Exam 3 Flashcards
Site of production for gastrin?
Stomach or antral G cells
Action and function of gastrin
~increases gastric acid secretion from parietal cells
~increases antral motility & gastrointestinal growth
~stimulates secretin
~inhibits gastrin secretion
~increases cholecystokinin induced release of digestive enzymes
Regulation of gastrin
-increased in response to gut digestion (expansion) caused by food intake
-increased in response to gastrin releasing peptide
Gastrin Action Chart
**
Where is secretin produced?
S cells of small intestine
How is secretin regulation
stimulated by gastric acid
Actions of secretins
-stimulates HCO3/bicarbonate secretion
-increases CCK induced release of digestive enzymes
Where is cholecystokinin produced?
I cells of the small intestine
Actions of cholecystokinin
-stimulates pancreatic secretion of bicarbonate
-reduces gastric emptying
-promotes satiety (feeling of fullness)
-increased amounts promotes excessive eating
How is cholecystokinin regulated?
by peptides/amino acids
Site of production of gastric inhibitory peptide
K cells in stomach
Action of Gastric Inhibitory peptide
-inhibits gastric emptying
-inhibits gastric acid secretion
-stimulates glucose-mediated insulin release
How is gastric inhibitory peptide regulated?
Gastric inhibitory peptide is stimulated by elevated ingestinal glucose, amino acid and fatty acid
Grehlin is produced where?
in the stomach
Gastric inhibitory peptide works through what receptor?
GIP receptors
Insulin is an anabolic hormone which means it
produces energy stores through metabolic hormones
Insulin is produced by?
Beta cells of islet of lagerhans
Insulin action
decrease blood glucose
-stimulates glucose uptake
-promotes triglyceride
and proetin synthesis
-works oppositely to glucagon
Insulin regulation
-stimulated by high bp & gastric inhibitory peptides
-inhibited by epinephrine and glucagon
Insulin receptors
tyrosine kinase
Insulin deficiency leads to
diabetes, lipolysis, ketogenesis and proteolysis
Glucagon is a catabolic hormone which means it
stimulate the breakdown of molecules and the production of energy
Glucagon is produced
alpha cells of pancreatic islet of Langerhans
Glucagon action
increase blood glucose
-promotes lipolysis, glycogenolysis, amino acids to glucose and glycerol
Glucagon is regulated by
low blood glucose levels and inhibited by insulin
What is type 1 diabetes
insulin-dependent, when no insulin is produced
What causes type 1 diabetes
destroyed Beta cells
Effects of type 1 diabetes
polyuria(excess urine)
polydipsia (excess thirst)
ketoacidosis (ketone production)
Type 1 diabetes treatment
insulin
What is type 2 diabetes?
non-insulin-dependent, insulin produced just tissue resisted
Type 2 diabetes effect
Central obesity
adipokines secretion(adiponectin & resisten)
Type 2 diabetes treatment
diet, exercise
neuropeptide Y produced
hypothalamus/brain
neuropeptide y general function and action
-stimulates appetite/food intake
Agouti-related peptide produced
in the brain
Agouti-related peptide general action and function
stimulates feeding
reduces metabolism and energy
Agouti-related peptide regulation
inhibited by leptin
Grehlin produced
stomach
Grehlin’s general function and action
-stimulate appetite
-activates neuropeptide Y and agouti related peptide
-stimulates growth hormone
Ghrelin regulation
fasting and stomach shrinkage increase it
Melanocortins produced
in brain
Melanocortin’s general function and action
inhibit apetite, mutation leads to obesisty
Leptin is produced in
white adipose, fat
Leptin general function and action
inhibit appetite
reduce weight gain
inhibits appetite-stimulating hormones
Leptin receptor
cytokine
IGF-1 produced in
liver
IGF-1 general action and function
cell proliferation
dual effector hypothesis
The dual effector hypothesis is
when GH induces differentiation of certain precursor cells which leads to IGF-1 responsiveness and expression.Later bone formation
IGF-1 regulation
GH and androhgens stimulates
glucocorticoids and estrogen inhibit
IGF-1 receptor
tyrosine kinase
IGF-2 produced
liver and brain
IGF-2 general action and function
works through IGF-1 receptors
regulate cell proliferation
IGF-2 is regulated by
GH, it’s dependent on GH
Epidermal growth factor is produced
salivary gland
Epidermal growth factor general action and function
induces cell proliferation
promotes wound healing
Epidermal growth factor receptor
tyrosine kinase
TGF-alpha general action and function
normal development
enhances cell proliferation
TGF-alpha is regulated by
wounds
TGF-beta general action and functions
-inhibits proliferation
-stimulates other growth factors (low levels favor growth while high levels inhibit growth)
-stimulate blood vessel formation (keloids)
Mullerian inhibiting hormone produced
embryonic mammalian testes
Mullerian hormone general function and action
-thwarts uterus and oviduct development
Inhibin & activins produced
in gonads or hypothalamus
Inhibins and activins general function and action
-inhibin inhibits FSH, GnRH
-activin stimulates FSH synthesis & secretion, wound repair
-both induces mesodermal structures
Myostatin produced
muscle
Myostatin general action and function
inhibits muscle growth
Mutation in myostatin causes
double muscling or proliferation of muscle tissue
Platelet-derived growth factor action and general function
wound repair
Platelet-derived growth factor receptor
tyrosine kinase receptor
Erythropoietin produced
kidney and astrocytes
Erythropoietin general function and action
Works to fix low blood oxygen (hypoxia)
-stimulate red blood cell proliferation
-increase hemoglobin content
-increases stamina
What do hematopoietic growth factors do?
regulate differentiation of a hematocytoblastic stem cell
What are hematopoietic growth factors?
erythropoietin
colony-stimulating factors
some interleukins
What are eicosanoids
inflammatory hormones
1.protoglandins
2.leukotrienes
3.lipoxins
4. thromboxines
Actions of eicosanoids
- mediation of inflammation
- prevent blood loss
smooth muscle contraction
Prostoglandins & leukotrienes action
stimulate blood vessel dilation to produce edema (swelling of tissue), provoke pain and fever and stimulate lysosome release
Lipoxins action
counteract inflammatory responses
Thromboxines
constrict blood vessels and promote platelet aggregation
Sex determination is
process whereby the bipotential gonad develops into testes or ovaries
Sex differentiation required
the developing gonad to function appropriately
Sex determination is regulated by what two things
chromosomes, environment or a combination
When a fish is synchronous then
sheds both eggs and sperm at the same time
When a fish is asynchronous then
initially one sex and then reverses to the opposite sex
In turtles temperature determines sex, hot _______ and ______ dudes
hot, cool
Chromosomal sex is
when there is a Y or X chromosome
Gonadal sex is
the presence of testis or ovaries
Phenotypic/anatomic sex is
the presence of male or female external and internal genitalia
Only ___ copy of the X chromosomes is active in females
1
The “Y” chromosome determines
maleness
Y chromosome contains SRY gene that
encodes for testes determine the factor
If SRY gene is deleted then
testes won’t be developed
Sertoli cells
-produce androgen binding proteins and inhibin
-secrete anti-Mullerian hormone/ or Mullerian inhibiting factor
anti-Mullerian hormone/ or Mullerian inhibiting factor general function or action
inhibits the development of parts of the female gonad
Leydig cells
secretes testosterone to produce the male gonad
Testosterone is produced
Leydig cells
Testosterone general function and action
-induces adult male secondary sex characteristics
-male brain/behavior
-induces male gonad formation
-promote skeletal and muscle growth
-brood patch formation
Androgens are considered pure because
they cannot be converted to estrogen
Wolffian Ducts lead to
vas deferns
seminal vesicles
epididymis
Turner’s Syndrome
XO or X
Female gonadal dysfunction
Can be treated with estrogen
Klinefelter’s Syndrome
Extra X chromosome, XXY
Lack of adequate male gonads
Low testosterone or higher-than-average estrogen
It can be treated with androgens
Hermaphroditism
having both male and female reproductive organs
Testicular Feminization
male pseudohermaphrodites
mutation in androgen receptor
less pubic hair, large breasts
5alpha reductase deficiency
enzyme converts testosterone to dihydrotestosterone
Congenital Adrenal Hyperplasia
female psedohermaphrodites
excess androgen
masculinized appearance
