Endocrine System Flashcards
What do exocrine glands secrete into?
A duct which carries secretion to body surface
Examples include sweat, mucous, salivary, and alimentary glands.
How do endocrine glands secrete hormones?
Into extracellular fluid surrounding the gland, then into capillaries and transported by blood.
What are hormones?
Chemicals secreted by endocrine glands transported throughout the body in blood.
How do hormones change the functioning of a cell?
By changing cell activity such as quantity of protein produced and influencing the concentration of enzymes.
What can hormones activate in cells?
A gene so that an enzyme or protein is produced.
What is the lock and key analogy in relation to hormones?
Receptor proteins are specific and only bind to one specific molecule.
What are the three types of hormones?
- Steroids
- Proteins
- Amines
Name two examples of steroid hormones.
- Oestrogen
- Progesterone
What is the solubility characteristic of steroid hormones?
Lipid soluble (don’t dissolve in water).
How do steroid hormones reach their target?
In blood, they bind to transport proteins, detach from transporter, and diffuse through plasma membrane.
What is the effect of steroid hormones on gene activity?
Receptor-hormone complex activates genes by binding to promotor region, stimulating or inhibiting transcription.
How do protein and amine hormones act on target cells?
Attach to receptor proteins on membrane of target cell.
What is the role of the secondary messenger triggered by protein and amine hormones?
To diffuse through the cell and activate enzymes.
What is enzyme amplification?
One hormone activates thousands/billions of enzymes through a cascading series of reactions.
What happens to hormones after their required effect?
They are turned off by breaking down, mostly in the liver and kidneys.
How are degraded hormones excreted from the body?
In bile or urine.
What regulates hormone secretion to maintain homeostasis?
Negative feedback systems.
True or False: Hormones can influence any cell in the body regardless of receptor presence.
False.
Fill in the blank: Hormones only influence cells with the correct _______.
receptor.
What is the saturation point in hormone receptor activity?
A limit on the number of receptors in the membrane where additional hormone will have no effect.
What is the typical response time for protein and amine hormones?
Quick response, short lasting.
What is the typical response time for steroid hormones?
Slow effect but long lasting.
What is the primary organ for hormone degradation?
Liver.
