Endocrine system + Hormones

Question 1

What do exocrine glands secrete into?

Answer 1

A duct which carries secretion to body surface

Examples include sweat, mucous, salivary, and alimentary glands.

Question 2

How do endocrine glands secrete hormones?

Answer 2

Into extracellular fluid surrounding the gland

The hormone usually passes into capillaries and is transported by blood.

Question 3

What are hormones?

Answer 3

Chemicals secreted by endocrine glands transported throughout the body in blood

They change the functioning of a cell by altering cell activity.

Question 4

What can hormones activate?

Answer 4

A gene so that an enzyme or protein is produced

They can also change the shape of an enzyme or the production rate of an enzyme.

Question 5

What is required for hormones to influence cells?

Answer 5

The correct receptor

Receptors could be on every cell in the body or a group of target cells or target organs.

Question 6

What are the three types of hormones?

Answer 6

Steroids, proteins, amines

Question 7

What are examples of steroid hormones?

Answer 7

Oestrogen, progesterone, cortisol, aldosterone

Steroid hormones are lipid soluble and bind to transport proteins in blood.

Question 8

How do steroid hormones act on target cells?

Answer 8

They diffuse through the plasma membrane and combine with receptor protein in cytoplasm or nucleus

The receptor-hormone complex activates genes by binding to the promoter region.

Question 9

How do protein and amine hormones act on target cells?

Answer 9

They attach to receptor proteins on the membrane of the target cell

This triggers a secondary messenger to diffuse through the cell.

Question 10

What is the lock and key analogy in relation to hormones?

Answer 10

Receptor proteins are specific and only bind to one specific molecule

Question 11

What limits the reaction rate of hormones?

Answer 11

The number of receptors in the membrane

Reaction rate reaches a saturation point with additional hormone having no effect.

Question 12

What is enzyme amplification?

Answer 12

One hormone activates thousands/billions of enzymes through a cascading series of reactions

This increases the number of reacting molecules.

Question 13

How are hormones cleared from the body?

Answer 13

By breaking down in the target cell or mostly in the liver and kidneys and excreted in bile or urine

Question 14

True or False: All cells have the same number of hormone receptors.

Answer 14

False

Different cells have different numbers of receptors, leading to varying sensitivities to hormones.

Question 15

Examples of exocrine glands

Answer 15

Sweat glands, mucous glands, salivary glands, glands of alimentary canal

Question 16

What is the primary role of the pituitary gland?

Answer 16

Controls the function of many other glands

The pituitary gland is often referred to as the master gland due to its regulatory role.

Question 17

How does the hypothalamus interact with the pituitary gland?

Answer 17

Works with the hypothalamus as the command centre of the body

Question 18

What two systems does the hypothalamus connect?

Answer 18

Endocrine and nervous systems

Question 19

List three functions regulated by the hypothalamus.

Answer 19

• Body temperature
• Water balance
• Heart rate

Question 20

Where is the hypothalamus located?

Answer 20

At the base of the brain, below the thalamus and above the pituitary gland

Question 21

What size is the hypothalamus approximately?

Answer 21

About the size of an almond

Question 22

What do releasing factors from the hypothalamus do?

Answer 22

Stimulate the secretion of hormones from the pituitary gland

Question 23

What do inhibiting factors from the hypothalamus do?

Answer 23

Slow secretion of hormones from the pituitary gland

Question 24

What is the anterior pituitary also known as?

Answer 24

Adenohypophysis

Question 25

What is the posterior pituitary also known as?

Answer 25

Neurohypophysis

Question 26

What connects the pituitary gland to the hypothalamus?

Answer 26

A stalk called the infundibulum

Question 27

What is the size of the pituitary gland?

Answer 27

Size of a pea

Question 28

How many lobes does the pituitary gland have?

Answer 28

Two functionally distinct lobes: anterior and posterior

Question 29

Does the anterior pituitary have a direct nerve connection to the hypothalamus?

Answer 29

No direct nerve connection

Question 30

What hormones are produced by the anterior pituitary?

Answer 30

* Gonadotropins (FSH & LH) * Growth hormone (GH) * Thyroid-stimulating hormone (TSH) * Adrenocorticotropic hormone (ACTH) * Prolactin (PRL)

Question 31

What does follicle-stimulating hormone (FSH) stimulate?

Answer 31

Maturation of ovarian follicles and sperm production

Question 32

What is the function of luteinising hormone (LH)?

Answer 32

Triggers ovulation, promotes corpus luteum formation, and stimulates testosterone production

Question 33

What does growth hormone (GH) stimulate?

Answer 33

Growth, protein synthesis, and organ maintenance

Question 34

What is the role of thyroid-stimulating hormone (TSH)?

Answer 34

Regulates the thyroid gland’s hormone production

Question 35

What does adrenocorticotropic hormone (ACTH) control?

Answer 35

Hormone release from the adrenal cortex

Question 36

What does prolactin (PRL) do?

Answer 36

Works with other hormones to initiate and maintain milk production

Question 37

How is the posterior pituitary connected to the hypothalamus?

Answer 37

By nerve fibres

Question 38

Does the posterior pituitary produce hormones?

Answer 38

No, it stores and releases hormones

Question 39

What hormones are secreted by the posterior pituitary?

Answer 39

* Oxytocin (OT) * Antidiuretic hormone (ADH, Vasopressin)

Question 40

What is the function of oxytocin (OT)?

Answer 40

Stimulates uterine contractions during labour and milk ejection

Question 41

What role does antidiuretic hormone (ADH) play in the body?

Answer 41

Regulates water balance by reducing urine production

Question 42

True or False: Antidiuretic hormone can help regulate blood pressure at high concentrations.

Answer 42

True

Question 43

What is the size and location of the Pineal Gland?

Answer 43

Pea-sized, located deep inside the brain. ## Footnote The pineal gland is responsible for producing melatonin.

Question 44

What hormone does the Pineal Gland produce and what does it regulate?

Answer 44

Melatonin – regulates sleep patterns. ## Footnote Its production is stimulated by darkness and inhibited by light.

Question 45

Where is the Thyroid Gland located?

Answer 45

In the neck, below the larynx. ## Footnote It consists of two lobes connected by tissue in front of the trachea.

Question 46

What hormones are produced by the Thyroid Gland?

Answer 46

Thyroxine (T4) & Triiodothyronine (T3). ## Footnote T3 contains three iodine atoms, while T4 contains four iodine atoms.

Question 47

What is the difference in activity between T3 and T4?

Answer 47

T4 is less active (80%) but lasts longer, while T3 is more active (20%). ## Footnote Enzymes in the body convert T4 into T3 for use.

Question 48

What are the functions of the Thyroid Gland?

Answer 48

Regulates metabolism and produces calcitonin. ## Footnote Calcitonin regulates calcium and phosphorus levels in the blood.

Question 49

What does calcitonin do when calcium levels are high?

Answer 49

Reduces Ca reabsorption in the kidneys and slows bone breakdown. ## Footnote It also moves phosphorus into bones and reduces kidney reabsorption.

Question 50

Where are the Parathyroid Glands located?

Answer 50

At the rear surface of the thyroid lobes. ## Footnote There are four pea-sized glands.

Question 51

What hormone is secreted by the Parathyroid Glands?

Answer 51

Parathyroid Hormone (PTH). ## Footnote PTH increases blood calcium levels and promotes phosphate excretion in urine.

Question 52

What is the location and function of the Thymus?

Answer 52

Above the heart, behind the sternum; secretes thymosin which influences the maturation of T-lymphocytes. ## Footnote The thymus shrinks after puberty.

Question 53

Where are the Adrenal Glands located?

Answer 53

On top of each kidney. ## Footnote They consist of two regions: adrenal medulla and adrenal cortex.

Question 54

What hormones are produced by the Adrenal Medulla?

Answer 54

Adrenaline (epinephrine) and noradrenaline. ## Footnote They prepare the body for the fight-or-flight response.

Question 55

What is the role of the Adrenal Cortex?

Answer 55

Produces 20 different corticosteroid hormones. ## Footnote Includes hormones like aldosterone and cortisol.

Question 56

What does aldosterone regulate?

Answer 56

Kidney function by reducing sodium levels and increasing potassium excretion in urine.

Question 57

What are the functions of cortisol?

Answer 57

Regulates metabolism, helps withstand stress, and aids in tissue repair.

Question 58

Where is the Pancreas located?

Answer 58

Below the stomach. ## Footnote It is a soft, 15 cm long organ.

Question 59

What roles does the Pancreas serve?

Answer 59

Acts as both an exocrine and endocrine gland.

Question 60

What is the exocrine role of the Pancreas?

Answer 60

Secretes digestive enzymes into the small intestine via the pancreatic duct.

Question 61

What hormones are secreted by the Islets of Langerhans in the Pancreas?

Answer 61

Insulin and Glucagon.

Question 62

What is the function of insulin?

Answer 62

Lowers blood glucose levels by promoting glucose uptake into cells.

Question 63

What does glucagon do?

Answer 63

Increases blood glucose levels by breaking down glycogen into glucose.

Question 64

What hormones do the Gonads produce?

Answer 64

Androgens (e.g., testosterone), Oestrogens, and Progesterone.

Question 65

What are the functions of androgens?

Answer 65

Develop and maintain male sex characteristics.

Question 66

What do oestrogens and progesterone regulate?

Answer 66

The menstrual cycle, ovarian cycle, and pregnancy.

Question 67

What endocrine functions do the Stomach and Small Intestine serve?

Answer 67

Secrete hormones that coordinate digestion and regulate exocrine gland function.

Question 68

What hormone do the Kidneys secrete?

Answer 68

Erythropoietin (EPO). ## Footnote EPO stimulates red blood cell production in the bone marrow.

Question 69

What hormone does the Heart produce?

Answer 69

A hormone that lowers blood pressure.

Question 70

What is the role of the Placenta in the endocrine system?

Answer 70

Supports pregnancy by assisting fetal development and stimulating mammary glands.