Exocrine And Endocrine Glands

Question 1

What are glands?

Answer 1

Epithelial cells that produce secretions
(Ectodermal origin)

Question 2

What do endocrine glands do?
Do they have ducts?

Answer 2

Produce hormones
No ducts

Question 3

Where do secretions (hormones) pass out of the endocrine glands?

Answer 3

Pass out into the interstitial tissue then into blood capillaries scattered within tissues of these glands

Question 4

What type of secretions do exocrine glands produce and what do they secrete?

Answer 4

Mucous secretions and they secrete many different substances

Question 5

Where do exocrine glands ducts release their secretions?

Answer 5

Lumen or onto surfaces of organs

Some are enzymes and some saliva

Question 6

What are endocrine glands?

Answer 6

Part of epithelial surface (lining of digestive tract)
Or separate organs such as thyroid/ pituitary gland

Question 7

What do endocrine hormone secretions do?

Answer 7

Regulate bodily functions
Maintain homeostasis

Question 8

Name the 3 patterns of hormone secretion in endocrine glands?

Answer 8

Chronic
Acute
Episodic

Question 9

What is chronic pattern of secretion like in endocrine glands?

Answer 9

Regular increases or decreases throughout the day
(Thyroxin)

Question 10

What is acute pattern of secretion like in endocrine glands?

Answer 10

Amount secreted depends on stimulus

Ie. Some stimuli may cause secretion of large amounts (stressed)
While other stimuli may result in less hormones being secreted

(Adrenaline of cortisol)

Question 11

What is episodic pattern of secretion like in endocrine glands?

Answer 11

Episodes of hormones produced and episodes of no production

Eg. Growth hormone
Insulin = increased secretion after eating

Question 12

Name the 3 types of regulation of hormone secretion in endocrine glands ?

Answer 12

Humoral secretion
Neutral regulation
Hormonal regulation

Question 13

Describe Humoral regulation in endocrine glands.

Answer 13

Prescience of blood borne molecules
Eg. High glucose levels stimulates insulin secretion

Question 14

Describe neutral regulation in endocrine glands.

Answer 14

Neuron stimulates hormone production
Eg. Sympathetic nervous system (fight or flight) stimulates epinephrine release.

Question 15

Describe hormonal regulation in endocrine glands.

Answer 15

Hormone secretion stimulus another hormone to be secreted
Eg. Hormones from pituitary gland stimulates tested to make testosterone

Question 16

Give 3 classes of hormones?

Answer 16

Proteins and polypeptides
Steroids
Derivative of amino acid tyrosine

Question 17

Describe proteins and polypeptides type of hormone.

Answer 17

Secreted by pancreas and parathyroid gland
Stored within cell and released on demand

Eg. Pancreas, parathyroid gland

Question 18

Describe steroid type of hormone.

Answer 18

Synthesised from cholesterol
Released directly into circulation
Can’t be stored

Eg. Adrenal cortex, ovaries, placenta

Question 19

Describe derivative of amino acid tyrosine type of hormone.

Answer 19

Secreted by the adrenal medulla and thyroid

Question 20

Where is the thyroid gland located and what is it formed of?

Answer 20

Location in midline of neck in front of trachea

Formed from 2 parts joined together by central isthmus

Question 21

How many parathyroid glands are there?
Where are they located?
What are they separated by?

Answer 21

4
Corners of thyroid gland
Separated from thyroid by layer of fibrous tissue

Question 22

Structure of parathyroid glands?

Answer 22

Single layer of cuboidal epithelium
Contain colloid
Increase in size (columnar) when active

Question 23

Structure of thyroid glands?
- what is main bulk made up of?
- what is follicular epithelium?
- what do follicles store?

Answer 23

Main bulk made up of follicles
Single layer of cuboidal epithelium that lines thyroid glands
Collied that is secreted by the follicular epithelial

Question 24

What does colloid contain?

Answer 24

Thyroxine T4
Tri-iodothyronine T3 (active hormone)

Question 25

What is 10% of thyroid gland made up of? What is the structure of this? Where is it found?

Answer 25

C cell (Parafollicular cell) Has clear cytoplasm Present within interstitial tissues surrounding follicles

Question 26

What do C cells produce?

Answer 26

Calcitonin - hormone that regulates calcium

Question 27

What do chief cells produce and what is it important for?

Answer 27

Parathyroid hormone important for calcium metabolism

Question 28

How many chief cells are there and where are they found?

Answer 28

4 1 in each corner of thyroid gland

Question 29

What does the parathyroid hormone act on?

Answer 29

Osteoclasts (large multi nucleated cells responsible for bone resorption)

Question 30

Shat happens when calcium and other mineral levels decrease?

Answer 30

Parathyroid glands secrete hormone which activates the osteoclasts to break down bone Minerals are released into the body which bring the levels up to within normal range. Secretion stops

Question 31

What does Hyperparathyroidism result in?

Answer 31

Increased activity/ size of parathyroid glands (benign tumours or hyperplasia This results in increased hormone secretion, bone resorption and calcium level.

Question 32

What effect does Hyperparathyroidism have on bone?

Answer 32

Bone shows soft tissue lesions developing within the mineralised tissue. Jaw/skull bones and skeletal system also affected

Question 33

What are the 3 most important calcium metabolisms?

Answer 33

Calcitonin Parathyroid hormone Vitamin D

Question 34

What 2 cells populations are the parathyroid glands composed of?

Answer 34

Chief cells Ocyphill cells

Question 35

What is an ocyphill cell?

Answer 35

Present in clusters Larger but less number than chief cells Cytoplasm as granular as there’s lots of mitochondria Exact function = unknown

Question 36

Function of chief cells?

Answer 36

Synthesise and secrete parathyroid hormone

Question 37

Describe exocrine gland secretions

Answer 37

Released through ducts that open onto epithelial cells or directly to surface

Question 38

What is a unicellular gland?

Answer 38

Gland made up if 1 cell only Eg. Goblet cell

Question 39

2 arrangements of multicellular glands?

Answer 39

Secretory sheets = arranged in sheets as part of other organ Pockets - gland cells set back from epithelial surface

Question 40

Are majority of exocrine glands unicellular or multicellular?

Answer 40

Multicellular

Question 41

Name 5 simple multicellular glands?

Answer 41

Simple tubular Simple branched tubular Slime cooler tubular Simple acinar Single branched acinar

Question 42

Name 3 compound multicellular list glands?

Answer 42

Compound tubular Compound acinar Compound tubuliacinar

Question 43

Describe the merocrine gland.

Answer 43

Substance produced stored in vesicles When need vesicles move up and substance is released only the duct - salivary

Question 44

Describe the apocrine gland.

Answer 44

Substances produced stored within cell When needed moves up into apical part of the cell Top part (containing product) seperste from rest of cell Drops off into duct and travels through it into surface - mamory gland

Question 45

Describe the Holocrine gland.

Answer 45

Entire cells drops off into duct with product and it’s secreted to surface Replacement cell is formed - cervacious gland

Question 46

What are serous secretions?

Answer 46

Watery secretions containing enzymes Protein rich secretion

Question 47

What are mucous secretions?

Answer 47

Contain mucins which hydrate to form mucous Thicker Contain water and microproteins

Question 48

What is a mixed secretion?

Answer 48

Mixture of both serous and mucous

Question 49

What are the 3 pairs of salivary glands? Where are they found? What type of secretions do they produce?

Answer 49

Parotid (in front of ear) - serous secretion Submandibular - both secretion Sublingual (under tongue) - mucous secretion

Question 50

Describe features of mucous acini.

Answer 50

Cuboidal/ columnar in shape Contain mucus Nuclei are flat and pushed to bottom of cell Have ducts

Question 51

Describe features of serous acini.

Answer 51

Round Nuclei not as flat and near bottom of cell Contain granuals Enzymes and proteins that enter into secretions

Question 52

What types of secretions in pancreas?

Answer 52

Endocrine = 2% Exocrine = majority

Question 53

Name substances found in pancreas.

Answer 53

Islets of langerhans Insulin Alpha cells producing glucagon Delta cells (nuclei) F cells producing pancreatic polypeptide

Question 54

What is found in exocrine proportion of pancreas

Answer 54

Lipase Amylase Proteinases

Question 55

Name 2 diseases of the pancreas.

Answer 55

Pancreatic cancer Diabetes myellitus

Question 56

What is the difference between type 1 and type 2 diabetes? Describe similarity.

Answer 56

1. Insulin dependent 2. Insulin resistant Both have effect on most systems in body.

Question 57

Describe type 1 diabetes.

Answer 57

Insulin dependent Destruction of beta cells 5-10% of all people with diabetes

Question 58

Describe type 2 diabetes.

Answer 58

Insulin resistant Tissues lose their sensitivity to insulin so it becomes ineffective

Question 59

3 oral effects of diabetes.

Answer 59

Periodontitis Dry mouth Susceptibility to infections

Question 60

What is periodontitis?

Answer 60

Inflammation of tissue that holds teeth (periodontal ligament)

Question 61

Factors affecting periodontitis?

Answer 61

Lack of response of immune cells to bacteria or changes to blood vessels and blood reaching area

Question 62

What does dry mouth lead to?

Answer 62

Low saliva secretion therefor more susceptible to fungal infections (thrush)

Question 63

What is hypofunction of endocrine system? What does it lead to?

Answer 63

Reduced hormone secretion Autoimmune diseases Infections

Question 64

What is hyperfunction of endocrine system? What does it lead to?

Answer 64

Excessive hormone release Results in tumour

Question 65

What is diabetes mellitus in endocrine system?

Answer 65

Hormone resistance Autoimmune condition Body is resistant to insulin

Question 66

What can cause changes in endocrine system?

Answer 66

Pregnancy Menopause Stress Obesity