PHGY 216- Midterm 1 Exam Questions
and All Solved Solutions.
What are the six primary functions of the endocrine system - Answer 1. maintain constant
internal environment
2. growth and development
3. adaptive stress response
4. reproduction
5. red blood cell production
6. integrating with ANS regulating digestive functions
Define lipophilic hormones - Answer water insoluble, can pass through plasma membrane but
need a carrier transport to move through the blood, cellular receptors are within the cell-
include steroid hormones and thyroid hormones
Define hydrophilic hormones - Answer hormones that are water soluble and do not need
transporter in the blood. Cannot pass through plamsa membrane and act on membrane
receptors. Include catecholamines and peptide hormones
Explain the synthesis of hydrophilic hormones - Answer 1. preprohormones made by
ribosomes in the endoplasmic reticulum
2. packaged and sent to the golgi where they are turned into active hormones
3. stored in vesicle until signal is received- this initiates endocytosis to release hormones into
blood
Synthesis of lipophilic hormones - Answer made by specific tissues that posses enzymes
needed for synthesis- not made before needed as they cannot be stored- therefore production
is regulated
Describe the binding process of hydrophilic hormones- using cAMP - Answer bind to receptor
in membrane, causes activation of g-protien, this activates adenylyl cyclase which turns ATP into
cAMP which is a secondary messanger that activates kinase A- this activates target protein by
interact with genes
Describe the binding process of hydrophilic hormones- using calcium - Answer - hormone
binds to membrane receptor, activates g-protein, which activates phopholipase C enzymes thta
convert PIP2 into IP3 and DAG. IP3 mobilizes intracellular calcium to bind to calmodulin. This
complex can then activate calmodulin-Ca2+ protein kinase to interact with target protein
,Explain the binding complex of lipophilic proteins - Answer -passes through membrane and
into cell where it binds with receptor and this complex binds to the hormone element in the
DNA which affects production of mRNA and thus affects transcription
What are some key differences between the nervous and endocrine system - Answer nervous:
short duration, quick, close proximity
endocrine: long duration, slower, can target large range of tissues
What type of tissue is the posterior pituitary - Answer neruhypophysis
What type of tissue is the anterior pituitary - Answer adenohypophysis
Where are the hormones released by posterior pituitary produced - Answer hypothalamus
Where are the hormones released by the anterior pituitary produced? - Answer anterior
pituitary (stimulated by hypophysiotropic hormones)
What are the two types of neurons that connect the posterior pituitary - Answer supraoptic
nucleus and the paraventricular nucleus
What is the connection between the anterior pituitary and the hypothalamus - Answer
hypothalamus- hypophyseal portal system (arteries and capillaries)
What are the hormones released by the posterior pituitary - Answer Vasopressin/ ADH-
controls water retention, Oxytocin
What are the hormones released by the anterior pituitary - Answer GH, ACTH, TSH, FSH, LH,
PRH
List the hypophyseal tropic hormones - Answer Thyrotropin releasing hormone (TRH)- release
of prolactin and TSH, Gonadotropin releasing hormone (GnRH), Gonadotropin inhibiting
hormone (GnIH), Growth hormone releasing hormone (GHRH), Growth hormone inhibiting
hormone (GHIH), Cortiotropin releasing hormone (CRH)- stimulates release of ACTH, Prolactin
releasing hormone (PRH), Prolactin inhibiting hormone (PIH)
What are the cellular components of the thyroid glands - Answer follicular cells
colloid (storage)
c-cells (produce calcitonin)
, What are the major components of the thyroid hormone - Answer tyrosine and iodine
What are the functions of the thyroid hormone? - Answer 1. increases metabolic rate and heat
production
2. intermediary (fuel) metabolism
3. sympathetic- increases amount of catecholamine receptors
4. cardiovascular- sympathetic effect on heart rate, strength of contraction to increase CO
5. growth- stimulates release of GH and insulin from tissues
What are the two major types of thyroid horomones - Answer tetraiodothryonine hormone
(T4)
Triiodotyronine hormone (T3)
What is the function of tetraiodothryonine hormone - Answer - inactive form but makes up
90% of hormone present
What is the function of triiodothyronine hormone - Answer - active form making up 10% of
hormone produced
Explain thyroid synthesis - Answer 1. tyrosine containing hemoglobin are profuced within the
follicular cells and transported to the colloid
2. follicular cells uptake iodine molecules into colloid through Na+ facililitated transport- as it is
moved it is turned into active state Io which immediately attached to tyroglobin molecule
3. attachment of one iodine makes monoiodotyrosine and attachment of another make
diiodotryosine.
4. a mono and diiodtryosine make T3,two diiodotyrosine make T4
- remain attached to thryoglobin
Explain the release of T3 and T4 - Answer 1. follicular cells engulf part of colloid containing the
T3 and T4 through phagocytosis
2. the vesicles fuse with lysosome which release all MIT, DIT, T3 and T4 from thyroglobin
3. T3 and T4 are lipophilic and pass through membrane into blood- they bind with thryoid-
binding globin for blood transport
What are the three causes of hypothyroidism - Answer 1. primary failure of thyroid gland (cant
make enough T3 and T4 despite high levels of TSH)
and All Solved Solutions.
What are the six primary functions of the endocrine system - Answer 1. maintain constant
internal environment
2. growth and development
3. adaptive stress response
4. reproduction
5. red blood cell production
6. integrating with ANS regulating digestive functions
Define lipophilic hormones - Answer water insoluble, can pass through plasma membrane but
need a carrier transport to move through the blood, cellular receptors are within the cell-
include steroid hormones and thyroid hormones
Define hydrophilic hormones - Answer hormones that are water soluble and do not need
transporter in the blood. Cannot pass through plamsa membrane and act on membrane
receptors. Include catecholamines and peptide hormones
Explain the synthesis of hydrophilic hormones - Answer 1. preprohormones made by
ribosomes in the endoplasmic reticulum
2. packaged and sent to the golgi where they are turned into active hormones
3. stored in vesicle until signal is received- this initiates endocytosis to release hormones into
blood
Synthesis of lipophilic hormones - Answer made by specific tissues that posses enzymes
needed for synthesis- not made before needed as they cannot be stored- therefore production
is regulated
Describe the binding process of hydrophilic hormones- using cAMP - Answer bind to receptor
in membrane, causes activation of g-protien, this activates adenylyl cyclase which turns ATP into
cAMP which is a secondary messanger that activates kinase A- this activates target protein by
interact with genes
Describe the binding process of hydrophilic hormones- using calcium - Answer - hormone
binds to membrane receptor, activates g-protein, which activates phopholipase C enzymes thta
convert PIP2 into IP3 and DAG. IP3 mobilizes intracellular calcium to bind to calmodulin. This
complex can then activate calmodulin-Ca2+ protein kinase to interact with target protein
,Explain the binding complex of lipophilic proteins - Answer -passes through membrane and
into cell where it binds with receptor and this complex binds to the hormone element in the
DNA which affects production of mRNA and thus affects transcription
What are some key differences between the nervous and endocrine system - Answer nervous:
short duration, quick, close proximity
endocrine: long duration, slower, can target large range of tissues
What type of tissue is the posterior pituitary - Answer neruhypophysis
What type of tissue is the anterior pituitary - Answer adenohypophysis
Where are the hormones released by posterior pituitary produced - Answer hypothalamus
Where are the hormones released by the anterior pituitary produced? - Answer anterior
pituitary (stimulated by hypophysiotropic hormones)
What are the two types of neurons that connect the posterior pituitary - Answer supraoptic
nucleus and the paraventricular nucleus
What is the connection between the anterior pituitary and the hypothalamus - Answer
hypothalamus- hypophyseal portal system (arteries and capillaries)
What are the hormones released by the posterior pituitary - Answer Vasopressin/ ADH-
controls water retention, Oxytocin
What are the hormones released by the anterior pituitary - Answer GH, ACTH, TSH, FSH, LH,
PRH
List the hypophyseal tropic hormones - Answer Thyrotropin releasing hormone (TRH)- release
of prolactin and TSH, Gonadotropin releasing hormone (GnRH), Gonadotropin inhibiting
hormone (GnIH), Growth hormone releasing hormone (GHRH), Growth hormone inhibiting
hormone (GHIH), Cortiotropin releasing hormone (CRH)- stimulates release of ACTH, Prolactin
releasing hormone (PRH), Prolactin inhibiting hormone (PIH)
What are the cellular components of the thyroid glands - Answer follicular cells
colloid (storage)
c-cells (produce calcitonin)
, What are the major components of the thyroid hormone - Answer tyrosine and iodine
What are the functions of the thyroid hormone? - Answer 1. increases metabolic rate and heat
production
2. intermediary (fuel) metabolism
3. sympathetic- increases amount of catecholamine receptors
4. cardiovascular- sympathetic effect on heart rate, strength of contraction to increase CO
5. growth- stimulates release of GH and insulin from tissues
What are the two major types of thyroid horomones - Answer tetraiodothryonine hormone
(T4)
Triiodotyronine hormone (T3)
What is the function of tetraiodothryonine hormone - Answer - inactive form but makes up
90% of hormone present
What is the function of triiodothyronine hormone - Answer - active form making up 10% of
hormone produced
Explain thyroid synthesis - Answer 1. tyrosine containing hemoglobin are profuced within the
follicular cells and transported to the colloid
2. follicular cells uptake iodine molecules into colloid through Na+ facililitated transport- as it is
moved it is turned into active state Io which immediately attached to tyroglobin molecule
3. attachment of one iodine makes monoiodotyrosine and attachment of another make
diiodotryosine.
4. a mono and diiodtryosine make T3,two diiodotyrosine make T4
- remain attached to thryoglobin
Explain the release of T3 and T4 - Answer 1. follicular cells engulf part of colloid containing the
T3 and T4 through phagocytosis
2. the vesicles fuse with lysosome which release all MIT, DIT, T3 and T4 from thyroglobin
3. T3 and T4 are lipophilic and pass through membrane into blood- they bind with thryoid-
binding globin for blood transport
What are the three causes of hypothyroidism - Answer 1. primary failure of thyroid gland (cant
make enough T3 and T4 despite high levels of TSH)
