Chapter 10
Lecture Slides
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Learning Outcomes
• The Nature of Hormones
1. Distinguish between endocrine and exocrine glands.
2. Distinguish between hormones and prostaglandins.
3. Explain the negative-feedback control of hormone secretion.
• Pituitary Gland
4. Describe the control and actions of anterior lobe hormones.
5. Describe the control and actions of posterior lobe hormones.
6. Describe the major disorders.
Learning Outcomes
• Thyroid Gland
7. Describe the control and actions of thyroid hormones.
8. Describe the major disorders.
• Parathyroid Glands
9. Describe the control and actions of parathyroid hormone.
10. Describe the major disorders.
• Adrenal Glands
11. Describe the control and actions of adrenal hormones.
Learning Outcomes
• Pancreas
12. Describe the control and actions of pancreatic hormones.
13. Describe the major disorders.
• Gonads
14. Describe the control and actions of male and female gonadal
hormones.
• Other Endocrine Glands and Tissues
15. Describe the action of melatonin.
16. Describe the function of the thymus.
• Endocrine system provides slow, long
lasting coordination of body functions
• It consists of glands and tissues that
secrete hormones
• Hormones are transported by blood to
other tissues and organs
– Hormone secretion is regulated by
negative feedback
• A hormone secreted when the
concentration of a substance is too low
• The hormone causes body cells to bring
the substance level back to normal
• Once normal levels are reached,
hormone secretion and concentration
decreases
10.2 Pituitary Gland (hypophysis)
• Attached to the hypothalamus by a
short stalk
• Consists of two parts with different
functions
– Anterior lobe
– Posterior lobe
Anterior Lobe Hormones
• Growth hormone (GH)
– Stimulates the division and growth of body
cells
• Promotes synthesis of proteins and other
biological molecules
• Increases available energy for producing these
molecules
– Most abundant during growth years
– Disorders
• Giantism is caused by excess GH
during growing years
– Extremely tall
• Acromegaly is caused by excess GH
after growth years
– Only bones of hands, face, and feet
continue to grow
• Hypopituitary dwarfism is caused by
too little GH during growth years
– Well proportioned body parts but small in
stature
• Thyroid-Stimulating Hormone (TSH)
– Stimulates the thyroid gland to produce
thyroid hormone
– Regulates metabolism
• Adrenocorticotropic Hormone (ACTH)
– Controls secretion of hormones by the a
portion of the adrenal cortex
– Releases cortisol
– Excess stress can cause excess ACTH
production
• Gonadotropins
– There are two types of gonadotropins
• Follicle-stimulating hormone (FSH)
• Luteinizing hormone (LH)
– FSH functions
• Females: promotes development of
ovarian follicles
• Males: promotes sperm production
– LH functions
• Females: stimulates ovulation and
progesterone production
• Males: stimulates testosterone
production
• Prolactin
– Initiates and maintains milk production by
mammary glands after child birth
Posterior Lobe Hormones
• Hormones are produced by neurons in
the hypothalamus
• Two types of hormones are released
from the posterior lobe
– Antidiuretic hormone (ADH)
– Oxytocin
• Antidiuretic Hormone (ADH)
– Promotes water reabsorption by the kidneys to
reduce water volume in urine
• Helps regulate blood volume and blood pressure
• Oxytocin
– Stimulates and strengthens
contraction of smooth muscle of the
uterus during labor
– Causes milk ejection due to infant
suckling
– Secretion is controlled by positive
feedback
• Calcitonin
– Another hormone produced by the
thyroid gland
– Lowers blood calcium by stimulating
calcium deposition by osteoblasts in
bones
10.4 Parathyroid Glands
• Small glands on
posterior surface of
the thyroid gland
• Two glands on each
lobe
• Parathyroid Hormone (PTH)
– Increases the concentration of blood
calcium levels three ways
• Promotes calcium removal from bones
by osteoclasts and inhibiting calcium
deposition by osteoblasts
• Promotes calcium absorption into blood
by the intestine
10.5 Adrenal Glands
or Suprarenal Glands
• 2 adrenal
glands, one atop
each kidney
• Glands consist
of two portions
– Inner adrenal
medulla
– Outer adrenal
cortex
• Hormones of Adrenal Medulla
– Secretes epinephrine and
norepinephrine
– Regulated by sympathetic division of the
autonomic nervous system
• Secreted during times of stress
• Disorders
– Cushing’s syndrome is due to excess
ACTH
• Symptoms
–
–
–
–
–
–
–
–
–
High blood pressure
High blood glucose level
Protein loss
Osteoporosis
Fat accumulation on trunk
Fatigue
Edema
Decreased immunity
Full, round face
10.6 Pancreas
• Elongated organ
posterior to the
stomach
• Secretes
digestive
enzymes
• Releases insulin
to decrease
blood sugar.
Glucagon to
increase blood
sugar
– Blood glucose controls secretion by
negative feedback
• Low blood glucose stimulates secretion
• High blood glucose inhibits secretion
10.7 Gonads
• Gonads are sex glands
– Females: ovaries
• Produce ova and sex hormones
– Males: testes
• Produce sperm and sex hormones
• Female Hormones
– Ovaries
• Located in pelvic cavity
• Small, almond shaped
• Activate at puberty in response to FSH
and LH
• FSH and LH interact in a 28-day ovarian
cycle
– Estrogens, primary female sex
hormone
• Secreted by developing ovarian follicles
• Functions
– Development and maturation of female sex
organs
– Secondary sex characteristics
– Maintain uterine lining during pregnancy
– Progesterone
• Functions
– Prepare uterus for receiving an embryo
– Maintains pregnancy
– Prepares mammary glands for milk
production
• Male Hormone
– Testes
• Paired, ovoid organs located in scrotum
• Interstitial cells secrete testosterone
– Testosterone, male sex hormone
• Functions
– Development and maturation of male sex
organs
– Secondary sex characteristics
– Male sex drive
10.8 Other Endocrine Glands
and Tissues
• Other glands and tissues in the body
can also secrete hormones
– Pineal gland
– Thymus gland
– Small glands of stomach and small
intestine
– Placenta
• Pineal Gland
– Small, cone-shaped gland within the
brain
– Secretes melatonin
– Melatonin functions
• Regulates wake-sleep cycles: makes the
body sleepy
– When exposed to light, melatonin production is
reduced
– At night, melatonin production is increased
• Thymus
– Large in infants but gets smaller with
age
– Functions
• Crucial role in development of immunity
• Produces thymosin, which aids in
lymphocyte maturation