Hypothalamus And Pituitary Glands Flashcards
What does the hypothalamus help to maintain by regulating endocrine system
Homeostasis
Explain the basic structure of the hypothalamic- pituitary axis
Hypothalamus at the brain attached to the anterior and posterior pituitary glands
What is the real name of pituitary glands
Hypophysis
What are the 2 neurones called which extend from hypothalamus into the POSTERIOR PITUITARY
Magnocelullar neurones
What is the name of the posterior pituitary
Neuro hypophysis
Where are the cell bodies with nuclei found on the magnocellular neurones
In the hypothalamus
Give the name of the 2 nuclei of the magnocellular neurones (to posterior pituitary)
Paraventricular nuclei
Supraoptic nuclei
Where are peptide hormones produced at the nuclei of the magnocellular neurones transported down
Down the supraoptic hypothalamus tract
What are the 2 posterior hormones produced called and where are they stored
Oxytocin
ADH (anti diuretic hormone)
When they go down the supraoptic hypothalamus tract they are stored in vesicles at the posterior pituitary neurone ending
What does oxytocin peptide hormone do (when released from posterior)
Uterine muscle contraction in labour of a woman
Breast epithelial contraction for breastfeeding
When is ADH released by posterior pituitary vesicles
When hypothalamus detects dehydrated = increases water uptake at kidneys
What is the anterior pituitary called
Adeno hypophysis
What are the neurones connecting the hypothalamus with the anterior pituitary (adeno hypophysis) called
Parvocellular neurones
What do parvoceullar neurones do
Release hormone factors down to the anterior pituitary down blood vessels
Trigger release of hormones by secretory cells in anterior pituitary
What are the blood vessels called that allow release factors from the parvocellular neurones to reach anterior pituitary secretory cells
Hypophyseal portal vessels including the hypophyseal artery
Name the 6 release factors released by the parvocellular neurones to the anterior pituitary
1- THYROTROPIN releasing hormone
2- GONADOTROPIN releasing hormone
3- CORTICOTROPIN releasing hormone
4- GROWTH FACTOR releasing hormone
5- GROWTH FACTOR inhibiting hormone
6- DOPAMINE
What secretory cells in the anterior pituitary do the 6 releasing hormones act on
THYROTROPIN RH - thyrotroph cells
Gonadotropin rh - gonadotrophs
Corticotrophin RH - corticotrophs
Growth factor inhibitor and releasing hormones - somatotrophs
Dopamine - lactotrophs
What does THYROTROPIN RH do when released to anterior pituitary?
Release Thyroid stimulating hormone and prolactin release
What does prolactin do
Milk production
What does gonadotrophin RH do when released to anterior pituitary
Release FSH follicle stimulating hormone
And LH (leutenising hormone)
What does corticotrophin RH do when released by parvocellular neurones
Stimulate adrenocorticotropic hormone = cortisol release
And prolactin release
What does growth factor RH do
Growth hormone release = growth
What does growth factor inhibiting hormone do other than inhibit growth factor hormone
Inhibit insulin, glucagon and gastrin
What does dopamine do when released into the hypophyseal vessels
Prolactin release
What does thyroid stimulating hormone released by the THYROTROPIN RH do
Stimulate thyroid hormone release
What type of hormone are secreted when gonadotropin is released
Sex steroid hormones (FSH and LH)
What type of hormone is growth factor hormone
A peptide hormone
What cell secreted growth factor hormone
Somatotroph cell at the anterior pituitary (adeno hypophysis)
What does growth factor hormone do
Stimulates growth, cell reproduction and regeneration
What are the 4 direct effects of growth hormone when released by anterior pituitary
1- releases fatty acids from adepose tissues to covert into acetyl coA
2- reduce glucose uptake in cells
3- increase gluconeogenesis in liver
4- increase production of IGF-1
What is IGF1
Insulin like growth factor
What are the long term effects of GH due to increased IGF-1
Promotion of growth of bond, cartilage and muscle
Promotion of amino acid uptake and protein synthesis (for growth eg of muscle)
Insulin - like endocrine effects such as glucose uptake = oppose large glucose concentration
