Endocrine System 133-149 Flashcards
Glands that secrete substances into ducts that open onto an internal or external surface are?
Exocrine glands
ie. single goblet cells or multicellular sweat glands in the skin.
What are the glands that secrete hormones directly into the blood or tissue fluid?
Endocrine glands
What is the function of the endocrine system?
It’s the main regulator of metabolism, of growth and development, helps regulate water and electrolyte balance, critical in reproductive processes and in the response to stress. Extremely important in homeostasis.
***The endocrine system interacts with the ______ to coordinate and integrate the activity of body cells.
Nervous system
The endocrine glands located in the brain are…
Hypothalamus, pituitary gland, pineal gland
The endocrine glands located in the neck are…
Thyroid gland, parathyroid gland
What Endocrine gland is located on the heart?
Thymus
The endocrine gland located in the abdomen are….
Adrenal gland located on the kidneys and the pancrea
A _______ is a substance secreted by a cell that affects the function of another cell.
Hormone
Define target cells?
Cells that are affected by a particular hormone;
The hormone is only going to affect cells that have receptors for that particular hormone on their cell surfaces.
Hormones are _________ substances that are very potent and can cause changes in their target cells even in extremely low concentrations.
A. Organic
B. Inorganic
Organic
What is the normal concentration for hormones in the body?
A. 1x10^-9
B. 1x10^-6
C. 0.325
A. Pharmacological concentrations are at 0.325
Normal concentrations
0.000000001
Name the different types of hormones.
Steroids, comedians, peptides, proteins, or glycoproteins
What is the most common type of hormones?
Steroids
___________ are compounds made from cholesterol.
Steroids
They are also made of complex rings of carbon hydrogen atoms.
Aldosterone and cortisol are steroid hormones that are secreted by__________.
The adrenal cortex
How do steroids get into the cells?
Because they are lipid soluble they pass through the membrane via diffusion easily and combine with receptors inside the nucleus.
After a steroid has gained access to a cell, what are its next steps?
Finds tDNA molecules and activates certain genes which then cause mRNA to be synthesized (transcription) which causes certain proteins to be synthesized (translation).
The proteins are synthesized in response to the hormone can…
- act as enzymes and alter rates of metabolic processes
- act as parts of membrane transport systems (pores, carrier proteins)
- activate or inhibit other enzymes
Norepinephrine and epinephrine properties from amino acids and are examples of…
A. Steroidal hormones
B. Nonsteroidal hormones
Nonsteroidal hormones
List some nonsteroidal hormone facts.
Peptide hormones are made of short chains of amino acids.
Protein hormones are made of many amino acids.
Act through secondary messengers
Produce amplified results
Nonsteroidal hormones do not passively cross the lipid bilayer, instead they…
Attached to specific receptors on the cell. From there they Control actions of the cell from the outside.
List four types of second messengers
cAMP
cGMP
Calcium
Polyphosphoinositides
cAMP activates enzymes called…
Protein kinases
Cellular responses to second messengers include…
- Altering cell membrane permeability
- activating enzymes
- Promoting synthesis of various proteins
- Stimulating or inhibiting certain metabolic pathways.
- Causing the secretion of other substances and hormones
***cAMP is inactivated by…
Phosphodiesterase. So the action does not last a long time.
Hormones whose actions involve cAMP?
TSH ACTH FSH ADH PTH RELEASING HORMONES, NOREPINEPHRINE, EPINEPHRINE, CALCITONIN, AND GLUCAGON
Norepinephrine and epinephrine are released by…
Adrenal Medela
This hormone allows us to hold onto our water longer without it we die.
ADH
Calcium enters a cell through…
Active transport, this is because it is nonsteroidal
cGMP is formed from which enzyme
Guanylate cyclase
***Used by the body to maintain homeostasis, keeps systems within a narrow range. The output of the system will “feedback” on itself to decrease its output.
Negative feedback
True or false
Blood clotting/supplying complex does not use negative feedback
True
Endocrine glands are stimulated to produce and release their hormones by three major types of stimuli, they are…
Humoral, neural, hormonal stimuli