Endocrine System

Question 1

What are exocrine glands?

Answer 1

Secrete into ducts that carries the secretions to the body surface or to one of the body cavities

Question 2

What are endocrine glands?

Answer 2

Secrete hormones into extracellular fluid that surrounds the cells that make up the gland

Question 3

What are hormones?

Answer 3

Chemicals which are secreted by endocrine glands. They change the function of cells by changing the factors of proteins

Question 4

Are steroid hormones lipid or water soluble?

Answer 4

Lipid soluble, so they don’t dissolve in water, this means they can pass through the cell membrane

Question 5

Are amine hormones lipid or water?

Answer 5

Water soluble, so they dissolve in water, this means that they can’t pass through the cell membrane

Question 6

How do steroid hormones pass through the cell membrane?

Answer 6

Released by endocrine glands into the bloodstream, hormones bind to transport proteins, so they can travel in the bloodstream. They reach the target cells, they separate from the transport proteins and diffuse across the cell membrane, inside the cell they combine with a hormone receptor.

Question 7

How do amine hormones pass through the cell membrane?

Answer 7

The attach the hormone receptor process across the cell membrane of the target cells. The combination of the hormones with the receptor causes a secondary messenger substances to diffuse through the cell and activate particular enzymes

Question 8

What are hormone receptors-

Answer 8

Receptor proteins are specific. Each receptor will only bind with one specific molecule.

Question 9

What is enzyme amplification?

Answer 9

One hormone molecule does not cause the activation of just one. The hormone triggers a cascading effect in which the number of reacting molecules involving is increased by hundreds or thousands of times for each step along the metabolic pathway

Question 10

What is hormone clearance?

Answer 10

Hormones that have produced the required effect must be turned ‘off’

Question 11

How is hormone secretion regulated?

Answer 11

Negative and positive feedback loops

Question 12

What does the hypothalamus do?

Answer 12

Regulates many basic body functions- Heart rate, water balance, temperature.
The hypothalamus secretes releasing factors, these factors stimulate the secretion of a hormone, the hypothalamus also secretes inhibiting factors which slows down the secretion of a hormone.

Question 13

How do releasing and inhibiting factors travel?

Answer 13

These factors travel though the blood vessels to the anterior lobe of the pituitary gland, affecting the secretion of its hormones, other hormones are produced by the hypothalamus and pass along the nerve fibers to the posterior lobe of the pituitary gland, this is where they are released.

Question 14

What does the anterior lobe of the pituitary gland do?

Answer 14

-NO nerve connecting to the hypothalamus
-Releases a number of hormones, that regulate the bodily functions + activities .
-The secretion of anterior lobe is controlled by releasing and inhibiting factors

Question 15

what hormones are released by the anterior lobe?

Answer 15

-Gonadotrophins (Follicle-stimulating hormone + luteinising hormone)
-Growth hormone OR somatotrophins (GH)
-Thyroid-stimulating hormone (TSH)
-Adrenocorticotropic hormone (ACTH/ PAIN)
Prolactin (Mammary gland) (PRL)

Question 16

What does the posterior lobe do?

Answer 16

the posterior lobe of this gland releases 2 hormones (Anti-diuretic hormone and oxytocin). They aren’t manufactured in the posterior lobe

Question 17

What does FSH do? + Target organ

Answer 17

Effect- Growth of follicles, and production of sperm
Target organ- Ovaries and testes

Question 18

What does LH do? + Target organ

Answer 18

Effect- Ovulation + maintenance of corpus luteum, secretion of testosterone
Target organ- Ovaries and testes

Question 19

What does GH do? + Target organ

Answer 19

Effect- Growth and protein synthesis
Target organ- All cells

Question 20

What does TSH do? + Target organ

Answer 20

Effect- Secretion of hormones from the thyroid
Target organ Thyroid gland

Question 21

What does ACTH do? + Target organ

Answer 21

Effect- Secretion of hormones from the adrenal cortex
Target organ- Adrenal cortex

Question 22

What does PRL do? + Target organ

Answer 22

Effect- Milk production
Target organs- Mammary glands

Question 23

What does ADH do? + Target organ

Answer 23

Effect Reabsorption of water
Target organ- Kidneys

Question 24

What does OT do? + Target organ

Answer 24

Effect- Contractions of uterus during childbirth
Target organ- Uterus and mammary gland

Question 25

What does the pineal gland do?

Answer 25

Secretes melatonin, which is involved in the regulation of sleep. The production of melatonin is stimulated by darkness.

Question 26

What does the thyroid gland do?

Answer 26

The follicular cells secrete 2 hormones- Thyroxine and triiodothyronine, or T3 and T4. These hormones help to control/ regulate the body metabolism by regulating reactions in which complex molecules are broken down to release energy, Some energy is released in the form of heat, to maintain body temperature, thy thyroid gland also plays a role in regulating levels of calcium and phosphate in the blood through the release of calcitonin by c-cells.

Question 27

What does the parathyroid do?

Answer 27

This gland secretes the parathyroid hormone or parahormone, this hormone increase the calcium levels in the blood and phosphate excretion in the urine.

Question 27

What does the thymus do?

Answer 27

Its larger in children, as this is the main gland that builds up there immune system, and as you get older, they gland decreases in size. They thymus is in charge of the secretion of a group of hormones called thymosin, which influences the maturation of disease fighting cells called T-lymphocytes

Question 28

What are the two subunits of the adrenal gland?

Answer 28

1. Adrenal Medulla 2. Adrenal Cortex

Question 29

What two hormones does the adrenal medulla release?

Answer 29

Adrenaline and noradrenaline These are also called epinephrine and norepinephrine

Question 30

What do these two hormones do?

Answer 30

Adrenaline- Prepares the body for reaction in a threatening situation Noradrenaline- Increases the rate and force of heartbeat to increase blood pressure

Question 31

What hormones are released from the adrenal cortex?

Answer 31

Aldosterone and cortisol

Question 32

What do these hormones do?

Answer 32

Aldosterone- Reduces the amount of sodium and increase the amount of potassium in the urine Cortisol- Natural metabolism

Question 33

What are the two hormones that the pancreas secretes?

Answer 33

Insulin Glucagon

Question 34

What does insulin do?

Answer 34

Insulin is secreted by the beta cells of the islets of Langerhans. Reduces the amount of glucose in the blood.

Question 35

What does glucagon do?

Answer 35

Glucagon is secreted by the Alpha cells of the islets of Langerhans. It stimulates the breakdown of fat in the liver and fat in storage.

Question 36

What are the two organs/ glands that are the gonads?

Answer 36

Ovaries and testes

Question 37

What hormones is produced by the testes?

Answer 37

Androgens. Androgens are responsible for the development and maintenance of the male sex characteristics

Question 38

What hormones are produced by the ovaries?

Answer 38

Progesterone and oestrogen They stimulate the development of female sex characteristics.