INTS11 - Hypothalamic Pituitary Axes Flashcards
Define endocrine gland
Group of cells which secrete messenger molecules in form of hormones
Define a hormone
Bioactive messenger molecules secreted by endocrine glands
Define the endocrine system
Consist of the endocrine glands and the hormones they secrete
What are the differences in chemical messengers between the endocrine and nervous systems
Endocrine - hormones in blood circulation
Nervous - neurotransmitters released at synapses
What are the differences between the actions of signals in endocrine and nervous systems
Endocrine - signal acts on many cells
Nervous - signal acts on innervated neurons only
What are the differences between the speed of effect and length of duration between endocrine and nervous system
Endocrine - can take longer and exist over long periods
Nervous - quick effects with short periods of time
Name some types of differences between endocrine and nervous systems
Type of chemical messengers
Number of cells the signal acts on
Time taken for action
Duration of signal
What is the location of the hypothalamus
Base of the Brain
Which pituitary gland is connected directly to the hypothalamus
Posterior pituitary lobe
How is the anterior pituitary lobe and the hypothalamus connected
By short blood vessels
Define location and general overview of thyroid gland
Located in the neck and regulates metabolism and growth
What are the parathyroid glands and how are they structurally related to the thyroid gland
Glands located at posterior surface of thyroid glands, involved in calcium metabolism and regulation.
Give role and location of adrenal glands
Located at top of kidneys. Involved in release of glucocorticoids for stress responses e.g. adrenaline and epinephrine and release of mineralocorticoids for regulation of salt and water balance.
Give location and role of pancreas
Located at posterior of the stomach. Involved in regulation of blood glucose concentration.
What are the two types of gonads, which system are they part of and what do they do.
Testes and ovaries.
Reproductive system.
Release of sex steroids/hormones.
Where is the kidney located and what is it’s roles
Located at posterior of middle of trunk.
Involved in the regulation of blood pressure, water reabsorption and calcium regulation.
Discuss the role of the heart as an endocrine organ.
Heart is not an endocrine organ but has endocrine function. Releases natriuretic peptides which have varying physiological effects.
What are natriuretic peptides
Hormones secreted by the heart into blood circulation involved in regulation of sodium excretion in kidney
What is role and location of the thymus gland.
Location - upper anterior of trunk behind the sternum.
Releases thymus in to regulate immune function.
Discuss endocrine role of gastrointestinal tract.
Contains endocrine cells but is not considered an endocrine organ. Hormones involved in digestion etc.
Discuss the endocrine role of adipose tissue
Releases hormones known as adipokines (also releases cytokines) that give information on fat stores and regulation of appetite.
Which cell organelles would be present in high numbers in endocrine cells and why
Mitochondria - endocrine cells have high metabolism so require ATP
Rough ER- protein synthesis which makes up most of the hormones.
Secretory granules - storage of hormones until stimulus signalling their release is required.
Which feature of the circulatory system is located near the endocrine cells
Blood capillaries. Allows hormones released from cells to be directly entered into circulation.
Discuss what neurosecretory cells are and how they function.
Neurons with typical neuronal morphology but can also release hormones which are stored in secretory vesicles at the axon terminal. Hormones released into circulation.