Hormones - Text Text Lab starts this week already. Attend...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Text Text Lab starts this week already. Attend or be dropped Karla Paulson and Emily Bishop will be at the back after lecture with add codes. ! Approximate Lecture Schedule Text Come to lectures Study consistently!!! Study! Study! Study! 41 Animal Hormones Testosterone Abuse Testosterone - Binds receptors - Alters gene expression Performance enhancing steroid drugs Male secondary sex characteristics: Deep voice Facial and body hair Increased muscle mass Greatly increased risk of cancer and heart, liver and kidney disease 41 What are Hormones? Hormones are chemical messages that allow slow communication between distant cells in the body. Hormones act on a time scale of several seconds to days. " can control longer-term physiological processes " not useful for controlling rapid actions 41 Endocrine cells Hormone-secreting cells are called endocrine cells . " ...they secrete hormones into the interstitial space and/or blood stream In contrast, exocrine cells secrete substances into ducts that are connected to the outside world " ...examples? Epithelial cells face the outside world ~60% of the recognized major human cell types are classified as epithelial cells Figure 42.1 Chemical Signaling Systems Paracrine Hormones affect cells in their immediate vicinity Endocrine glands secrete circulating hormones 41 Auto/Paracrine Hormones Some hormones act locally. Autocrine hormones act on the secreting cell itself. Paracrine hormones act on cells near the site of release. Auto/paracrine hormones are released in tiny amounts, or are inactivated rapidly by enzymes, or are taken up efficiently by local cells. They never get into the circulatory system. 41 Circulating Hormones Circulating hormones diffuse into the blood, which distributes them throughout the body. When the hormone message encounters a cell with the proper receptor , it binds and triggers a response. The same hormone can cause different responses in different types of cells. An example is epinephrine (=adrenaline). The nervous system reacts to an emergency very quickly and stimulates adrenal cells to secrete epinephrine. The result is the fight-or-flight response . 41 Hormones and Their Actions Epinephrine acts on different cells in the body: " In the heart, it stimulates faster and stronger heartbeat. " Blood vessels in some areas constrict to send more blood to muscles. " In the liver, glycogen is broken down to glucose to provide quick energy. " In fat tissue, fats are mobilized as another energy source. show movie: effects of epinephrine (1min) Figure 42.14 Some Hormones Can Activate a Variety of Signal Transduction Pathways Epinephrine Norepinephrine G-protein coupled receptors 41 mones can be classified into three main groups: 1) Peptides or proteins # Are water soluble...
View Full Document

This note was uploaded on 10/08/2010 for the course MCDB MCDB 1B taught by Professor Weimbs,finklestein during the Summer '09 term at UCSB.

Page1 / 18

Hormones - Text Text Lab starts this week already. Attend...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online