Class Notes (835,342)
Canada (509,116)
ANP1105 (323)

endocrine system.doc

9 Pages
Unlock Document

Anatomy and Physiology
Jacqueline Carnegie

Chapter 16 The Endocrine Systemendocrinology the study of hormones and the endocrine glands the endocrine system influences metabolic activity by means of hormones chemical messengers released into the blood to be transported throughout the bodyendocrine glands ductless glands release their hormone into the surrounding tissue fluid and have a rich vascular and lymphatic drainage that receives their hormones includes the pituitary gland thyroid gland parathyroid gland adrenal gland and pineal glandthe hypothalamus is considered to be a neuroendocrine organ since it produces and releases hormone along with its neural function autocrines chemicals that exert their effects on the same cells that secrete them paracrines chemicals that act locally but affect cell types other than those releasing the paracrine chemicals Chemistry of Hormoneshormones chemical substances secreted by cells into the extracellular fluids that regulate metabolic function of other cells in the bodycan be classified chemically as either amino acid based or steroidslong distance chemical signals that travel in blood or lymph throughout the boy amino acid based hormones vary from simple amino acid derivatives to peptides to proteinssteroid hormones are synthesized from cholesterol only gonadal and adrenocorticol hormones are steroidseicosanoids leukotrienes and prostaglandins are biologically active lipids made for arachidonic acid and are released by nearly all cell membranesleukotrienes are signalling chemicals that mediate inflammation and some allergic reactionsprostaglandins have multiple targets and effectssince the effects of eicosanoids are typically highly localized they generally act as autocrines and paracrines and do not fit the definition of a true hormone Mechanisms of Hormone Action a hormone influences the activity of only certain tissues target cells hormones alter cell activity increase or decrease the rates of normal cellular processeshormonal stimulus typically produces one or more of the following changes1 alters plasma membrane permeability or membrane potential or both by opening or closing ion channels 2 stimulates synthesis of proteins or regulatory molecules such as enzymes within the cell
More Less

Related notes for ANP1105

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.