Lecture: Introduction to endocrine system

Question 1

Hypothalamus
contains

Answer 1

ADH, Oxytocin

Question 2

Pineal

Answer 2

melatonin

Question 3

Parathyroid

Answer 3

PTH

Question 4

Pituitary
Anterior

Answer 4

ACTH, TSH, GH, PRL
FSH, LH, MSH,

Question 5

Pituitary
posterior

Answer 5

ADH, Oxytocin

Question 6

Thyroid

Answer 6

Thyroid
Thyroxine (T4)
Triodothyronine (T3)
Calcitonin

Question 7

Thymus

Answer 7

Thymosins

Question 8

Gonads

Answer 8

androgens (male)
Oestrogens, progesterone (female)

Question 9

Adrenals- medulla

Answer 9

adrenaline, noradrenaline

Question 10

endocrine glands

Answer 10

are ductless
secrete hormones into circulation

Question 11

Adrenals
-cortex

Answer 11

Cortisol, corticosterone,
cortisone, aldosterone, androgens

Question 12

Pancreas

Answer 12

Insulin, glucagon

Question 13

Digestive tract

Answer 13

. gastrin, CCK, secretin

Question 14

Kidney

Answer 14

renin, erythropoietin

Question 15

Heart

Answer 15

Atrial natruiretic peptide

Question 16

Parathyroid

Answer 16

PTH

Question 17

cell to cell signaling

Answer 17

Intracrine

Autocrine

Paracrine

Endocrine

Neuroendocrine

Question 18

Intracrine function

Answer 18

Intracrine signaling involves the production and action of signaling molecules within the same cell, without their release into the extracellular space or bloodstream.

Question 19

Autocrine function

Answer 19

Autocrine signaling occurs when a cell produces signaling molecules that bind to receptors on its own surface, influencing its own behavior or function.

Question 20

paracrine function

Answer 20

Paracrine signaling refers to the mode of cell communication where signaling molecules are secreted by one cell and act on neighboring cells in the local microenvironment.

Question 21

endocrine cell function

Answer 21

Endocrine signaling involves the release of hormones into the bloodstream by specialized glands, which then travel to distant target cells to regulate various physiological processes.

Question 22

neuroendocrine function

Answer 22

Neuroendocrine signaling involves the release of hormones from neurons into the bloodstream, regulating physiological processes and acting as a bridge between the nervous and endocrine systems.

Question 23

Endocrine functions

Answer 23

Endocrine organs release hormones that are important in four broad areas:
Reproduction

Growth and development

Maintenance of internal environment

Regulation of energy

Question 24

Hormones

Answer 24

Produced by glands and released directly into circulation

Present in low concentrations (10-7 - 10-12 M)

Bind to specific, high affinity recognition sites or receptors on/in target cells

Single hormone may have different tissue-specific effects

Single function may be regulated by different hormones

Question 25

Hormones Structures and Synthesis

Answer 25

Three major chemical classes of hormones Amino acids/Amines Peptides and proteins Steroids

Question 26

Amine hormones

Answer 26

Catecholamines derived from tyrosine adrenaline, noradrenaline Thyroid Hormones also derived from tyrosine thyroxine, triiodothyronine (Indoleamines derived from tryptophan Melatonin)

Question 27

c...... derived from tyrosine

Answer 27

Catecholamines derived from tyrosine adrenaline, noradrenaline

Question 28

t........ h...... also derived from tyrosine

Answer 28

Thyroid Hormones also derived from tyrosine thyroxine, triiodothyronine

Question 29

in...... derived from trypotophan

Answer 29

Indoleamines derived from tryptophan Melatonin)

Question 30

adrenal catecholamine synthesis

Answer 30

tyrosine- tyrosine hydroxylase- L-dopa- Dopa decarboxylase- Dopamine- (Dopamine - beta - hydroxylase)- noradrenaline- phenylethanolamine N-methyl transferase - Adrenaline

Question 31

to make a thyroid hormone you need

Answer 31

an iodine molecule

Question 32

tyrosine + 1

Answer 32

mono-iodotyrosine to di-iodotyrosine

Question 33

(2+ tyrosine) + (2+ tyrosine)

Answer 33

DIT (di-iodotyrosine) x 2 = thyroxine T4

Question 34

(1 + tyrosine)+ 2+ tyrosine

Answer 34

DIT + MIT = triiodothyronine

Question 35

steroids

Answer 35

The structure common to all steroids is called a "steroid nucleus" or "steroid backbone." It consists of three cyclohexane rings (designated as rings A, B, and C) and one cyclopentane ring (designated as ring D), fused together in a specific arrangement. This structure serves as the foundation for the diverse array of steroid hormones found in living organisms. Steroid hormone synthesis is the process by which cells and glands in the body produce steroid hormones from cholesterol, involving multiple enzymatic reactions in various organs such as the adrenal glands, gonads, and placenta. example adrenal hormones sex hormones vitamin D ( calcitriol)

Question 36

Peptide & protein hormones

Answer 36

Peptides Short amino acid chains e.g. ADH (9 AA) Oxytocin (9 AA) Polypeptides e.g. Insulin (135 AA) Prolactin (198 AA) Proteins Thyroid stimulating hormone Follicle stimulating hormone Growth hormone

Question 37

Peptide & protein hormones: synthesis

Answer 37

Release by exocytosis as prohormone or hormone into blood stream

Question 38

Hormone Receptors

Answer 38

The ability of a cell to respond to a hormone depends upon the presence of receptors for that hormone on or in the target cell. The number of receptors for a hormone can increase (up-regulation) or decrease (down-regulation). May be Cell surface receptors Intracellular receptors

Question 39

Endocrine communication

Answer 39

Messages disseminated from glands to effector via circulation Relatively slow transfer of information Can be long lasting All cells contacted, specificity conferred by receptors slow maintenance of cellular homeostasis

Question 40

Positive and negative feedback loops

Answer 40

long-loop - neuro endocrine pathway short-loop contractions in giving birth positive feedback

Question 41

Endocrine disorders

Answer 41

Hypo-secretion e.g. type I diabetes Hyper-secretion e.g. pancreatic endocrine tumour Hypo-responsive e.g. insulin resistant type II diabetes Hyper-responsive TSH receptor constitutive activation => hyperthyroidism