Glands

Question 1

Define a gland

Answer 1

An epithelial cell or an aggregate (cluster) of epithelial cells that are specialised for the secretion of a substance

Question 2

Define secretion

Answer 2

Production and release of materials by a cell or aggregate of cells

Question 3

How are glands classified? (2)

Answer 3

Their structure

How their products are released

Question 4

What are the two types of glands?
What is the key difference?

Answer 4

Endocrine - ductless, so secrete directly into the blood

Exocrine - ducted, so secrete into the duct

Question 5

What do endocrine glands secrete?

Answer 5

Hormones

Question 6

What do exocrine glands secrete?

Answer 6

Enzymes or lubricants

Question 7

Give 3 examples of an endocrine gland

Answer 7

Pituitary gland
Thyroid gland
Parathyroid gland

Question 8

Give 3 examples of an exocrine gland

Answer 8

Salivary gland
Pancreas
Mammary gland
Sweat glands
Sebaceous gland
Lachrymal gland

Question 9

What do mammary glands secrete?

Answer 9

Colostrum and milk

Question 10

What do sebaceous glands secrete?

Answer 10

Sebum onto the skin and in the ear

Question 11

What do lachrymal glands secrete?

Answer 11

An aqueous fluid to the moisten the eye

Question 12

What cells secrete hormones in endocrine glands?

Answer 12

All epithelial cells in the gland

Question 13

What cells secrete hormones in exocrine glands?

Answer 13

Cells at the apex of the duct (the bottom)

Question 14

What is the process in which glands develop?

Answer 14

Adenogenesis

Question 15

What are the three steps of general gland formation?

Answer 15

1. Growth signal received
2. Proliferation of cells occurs and extracellular protein degradation enzymes produced
3. Epithelial cells invade subjacent connective tissue

Question 16

What does it mean when cells proliferate?

Answer 16

An increase in the number of cells as a result of cell growth and cell division

Question 17

What happens after cells invade the space in the development of exocrine glands?

Answer 17

Central cells die off
A duct is produced
Branching

Question 18

What happens after cells invade the space in the development of endocrine glands?

Answer 18

1. Angiogenic factors produced - stimulates blood vessel growth
2. No branching

Question 19

Which type of gland is not linked to mother cells?
How is it not?

Answer 19

Endocrine
Broken through apoptosis

Question 20

How does branching occur?

Answer 20

1. FG10 released by immature fibroblasts
2. Epithelial cells move towards the signal

Question 21

If the duct doesn’t branch what would it do in response to growth factors?

Answer 21

Tubule elongation

Question 22

What stops elongation and branching?

Answer 22

Sonic the hedgehog

Question 23

What stimulates
Tubule elongation?
Tubule branching?

Answer 23

GF1 active + GF2 inactive
GF1 inactive + GF2 active

Question 24

What do the two types of cells in exocrine glands do?

Answer 24

Line the duct

Make secretory products

Question 25

What are the two types of tubular secretory structure?

Answer 25

Simple duct - does not branch Compound duct - branches

Question 26

What happens to some of the cells at the secretory ends of the ducts? What is their function?

Answer 26

Turn into myoepithelial cells Help eject secretions

Question 27

What are the two types of secretion for salivary glands?

Answer 27

Mucous Serous

Question 28

What hormones stimulates the the breast to grow? Where are they produced?

Answer 28

Estrogen and progesterone Ovaries

Question 29

What stimulates the production of breast secretion during pregnancy?

Answer 29

Prolactin

Question 30

What are the four types of secretion?

Answer 30

Merocrine Apocrine Holocrine Cytocrine

Question 31

What is merocrine secretion?

Answer 31

Fusion of vesicle with apical membrane (Exocytosis)

Question 32

What is apocrine secretion?

Answer 32

Partial loss of cytoplasm

Question 33

What is holocrine secretion?

Answer 33

Complete loss of cytoplasm

Question 34

What is cytocrine secretion? Give an example

Answer 34

Cells are released as a secretion Spermatid

Question 35

What are the two pathways for merocrine secretion?

Answer 35

Regulated Constitutive

Question 36

What are the three steps of regulated merocrine secretion?

Answer 36

1. Vesicle migrates to cell surface along microtubules 2. Membrane of vesicle fuses with plasmalemma, in the prescience of Ca2+ 3. Contents released to extracellular space

Question 37

What does active secretion of regulated merocrine secretion require?

Answer 37

Ca2+

Question 38

Describe constitutive secretion How is it different from regulated?

Answer 38

Vesicles continuously released to the cell surface Few or no secretory granules

Question 39

Describe holocrine secretion

Answer 39

1. Secretory cells fill up with secretory granules 2. Cell organelles degenerate 3. Cells die 4. Plasma membrane breaks 5. Contents empties 6. Dead cells replaced by mitotic division of basal cells

Question 40

What is the definition of glycosylation?

Answer 40

Covalent attachment of sugars by enzymes to proteins and lipids to form glycoproteins and glycolipids

Question 41

What is the definition of glycation?

Answer 41

Covalent attachment of sugars WITHOUT enzymes to proteins and lipids to form glycoproteins and glycolipids

Question 42

What is the purpose of glycosylation? (3) What is the organelle that it happens to most frequently?

Answer 42

- aids protein folding - prevents protein/lipid digestion by intracellular proteases/lipases - cell recognition and cell matrix attachment Golgi apparatus

Question 43

Define exocytosis

Answer 43

Secretion of molecules outside the cell via a vesicle fusing to a membrane

Question 44

Define endocytosis

Answer 44

Engulfing of molecules inside the cell via vesicle formation

Question 45

Where do endocrine cells discharge their secretions?

Answer 45

Directly into blood vessels or lymphatic system

Question 46

What are the two types of exocrine glands? Where do they excrete their products?

Answer 46

Unicellular - surface of epithelium Multicellular - into a duct

Question 47

What do goblet cells secrete? What is their secretion used for? (3)

Answer 47

Mucus Lubricates the passage Moistens the air Entraps particles

Question 48

What is the most common symptom for people with cystic fibrosis? Why does this occur? What can this lead to?

Answer 48

Thick mucus Cannot release Cl- into lumen of duct Water travels with Cl-, so less water in secretion A blocked duct

Question 49

What is phagocytosis? Where does it occur mainly?

Answer 49

Process of phagocytes enveloping or engulfing cells or particles Immune system

Question 50

What is pinocytosis? Where does it occur mainly?

Answer 50

Process of cells ingesting liquid droplets Smooth muscle cells

Question 51

What are two examples of endocytosis?

Answer 51

Phagocytosis Pinocytosis

Question 52

What is transepithelial transport known as?

Answer 52

Transcytosis

Question 53

Where are the parotid glands?

Answer 53

Next to the ear

Question 54

What are the three ways of controlling gland secretion?

Answer 54

Hormonal Neural Humoral

Question 55

Explain four examples of transcytosis

Answer 55

By carrier proteins or counter transport processes Aqueous channels in the intracellular junction Through lipid cell membranes Bind to surface receptors, by engulfed by endocytosis and then released by exocytosis

Question 56

What is the function of a striated duct?

Answer 56

Prevent water loss

Question 57

Describe how endocytosis and secretion combine to give transepithelial transport

Answer 57

A cell binds to cell surface receptors The cell is engulfed by the cell membrane - endocytosis Released inside the cell Or expelled via membrane limited vesicles into the extracellular space - exocytosis

Question 58

Describe humoral secretion control

Answer 58

Stimulated by changes in extracellular fluid

Question 59

Describe hormonal secretion control

Answer 59

Hormone released Stimulates another hormone to be released from another cell

Question 60

Describe neural secretion control

Answer 60

Neuron releases a neurotransmitter Binds to a cell Stimulating hormone secretion

Question 61

What are the mooring of ductless glands derivatives of?

Answer 61

Epithelial tissue

Question 62

Describe the portal circulatory route

Answer 62

Blood passes through two sets of smaller vessels before returning to the heart Blood from the first capillaries collects in portal vessels The portal vessels branch off to supply a capillary network The capillary network enters a series of veins, which leads to the heart

Question 63

What are two key examples of portal circulatory routes?

Answer 63

Hypothalamus Anterior pituitary gland

Question 64

Name two functions of parafollicular cells Where are they found?

Answer 64

Produce thryocalactitonin Monitor plasma Ca2+ conc Parathyroid glands

Question 65

What is salivary secretion controlled by?

Answer 65

Neural

Question 66

Describe how the ANS controls saliva production

Answer 66

Parasympathetic - large volume of watery, enzyme rich salvia Sympathetic - small volume of thick, mucus rich saliva

Question 67

What are the three different types of capillaries?

Answer 67

Continuous Brain Fenestrated Pituitary, small intestines, kidneys Sinusoid - have an incomplete basement membrane Spleen, bone marrow

Question 68

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