Endocrine System Flashcards
Define the endocrine glands
Special groups of cell within the endocrine system that produce and secrete hormones.
Define the endocrine system
A network of glands throughout the body that produce and secrete hormones.
Define hormones
Chemical messengers of the body that travel through the bloodstream and influence many factors like mood, stress response or bonding between a mother and newborn.
Define the pituitary gland
Known as the master gland. Its primary function is to influence the release of hormones from other glands.
Name all the glands involved in the endocrine system
Hypothalamus Pituitary gland Adrenal Glands Ovary Testes
What is the endocrine system regulated by? Include an example
By feedback i.e how a thermostat regulates temperature. FOR EXAMPLE: A signal is sent from the hypothalamus to the pituitary gland to secrete a stimulating hormone into the bloodstream. This hormone then targets its target gland ie adrenal glands to secrete its hormone
What happens as levels of hormones rises in the bloodstream?
The hypothalamus shuts down the secretion of the releasing hormone and the pituitary shuts down the secretion of the stimulating hormone. So, secretion of the target glands hormone is slowed down creating a stable concentration of hormones that are circulating in the bloodstream.
How do target cells respond to a particular hormone?
They only respond because they have receptors for that specific hormone.
What is critical for normal functioning?
Timing of hormone release and and levels of hormone release. If not controlled can result in dysfunction of bodily systes. ie) too much cortisol can lead to Crushing’s syndrome where there is high blood pressure and depression. Too much cortisol = result of tumour in pituitary gland leading too much ACTH being produced causing adrenal glands to make too much cortisol.
What does high levels of hormones in the endocrine glands do?
Stop pituitary and hypothalamus from making their own hormones, called negative feedback and stops hormone levels from being too high.
What are the 2 main parts of the pituitary gland and explain the anterior
The anterior pituitary (font part) and posterior pituitary (back part).
Both release different hormones that target different body parts.
Anterior - releases ACTH as a response to stress. Also produces 2 hormones vital for reproductive functioning and sexual characteristics: LH - Luteinising hormone and FSH - follicile stimulating hormone. In women these hormones help ovaries produce oestrogen and progesterone and in males stimulate the testes to produce sperm and testosterone.
Describe the posterior pituitary
Releases Oxytocin, which stimulates contraction of uterus when giving birth and is vital in child and mother bonding. Research has found oxytocin levels decrease with age and are vital for repair and maintenance.
Where do the 2 adrenal glands sit?
On top of the kidneys.
What are the outer and inner parts of the adrenal glands?
Outer = adrenal cortex Inner = adrenal medulla
What’s the main distinction between the 2 adrenal glands?
Hormones produced by adrenal cortex = vital for life. Those produced by adrenal medulla are not.
