Download PPT 09c Thyroid Parathyroid

PowerPoint® Lecture Slide Presentation
by Patty Bostwick-Taylor,
Florence-Darlington Technical College
The Endocrine
System
Thyroid &
Parathyroid
9
PART B
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Found at the base of the throat
 Consists of two lobes and a connecting isthmus
 Produces two hormones
 Thyroid hormone
 Calcitonin
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Thyroid hormone
 Major metabolic hormone
 Composed of two active
iodine-containing hormones
 Thyroxine (T4) —
secreted by thyroid
follicles
 Triiodothyronine (T3) —
conversion of T4 at
target tissues
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Thyroid hormone disorders
 Goiters
 Thyroid gland enlarges
due to lack of iodine
 Salt is iodized to
prevent goiters
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Thyroid hormone
disorders
 Cretinism
 Caused by
hyposecretion of
thyroxine
 Results in
dwarfism during
childhood
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Thyroid hormone disorders (continued)
 Myxedema
 Caused by hypothyroidism in adults
 Results in physical and mental
sluggishness
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Thyroid hormone disorders (continued)
 Graves’ disease
 Caused by hyperthyroidism
 Results in increased metabolism, heat
intolerance, rapid heartbeat, weight loss,
and exophthalmos
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Thyroid Gland
 Calcitonin
 Decreases blood calcium
levels by causing its
deposition on bone
 Antagonistic to
parathyroid hormone
 Produced by parafollicular
cells
 Parafollicular cells are
found between the follicles
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Parathyroid Glands
 Tiny masses on the posterior of the thyroid
 Secrete parathyroid hormone (PTH)
 Stimulate osteoclasts to remove calcium from
bone
 Stimulate the kidneys and intestine to absorb
more calcium
 Raise calcium levels in the blood
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcitonin
stimulates
calcium salt
deposit
in bone
Calcitonin
Thyroid gland
releases
calcitonin
Thyroid
gland
Rising
blood
Ca2+
levels
Falling
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Thyroid
gland
Osteoclasts
degrade bone
matrix and release
Ca2+ into blood
Parathyroid
glands
PTH
Parathyroid
glands release
parathyroid
hormone (PTH)
Figure 9.10
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Rising
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Figure 9.10, step 1
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Thyroid
gland
Rising
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Figure 9.10, step 2
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcitonin
Thyroid gland
releases
calcitonin
Thyroid
gland
Rising
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Figure 9.10, step 3
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcitonin
Thyroid gland
releases
calcitonin
Calcitonin
stimulates
calcium salt
deposit
in bone
Thyroid
gland
Rising
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Figure 9.10, step 4
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcitonin
Thyroid gland
releases
calcitonin
Calcitonin
stimulates
calcium salt
deposit
in bone
Thyroid
gland
Rising
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Figure 9.10, step 5
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcium homeostasis of blood
9–11 mg/100 ml
Falling
blood
Ca2+
levels
Figure 9.10, step 6
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcium homeostasis of blood
9–11 mg/100 ml
Falling
blood
Ca2+
levels
Thyroid
gland
Parathyroid
glands
Figure 9.10, step 7
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcium homeostasis of blood
9–11 mg/100 ml
Falling
blood
Ca2+
levels
Thyroid
gland
Parathyroid
glands
PTH
Parathyroid
glands release
parathyroid
hormone (PTH)
Figure 9.10, step 8
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcium homeostasis of blood
9–11 mg/100 ml
Falling
blood
Ca2+
levels
Thyroid
gland
Parathyroid
glands
Osteoclasts
degrade bone
matrix and release
Ca2+ into blood
PTH
Parathyroid
glands release
parathyroid
hormone (PTH)
Figure 9.10, step 9
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcium homeostasis of blood
9–11 mg/100 ml
Thyroid
gland
Parathyroid
glands
Osteoclasts
degrade bone
matrix and release
Ca2+ into blood
PTH
Parathyroid
glands release
parathyroid
hormone (PTH)
Figure 9.10, step 10
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Hormonal Regulation of Calcium in Blood
Calcitonin
stimulates
calcium salt
deposit
in bone
Calcitonin
Thyroid gland
releases
calcitonin
Thyroid
gland
Rising
blood
Ca2+
levels
Falling
blood
Ca2+
levels
Calcium homeostasis of blood
9–11 mg/100 ml
Thyroid
gland
Osteoclasts
degrade bone
matrix and release
Ca2+ into blood
Parathyroid
glands
PTH
Parathyroid
glands release
parathyroid
hormone (PTH)
Figure 9.10, step 11
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings