Habibi Part 1 Flashcards
what are Hypophyseal hormones
Control secretion and peripheral actions.
Hormones secreted by the pituitary regulate: (5 examples)
Uterine contractility,
milk production and secretion,
water balance,
blood pressure,
reproduction or growth or metabolism
what are Hypothalamic Nuclei:
neurons in the hypothalamus that regulate pituitary function.
some examples of hypothalmic nuclei (3)
Supraoptic nuclei.
Paraventricular nuclei.
Preoptic nuclei.
formal name for pituitary is
hypophysis
Anterior Pituitary is also known as
adenohypophysis
the anterior pituitary is derived from
dorsal outgrowth of the buccal cavity (roof of the mouth).
Posterior Pituitary is also known as
neurohypophysis
posterior pituitary is dervied from
the brain
Intermediate Lobe is found between the ___and the __
which species dont have an intermediate lobe
anterior and posterior pituitary
some mammals, birds, lamprey
in the adenohypophysis (anterior pituitary), name the 3 subsections of it (pars…)
Pars Distalis (anterior lobe):
Pars Intermedia (intermediate lobe).
Pars Tuberalis (tuberal lobe)
in the adenohypophysis (anterior pituitary), which lobe is the primary hormone secretion site
in the anterior lobe (pars distalis)
2 sections of the neurohypophysis (posterior pituitary)
Pars Nervosa (neural lobe or posterior lobe).
Infundibulum (stalk connecting hypothalamus to pituitary)
pars nervosa is the
neural or posterior lobe
infundibulum is the
stalk connecting the hypothalamus to the pituitary
2 hormones produced by the posterior pituitary (neurohypophysis)
(AVP) vasopressin and oxytocin
____ is Also known as antidiuretic hormone (ADH).
AVP, vasopressin
vasopressin is a ____ hormone with _ amino acids
peptide hormone with 9 amino acids
which 2 examples of hypothalamic nuclei (neurons in hypothalamus that regulate pituitary function) synthesize vasopressin
supraoptic nuceli and paraventricular nuclei
where is vasopressin transported to
posterior pituitary
oxytocin is a ___ amino acid peptide
9 also, like vasopressin
what are the 2 amino acids that differentiate vasopressin and oxytocin
oxytocin has isoleucine (3) and leucine (8)
vasopressin has phenylalanine (3) and arginine (8)
what are the 2 types of vasopressin (adh) receptors
V1 and V2 receptors
V1 receptors involve…
Mediate vascular smooth muscle contraction.
V2 receptors involve
promote renal water absorption
3 functions of avp/adh
regulate blood pressure, regulate osmolality, memory consolidation
pathway of regulation of blood pressure
↓ Blood pressure → Baroreceptor activation → ↑ AVP secretion → increase Water retention (V2) + Vasoconstriction (V1), leads to increase blood pressure
Regulation of Osmolality pathway
↑ Plasma osmolality (more sodium) → Osmoreceptor activation → ↑ AVP secretion → Water retention (V2) + Na⁺ excretion (V2), increase urine concentration
A _ % change in __ can trigger AVP release.
1% in plasma osmolality
2 functions of oxytocin
milk ejection and uterine contractions
milk ejection is stimulated by ____, which activates __.
suckling, sensory nerves in nipples
Oxytocin contracts _______ to eject milk.
myoepithelial cells in mammary gland
For uterine contractions, oxytocin stimulates contraction of the ____ during labor.
myometrium
increased plasma osmolality means more relased
avp
explain the positive feedback loop for uterine contractions
Fetal descent stretches the uterus and cervix → ↑ Oxytocin → Stronger contractions → Further fetal descent and it keeps going
in the anterior pituitary, gonadotropes produce which hormones
LH and FSH
in the anterior pituitary, lactotropes produce which hormones
prolactin
in anterior pituitary, somatotropes produces (soma = grow)
growth hormone
in anteirpr pituitary, corticotropes produce
Adrenocorticotropic hormone (ACTH)
in anterior pituitary, thyrotropes produce
TSH (thyroid stimulating hormone)
Family I (Single Chain Proteins) include which 2 hormones
growth hormone, prolactin hormone
first family is growing, and need lactate milk for baby lol
Family II (Glycoproteins) include which hormones
TSH, FSH, LH
Family III (POMC-Derived) includes what 2 hormones
acth and msh
Growth hormone is stimulated by ____ and inhibited by ____.
Secretion influenced by: (3 things)
ghrh (growth hormone releasing hormone)
somatostatin
increased by Hypoglycemia (+),High protein meals (+) but INHIBITED by Fatty acids (-)
functions of growth hormone (3)
Promotes somatic growth via IGF-I (produced in the liver).
Increases blood sugar by decreasing glucose uptake.
Enhances lipolysis and protein synthesis.
a deficiency in growth hormone leads to these 2 diseases
dwarfism (childhood)
weakness, pale skin, low libido (adult)
an excess of growth hormone can caused these disorders
gigantism (before growth plate closure): excessive height
acromelagy (after growth plate closure): thickened bones
2 functions of prolactin
Stimulates milk production
Modulates reproductive function
prolactin function in females
Supports lactation (milk) and suppresses ovulation (fsh)
prolactin in males
Maintains LH receptors in testes and testosterone production
explain thyorid hormone synthesis (4 steps)
Iodide Trapping:
Oxidation:
Iodination:
Coupling:
Iodide Trapping:
Active transport of iodide into thyroid cells.
Oxidation:
Iodide → Iodine (mediated by peroxidase).
Iodination
Tyrosine residues on Tg form MIT/DIT.
coupling
DIT + DIT → T4;
DIT + MIT → T3
function of thyroid hormones
Increase oxygen consumption
Promote bone growth and brain development
2 disorders of thyroid
(less) hypothyroidism: Iodine deficiency
causes: growth retardation
fix: by thyroid hormone replacement
(more) hyperthyroidism: excess metabolism
fix: anti thyroid drugs or surgery
