The thyroid gland and parathyroid glands secrete important hormones. The thyroid gland is located below the larynx and secretes triiodothyronine (T3), thyroxine (T4), and calcitonin. T3 and T4 increase the basal metabolic rate and affect protein synthesis, while calcitonin constructs bone and reduces blood calcium. The parathyroid glands are located on the thyroid gland and secrete parathyroid hormone, which increases blood calcium levels through mechanisms like calcium reabsorption in the kidney and activation of vitamin D. Together these glands play key roles in metabolism and calcium regulation through their secreted hormones.

2. ANATOMY OF THYROID AND
PARATHYROID GLANDS
SUBMITTED TO: DR. ZEESHAN AKBAR SUBMITTED BY: 14-
ARID-2022
PMAS FAISAL SHAHZAD
SOMROO

3. HORMONES
“Hormones are chemicals messengers that are secreted by endocrine
glands and function in extremely small concentration”
Response of a Hormone:
• A nerve impulse travels rapidly and produces an almost instantaneous
response but one that lasts only briefly.
• In contrast hormones act more slowly and their effects may be long
lasting.
• Target cells respond to minute quantities of hormones and a
concentrations in the blood is always extremely low.

4. ENDOCRINE GLANDS
1. Hypothalamus Gland
2. Pituitary Gland
3. Pineal Gland
4. Thyroid Gland
5. Parathyroid Glands
6. Thymus Gland
7. Adrenal Glands
8. Pancreas
9. Liver
10.Kidneys
11.Heart
12.Testes
13.ovaries

5. LOCATION

6. THYROID GLAND
“The thyroid is a very vascular ductless gland, firm in
texture and dark red-brown in color”
Location:
It is situated below the larynx (Voice Box).
On the anterior part of trachea, first five or six rings of trachea, to which
it is loosely attached.

7. SECRETED HORMONES
1. Tri-iodo-thyronine(T3)
2. Tetra-ido-thyroxine(T4)
3. Calcitonin

8. 1.TRI-IODO-THYRONINE (T3)
From Cells:
“Thyroid Epithelial Cells”
Effect:
• Potent form of thyroid hormone.
• Increase the basal metabolic rate.
• Affect protein synthesis

9. 2. TETRA-IDO-THYROXIN (T4)
From Cell:
“Thyroid Epithelial Cell”
Effect:
• Less act form of thyroid hormone .
• Increase the Basal Metabolic rate.
• Often function as a pro-hormone.

10. 3. CALCITONIN
From Cell:
“Para-Follicular Cells”
Effect:
• Construct Bone
• Reduce Blood Calcium

11. ISTHMUS
“It is connected to with the lateral lobe at or near the
posterior end of the latter, and crosses the trachea about the
5th ring of trachea”

12. PARATHYROID GLAND
“The parathyroid are pale in color and not so dense as
thyroid”
Location:
They are small glandular bodies, found in the thyroid gland.
Posterior extremity or on the deep surface of the lateral lobes of the thyroid.

13. SECRETED HORMONE
It secretes only one hormone:
Parathyroid Hormone (PTH)
From Cell:
“Parathyroid Chief Cells”
Effect:
• Increase Blood calcium
a) Calcium reabsorption in kidney
b) Active vitamin D
• Slightly decrease blood phosphate

14. THANK YOU 