5.2 Hormonal Communication Flashcards
What are hormones ?
Chemical messenger in the endocrine system, that travel in the blood and works alongside the neuronal system to react to change. Can be steroids, proteins, polypeptides are amines.
What are endocrine glands ?
Group of cells which are specialised to secrete chemicals, which are hormone directly secreted into the blood stream.
What is the pituitary gland ?
Produces growth hormones, controlling growth of bones and muscles. Anti-diuretic hormones, which increases reabsorption of water and gonadotrophins, controlling development of ovaries and testes.
What is the thyroid gland ?
Produces thyroxine which controls the rate of metabolism and rate that glucose is used up in respiration.
What is the adrenal gland ?
Produces adrenaline which increases heart and breathing rate and raises blood sugar level.
What is the pineal gland ?
Produces melatonin which affects reproductive development and daily cycles.
What is the thymus ?
Produces thymosin which promotes production and maturation of white blood cells.
What is the pancreas responsible for ?
Produces insulin to convert glucose to glycogen and glucagon to convert glycogen to glucose.
What are the testes responsible for ?
Produces testosterone which control sperm production and sexual characteristics.
What are the ovaries responsible for ?
Produces oestrogen, controlling ovulation and progesterone that prepares the uterus lining for receiving an embryo.
Where are hormones directed to ?
Released in blood to reach target cells. Once bound to their receptors, hormones stimulate target cells to produce a response.
What are steroid hormones ?
Lipid soluble so can pass through lipid component of cell membrane and binds to form hormone-receptor complex.
What are non-steroid hormones ?
Hydrophilic so cannot pass directly through membrane, so binds to specific receptors on cell surface membrane of the target cell.
Hormonal vs neuronal communication ?
-Blood stream
-Relatively slow
-Widespread response
-Response is slow
-Response is long-lasting.
-Permanent and irreversible.
Neuronal vs hormonal communication ?
-Neurones
-Rapid transmission
-Specific parts of body
-localised response
-short-lived response
-effect is temporary and reversible.
Where are the adrenal glands located ?
Top of each kidney and are made up of adrenal cortex (produces vital hormones such as cortisol and aldosterone) and adrenal medulla 9produces non essential hormones like adrenaline)
What are glucocorticoids ?
Include cortisol to help regulate metabolism. Also includes corticosterone that works with cortisol to regulate immune response and supresses inflammatory reactions.
What are mineralocorticoids ?
Main one produced is aldosterone that helps blood control pressure by maintaining the balance between salt and water concentrations .
What are androgens ?
Small amounts of male and female sex hormones are released. Impact is small but is still important.
What hormones are secreted by adrenal medulla ?
Adrenaline responsible for flight or fight.
Noradrenaline responsible for responding to stress, such as increasing heart rate.
What are the two main functions of the pancreas ?
Produces enzymes and releases them into duodenum. Also produces hormones and releases them into the blood.
What are the Islets of Langerhans ?
Small regions of endocrine tissue that are responsible for producing insulin and glucagon and secreting these hormones directly into the blood stream.
What are alpha cells in Islets of Langerhans ?
They produce and secrete glucagon.
What are beta cells in Islets of Langerhans responsible for ?
These produce and secrete insulin.
