Regulation of carbohydrate, protein and to a lesser extent, fat
- Potent anti-inflammatory and immunosuppressive effects
- During fasting, maintains plasma glucose levels
- Metabolic adaptation in response to stressful stimuli
Melanocyte stimulating hormone
- What does it decrease?
- What does it increase?
- What stimulates it release?
- What inhibits its release?
- Which two conditions is it increased in?
- Decreases appetite
- Skin pigmentation
- CRH
- Dopamine
- Cushing’s and Addison’s disease
TSH - thyroid stimulating hormone
- What cells does it increase?
- What hormone secretion does it increase?
- What kind of secretion is it during the day?
- Thyroid follicular cells
- Thyroid hormone
- Pulsatile
Gonadotrophins: FSH and LH
- What 3 things are these involved in?
- In males these are involved in what?
- In females these are involved in which 2 things?
- Control of sexual differentiation, steroid hormone synthesis and gametogenesis
- Spermatogenesis
- Oestrogen biosynthesis and regulate hormones involved in the menstrual cycle