622
UNIT 3
Regulation and Integration of the Body
16
Table 16.5
Selected Examples of Hormones Produced by Organs Other Than the Major Endocrine Organs
SOURCE
HORMONE
CHEMICAL
COMPOSITION
TRIGGER
TARGET ORGAN AND EFFECTS
Adipose tissue
Leptin
Peptide
Secretion proportional to
fat stores; increased by
nutrient uptake
Brain: suppresses appetite;
increases energy expenditure
Adipose tissue
Resistin, adiponectin
Peptides
Secretion proportional
to fat stores for resistin,
inversely proportional for
adiponectin
Fat, muscle, liver: resistin
antagonizes insulin's action and
adiponectin enhances it
Gastrointestinal (GI) tract mucosa
Stomach
Gastrin
Peptide
Secreted in response to
food
Stomach: stimulates glands to
release hydrochloric acid (HCl)
Stomach
Ghrelin
Peptide
Secreted in response to
fasting
Hypothalamus and pituitary:
stimulates food intake and GH
release
Duodenum (of
small intestine)
Secretin
Peptide
Secreted in response to
food
Pancreas and liver: stimulates
release of bicarbonate-rich juice
Stomach: inhibits secretory
activity
Duodenum
Cholecystokinin (CCK)
Peptide
Secreted in response to
food
Pancreas: stimulates release of
enzyme-rich juice
Gallbladder: stimulates
expulsion of stored bile
Hepatopancreatic sphincter:
causes sphincter to relax,
allowing bile and pancreatic
juice to enter duodenum
Duodenum (and
other gut regions)
Incretins [glucose-dependent
insulinotropic peptide (GIP)
and glucagon-like peptide 1
(GLP-1)]
Peptide
Secreted in response to
glucose in intestinal lumen
Pancreas: enhances glucose-
dependent release of insulin and
inhibition of glucagon release
Heart (atria)
Atrial natriuretic peptide
(ANP)
Peptide
Secreted in response to
stretching of atria (by rising
blood pressure)
Kidney: inhibits sodium ion
reabsorption and renin release
Adrenal cortex: inhibits
secretion of aldosterone;
decreases blood pressure
Kidney
Erythropoietin (EPO)
Glycoprotein
Secreted in response to
hypoxia
Red bone marrow: stimulates
production of red blood cells
Skeleton
Osteocalcin
Peptide
Unknown; insulin promotes
its activation
Increases insulin production and
insulin sensitivity
Skin (epidermal cells)
Cholecalciferol
(provitamin D
3
)
Steroid
Activated by the kidneys to
active vitamin D
3
(calcitriol)
in response to parathyroid
hormone
Intestine: stimulates active
transport of dietary calcium
across cell membranes of small
intestine
Thymus
Thymulin, thymopoietins,
thymosins
Peptides
Unknown
Mostly act locally as paracrines;
involved in T lymphocyte
development and in immune
responses
previous page 656 Human Anatomy and Physiology (9th ed ) 2012 read online next page 658 Human Anatomy and Physiology (9th ed ) 2012 read online Home Toggle text on/off