Chapter 2 - Chemical Messengers

Question 1

What are the two types of glands found in the body?

Answer 1

• Endocrine glands

- Exocrine Glands

Question 2

How do Exocrine glands work?

Answer 2

Exocrine glands secrete into a duct that carries the secretion to the body surface or to one of the body cavities

Question 3

What are four examples of Exocrine glands?

Answer 3

• Sweat glands
• Mucous glands
• Salivary glands
• Glands of the alimentary canal

Question 4

How do Endocrine glands work?

Answer 4

Endocrine glands secrete hormones into the extracellular fluid that surrounds the cells that make up the gland - the secretion then usually passes into the capillaries to be transported by the blood

Question 5

What are four examples of Endocrine glands?

Answer 5

• Hypothalamus
• Pituitary gland
• Thyroid gland
• Adrenal glands

Question 6

What is a hormone?

Answer 6

A secretion of an endocrine gland

Question 7

What may hormones be?

Answer 7

• Proteins
• Steroids
• Amines

Question 8

What are amines?

Answer 8

Small molecules derived from amino acids

Question 9

How are hormones transported?

Answer 9

They are transported throughout the body in the blood

Question 10

What is a target cell?

Answer 10

A cell who’s activity is affected by a particular hormone

Question 11

What is a target organ?

Answer 11

An organ who’s activity is affected by a particular hormone

Question 12

What are paracrines? What is another name for paracrines?

Answer 12

Any chemical secreted by a cell that diffuses to and affects adjacent cells; also called a local hormone

Question 13

What is saturation?

Answer 13

When all the receptor molecules are occupied by hormone molecules

Question 14

What are hormone receptors?

Answer 14

Specific

Question 15

What type of solublity are proteins/amines able for?

Answer 15

Water soluble - they cannot pass through the cell membrane (facilitated diffusion)

Question 16

What type of solubility are steroids able for?

Answer 16

Lipid soluble - can easily pass through the cell membrane into the cytoplasm (diffusion)

Question 17

What do proteins/amines bind to?

Answer 17

Receptor molecules on the cell membrane (extracellular fluid) - does not enter the cell membrane

Question 18

What do steroids bind to?

Answer 18

Receptor proteins inside the cell, then binds to a recptor on the nucleus to form an active receptor complex

Question 19

When amine hormones bind to a receptor, what is produced?

Answer 19

A secondary message response

Question 20

What does the secondary message response do?

Answer 20

This response will activate particular enzymes in the cell

Question 21

What occurs when steroids bind to receptors in the nucleus?

Answer 21

Enzymes are activated in the nucleus - particular genes will be able to form a particular protein

Question 22

At what speed do amines/proteins act?

Answer 22

Fast acting - the effect occurs in seconds or minutes

Question 23

At what speed do steroids act?

Answer 23

Slow acting - the effect occurs in hours or days

Question 24

What are some examples of protein based hormones?

Answer 24

• Insulin
• The growth hormone
• Adrenaline

Question 25

What are some examples of steroid based hormones?

Answer 25

- Oestrogen - Testosterone - Progesterone

Question 26

What is enzyme amplification?

Answer 26

A series of chemical reactions in which the product of one step is an enzyme that produces an even greater number of product molecules at the next step

Question 27

Define releasing hormones

Answer 27

A hormone which is secreted by the hypothalamus that stimulates the release of hormones needed by the body

Question 28

Define inhibiting factors

Answer 28

A hormone that slows the release of other hormones of which there may be too much of in the body

Question 29

What is the difference between the location of the hypothalamus and pituitary gland?

Answer 29

Hypothalamus is located in the brain | Pituitary gland is located just underneath the brain

Question 30

What is the infundibulum?

Answer 30

A stalk which connects the hypothalamus to the pitutary gland and is vital to the normal functioning of the body

Question 31

What is the difference between what the hypothalamus and pituitary gland regulate?

Answer 31

``` Hypothalamus regulates basic body functions such as: - Heart rate - Water balance - Body Temperature The pituitary gland regulates body functions such as: - Growth - Metabolism - Reproductive cycles ```

Question 32

What can the hypothalamus control?

Answer 32

Can control the release of hormones from the pituitary gland into the blood (anterior pituitary) to be transported via nerve network into the posterior pituitary

Question 33

What does the hypothalamus act as?

Answer 33

It acts as a receptor | Will either secrete or inhibit hormones

Question 34

Which hormones does the hypothalamus produce?

Answer 34

- Oxytocin | - Antidiuretic Hormone (ADH)

Question 35

What type of hormones does the pituitary gland release?

Answer 35

It releases hormones that control other endocrine glands

Question 36

What is the pituitary gland also known as?

Answer 36

The "Master Gland"

Question 37

When are oxytocin and ADH released from the posterior lobe of the pituitary?

Answer 37

Are released when nerve impulses occur

Question 38

What are the two lobes of the pituitary gland?

Answer 38

- Posterior Pituitary Lobe (Back) | - Anterior Piuitary Lobe (Front)

Question 39

What is the difference about where hormones are produced in the posterior and anterior lobes?

Answer 39

Anterior: Hormones are produced and secreted from the anterior pituitary Posterior: Hormones are produced in cell bodies in the hypothalamus, stores hormones in the posterior lobe

Question 40

How is the anterior lobe connected to the hypothalamus?

Answer 40

Has no nerves connecting it to the hypothalamus, it has a complex blood vessel network

Question 41

How does the posterior lobe receive the hormones from the hypothalamus?

Answer 41

Hormones are transported down the axons (neurons) to the posterior lobe

Question 42

What is the difference about how the posterior and anterior lobe release hormones?

Answer 42

Anterior: Release hormones via chemical/hormonal stimulation Posterior: Release hormones via nerve stimulation from the hypothalamus (does not secrete hormones)