Human A&P Warm Up

When the carnival came to town, the local health professionals and consumer groups joined forces to enforce truth-in-advertising laws to protect selected employees of the carnival. They demanded that the fat man, the dwarf, the giant, and the bearded lady be billed as “people with endocrine system problems”. Identify the endocrine disorder in each case and explain how the disorder produced the characteristic features of these four show people.

Warm Up continued

• Fat man

• Dwarf

• Giant

• Bearded lady

• T3 & T4 not being produced efficiently

• GH deficiency

• Hypersecretion of GH

• Tumor on the adrenal cortex

Objective

• We will…….discuss the function of the thyroid gland, parathyroid, ovaries and testes.

Video

• Nova: Epigenetics

Thyroid GlandThyroid Gland

Slide 9.23aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Found at the base of the throat

Consists of two lobes and a connecting isthmus

Produces two hormones Thyroid hormone

Calcitonin

Thyroid GlandThyroid Gland

Slide 9.23bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 9.6

Thyroid HormoneThyroid Hormone

Slide 9.24Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Major metabolic hormone

Composed of two active iodine-containing hormones

Thyroxine (T4) – secreted by thyroid follicles

Triiodothyronine (T3) – conversion of T4 at target tissues

CalcitoninCalcitonin

Slide 9.25Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Decreases blood calcium levels by causing its deposition on bone

Antagonistic to parathyroid hormone

Produced by C (parafollicular) cells

Figure 9.9

Conditions of Thyroid Gland

Goiter: enlargement of thyroid due to iodine deficiency.

Cretinism: Dwarfism coupled with mental retardation; caused by a hyposecretion of T4

Myxedema (hyposecretion in adults): mental and physical sluggishness

Graves disease (hypersecretion in adults): high metabolism, intolerance to heat, rapid heartbeat, weight loss, nervous, & agitated

Parathyroid GlandsParathyroid Glands

Slide 9.26Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Tiny masses on the posterior of the thyroid

Secrete parathyroid hormone

Stimulate osterclasts to remove calcium from bone

Stimulate the kidneys and intestine to absorb more calcium

Raise calcium levels in the blood

Hormones of the OvariesHormones of the Ovaries

Slide 9.36Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Estrogens Stimulates the development of secondary

female characteristics

Matures female reproductive organs

Helps prepare the uterus to receive a fertilized egg

Helps maintain pregnancy

Prepares the breasts to produce milk

Hormones of the OvariesHormones of the Ovaries

Slide 9.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Progesterone

Acts with estrogen to bring about the menstrual cycle

Helps in the implantation of an embryo in the uterus

Hormones of the TestesHormones of the Testes

Slide 9.38Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Produce several androgens

Testosterone is the most important androgen Responsible for adult male secondary sex

characteristics

Promotes growth and maturation of male reproductive system

Required for sperm cell production

Conditions of the Reproductive/Endocrine Organs

• Hyposecretion of testosterone can cause a male to be sterile.

• Hyposecretion of ovarian hormones will reduce a females chances to conceive and bear children.

Other Hormone-Producing Tissues Other Hormone-Producing Tissues and Organsand Organs

Slide 9.39Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Parts of the small intestine

Parts of the stomach

Kidneys

Heart

Many other areas have scattered endocrine cells

Endocrine Function of the PlacentaEndocrine Function of the Placenta

Slide 9.40Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Produces hormones that maintain the pregnancy

Some hormones play a part in the delivery of the baby

Produces HCG in addition to estrogen, progesterone, and other hormones

hCG

• hCG is the hormone that is detected in pregnancy test sold over the counter.

• hCG stimulates the continued production of estrogen and progesterone so that the lining of the uterus does not slough off

Developmental Aspects of the Developmental Aspects of the Endocrine SystemEndocrine System

Slide 9.41Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Most endocrine organs operate smoothly until old age Menopause is brought about by lack of

efficiency of the ovaries

Problems associated with reduced estrogen are common

Growth hormone production declines with age

Many endocrine glands decrease output with age

Closure

• A young girl is brought to the clinic by her father. The girl fatigues easily and seems mentally sluggish. You notice a slight swelling in the anterior neck. What condition do you suspect? What are some possible causes and their treatments?

• Hypothyroidism; iodine deficiency----treat with iodine