Chapter 16 Part 1 Flashcards
What is the endocrine system?
A intergrated system of small organs exerting large effects on cellular metabolic activity by hormonal means
What are hormone
Blood-borne chemical substancefunctioning as signaling (messengers) molecules
What is the hypothalamus and its function
A near endocrine organ producing/releasing several hormones. Major endocrine controller (“the boss”)
What are autocrines?
Exert their effects on same cells secreting them
What are paracrines?
Exerts their effects on cells that are nearby to those secreting them
Exocrine glands contain which glands?
Sweat, salivary glands, and digestive juices
Endocrine glands contain which glands?
Pituitary, thyroid, parathyroid, adrenal, pineal
mixed glands contain what type of glands?
Pancreas, testes ,and placenta
List three general characteristics all hormones
Regulate metabolicactivity of other cells, lagtimes, And prolonged effects
When dealing with amino-acids based, which chemical hormone class does it fall under?
Protein hormones
When dealing with steroids,which chemical hormones class does it fall under?
Cholesterol-based hormones
When dealing with Eicosanoids, which chemical hormone class does it fall under?
Biologically active lipids
How does amino-acid based hormones use membrane passage mechanisms?
Enters cell→finds a chaperone cell→complex migrates to nucleus→ binds to a internal receptor
How does steroid hormones used membrane passage mechanism
Binds to a extracelluiar receptor→signal transduction occurs→generates cAMP→ activates enzymes
5 hormone effects on target cells?
1) alters plasma membrane permeability (insulin)
2) stimulates protein synthesis (promote anabolic reactions)
3) activates or deactivates enzyme system (on and off)
4) induces secretory activity (causes substance release)
5) stimulates mitosis (supports growth, maintenance, and repair)
What are amino-acid based hormones?
What are the mechanism of steroid hormone activation ?
Binds to a extracellular receptor → signal transduction occurs→ activates a 2nd messenger system
What is the relationship between a target cell receptor and its hormone?
Receptor binding of hormone turns on a”pre-programmed” function
What are the Three target cell activation?
1) hormone blood levels (concentration)
2) relative number of target cells receptors (how many)
3) hormone-receptor affinity (attractive force/binding strength)
What are the principles of peptide hormone receptor up-regulation?
A persistently low hormone levels, which causesa increase in receptor numbers
What are the principles of peptide hormones receptor down-regulation?
Continuously high levels of circulating hormone causes a decrease in receptor numbers
What is the role of cAMP in peptide hormone signaling?
Triggers actuation of cytoplasmic enzymes like protein kinase
What are bound hormones?
Steriod/thyroid hormones attachedto blood carrier proteins
What are protein hormones?
Peptide hormones, lack carrier proteins
What are two major factorsthat determine the concentration of a hormone in the blood?
- Rate of release
2.speed of inactivation/body removal
What are three ways hormones can be removed from the body
Humoral- changing ion/nutrient blood levels (direct response)
Neural- nerve fiber innervation (stimulus release)
Hormonal- produces/ release different release (hormone released by 1st gland causing 2nd to →)
What is the major feedback mechanism controlling hormone release?
The negative Feedback system
What is hormone half-life?
Length of time required for a blood hormone level to decrease by 50%
What is a permissiveness hormone?
A hormone that cannot exert full effects without another hormone being present
What is a synergism hormone?
A hormone’s effect are multiplied by another hormone being present
(Effects on a target lens are additive)
What are antagonism hormones?
One or more hormones opposing action of another hormone
List two characteristics of blood hormone levels
1.) most removaloccurs by target cell enzyme degradation or kidney/liver action
2.) exhibit very low concentration
