chapter 2.3 other endocrine glands

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state the location, hormone/s secreted, and their effects of the pineal gland

located deep in the brain, shrinks in size after puberty. releases melatonin which is involved in the regulation of sleep patterns. production of melatonin is secreted by darkness and inhibited by light

state the location, hormone/s secreted, and their effects of the thyroid

located in the neck, bellow the larynx. it consists of 2 lobes connected by isthmus. it secretes thyroxine and triiodothyronine.

T4 (~20% of hormones produced) is much less active than T3 (~80% of hormones produced) but has longer lasting effects. once released enzyme deiodinase converts T4 to T3.

T3 and T4 control metabolism and thermatogenesis. the thyroid also releases calcitonins which regulate the levels of calcium and phosphate in the blood.

state the location, hormone/s secreted, and their effects of the parathyroid

located in the rear surface of the thyroid gland. they secrete parathyroid hormone (PTH)n which increases calcium levels in the blood and phosphate excretion in urine

state the location, hormone/s secreted, and their effects of the thymus

located in the chest just above the heart and behind the sternum. largest in infants and then shrinks after puberty.

secret thymosins which influence the maturation of disease-fighting cells called T-lymphocytes

state the location, hormone/s secreted, and their effects of the adrenal glands

there are 2 adrenal glands, both are located right above each kidney. they consist of an outer adrenal cortex, and and an inner adrenal medulla.

it can be considered '“2 seperate endocrine glands”

what hormones are produced in the adrenal medulla and what are their roles?

it produces adrenaline, which prepares the body for a reaction to a threatening situation (fight/flight), and noradrenaline which has a similar effect to adrenaline, it increases rate and force of heartbeats

what hormones are produced in the adrenal cortex and what are their roles?

over 20 hormones produced, they’re collectively known as corticosteriods.

the 2 main ones are aldostrone, which acts on the kidneys to reduce the amount of sodium and increase the amount of potassium in the urine, and cortisol, which helps promote normal metabolism, helping the body to withstand stress and repair damaged tissue.

state the location, hormone/s secreted, and their effects of the pancreas (include other relevent info)

the pancreas is located just below the stomach, alongside the duodenum. the pancreas is both an exocrine gland as it secretes digestive enzymes, but also an endocrine gland. the pancreas consists of clusters of cells called the islets of langerhans which secrete insulin (reduces amount of glucose in the blood) and glucagon (increases amount of glucose in the blood, also stimulates breakdown of fat in the liver)

what hormones do the gonads secrete and what do they do?

they secrete androgens, such as testosterone which are responsible for the development and maintainence of male sex characteristics

they also secrete oestrogen and progesterone which are responsible for the development of female sex characteristics, regulating the menstrual cycle, and pregnancy changes

what are some examples of endocrine tissues and their secretions

the stomach and small intestines secrete hormones involved in the digestive system

the kidneys secrete hormones including erythropoietin (EPO) which stimulates the production of red blood cells in bone marrow

the heart secretes a hormone that elps with blood pressure

the placenta secretes a number of hormones to help maintain pregnancy

name 2 endocrine glands that decrease with age

thymus and pineal

explain how insulin and glucagon are able to keep blood glucose at the correct levels

Insulin (released by the pancreas when blood glucose is high) promotes the uptake of glucose into cells for energy and storage as glycogen in the liver and muscles, lowering blood glucose levels.

Glucagon (released by the pancreas when blood glucose is low) stimulates the liver to break down glycogen into glucose and release it into the bloodstream, raising blood glucose levels.