hypothalamus and pituitary physiology Flashcards
what does it consist of
ductless endocrine glands that are scattered throughout the body
how do endocrine glands accomplish their functions
by secreting hormone into the blood
example of hormones that are hydrophilic
- peptide hormones
- catecholamines
- indoleamines
example of hormones that are lipophilic
- steroid hormones
- thyroid hormones
what are peptide hormones
chains of amino acids
what produces catecholamines
adrenal medulla
what produces indoleamines
pineal gland
what produces steroid hormones
adrenal cortex
what produces thyroid hormone
thyroid gland
what is the target cell of the hormones produced by the hypothalamus
anterior pituitary
what is the function of the hormones produced by the hypothalamus
control the release of anterior pituitary hormones
what hormones are produced by posterior pituitary
- vasopressin
- oxytocin
what is the target tissue of vasopressin
kidney tubules
what is the function of vasopressin
increases water reabsorption
what is the target cell of oxytocin
- arterioles
- uterus
- mammary glands
what is the function of oxytocin
- vasoconstriction
- contraction
- milk ejection from breasts
what hormones are produced by anterior pituitary
- thyroid stimulating
- adrenocorticotrtropic hormone (ACTH)
- growth hormone
- follicle-stimulating hormone
- luteinzing hormone
- prolactin
what does the zona glomerulosa of the adrenal cortex produce
aldosterone
what does the zona fasciulata and zona reticularis produce
cortisol
what does aldosterone do
increase sodium reabsorption and K+ secretion
what does the adrenal medulla produce
epinephrine
what does epinephrine do
reinforce sympathetic nervous system
what does the pancreas produce
- insulin
- glucagon
- somatostatin
what does the parathyroid gland produce
parathyroid hormone
what does the ovaries produce
oestrogen
what do the testes produce
testosterone
HYPOTHALAMUS AND PITUITARY
HYPOTHALAMUS AND PITUITARY
where is the pituitary gland located
in a bony cavity at the base of the brain
what is the pituitary gland below
hypothalamus
how is the pituitary connected to the hypothalamus
thin connecting stalk
how many lobes does the pituitary have
2
what is the name of the lobes of pituitary
- posterior
- anterior
what is the posterior pituitary termed
neurohypophysis
what is the anterior pituitary termed
enohypophysis
what does adeno
glandular
what is the release of hormones form the pituitary gland controlled by
hypothalamus
how is the posterior lobe connected to the hypothalamus by
neural pathway
how is the anterior lobe connected to the hypothalamus by
vascular link
what are the supporting cells in the posterior pituitary called
pituicytes
what lobe is an extension of the hypothalamus
posterior
does the posterior pituitary produce any hormones
no
what does the posterior pituitary do
stores and stimulates the release of 2 hormones
what 2 hormones does the posterior pituitary release
- vasopressin
- oxytocin
where are vasopressin and oxytocin produced
in the neuronal cell bodies of the hypothalamus
can the terminals of the posterior pituitary store both vasopressin and oxytocin
no only one
what is another name for vasopressin
antidiuretic hormone
what does vasopressin do
- enhances retention of water by the kidney nephrons during urine formation
- causes contraction of arteriolar smooth muscle
what does oxytocin do
stimulate contraction of the uterine smooth muscle to help expel the infant during child birth
what effect does oxytocin have on breast
promotes ejection of the milk from the mammary glands during breast feeding
what hormone facilitates bonding between a mother and child
oxytocin
does the anterior pituitary synthesise its own hormones
yes
how many hormones are secreted by the anterior pituitary
6
what do somatotrope cells of the anterior pituitary secrete
growth hormone
what does growth hormone do
regulates overall body growth
what does somato mean
body
what do thyrotrope cells secrete
thyroid stimulating hormone
what does thyroid stimulating hormone do
simulate secretion of thyroid hormone and growth of the thyroid gland
what do corticotropes of the anterior pituitary produce
adrenocorticotropic hormone (ACTH)
what does adrenocorticotropic hormone stimulate
secretion by the adrenal cortex of cortisol
what do gonadotropes of the anterior pituitary secrete
2 hormones:
- follicle stimulating hormone
- luteinising hormone
what does follicle stimulating hormone do
regulate gamete production in both sexes
what does luteinising hormone do
control sex hormones in both sexes
what do lacotropes of the anterior pituitary release
prolactin
what does prolactin do
enhances breast development and milk production (lactation)
what is ACTH synthesised as
large precursor molecule known as pro-opiomegancortin
what is pro-opiomegancortin cleaved into
- ACTH
- melanocyte stimulating hormone
- endorphin
what cells produce melanocyte stimulating hormone
melanocytes in response to UV light (causes tanning)
what does tropic hormone mean
that it regulates secretion of another specific endocrine gland
what are the secretion of hormones from the anterior pituitary reliant on
hypothalamus
how many hormones does the hypothalamus secrete
7
what are the 2 types of hormones released from the hypothalamus
- releasing
- inhibiting
example of prolactin-inhibiting hormone
dopamine
what is the endocrine axis
that the release of a hormone from the hypothalamus controls the release of hormones from the anterior pituitary that contorts the target organ
example of growth hormone inhibiting hormone
somatostatin
what is the largest and best portal system
hepatic portal system
where must all the blood to the anterior pituitary first pass through
the hypothalamus
how does the hypothalamic system work
via negative feedback loops
ENDOCRINE CONTROL OF GROWTH
ENDOCRINE CONTROL OF GROWTH
is growth hormone essential for growth
yes
is cortisol pro growth or anti growth
anti growth
what does cortisol promote that is anti growth
- promotes protein breakdown
- inhibits growth in long bones
- blocks the secretion of growth hormone
when does puberty being
age 11 in girls
age 13 in boys
what is the most abundant hormone produced by the anterior pituitary
growth hormone
what are the main target tissues of growth hormone
- adipose tissue
- skeletal muscles
- liver
what does growth hormone increase
fatty acid levels
what does increased fatty acid levels enhance
breakdown of triglyceride fat stored in adipose tissue
- mobilises fat stores
what is the only thing that the brain uses as metabolic fuel
glucose
can the nervous tissue use glucose
no
what is the major source of IGF-1
liver
what causes release of IGF-1
growth hormone
is IGF-II influenced by growth hormone
no
when is IGF-II important
during foetal development
how does growth hormone promote growth of soft tissues
- hyperplasia
- hypertrophy
what does growth hormone prevent
apoptosis
what are the bone cells that produce organic matrix known as
osteoblasts
is cartilage calcified
no
pgs 679 to 685 not done
pages 679 to 685 not done
PINEAL GLAND AND CIRDCADIAN RHYTHMS
PINEAL GLAND AND CIRCDADIAN RHYTHMS
where is the pineal gland located
centre of the brain
what does the pineal gland secrete
melatonin
page 685
page 685
