Hormones Flashcards
(19 cards)
What is a hormone?
A hormone is a chemical substance produced by a gland and carried by the blood, which alters the activity of one or more specific target organs.
What are the characteristics of hormones?
Hormones must be relatively small in size, soluble, and diffuse easily.
How do hormones travel in the body?
Hormones pass quickly from the cells that make them into blood capillaries, and later from blood into the target organ.
What happens to hormones after they produce their effects?
They are broken down in the liver into inactive components and excreted by the kidneys in urine.
What is the endocrine system?
The endocrine system is the collective name for the glands that produce hormones in animals.
What is an endocrine gland?
An endocrine gland is a ductless gland that secretes a hormone directly into the blood.
Why do endocrine glands have a good blood supply?
They need to quickly get hormones into the bloodstream to travel to target organs.
How do hormones affect cells?
Hormones only affect cells with target receptors that the hormone can bind to.
Where are hormone receptors found?
Receptors can be found on the cell membrane or inside cells.
What role does the liver play in hormone regulation?
The liver regulates levels of hormones in the blood, transforming or breaking down any that are in excess.
What is adrenaline?
Adrenaline is a hormone secreted by adrenal glands during emotional excitement, stress, or situations requiring sudden physical activity.
When is adrenaline secreted?
Adrenaline is secreted during emotional excitement, anger, anxiety, fear, or fight.
What is adrenaline commonly known as?
Adrenaline is known as the fight or flight hormone.
What stimulates the production of adrenaline?
Nerve impulses from the brain stimulate the adrenal glands to produce adrenaline.
What are some effects of adrenaline on the body?
Effects include:
* Conversion of glycogen to glucose
* Increasing pulse and breathing rates
* Diverting blood flow towards muscles
* Dilating pupils
Fill in the blank: Adrenaline causes the conversion of _______ to glucose in the liver.
glycogen
True or False: Hormones can affect any cell in the body.
False
What is the purpose of diverting blood flow during adrenaline release?
To ensure reactants of respiration are as available as possible to muscles.
What physiological changes occur to improve vision during adrenaline release?
Pupils are dilated to allow more light to reach the retina.
