{PULSE Lecture 1

Introduction to Endocrinology

E What the endocrine system is and its role in regulation of the human body (contrast endocrine system to exocrine system) in terms of temperature, blood sugar, calcium levels, etc.

E Organs of the endocrine system: ie. Pituitary, pineal gland, thymus, parathyroid, adrenal, thyroid gland, testis or ovary

E That the endocrine system carries out regulation via hormones (they should know the types of hormonal signaling, ie. Autocrine, paracrine, intracrine, endocrine, exocrine)

E Different classes of hormones (there are a variety of protein based and lipid/steroid based hormones) and how they act on a cell if they are protein based vs. steroid based due to hydrophobic vs hydrophilic properties

E The concept of secondary messenger systems and amplification E Negative feedback and positive feedback

Learning Objectives

from the Greek hormao: “to excite, to arouse, to put in quick motion”

Endocrinology

Hormone

from Greek ἔνδον, endo, "within"; κρῑνω, krīnō, "to sift or to separate"

Definition of an endocrine gland

The Endocrine System

Types of hormonal signaling

Types of hormonal signaling

Classes of Hormones

Steroid vs. Non-Steroid Hormones and Their Mechanism of Action

Hydrophilic v. Hydrophobic

Steroid Hormones and Their Mechanism of Action

Non-steroid or Protein-based and Their Mechanism of Action

Feedback loops

Endocrine Gland

Target Organ

HormoneEffect of

Target Organ

Feedback loops

Endocrine Gland

Target Organ

HormoneEffect of

Target Organ

Beta Cell of Pancreatic IsletHigh Glucose

Insulin

Skeletal Muscle: increase glucose

uptake

Decrease in blood glucose

Decrease stimulus to

insulin secretion

Feedback loops

Endocrine Gland

Target Organ

HormoneEffect of

Target Organ

Parathyroid GlandLow Calcium

PTH

Bone: To Increase Calcium

Mobilization

Increase in Blood Calcium

Decrease Stimulus to PTH

Sectretion