Glands and Hormones Flashcards
describe the location of the endocrine cells in the brain
hypothalamus is above the pituitary gland, the pineal gland is located above and in between the pons and medulla oblongata.
what interconnects the pituitary and hypothalamus
blood vessels, neuron bodies and the infundibulum
what are the roles of the hypothalamus
thermoregulation
hormone secretion
circadian rhythms
motivation
emotions
what are the hormone secretion roles of the hypothalamus
primary hormones and trophic hormones secretion
what is involved in motivation
thirst
feeding
sexual behaviour
what is monosodium glutamate
neurostimulator that kills a certain portion of hormones from the hypothalamus
become obsese despite eating the same food as another person.
concept of metabolical changes exists so there is metabolically a symbol.
describe urine in diabetes mellitus
sweet, due to sucrose and glucose
describe urine in the other diabetes
no sweet taste
how does the hypothalamus have a role in circadian rhythms
by responding to day and night cycles
what are circadian rhythms
the internal clock that makes us alert or sleepy
describe how the hypothalamus is related to the pituitary
it produces hormone releasing hormones that pass to the anterior pituitary via blood vessels and this triggers the secretion of hormones from the anterior pituitary
what are the blood vessels between the hypothalamus and the pituitary
hypothalmic pituitary portal vessels
how is the posterior pituitary connected to the hypothalamus
through axons that are form cells present in the hypothalamus.
describe the relationship between the hypothalamus and the posterior pituitary
hormones produced in the hypothalamus pass to the posterior pituitary along the nerve axons
released into circulation in the posterior pituitary
label this
label this
what are the hypothalmic hormones
- corticotropin releasing hormone
- gonadotropin releasing hormone
- thyrtropin releasing hormone
- growth hormone releasing hormone
- somastostain (growth hormone inhibiting)
- prolactin releasing hormone
- dopamine
what are trophic hormones
hormones that stimulate the release of other hormones
what are the anterior pituitary hormones
- adrenocorticotropin hormone
- follicle stimulating hormone
- luteinising hormone
- thyroid stimulating hormone
- growth hormone
- prolactin
describe the route of corticotropins
stressors stimulate the hypothalamus to release corticotropin realeasing hormone to the anterior pituitary gland to release ACTH to the adrenal cortex to release cortisol
describe the gonadotrophins course
stimulus on the hypothalamus to release gonadotrophin releasing hormone to the anterior pituitary gland to release follicle stimulating hormone/luteinising hormone to go to ovaries and testes
describe the action of the follicle stimulating hormone on the ovaries
ovum maturation and oestrogen production
describe the action of luteinising hormone on the ovaries
ovulation production of oestrogen and progesterone
describe the action of follicle stimulating hormone on the testes
sperm production
describe the action luteinising hormone on testes
testosterone production
describe the course of thryotropins
stimulus on the hypothalamus to release of thyrotropin releasing hormone to the anterior pituitary gland, which releases thyroid stimulating hormone to go to the thyroid gland to release thyroid hormones
describe the action of the somatotrophins
stimulus to the hypothalamus to release of growth hormone releasing hormone and growth hormone inhibiting hormone to the anterior pituitary gland to produce growth hormone
describe the course of action of prolactin
stimulus to the hypothalamus to release prolactin releasing hormone and prolactin inhibiting hormone to produce prolactin
what the action of prolactin
breast development and milk production
what are the posterior pituitary hormones
antidiuretic hormone
oxytocin
these are produced by neurons in the hypothalamus and pass along the axons to the posterior part of the pituitary
what are the two nuclei in the pituitary gland
paraventricular nucleus (ADH)
supraoptic nucleus (Oxytocin)
describe the course of the antiduiretic hormone
stimulus on the hypothalamus
release of ADH through axonal transport
to the posterior pituitary gland
release of ADH in plasma
to the kidney
water reabsorption in collecting ducts
describe the course of action of oxytocin
stretch of the uterus releases oxytocin from the hypothalamus to the posterior pituitary gland leading to oxytocin in the plasma and contraction of the uterus
describe the action of the infant suckling and how it affects hormone release
stimulating oxytocin release along axons from the hypothalamus to the posterior pituitary gland to produce oxytocin into the plasma and eject milk
what is released from the thyroid gland
thyroid hormones
T3
T4
calcitonin
what produces calcitonin
the parafollicular cells in the thyroid gland
what are the actions of thyroid hormone
- increase metabolic rate of all cells
- determine basal metabolic rate
- essential for normal fetal and childhood growth
- permissive effect on the action of adrenaline by upregulating adrenoreceptors
which thyroid hormone is more potent
T3, although it has a short half life
what is used if there is not enough thyroid hormone production
thyroxine medication
describe undersecretion of the thyroid gland
leads to cretinism and myxoedema
what does oversecretion of the thyroid gland lead to
graves disease
what is simple goitre
thyroid swelling associated with iodine deficiency
low levels of thyroxine result in increased secretion of TSH
iodide added to salt
how much of pancreatic tissue are taken up by islets of langerhans
1-2%
what surrounds the islets of langerhans
exocrine tissue
label this
what is this
an islet of langehans stained with immunocytochemistry
glucagon is green
somatostatin is red
how does immunocytochemistry work
stains make the tissue produce light
what is insulin released in response to
raised blood glucose and amino acids
glucose dependent insulinotropic peptide
vagus nerve
what does the insulin hormone act overall to do
lower blood glucose
how does insulin lower blood glucose
it facilitates its entry into:
- muscle cells
- adipocytes
glucose is taken in by the liver but not with the aid of insulin
what does insulin promote the formation of
glycogen
triglycerides
facilitate protein synthesis
what promotes release of insulin
increased blood glucose
increased blood amino acids
GIP
vagus nerve activity
what is GIP
glucose dependent insulinotropic peptide which is also known as the gastric inhibitory peptide
what inhibits insulin secretion
adrenaline
sympathetic nerves
somatostatin
what happens to insulin production when people are anxious
it decreases
what is glucagon released in response to
low blood glucose concentration
what does glucagon act to do
raise blood glucose levels
what are the actions of glucagon
glycogenolysis
gluconeogenesis
lipolysis and ketone synthesis
where does glycogenolysis occur
liver
what is glycogenolysis
this is the break down of glycogen to produce glucose
what is gluconeogenesis
this is when the liver produces glucose through the use of amino acids and fatty acids
what promotes the secretion of glucagon
decreased blood glucose
increased blood amino acids
cholescystokinin
autonomic nerve activity
what inhibits the secretion of glucagon
insulin and somatostatin
why are insulin glucagon and somatostatin all released in the same area
because they all work together to control blood glucose levels
describe diabetes mellitus
elevated blood glucose concentration, due to a decreased glucose uptake by cells.
what are the metabolic changes associated with diabetes mellitus
gluconeogenesis and lipolysis
what are the clinical features of diabetes mellitus
- polyuria
- poydipsia
- glycosuria
- diabetic neuropathy
- skin and oral diseases
what is polyuria
increased urine production
what is polydipsia
increased fluid intake due to an increase in thirst
what is glycosuria
glucose in the urine
describe type 1 diabetes
insulin dependent patients due to a decrease in insulin secretion from destruction of beta cells.
10% of cases, usual early onset
insulin injections and diet are the key treatment features
describe type 2 diabetes
insulin levels in the patients are norma, but the target cell no longer responds to it. related to obesity, usually has a late onset in life.
treated through control of diet and oral hypoglycaemic agents
what makes periodontitis different to gingivitis
loss of attachment
no bleeding
need an autoimmune component to have periodontal disease
greater risk of diabetes, can make diabetes worse and vice versa
why are adrenal glands described as supra renal
they lie on top of the kidneys
what are the hormones produced from the adrenal cortex
corticosteroids, such as
- aldosterone
- cortisol
- androgens
what are the hormones produced from the adrenal medulla
adrenaline and noradreanline, catelochomine hormones
what is the production of corticoids associated with
cholesterol chain reaction
describe cortisol
a glucocorticoid hormone that is produced by cells of the zona fasiculata of the adrenal cortex
controlled by ACTH
what controls the secretion of cortisol
ACTH
what are the actions of cortisol
metabolic
permissive
anti inflammatory
immnuosuppressant
describe aldosterone
a mineralcorticoid hormone that is produced by the cells of the zona glomerulosa
controlled by RAAS
describe the actions of aldosterone
promotes reabsorption of sodium and water in the kidney
increases excretion of hydrogen and potassium
what is the RAAS system
renin angiotensin aldosterone system
describe the series of events in the RAAS
- stimulus
- renin production from kidney
- angiotensinogen in the blood is converted by renin
- to become angiotensin 1
- ACE converts it to angiotensin 2
- travels to adrenal cortex
- increase aldosterone release
- increase sodium reabsorption in cortical collecting ducts
what is ACE
angiotensin converting enzyme
what are ACE inhibitors used to treat
hypertension
describe androgens
gonadocorticoid hormone produced from the zona fasiculata and reticularis of the adrenal cortex
what are the main hormones of the gonadocorticoid
androgens
what do androgens do
contribute to growth, which contribute to growth and sexual characteristics in boys and girls
cause pubertal growth spurt
what does an excess of glucocorticoids lead to
cushings syndrome
what are the symptoms of cushings disease
fat pads
moon face
pendulous abdomen
red cheeks
striae
bruisability
thin skin
poor muscle development
poor wound healing
what does an excess in the production of androgens lead to
andreno genital syndrome
what are the symptoms of andreno genital syndrome
baidness
receding hairline
adrenogenic flush
small breasts
heavy arms and legs
enlarged clitoris
describe the adrenal medulla
a modified sympathetic ganglion controlled by pre ganglionic sympathetic nerves
cells mostly produce adrenaline which augments the action of the sympathetic nervous system
what does addrenal insufficiency lead to
addisons disease
decreased adrenal function and reduced level of glucocorticoids and mineralcorticoids
very serious condition
