Lecture 8 - Enodcrine Tissues And Glands

Question 1

Name some examples of glands containing endocrine cells/tissue:

Answer 1

Hypothalamus
Pituitary gland
Thyroid gland
Parathyroid gland
Adrenal gland
Pancreas

Question 2

Where is the pituitary gland located?

Answer 2

At the base of the brain superior to the hypothalamus

Question 3

What hormones does the Hypothalamus secrete?

Answer 3

TRH
CRH
GHRH
GHIH
PRH
GnRH

Question 4

How is the pituitary gland structure?

Answer 4

Into 2 parts:
Anterior pituitary (front)
Posteriori pituitary (back)

Question 5

What hormones does the anterior pituitary gland secrete?

Answer 5

TSH
ACTH and MSH (Both have POMC precursor)
FSH
LH
Prolactin
GH

Question 6

Where is the Thyroid gland located and how is it structured?

Answer 6

Anterior to the trachea
2 lobes joined by a bridge called the Isthmus

Question 7

What hormones does the thyroid gland secrete?

Answer 7

T4 (thyroxine or tetraiodothyronine)
T3 (triiodothyronine)

Question 8

Where are the parathyroid glands located?

Answer 8

On the dorsal surface of the thyroid glands
4 of them in 2 pairs

Question 9

What do the parathyroid glands secrete?

Answer 9

PTH (parathyroid hormone)

Question 10

Where are the adrenal glands located?

Answer 10

On the top of the kidneys
Ad = on top of
Renal = kidneys

Question 11

How are the adrenal glands structured?

Answer 11

2 parts
Outer adrenal cortex
Inner adrenal medulla

Question 12

What hormones does the adrenal cortex secrete?

Answer 12

Mineralocorticoids
Glucocorticoids
Androgens

Question 13

Where is the pancreas located?

Answer 13

Left of and posterior to the stomach

Question 14

What are the exocrine secretions of the pancreas?

Answer 14

Digestive enzymes into duodenum

Question 15

What are the secretions from the endocrine portions of the pancreas and what are these portions called?

Answer 15

Islets of Langerhans

Alpha cells = glucagon
Beta cells = insulin
Delta cells = somatostatin

Question 16

What hormones does the posterior pituitary gland secrete but not produce?

Answer 16

ADH (anti-diuretic hormone)
Oxytocin

Question 17

What hormones dos the liver produce?

Answer 17

IGF (Insulin like growth factor)
Angiotensinogen
Angiotensin (increases blood pressure)
Thrombopoietin

Question 18

What hormones does the kidney produce?

Answer 18

Erythropoietin
Thrombopoietin
Renin
Calcitriol

Question 19

What are the 4 main types of hormones?

Answer 19

Peptide and Glycoprotein hormones
Steroid hormones
Amino-acid derived hormones
Lipid hormones

Question 20

How are Peptide hormones and glycoproteins synthesised and stored?

Answer 20

Made in advance
Stored in secretory vesicles

Question 21

How are Peptide hormones and glycoproteins transported in the blood?

Answer 21

Dissolved in plasma

Question 22

Where are the receptors for Peptide hormones and glycoproteins?

Answer 22

Plasma membrane of cells
(Water soluble)

Question 23

How do Peptide hormones and glycoproteins affect cells?

Answer 23

Activate a second messenger system
Activates gene expression

Question 24

Give some examples of Peptide hormones and glycoproteins:

Answer 24

Insulin
Glucagon
Prolactin
ACTH
PTH
Gastrin

Question 25

How are steroid hormones synthesised and stored?

Answer 25

They are not stored Synthesised on demand

Question 26

How are steroid hormones transported in the blood?

Answer 26

Bound to carrier proteins

Question 27

Where the receptors for steroid hormones?

Answer 27

Mainly in the cytoplasm or nucleus of a cell (Lipid soluble so can cross cell membrane)

Question 28

How do steroid hormones affect cells?

Answer 28

Activate genes for transcription and translation Normally bind to receptors Ono a region of DNA called Hormone Response Elements (HREs)

Question 29

Give some examples of steroid hormones:

Answer 29

Oestrogen Progesterone Cortisol Glucocorticoids Mineralocorticoids

Question 30

How are amino acid-derived hormones synthesised and stored?

Answer 30

Synthesised in advance and stored in secretory vesicles

Question 31

What are the 2 types of Amino acid-derived hormones?

Answer 31

Catecholamines Thyroid hormones

Question 32

How are Catecholamines transported in the blood?

Answer 32

Dissolved in the plasma

Question 33

Where are the receptors for Catecholamines?

Answer 33

Cell membrane

Question 34

How do Catecholamines affect cells?

Answer 34

Activate second messenger systems which affect gene expression

Question 35

Give some examples of Catecholamines and where are they produced?

Answer 35

Adrenal Medulla Adrenaline Noradrenaline Dopamine

Question 36

How are Thyroid Hormones transported in the blood?

Answer 36

Bound to carrier proteins Thyroxine binding globulin

Question 37

Where are Thyroid Hormones receptors found?

Answer 37

In the nucleus

Question 38

How do Thyroid Hormones affect cells?

Answer 38

Activates genes for transcription and translation

Question 39

What are the 2 thyroid hormones?

Answer 39

T3 T4

Question 40

How are lipid hormones synthesised and stored?

Answer 40

Synthesised on demand NOT STORED

Question 41

How are lipid hormones transported in the blood?

Answer 41

Dissolved in plasma AND Bound to carrier proteins

Question 42

Where are the receptors for lipid hormones?

Answer 42

Cell membrane

Question 43

How do lipid hormones exert there affects on cells?

Answer 43

Activates second messenger systems which affect gene expression

Question 44

Give some examples of lipid hormones:

Answer 44

Thromboxanes Prostaglandins Endocannabinoids

Question 45

What strucutre connects the hypothalamus to the pituitary gland?

Answer 45

Pituitary stalk (infundibulum)

Question 46

Which gland is central to homeostasis?

Answer 46

Hypothalamus

Question 47

How does blood travel through a portal system?

Answer 47

Travels through 2 sets of capillaries before returning to the heart Blood from first set of capillaries collects in portal vessels which then branch into another capilary network in another location before returning back to veins to the heart

Question 48

How is the Hypothalamo-hypophyseal portal system structured?

Answer 48

First capilary network in hypothalamus Then second capillary network in anterior pituitary

Question 49

What type of secretion occurs in the hypothalamus and pituitary?

Answer 49

Merocrine secretion Both regulated and constitutive

Question 50

In Graves’ disease what type of autoantibodies are acting and what do they cause?

Answer 50

Thyroid Stimulating Immunoglobulins Bind to TSH receptors acting like TSH Cause: -LOW TSH -HIGH T3 AND T4

Question 51

What happens in Hashimotos disease?

Answer 51

Auto antibodies destroy thyroid tissue Causes: -HIGH TSH -LOW T3 and T4 HYPOTHYROIDISIM

Question 52

What hormone do parafollicular cells produce and where are they found?

Answer 52

Calcitonin (Peptide hormone) Thyroid gland

Question 53

What type of cells are parafollicular cells?

Answer 53

Neuroendocrine cells

Question 54

What is the effect of parafollicular cells producing calcitonin?

Answer 54

DECREASES PLASMA Ca2+ LEVELS COUTERACTS PTH

Question 55

How does Calcitonin decrease plasma Ca2+ levels?

Answer 55

Inhibits osteoclast activity so inhibits bone resorption Inhibits renal calcium and phosphate re absorption

Question 56

What is the role of the parathyroid gland?

Answer 56

Monitors plasma calcium concentrations

Question 57

What hormone does the parathyroid gland produce which increases plasma Ca+ concentration?

Answer 57

PTH

Question 58

How does PTH increase Ca2+ levels in the plasma?

Answer 58

Stimulates osteoclast activity (stimulates bone resorption) Prevents calcium loss by kidneys and more calcium absorbed by GI tract

Question 59

What is indicative of Hypoparathyroidism?

Answer 59

Hypocalcaemia Hyperphosphatemia

Question 60

What occurs as a result of parathyroid dysfunction?

Answer 60

Affects ability to regulate Calcium levels Affects nerve conduction, muscle contraction, bone strength

Question 61

What is the shape of the right adrenal gland?

Answer 61

Pyramid

Question 62

What is the shape of the left adrenal gland?

Answer 62

Crescent shape

Question 63

Which part of the adrenal gland is endocrine tissue?

Answer 63

Adrenal cortex

Question 64

Which part of the adrenal gland is neuroendocrine tissue?

Answer 64

Adrenal Medulla

Question 65

What is the name of the parenchyma (functional cells) that produce the Catecholamines in the adrenal glands?

Answer 65

Chromaffin cells

Question 66

How are chromaffin cells special?

Answer 66

They are modified post-synaptic sympathetic neurones Pre-synaptic sympathetic nerve fibres pass directly to them

Question 67

What hormones (Catecholamines) do the Chromaffin cells produce?

Answer 67

Adrenaline Noradrenaline

Question 68

What 3 layer compromise the Adrenal Cortex?

Answer 68

Zona Glomerulosa (outer) Zona Fasiculata (middle) Zona Reticularis (inner) Remember GFR

Question 69

What steroid hormones (Corticosteroids) does the Zona Glomerulosa produce and what is their function?

Answer 69

Mineralocorticoids (e.g Aldosterone) Regulates Blood Pressure BP

Question 70

What steroid hormones (Corticosteroids) does the Zona Fasiculata produce and what is their function?

Answer 70

Glucocorticoids (e.g Cortisol or Cortisone) Increases blood glucose levels (Glycogenolysis, lipolysis, proteolysis)

Question 71

What steroid hormones (Corticosteroids) does the Zona Reticularis produce and what are their function?

Answer 71

Androgen precursors (DHEA) Go onto to make sex hormones

Question 72

What is the definition of Stress?

Answer 72

A state of real or perceived threat to homeostasis

Question 73

What is the stress response?

Answer 73

It is the complex range of responses involving the endocrine, nervous and immune systems collectively to maintain homeostasis in the presence of aversive stimuli/stressors

Question 74

What behavioural changes does the activation of the stress response cause?

Answer 74

Increased awareness Increased cognition Euphoria Enhanced analgesia (not feeling pain)

Question 75

What physiological adaptation are caused by the activation of the stress response?

Answer 75

Increased Cardiovascular tone Increased respiratory rate Increased intermediate metabolism

Question 76

In terms of sympathetic and parasympathetic pathways, what is the affect of cortisol?

Answer 76

Shuts down parasympathetic pathways

Question 77

What are the 3 overall affects of the corticosteroids produced by the adrenal cortex in the fight or flight response?

Answer 77

Inc BP Inc Blood glucose Inhibit parasympathetic pathways

Question 78

Where is Corticotropin Releasing Hormone made? What is its affect?

Answer 78

CRH made in hypothalamus Travels to anterior pituitary via Hypothalmo-hypophyseal portal system Simulates ACTH production (Adrenocorticotropic Hormone) ACTH binds to adrenal cortex simulating production of Adrenal corticosteroids

Question 79

Why is the secretion of adrenaline and noradrenalin considered neurocrine secretion?

Answer 79

Chromaffin cells = post syntactic neurones Release hormones directly into blood from neurone

Question 80

What is the long term stress response relative to the adrenal glands?

Answer 80

High Mineralocorticoids = High sodium low potassium, increased blood volume and pressure High Glucocorticoids = Increased proteolysis, lipolysis increased blood glucose then causes supressed immune system

Question 81

How are cells grouped in the pancreas?

Answer 81

In lobules

Question 82

Which part of the pancreas carries out the exocrine function?

Answer 82

Acinar glands/cells

Question 83

What are zymogen granules?

Answer 83

Specialised storage organelles which package, process and store they digestive enzymes in the exocrine pancreas

Question 84

What ducts are present in the pancreas?

Answer 84

Intercalated ducts join lobules which then join to the pancreatic duct which joins to the bile duct

Question 85

Where do the digestive enzymes of the pancreas get released into?

Answer 85

The duodenum

Question 86

What are the smaller paler sections called found in the pancreatic lobules?

Answer 86

Islets of Langerhans

Question 87

What are the main important cells in the islets of Langerhans and what do they produce?

Answer 87

A = glucagon B = Insulin Delta = Somatostatin

Question 88

Function of glucagon:

Answer 88

Increase blood glucose

Question 89

Function of insulin:

Answer 89

Decrease blood glucose

Question 90

Function of somatostatin:

Answer 90

Inhibits insulin and glucagon secretion

Question 91

What is the name if the cell that produces the digestive enzymes in the pancreas?

Answer 91

Acini