Endocrine Glands

What is the thyroid gland?

Releases hormones that are important in metabolic process
Mainatins body temperatture as energy released from metabolism can be in the form of heat
Regulates levels of calcium and phosphate in the blood

What is hormones produced from the thyroid gland?

Thyroxine
Tri-iodothryonine
Calcitonin

What is thryoxine?

Targets: All body cells
Function: Controls body metabolism by regulating both catabolic reactions (breaking down complex molecules to release energy) and anabolic reactions (synthesizing complex molecules from simple ones). The overall effect is increased energy production, with some energy released as heat, helping maintain body temperature.

What is triodothyronine?

Targets: All body cells
Function: Regulating metabolism and is the active form of thyroxine

Whats the difference between thyroxine and triodothyronine?

Tri-iodothryonine has three iodine atoms attached while Thryoxine has four iodine atoms attached.
Thyroxine is much less active than triiodothyronine but lasts a lot longer.
Approximately 80% of the thyroid hormones produced are thyroxine and only 20% are triiodothyronine. Once released, enzymes convert Thryoxine into Tri-iodthyron
ine in target tissues (Thyroxine acts as a storage form)

What is calcitonin?

Target: Bone and kidneys
Function: Regulates calculation and phosphate in blood, primarily by lowering blood calcium levels (MAIN ROLE)
Lowers calcium levels in the blood by blocking break down of bone and decreasing reabsorption by kidneys from the reneal tubules
Initates phosphate to move into bone cells and bone fluid

What is the parathyroid gland?

Set of four endocrine gland which release hormones that regulate the amount of calcium, phosphorus and magnesium in bones and blood. Also increases levels of phosphate in the excretion of urine.

What hormone is released by the parathyroid gland (located on the thyroid gland)?

Parathyroid hormone

What is the parathyroid hormone

Targets: Bones, kidneym small intestine
Function: Acts opposite to calcitonin. Increases calcium levels in blood (as well as phosphorous) by increasing the break down of bone, increasing the reabsorption in kidneys and increases absorption in small intestine
-Calcium is used for muscle contraction and synpases

What is the pancreas?

Makes hormones that help control blood sugar levels (secretes different amount of hormone based on the amount of glucose in the blood). Does this by:
-Reduces amount of glucose in blood: Promotes the uptake of glucose from bloood by cells and in the liver having glucose converted to glycogen and fat
-Increases amount of glucose in blood: Promotes the breakdown of glycogen to glucose in the liver and stimulates the breakdown of fat in the liver and storage tissue

What are the hormones produced by the pancreas?

Insulin
Glucagon
(Antagonistic pairs)

What is insluin?

Tagrets: All body cells
Function: Reduces blood suagr levels (blood glucose regulation). Does this by:
-Promoting the uptake of glucose in blood from cells so they can use glucose for energy
-Liver: Causes converison of glucose to glycogen and fat (glycogenesis and lipogenesis)
-Skeletal muscles: Causes formation of glycogen from glucose (glycogenesis)
-Fat storage tissue: Causes glucose to be converted into fats (lipogenesis)

What is glucagon?

Tagret: All body cells
Function: Increases blood sugar levels (blood glucose regulation). Does this through
-Liver: Promoting breakdown of glycogen to glucose (glycogenolysis). Also stimulates breakdwon of fats (lipolysis)
-Fat storage tissue: Stimulates the breakdown of fats (lipolysis).

What is the thymus?

A endocrine gland which is large in infants and children but begins to shrink after puberty (meaning it weakens because it becomes smaller so it makes it harder for the body to deal with infections). The hormones it secretes influences the maturation of T-cells

What are the hormones produced by the thymus?

Thymosin

What is thymosin?

Target: Lymphocytes
Function: STimulates the production and maturation of Helper T-ells

What do the gonads do?

Testis: Secretes hormones (testosterone) which maintain and develop male sex characteristics
Ovary: Release hormones (oestrogen and progesterone) which stimulate the development and maintance of female sex characteristics and, alongside the pituituary gland, regulates the menstural cycle

What are the hormones of the gonads?

Testosterone
Oestrogen
Progesterone

What is testosterone?

Target: All cells
Function
•Development of secondary sex characteristics
•Enhances sex-drive, bone and muscle mass

What is oestrogen?

Target: All cells
Function: Development of secondary sex characteristics
Regulates menstrual cycle

What is progresterone?

Target: Uterus
Function: Prepare the uterus for pregnancy by thickening the uterine lining (endometrium) and inhibiting uterine contraction

What is the pineal gland?

Small endocrine gland and the hormone it secretes regulates sleep patterns. It is stimulated by darkness and inhibited by light.

What homrone is produced by the pineal gland?

Melatonin

What is melatonin?

Target: All cells
Function: Regulates wake/ sleep cycle, produced in high amounts during night (stimulated by darkness)

What is the role of the adrenal glands in homostasis?

Regulates metabolism. immune system (cortisol), blood pressure, electrolyte balance (aldosterone) and response to stress (adrenaline and noradrenaline)

What is the adrenal medulla?

Located above the kidneys with the medulla being the inner section. It releases hormones during the flight or fight response (increases rate and force of heart beat)

What hormones are produced by the adrenal medulla (middle)?

Adrenaline (Epinephrine)
Norepinephrine

What is Adrenaline (epinephrine)?

Target: All body cells
Function: Plays a role in responding to danger, functions to increase cardiac output and increase blood glucose level.
Helps prepare the body for the reaction during threatening situations

What is norepinephrine?

Target: All body cells
Function: Increase arousal, attention and alternes
Constricts blood vessel to maintain blood pressure (main role is to cause blood pressure to rise by vasoconstriction)
Affects sleep-wake cycle
Increases rate and force of heart beat

What is the adrenal cortex?

Outer portion of the adrenal gland

What are the hormones produced by adrenal cortex?

Cortisol
Aldosterone

What is cortisol?

Target: All body cells
Function: Released in response to stress (helps body withstand stress)
Regulates/ promotes normal metabolism, blood pressure, blood sugar
Suppresses inflammation and promotes the repair of damage tissue)

What is aldosterone?

Target: Colon (large intestine) and kidneys
Function: Regulate blood pressure by managing the levels of sodium and potassium in your blood (this helps regulate water balance)
Signals tubules to increase amount of sodium absorbed and increase amount of potassium excreted in urine.
-Water is rebasorbed along the sodium ions which increases water volume in blood
Regulates blood pressure by signaling colon and kidneys to increase retention (continued use of) of sodium and potassium
Reduces amount of sodium and increases amount of potassium in urine to regulate salt and water balance.