BIO 265 – Human A&P
Chapter 16 – Part B - Endocrine
Glands
Intro. To Endocrine Glands
– Figure 16.1
Pituitary Gland and Hypothalamus
 The pituitary gland secretes 9 major
hormones that regulate numerous body
functions
– The hypothalamus regulates the secretory
activity of the pituitary gland
– Important structures:
• Infundibulum
• Posterior pituitary (composed of nervous tissue)
• Anterior pituitary (true gland tissue)
– Figures from other text
Pituitary Gland and Hypothalamus
 Regulation of hormone secretion
– Anterior pituitary
• The hypothalamus secretes releasing or
inhibiting hormones
• Figure from other text
Pituitary Gland and Hypothalamus
– Posterior pituitary (neurohormones) – Figure
Pituitary Gland and Hypothalamus
 Hormones of the Pituitary Gland
– Table 16.1
Pituitary Gland and Hypothalamus
 Hormones of the Anterior Pituitary
– Some of these are tropic hormones that regulate
the secretion of hormones from other glands
– Gonadotropins – control the production of sex
hormones as well as gametes
• Luteinizing hormone (LH) and Follicle
stimulating hormone (FSH)
• Regulation by gonadotropin releasing hormone
(GnRH) – Figure 18.3
• More in chapter 28.
Pituitary Gland and Hypothalamus
– Growth hormone (GH) – stimulates growth in
most tissues and regulates metabolism
• stimulates the breakdown of fats in adipose
tissue
• Secretion is stimulated by stress and low blood
glucose levels
• Figure 18.6
Pituitary Gland and Hypothalamus
– Thyroid stimulating hormone (TSH)
– others
Thyroid Gland
 Location in the body – Figures 16.1 and
16.7
Thyroid Gland
 Hormones:
– Calcitonin – what does this do?
– Thyroid Hormones - Triiodothyronine (T3) and
thyroxine (T4)
• These interact with intracellular receptors
• They affect metabolism and growth of tissues
• Regulation of secretion – Figure and CD
animation
Parathyroid Glands
 Secretes Parathyroid Hormone (PTH)
– What does this hormone do?
– Bone – increased osteoclast activity
– Kidney – increased reabsorption of calcium and
production of Vit. D
– Intestines –increases calcium uptake
– Figure 16.11 and CD animation
Adrenal Glands
 Location – Figure 16.1 and 16.12
Adrenal Glands
– Composed of an inner medulla and an outer
cortex
– The adrenal cortex produces aldosterone
• This increases sodium reabsoption in the
kidneys
• which increases water reabsorption and
therefore blood volume
• How would this hormone be related to ADH?
Adrenal Glands
– The adrenal medulla produces epinephrine
(adrenalin) and norepinephrine (noradrenalin)
– These hormones bind to adrenergic receptors
that function through G-protein systems
– Regulation and functions – Figure 16.15
The Pancreas
 The pancreas is both an endocrine gland and
an exocrine gland
– Exocrine – acini (digestive enzymes)
– Endocrine – pancreatic islets (islets of
Langerhans)
– Figure 16.1
Pancreas
 Effect of glucagon
– Affects the liver
– It increases glycogen breakdown and glucose
synthesis and secretion
– When would glucagon be released?
Pancreas
 Effect of insulin
– Target tissues: liver, adipose tissue, and skeletal
muscle
– Binds to a membrane-bound receptor and
increases glucose uptake
• Glucose is then converted to glycogen in muscle
and liver cells and fat in adipose cells
– Without insulin adipose tissue and skeletal
muscle take up and use very little glucose and
amino acids
Pancreas
 Regulation of insulin secretion?
 Figure 16.17 and CD animation
Pancreas
 Diabetes mellitus
– Type 1 or insulin-dependent diabetes mellitus
• Caused by the autoimmune destruction of
pancreatic islets
• Only 3% of total diabetes cases
• Usually seen in young people
– Type 2 Diabetes (insulin independent or adultonset diabetes)
• Results from the inability of tissues to respond
to insulin
• Cause is unknown (genetic?)
Pancreas
• It is sometimes referred to as insulin resistance
• 97% of total diabetes cases
Reading
 Reading Sections in Chapter 16