Cortisol inhibition of corticotrophin releasing hormone (CRH) secretion is an example of?
paracine action
endocrine action
autocrine action
neurocrine action
The anterior pituitary receives hypothalamic input via:
the hypothalamo-physio-portal blood system
nervous innervation
paracrine inhibition by the pars nervosa
neurocrine stimulation
Production of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3) occurs within:
thyrotroph cells
C cells
thyroglobulin
mitochondria
thyrotrophin releasing hormone (TRH) neurons
Which of the following symptoms might be observed in a patient with an activating mutation in the adrenocorticotrophin hormone (ACTH) receptor?:
decreased prolactin secretion
elevated cortisol production
absent Synacthen response
Bothelevated cortisol production and absent Synacthen response
Both decreased prolactin secretion and absent Synacthen response
Gonadectomy (removal of either testes or ovaries) would result in:
elevated gonadotrophin releasing hormone (GnRH) production
elevated luteinising hormone production (LH)
gonadotroph hyperplasia
All of the possible answers
None of these answers
Prostaglandins normally exert their biological effects via:
nuclear hormone receptors
tyrosine kinase receptors
immunoglobulin receptors
ion channels
G-protein coupled receptors (GPCRs)
Mutations in the Pit-1 gene could cause disruption in the development of:
somatotroph and thyrotroph cells
pancreatic b cells
gonadotroph and thyrotroph cells
somatostatin neurons
pancreatic a cells
The processing of which two peptide hormones requires the proconvertase enzymes, PC1 and PC2?:
insulin and adrenocorticotrophin hormone (ACTH)
insulin and prolactin
prolactin and somatostatin
ACTH and prolactin
prolactin and growth hormone (GH)
What binds to unoccupied glucocorticoid receptors (GRs) to prevent their translocation to the nucleus?:
heat shock proteins
lipid molecules
mineralocorticoids
other unoccupied GRs
unoccupied mineralocorticoid receptors (MRs)
What confounding issue renders the measurement of circulating cortisol inconclusive?:
cortisol is secreted at different levels throughout the day
the presence of binding proteins
thyroxine cross-reacts in the cortisol radioimmunoassay
insufficient concentrations of cortisol are secreted for accurate measurement
the absence of binding proteins
The major physiological regulator of aldosterone synthesis and secretion is:
the renin-angiotensin system
catecholamine release from the adrenal medulla
oestradiol
cortisol
calcium excretion
Mutations in the orphan nuclear receptor Steroidogenic factor-1 (SF-1) gene can cause:
absent renal development
absent pancreatic development
elevated luteinising hormone (LH) secretion
decreased PRL secretion
absent adrenal development
Which two of the following peptide hormones are composed of less than 15 amino acids in their mature form?
insulin and growth hormone (GH)
GnRH and TRH
thyrotrophin releasing hormone (TRH) and GH
GH and gonadotrophin releasing hormone (GnRH)
GnRH and insulin
A receptor that couples to a Gas G-protein will directly activate:
tyrosine kinase activity
protein kinase G
adenylyl cyclase activity
protein kinase C
none of the above
The proopiomelanocortin (POMC) gene encodes which of the following peptide hormones?:
adrenocorticotrophin hormone (ACTH)
melanocyte stimulating hormone (MSH)
aMSH
all of the answers
b-Endorphin
The range of temperatures in a species preferred optimum temperature zone (POTZ) is essential in the captive environment because:
reptiles are homeothermic
not all systems function optimally at the same temperature
reptiles are endothermic
males need a lower temperature for spermatogenesis
higher temperatures are necessary for hormone production
Amphibians are considered to be ‘cold-blooded’ because the major influence on their body temperate is external. However this term is inappropriate and amphibians should be defined as:
Poikilothermic
Endothermic
Homeothermic
Warm-blooded
Homothermic
What makes up the posterior pituitary?
Pars nervosa known as the neurohypophysis
Pars tuberalis, pars distalis and pars intermedia known as the adenohypophysis
Pars tuberalis, pars distalis and pars intermedia known as the neurphypophysis
Pars nervosa known as the adenohypophysis
What makes up the anterior pituitary?
Pars tuberalis, pars distalis and pars intermedia known as the neurohypophysis
From what germ cell layers does the pars distalis and pars nervosa develop from respectively?
Ectoderm and neuro-ectoderm
Neuro-ectoderm and ectoderm
Mesoderm only
Endoderm only
The adrenal gland releases aldosterone from which zona?
Zona glomerulosa
Zona fasciculata
Zona reticularis
Adrena medulla
The adrenal gland secretes cortisol primarily from which zone?
Zona fasciiculata
Zone reticularis
Adrenal medulla
The adrenal gland secretes the adrenal androgens from which zone?
The adrenal gland secretes epinephrine and norepinephrine from which zone?
Which chain in the glycoprotein peptide hormones are identical?
Alpha subunits
Beta subunits
Which class of steroids is cortisol and aldosterone?
Corticosteroids (C21)
Progestagens (C21)
Androgens (C19)
Oestrogens (C18)
The cholesterol enter mitochondria during steroid biosynthetic pathway from action of...?
StAR (Steroidogenic acute regulatory protein)
Steroidogenic Factor 1
Heat shock proteins
cAMP
Which hormones are derived from tyrosine?
Adrenaline and noradrenaline
Dopamine
T3/T4
All of the above
Which lipid soluble hormone(s) exert their effects on plasma membrane receptor?
Prostaglandins and Leukotrienes (the Eicosanoids)
Cortisol
Aldosterone
Aldosterone (mineralocorticoid) and Cortisol (Glucocorticoids) are structurally similar and so can bind to each other's receptors. How is this overcome?
11 beta hydroxyl steroid D enzyme converts cortisol to inactive cortisone which won't activate the aldosterone receptor
11 beta hydroxyl steroid D enzyme converts aldosterone to inactive aldostisone which won't activate the cortisol receptor
The anabolic actions of cortisol involves what and occurs where?
Glycogenesis, gluconeogeneis and protein synthesis in the liver
Glycogenesis, gluconeogeneis and protein synthesis in muscle and fat cells
The catabolic actions of cortisol involve what and occur where?
Protein breakdown and lipolyis in muscle and fat cells
Protein breakdown and lipolyis in brain
Dexamethazone is used to test? Inhibits ACTH from anterior pituitary and CRH from hypothalamus.
Primary hyperadrenocorticism
Primary Hyperaldosteronism
Secondary Hyperaldosteronism
Corticotrophenioma tumour
Where are these hormones secreted from? Oxytocin and ADH
Posterior pituitary
Anterior pituitary
Hypothalamus
Adrenal gland
Thyroid
Where are these hormones secreted from? LH & FSH, GH, TSH, Prolactin and ACTH
Anterior pituitary hormone
Posterior pituitary hormone
Out of all the hypothalmus hormone secretions which one is the only one classed as catecholamine hormone whilst all the others are peptide?
GnRH
GHRH
SST
TRH
CRH
The hormones of hypothalamus all act on GPCR.
The posterior pituitary has no neural connections with hypothalamus and so hormones from the hypothalamus are transported via the hypothalamo-pituitary portal vessels
Which hormone below is NOT released from the thyroid gland?
Calcitonin
Tri-iodothryonine
Thyroxine
PTH
Which one of these transcription factors is involved with thyroid development?
Pax8
Foxe1
All the answers
Hhex
The thyroid hormones are regulated to increase their activity by?
Phosphorylation
Sumoylation- binding sumoproteins to to the nuclear thyroid receptors
Increased secretion
Increased binding to thyroid binding proteins
The thyroid hormones are regulated to decrease their activity by?
Sumoylation- binding sumoproeins to nuclear thyroid hormones
Decreased secretion
IgG binding to or near TSH receptors causing an increase in cAMP activating TSH signalling leading to hyperthyroidism is known as what?
Graves' disease
Hashimoto's disease
Addison's disease
Cushing's syndrome
Thyroid hyperplasia and lymphocytic infiltration leading to loss of thyroid function leading to Hypothyroidism is known as what?
Grave's disease
Heat produced from metabolism:
Endothermy
Homeothermy
Tachmetabolism
Ectothermy
Heterothermy/ poikilothermy
Bradymetabolism
Constant body temperature:
Heterothermy/poikilothermy
High metabolism:
Heat from exogenous sources:
Body temperature fluctuates:
Low metabolism:
Whats the one main advantage Heterothermy/poikilothermys have over homeothermias?
Need to eat less often
Longer duration of activity
Can perform actions throughout different times of day
Protection against infection as it is too hot for many pathogens such as fungi
Stress leukogram blood test for someone with high cortisol will show what?
High neutrophils, low esoinophils, low lymphocytes and High platelets
Low neutrophils, low esoinophils, low lymphocytes and low platelets
High neutrophils, high esoinophils, low lymphocytes and low platelets
High neutrophils, low esoinophils, high lymphocytes and low platelets
High neutrophils, high esoinophils, high lymphocytes and high platelets