APK 3110C Study Guide - Midterm Guide: Homeostasis, Adipose Tissue, Adrenocorticotropic Hormone
6 May 2018
School
Department
Course
Professor
Basics of hormones- what stimulates their release, what they need to work,
how they work, what changes their concentration in the plasma.
How the Endocrine system works:
• Endocrine glands secrete hormones into extracellular spaces which
diffuses into the blood. Since they’re now in the blood the hormones can
travel throughout the body. They then bind to receptors that are on the
target organs. Once on the target organs they exert their effect.
Hormones
• Chemical substances that are synthesized and released by host gland
• Steroid derived
o Made from lipids (usually cholesterol)
o Insoluble in plasma
• Poly peptide hormones (MOST COMMON)
o Soluble in plasma
o Made from amino acids
• Amine
o Soluble in plasma
o Derived from tyrosine (amino acid)
• Half-life time needed to decrease hormones blood concentration by ½
o Indication of how long effect could last
• Stimulate nuclear DNA which leads to rate of intracellular protein
synthesis
• Changes enzyme activity rate
• Cellular response to hormone is only achieve if there is a receptor to
bind!!!
What hormones need to work:
• Activation of target cell by hormone depends on:
o Hormone concentration in blood
o Number of hormone receptors on cell
▪ Manipulated to meet needs – up or down regulated
o Characteristics of binding to receptor
find more resources at oneclass.com
find more resources at oneclass.com
How Hormones function:
• Lock and key action:
o Hormone (key) binds to a receptor (lock). When they match they
are allowed to exert their function?
▪ Leads to cellular action
• There are two types of functions:
o Autocrine Function
▪ Production of hormone by specific tissue to act upon itself
▪ Cellular action within that tissue
▪ Produced by tissue to affect THAT tissue
o Paracrine Function
▪ Production of hormone by specific tissue to act on adjacent
tissue
▪ Cellular action on different tissue
▪ Produced by tissue to affect NEIGBORING tissue
Hormone Action:
• Hormones cannot function without the appropriate receptor
• No RECEPETOR = NO ACTION
o If you pump yourself up with testosterone and didn't have the
appropriate receptor available nothing would happen
• Changes in hormone concentration are not predictive of an action
• Increase in enzyme activity
o Stimulates enzyme production
• Primary effect: promote or inhibit cellular uptake
• Secondary effect: What the primary effect stimulates
find more resources at oneclass.com
find more resources at oneclass.com
Stimulation of hormones:
• Hormonal – hormones stimulate or inhibit release of other hormones at
same or different tissue
• Humoral – ions and nutrients in blood, bile, body fluids stimulate
hormone release
o Example) if you have an increase in blood glucose your body is
going to release insulin
• Neural - neural control can overcome normal endocrine control to
maintain homeostasis
How is the action of a hormone controlled?
• Its controlled by the Negative Feedback System
o Increased hormone effects on target organs can inhibit further hormone
release
Hormone Concentration:
• Plasma concentration of hormones are determined by
o The number of hormones synthesized in the endocrine organ
o The rate of secretion into blood
o Transport volume changes
o Rate of catabolism/uptake
Training effects on endocrine function:
• For the most part, there is no difference between trained and untrained people if they’re
working at the same relative intensity/ vo2max
• Although, if there is a give workload trained athletes will have a lower hormonal
response
o This is because they have improved target tissue sensitivity and responsiveness
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Basics of hormones- what stimulates their release, what they need to work, how they work, what changes their concentration in the plasma. How the endocrine system works: endocrine glands secrete hormones into extracellular spaces which diffuses into the blood. Since they"re now in the blood the hormones can travel throughout the body. They then bind to receptors that are on the target organs. Once on the target organs they exert their effect. What hormones need to work: activation of target cell by hormone depends on, hormone concentration in blood, number of hormone receptors on cell, manipulated to meet needs up or down regulated, characteristics of binding to receptor. How hormones function: lock and key action, hormone (key) binds to a receptor (lock). How is the action of a hormone controlled: its controlled by the negative feedback system. Increased hormone effects on target organs can inhibit further hormone release.
