Hypothalamus And Pituitary Flashcards
What are the visceral organs
Lungs, heart, organs of the digestive, excretory, reproductive, and circulatory systems
What is the gastrointestinal system
All major organs of digestive system
Mouth, throat, esophagus, stomach, small intestine, large intestine, rectum, and anus
What is the role of the liver
All blood leaving stomach and intestines passes through the liver
Filtration, Digestion, metabolism, detoxification, protein synthesis, storage of vitamins and minerals
What are the main functions of the kidneys
Remove wastes and extra fluid from your body
Where are neurotransmitters made, and how do they reach axon terminals
Neurotransmitters and neurohormones are made in the neuron cell body, and transported to the axon terminals in vesicles that are walked along microtubules by motor proteins
Where is the pituitary gland located, and what are its distinct lobes
Located at base of brain and is attached to the hypothalamus, has posterior and anterior lobes
What is the broad role of the hypothalamus
The hypothalamus controls the secretion of pituitary hormones - when activated by neural input, hypothalamus stimulates the pituitary gland to secrete hormones
How is the posterior lobe of the pituitary gland connected to the hypothalamus, and what’s its secretion role
Connected to the hypothalamus by neurons (cell bodies in hypothalamus, long axons terminate in posterior lobe)
Secretes hormones into blood stream
Where are posterior pituitary hormones made, and how does hypothalamus communicate with posterior pituitary lobe
Posterior pituitary hormones are made in the hypothalamus (neuron cell body), travel down the axon, and are stored at the axon terminal until required.
Neural communication between hypothalamus and posterior lobe to release hormones into the blood
What hormones are involved in the posterior pituitary lobe
Antidiuretic hormone (ADH) or oxytocin
What are the effects of antidiuretic hormone
Stimulates the kidneys to reabsorb water/reduce urine production
What are the effects of oxytocin hormone
Stimulates the contraction of uterine muscles during childbirth (positive feedback loop)
Stimulates milk release in breastfeeding (milk ejection reflex)
How is the anterior lobe of pituitary gland connected to the hypothalamus
Connected to the hypothalamus by blood vessels
How does hypothalamus communicate with the anterior pituitary
Stimulus - neural input within hypothalamus
Hypothalamus signals anterior pituitary to release hormones by hormonal stimulation, secreting stored releasing hormone portal vessels
Hormone binds to receptor on membrane of specific cell, anterior pituitary hormone is secreted into systemic circulatory system e.g. growth hormone
Outline the differences between the neurons involved in the anterior and posterior pituitary lobes
Both have cell bodies originating in hypothalamus
Posterior axons are long, extend into and terminate in posterior lobe
Anterior axons are short, and terminate releasing hormones into capillaries
Outline the feedback regulation of the anterior pituitary gland
Hypothalamus receives neuro activation
Releases releasing hormone
triggers anterior pituitary gland to release pituitary hormone
Hormone stimulates target organ to release hormone that has desired effect
Final hormone acts as inhibitor for hypothalamus signal and anterior pituitary secretion
What are the anterior pituitary gland hormones
GH-RH
GH-IH
TRH
CRH
Outline the growth hormone release cycle
Stimulus received
GHRH released from hypothalamus
Anterior I pituitary gland is stimulated, and releases growth hormone
Effects are direct in muscle and fat
Liver is stimulated, releases IGF 1, which then goes on to cause desired bodily response
IGF 1 stimulates hypothalamus release of GHIH
GHIH inhibits release of growth hormone from anterior pituitary gland
What are the direct effects of GH in Muscle, Liver, and fat
Muscle - stimulates protein synthesis (long term), and inhibits cellular uptake of glucose (short term)
Liver - simulates glucose synthesis (short term)
Fat - increase triglyceride breakdown in adipose tissue (short term)
What are the indirect effects of GH
Promotes growth of bones, muscle, and other tissues by causing release of somatomedin C, which promotes cell devision (long term)
What is GH effect on growth and metabolism
Long term effect on growth
Short term effect on metabolism
Outline the pattern of growth hormone secretion over a day
GH concentrations have peaks and troughs throughout the whole day
GH concentrations are highest during sleep
