BIOL460 EXAM3 QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
What do endocrine glands do?
secrete hormones into the blood
Are endocrine glands ductless or do they have ducts?
Ductless
Examples of organs that are endocrine glands:
Heart, liver, kidneys, skin, stomach
The target cells that hormones act on are called what?
Receptors
Nuerohormones
secreted by specialized cells of the hypothalamus
ex) oxytocin, vasopressin
Hormones
regulate body metabolism, growth, and reproduction
Chemical classification: Amines
- hormones derived from tyrosine & tryptophan
ex) epinephrine and norepinephrine (from adrenal medulla), thyroid hormone
Chemical classification: Polypeptides + Proteins
Proteins: insulin, growth hormone (GH)
Polypeptides: antidiuretic hormone (ADH)
,Chemical classification: Glycoproteins
- long polypeptides bound to a carbohydrate
ex) Lutenizing hormone (LH) and Follicle-stimulating hormone (FSH)
*these are both gonadotropins
Chemical classification: Steroids
- lipids derived from cholesterol
ex) sex steriods (testosterone, estrogen, etc.), corticosteroids (from adrenal cortex)
Action Classification: Lipophilic
-nonpolar, hydrophobic
- able to pass thru cell membrane, receptors in cell or in nucleus
- genomic action; turn genes on or off
- can be taken orally; quickly absorbed, not broken down by digestive system
ex) steroid hormones, thyroid hormones, melatonin
Action Classification: Polar
- water soluble hormones, hydrophilic, lipophobic
- can't be taken orally
ex) insulin must be injected
- can't cross the membrane, receptors are on the membrane & secondary messengers
are used to effect target cells
- turn on or off enzymes
- open and close ion channels
, ex) polypeptides, glycoproteins, catecholamines
Prehormone
Molecule released by an endocrine gland that is then modified into a functional hormone
by the target cell
ex) prehormone T4, aka thyroxine - the functional hormone is T3
Prohormone
Inactive hormones cut and spliced within the gland into the functional hormone
ex) proinsulin is cut/spliced into insulin
How are steroid hormones transported through blood?
steroid hormones are lipophilic (hydrophobic) so for transport they bind (weakly) to a
carrier protein
Androgens + Estrogens bind to what carrier protein?
Sex hormone binding globulin (SHBG)
Corticosteroids bind to what carrier protein?
transcortin
Where are the receptors of steroid hormones located?
in the cytoplasm and sometimes the nucleus
-remember that they a hydrophobic (lipophilic) and therefore able to move through the
membrane
Steroid hormones act in the ________ on ___________ ____________. Typically
turning on genes, but sometimes off as well.
COMPLETE SOLUTIONS VERIFIED
What do endocrine glands do?
secrete hormones into the blood
Are endocrine glands ductless or do they have ducts?
Ductless
Examples of organs that are endocrine glands:
Heart, liver, kidneys, skin, stomach
The target cells that hormones act on are called what?
Receptors
Nuerohormones
secreted by specialized cells of the hypothalamus
ex) oxytocin, vasopressin
Hormones
regulate body metabolism, growth, and reproduction
Chemical classification: Amines
- hormones derived from tyrosine & tryptophan
ex) epinephrine and norepinephrine (from adrenal medulla), thyroid hormone
Chemical classification: Polypeptides + Proteins
Proteins: insulin, growth hormone (GH)
Polypeptides: antidiuretic hormone (ADH)
,Chemical classification: Glycoproteins
- long polypeptides bound to a carbohydrate
ex) Lutenizing hormone (LH) and Follicle-stimulating hormone (FSH)
*these are both gonadotropins
Chemical classification: Steroids
- lipids derived from cholesterol
ex) sex steriods (testosterone, estrogen, etc.), corticosteroids (from adrenal cortex)
Action Classification: Lipophilic
-nonpolar, hydrophobic
- able to pass thru cell membrane, receptors in cell or in nucleus
- genomic action; turn genes on or off
- can be taken orally; quickly absorbed, not broken down by digestive system
ex) steroid hormones, thyroid hormones, melatonin
Action Classification: Polar
- water soluble hormones, hydrophilic, lipophobic
- can't be taken orally
ex) insulin must be injected
- can't cross the membrane, receptors are on the membrane & secondary messengers
are used to effect target cells
- turn on or off enzymes
- open and close ion channels
, ex) polypeptides, glycoproteins, catecholamines
Prehormone
Molecule released by an endocrine gland that is then modified into a functional hormone
by the target cell
ex) prehormone T4, aka thyroxine - the functional hormone is T3
Prohormone
Inactive hormones cut and spliced within the gland into the functional hormone
ex) proinsulin is cut/spliced into insulin
How are steroid hormones transported through blood?
steroid hormones are lipophilic (hydrophobic) so for transport they bind (weakly) to a
carrier protein
Androgens + Estrogens bind to what carrier protein?
Sex hormone binding globulin (SHBG)
Corticosteroids bind to what carrier protein?
transcortin
Where are the receptors of steroid hormones located?
in the cytoplasm and sometimes the nucleus
-remember that they a hydrophobic (lipophilic) and therefore able to move through the
membrane
Steroid hormones act in the ________ on ___________ ____________. Typically
turning on genes, but sometimes off as well.
