Topic 2:

The Endocrine System

2.1 Systems of chemical mediation and communication

2.2 A comparison of endocrine and exocrine cells (Part 1)

2.2 A comparison of endocrine and exocrine cells (Part 2)

Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn

Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.

Figure 3.12: Exocytosis, p. 78.

Extracellularfluid

Cytoplasm

Molecules tobe secreted

VesicleSNARE

Plasma membraneSNARE

Secretory vesicle

(a)

(b)

Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn

Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.

Figure 3.13: Clathrin-mediated endocytosis, p. 79.

Recycling ofmembrane andreceptors (if present)to plasma membrane

CytoplasmExtracellular fluid

Extracellularfluid

Plasmamembrane

Detachmentof clathrin-coatedvesicle

Clathrin-coatedvesicle

Uncoating

Uncoatedvesicle

Uncoatedvesiclefusing withendosome

To lysosomefor digestionand releaseof contents

Transcytosis

Endosome

Exocytosisof vesiclecontents

Clathrin-coatedpit

Plasmamembrane

Ingestedsubstance

Clathrinprotein

(c) Receptor-mediated endocytosis

Extracellularfluid

Cytoplasm

Bacteriumor otherparticle

Pseudopod

Clathrinprotein

(b) Phagocytosis

Clathrinprotein

Membranereceptor

(a) Clathrin-mediated endocytosis

1

3

2

2.3 The major endocrine glands and tissues in humans

Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn

Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.

Figure 16.3: PIP second-messenger mechanism of amino acid-based hormones, p. 608.

PIP2

IP3

ReceptorGTP

GTP

CatecholaminesTRHADHGnRHOxytocin

Triggers responses of target cell

GDP

Extracellular fluid

Cytoplasm

Inactiveprotein kinase C

Activeprotein kinase C

Phospholipase C

Gq

Ca2+ Ca2+-calmodulin

Hormone

Endoplasmicreticulum

DAG

GTP

1

2 34 5

5

6

2.4 The hypothalamus

2.5 The pituitary gland

2.6 Hypothalamic communication with the anterior and posterior pituitary

2.7 The thyroid gland (Part 1)

2.7 The thyroid gland (Part 2)

Figure 23.20

2.8 The pancreas (Part 1)

Six primary hormones produced by the pancreas:

1.Insulin - causes cells in the liver, muscle and fat to uptake gluclose from the blood to store as glycogen in muscle and liver.

2. Glucagon – released when blood glucose levels are too low , causing the liver to convert stores of glycogen into glucose. The glucose is released into the bloodstream

3.Somatostatin - suppresses the release of various gastrointestinal hormones.

4.Ghrelin – hunger stimulating hormone

5.Pancreatic polypeptide – regulates secretion of the endocrine and exocrine chemicals of the pancreas. In humans , secretion is increased after a protein meal, fasting, exercise.

6.Amylin - functions as a synergistic partner to insulin, but seems to be more intimately involved in determination of the glycemic index than insulin in readings related to A1C.

2.8 The pancreas (Part 2)

Alpha cells will produce glucagon.Beta cells will produce insulin and amylin.Delta cells will produce somatostatinPP cells will produce pancreatic polypeptide.Epsilon cells will produce ghrelin.

2.9 The adrenal glands (Part 1)

2.9 The adrenal glands (Part 2)

2.10 The pineal gland (Part 1)

2.10 The pineal gland (Part 2)

This is the point where we have concluded Chapter 2 materials relevant to lecture exam #1. The remainder of the materials that follows will be part of lecture exam #2.

Figure 27.1

Figure 27.3a

2.11 The testes

Figure 27.11

Figure 27.12a

Figure 27.12b

Figure 27.14a

2.12 The ovaries (Part 1)

2.12 The ovaries (Part 2)

2.13 Protein and peptide hormone receptors

2.14 A tyrosine kinase receptor

Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn

Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.

Active siteAmino acids

Enzyme (E)Enzyme-substratecomplex (E-S)

Internal rearrangementsleading to catalysis

Dipeptide product (P)

Free enzyme (E)

Substrates (S)

Peptide bond

H2O

+

2.15 A G protein

2.16 Signal amplification by second messengers

2.20 Known amino acid sequences of releasing hormones (Part 1)

2.20 Known amino acid sequences of releasing hormones (Part 2)

2.21 Primary structures of species-specific forms of GnRH

2.23 Primary structure of the nonapeptides secreted by the posterior pituitary

2.25 Milk letdown is mediated by oxytocin (Part 1)

Figure 27.17

2.25 Milk letdown is mediated by oxytocin (Part 2)

2.26 Thyroid hormone synthesis

2.28 Steroid chemical structure and nomenclature

2.29 Steroid hormone receptors are generally located in the cytosol or nucleus of a cell

2.30 Biochemical pathways in steroid formation (Part 1)

2.30 Biochemical pathways in steroid formation (Part 2)

2.31 Androgens (Part 1)

2.31 Androgens (Part 2)

2.32 Estrogens (Part 1)

2.32 Estrogens (Part 2)

2.33 Epinephrine, norepinephrine, and dopamine are catecholamines

2.35 Models of negative and positive feedback

2.36 Negative feedback

Box 2.1(A) Life cycle of the silkworm moth

Box 2.2 The Discovery of Secretin