endocrine system Flashcards
Distinguish between exocrine and endocrine glands.
Exocrine glands have ducts which secrete substances into a duct and this is carried to the surface (eg. Sweat gland). Endocrine glands are ductless and hormones are secreted into intercellular fluid surrounding cells and diffuse into the blood.
Explain the specificity of hormones, using the target organ/target cell concept.
Hormones bind to receptor proteins that must have the corresponding receptor, they are specific in their action and only bind to corresponding proteins.
State the three types of hormones and describe how they change the functioning of their target organ’s cells.
Proteins, Amines and steroids
1. Activate certain genes
2. change the shape/structure of enzyme
3. change rate of transcription/translation.
State the three types of hormones and describe the mode of action.
- Proteins and Amines (water soluble)
dissolve in blood plasma, attach to protein receptors in the membrane of target cells (outside cell), signals a secondary messenger, cascade of reactions inside the cell follows, activates particular enzymes. - Steroids (lipid soluble)
Attach to transport proteins to travel in blood, attach to protein receptors inside cell on the mitochondria or in nucleus, in nucleus – gene is activated, changes to proteins being made.
Name the hormones produced by the POSTERIOR pituitary, their target cells and their effect on those cells.
Pituitary - POSTERIOR
Oxytocin - targets the uterus for the Contraction of uterus during childbirth. Also targets the Mammary glands for the release of milk.
Antidiuretic hormone (ADH) - targets kidneys for Reabsorption of water.
Name the hormones produced by the ANTERIOR pituitary, their target cells and their effect on those cells.
Pituitary - ANTERIOR
Follicle stimulating hormone (FSH) - targets the Ovaries for the Growth of follicles. Also targets the testes for the production of sperm.
Luteinising hormone (LH) - targets ovaries for Ovulation and maintenance of corpus luteum. Also targets testes for the secretion of testosterone.
Growth hormone (GH) - targets All cells for Growth and protein synthesis
Thyroid stimulating hormone (TSH) - targets Thyroid gland for the secretion of hormones from the thyroid.
Adrenocorticotropic hormone (ACTH) - targets the adrenal cortex for the secretion of hormones (cortisol) from the adrenal cortex.
Prolactin - targets Mammary glands for Milk production.
Name the hormones produced by the thyroid, its target cells and their effect on those cells.
Thyroid
Thyroxine - targets most body cells to increase metabolic rate and therefore oxygen and heat production.
calcitonin - targets Bones, kidneys to decrease calcium and phosphate levels in the blood.
Name the hormones produced by the parathyroid, its target cells and their effect on those cells.
Parathyroid
Parathyroid hormone (PTH) - targets Bones, kidneys to increase level of calcium in blood.
Name the hormones produced by the pancreas, its target cells and their effect on those cells.
Pancreas – islets of Langerhans (BETA cells)
Insulin - targets most body cells and stimulates the uptake of glucose; lowers blood glucose levels
“low glucose? beta get some insulin”
Pancreas – islets of Langerhans (ALPHA cells) glucagon - targets liver and fat storage tissues which stimulates breakdown of glycogen and fat; increases blood glucose level.
Name the hormones produced by the adrenal medulla, its target cells and their effect on those cells.
Adrenaline/noradrenaline - targets most body tissues as it prepares the body for fight-or-flight responses; reinforces the effects of the sympathetic nervous system
Name the hormones produced by the adrenal cortex, its target cells and their effect on those cells.
Aldosterone - targets kidneys so it increases reabsorption of Sodium ions and excretion of potassium ion.
Glucocorticoid (Cortisol) - targets most body cells as it Promotes normal metabolism; helps the body deal with stress; and promotes repair of damaged tissues.
Describe the relationship between the hypothalamus and the pituitary.
Hypothalamus controls pituitaries releasing of hormones.
Explain how the hypothalamus regulates the release of anterior pituitary hormones and the release of posterior pituitary hormones.
anterior pituitary hormones are regulated from the hypothalamus’s realising and inhibiting factors. The posterior pituitary hormones are controlled by the hypothalamuses initiation of neural impulses.
Distinguish between inhibiting factors/hormones and releasing factors/hormone.
inhibiting factors halt the release of hormones/ response to feedback of too much hormone release whereas releasing factors/hormones are the production and release of more hormones due to feedback of not enough produced.
List the hormones of the anterior pituitary, along with their target organ and their general effect.
Follicle stimulating hormone/FSH- targets ovaries and stimulates the follicles in the ovaries.
luteinising hormone/LH - targets ovaries and stimulates ovaries for ovulation and maintains the corpus luteum.
growth hormone/GH - targets all body cells
adrenocorticotropic hormone (ACTH) - targets adrenal cortex to secrete hormones.
prolactin - targets mammary glands for milk production.
thyroid stimulating hormone/TSH - targets thyroid to release hormones.
