Endocrine System

Question 1

The endocrine system?

Answer 1

The endocrine system?

.Duct less glands which produce hormones, the body’s chemical messengers.

.Works with the nervous system.

Question 2

Hormones?

Answer 2

Hormones?

.Endocrine glands secrete hormones in response to a stimulus e.g. nerve impulses, high glucose levels.

.Hormones are chemical messengers, which are produced in the gland and then secreted directly into the blood to travel to the target organ.

.Hormones may be steroids, proteins or amines (derived from amino acids).

.Regulate the activity of the target organ.

.Only the target organ is affected by the hormone.

.Not all hormones are secreted by endocrine glands e.g. gastrin by gastric glands.

Question 3

Endocrine gland?

Answer 3

Endocrine gland?

.A ductless gland which produces hormones.

Question 4

Pituitary gland anterior functions?

Answer 4

Pituitary gland anterior functions?

.Height and growth

.Controls thyroid gland

.Controls adrenal cortex

.Milk during lactating

.Controls sexual development

.Regulating the use of energy

Question 5

Thyroid glands function?

Answer 5

Thyroid glands function?

.Thyroxin and triiodothyronine - stimulates tissue metabolism. Over production of hormones causes increase in metabolic rate (hyperthyroidism)

.Calcitonin - deposits calcium in bone for when needed.

Question 6

Parathyroid glands function?

Answer 6

Parathyroid glands function?

.Resorbs calcium from bone when needed.

.Stimulates calcium absorption in kidneys.

Question 7

Adrenal glands function?

Answer 7

Adrenal glands function?

.They sit on top of each kidney.

.Adrenal cortex - produces sex hormones. Regulates acid-base balance of plasma and ECF.
Produces approx 30 different steroid hormones.

.Adrenal medulla - produces adrenaline and noradrenaline for the fight or flight response.

Question 8

Pancreas endocrine function?

Answer 8

Pancreas endocrine function?

.Produces insulin and glucagon to help glucose enter cells thus regulating blood sugar levels.

.Decrease in secretions causes diabetes mellitus (hyperglycemia). Not enough insulin being produced causes glucose to build up in the blood.

.Increase in secretions causes hypoglycemia. Too much insulin is produced causing too much glucose leaving the blood.

Question 9

Ovaries?

Answer 9

Ovaries?

.Produces oestrogen which prepares the reproductive tract and genitalia for mating

.Produces progesterone to prepare the reproductive tract for pregnancy and stops further oestrous cycles until parturition occurs.

Question 10

Testes?

Answer 10

Testes?

.Produces testosterone responsible for sperm production, male behaviour patterns and characteristics.

.Produces oestrogen in small amounts.

Question 11

Pineal body?

Answer 11

Pineal body?

.Produces melatonin.

Question 12

Thymus gland?

Answer 12

Thymus gland?

.Part of the immune system in the development of T lymphocytes.

Question 13

Antidiuretic hormone ADH/ Vasopressin?

Answer 13

Antidiuretic hormone ADH/ Vasopressin?

.Produced by the hypothalamus but stored in the posterior pituitary gland.

.Tells your kidneys how much water to conserve.

.Regulates and balances the amount of water in your blood (homeostasis).

Question 14

Pituitary gland posterior functions?

Answer 14

Pituitary gland posterior functions?

.Hormones stored here but produced by the hypothalamus e.g. ADH and oxytocin.

Question 15

Oxytocin?

Answer 15

Oxytocin?

.At the end of gestation it causes the contraction of the uterus to give birth.

.Acts on the mammary glands at the end of pregnancy to release milk for neonates.

Question 16

Corticosteroids?

Answer 16

Corticosteroids?

.Hormones known as steroids secreted by the adrenal cortex in low levels.

.When present in large quantities, they depress the inflammatory reaction to reduce swelling and inflammation e.g. prednisolone.

Question 17

Thyroid gland?

Answer 17

Thyroid gland?

.Produces two important hormones thyroxine (T4) and tri-iodothyronine (T3). They control metabolic rate.