17-18 - Endocrine System & Female Contraception Flashcards
The endocrine system in organised in terms of endocrine ______/____ which secrete into the _____ _________
The endocrine system in organised in terms of endocrine endocrine glands/cells which secrete into the blood stream.
The endocrine system differs from the nervous system in that it uses _______ which are secreted into the blood stream and have their effects at ________________
The endocrine system differs from the nervous system in that it uses hormones which are secreted into the blood stream and have their effects at non-adjacent sites
The two classes of hormone are…
- Steroid
- Non-steroid
Steroid hormones are structurally _____ &_______. They effect ____ __________ and ________ ________, which makes them ( fast / slow ) acting.
Steroid hormones are structurally small & lipophilic. They effect DNA synthesis and protein synthesis, which makes them slow acting.
Non-steroid hormones can be…
- Amines
- Peptides
- Glycoproteins
They’re hydrophobic (can’t pass through cell membranes) and their effects are faster than steroid hormones.
Steriod hormones are derived from…
Cholesterol
Regulation of renal function by ADH (vasopressin)
Low blood pressure is detected by ___________ , which send signals to the _______ ________ to trigger ADH release.
Regulation of renal function by ADH (vasopressin)
Low blood pressure is detected by baroreceptors , which send signals to the posterior pituitary to trigger ADH release.
Regulation of renal function by ADH (vasopressin)
ADH acts on the _____ through V1 and V2 receptors.
V1 stimulates ___________
V2 receptors in the ______ _________ stimulate water reabsorption.
Regulation of renal function by ADH (vasopressin)
ADH acts on the kidney through V1 and V2 receptors.
V1 stimulates vasoconstriction
V2 receptors in the distal tubule stimulate water reabsorption.
Regulation of metabolism by corticosteriods
Stress stimulates the __________ _____ which releases CRH which acts on the anterior pituitary.
The anterior pituitary releases ________________ (ACTH) which acts on the ______ ______ leading to the rease of ________.
Feedback control occurs as ________ levels influence the intial release of CRH.
Regulation of metabolism by corticosteriods
Stress stimulates the hypothalamic nuclei which releases CRH which acts on the anterior pituitary.
The anterior pituitary releases adrenocorticotrophic hormone (ACTH) which acts on the andrenal cortex leading to the rease of cortisol.
Feedback control occurs as cortisol levels influence the intial release of CRH.
Regulation of blood glucose by insulin
High blood glucose stimuates the _______ to release insulin.
This is an example of ______ control (direct influence by blood levels
Regulation of blood glucose by insulin
High blood glucose stimuates the pancrease to release insulin.
This is an example of substrate control (direct influence by blood levels
As with neurotransmitters in the nervous systems, drugs can target various stages of hormone production to influence their function. These targets are…
- Synthesis
- Release
- Receptors
- Metabolism
- Replacement
Example of drug targeting hormone synthesis…
- Treatment for Cushing’s syndrome with Metyrapone
- Inhibits 11β-hydroxylase (cortisol synthesising enzyme)
Example of drug targeting hormone release…
- Sulphonylereas (e.g. glibenclamide)
- Block K+ channels in the β-cells (like ATP) causing insulin secretion
Example of drug targeting hormone receptors…
Lypressin, desmopressin are V2 agonists (like ADH) decrease water reabsorption to treat copius hypotonic urine due to insufficient ADH in Diabetes insipidus
Example of drug that target the metabolism of hormones…
- Carbenoxolone (and licorice) increase cortisol levels by blocking 11β HSD which normally metabolises cortisol.
- Increased cortisol levels in pregnancy associated with low birth weight, behavioural differences.
HPA
The hypothalamus signals the pituitary which signals the ovaries to produce _________ and ______.
This then gives _______ feedback to the pituitary and hypothalamus.
HPA
The hypothalamus signals the pituitary which signals the ovaries to produce progesterone and estrogen.
This then gives negative feedback to the pituitary and hypothalamus.
Briefly outline the process of folliculogenesis…
- Maturation of primordial follucle into oocyte
- grafian folicle
- ovum released into fallopian tube
- remains form corpus luteum
- corpus luteum degrades to form corpus albicans
The oral contraceptive (combined) pill consists of…
Exogenous progesterone and estrogen which signal pregnancy to the hypothalamus, thus inhibiting GRH, FSH, LH.
