Histology & Gross Anatomy

1. Gross Anatomy & Histology of
Parathyroid Glands
Dr. Rabia Inam Gandapore
Assistant Professor
Head of Department Anatomy
(Dentistry-BKCD)
B.D.S (SBDC), M.Phil. Anatomy (KMU),
Dip. Implant (Sharjah, Bangkok, ACHERS) , CHPE
(KMU),CHR (KMU), Dip. Arts (Florence, Italy)

2. Teaching Methodology
 LGF (Long Group Format)
 SGF (Short Group Format)
 LGD (Long Group Discussion, Interactive discussion with the use of
models or diagrams)
 SGD (Short Group)
 SDL (Self-Directed Learning)
 DSL (Directed-Self Learning)
 PBL (Problem- Based Learning)
 Online Teaching Method
 Role Play
 Demonstrations
 Laboratory
 Museum
 Library (Computed Assisted Learning or E-Learning)
 Assignments
 Video tutorial method

3. Goal/Aim (main objective)
 To help/facilitate/augment the students about the:
1. Describe Gross features of Parathyroid gland.
2. Describe the Histological features of Parathyroid gland
3. Describe Blood & Nerve supply of Parathyroid gland.

4. Specific Learning Objectives (cognitive)
At the end of the lecture the student will able to:
 Recognize the gross anatomical & Histological features of the Parathyroid
Gland
 Sketch labeled diagram of the Histology of Parathyroid Gland

5. Psychomotor Objective: (Guided response)
 A student to draw labelled diagram of the Histology of Parathyroid Gland

6. Affective domain
 To be able to display a good code of conduct and moral values in the class.
 To cooperate with the teacher and in groups with the colleagues.
 To demonstrate a responsible behavior in the class and be punctual, regular, attentive and on
time in the class.
 To be able to perform well in the class under the guidance and supervision of the teacher.
 Study the topic before entering the class.
 Discuss among colleagues the topic under discussion in SGDs.
 Participate in group activities and museum classes and follow the rules.
 Volunteer to participate in psychomotor activities.
 Listen to the teacher's instructions carefully and follow the guidelines.
 Ask questions in the class by raising hand and avoid creating a disturbance.
 To be able to submit all assignments on time and get your sketch logbooks checked.

7. Lesson contents
Clinical chair side question: Students will be asked if they know what is the function of
Outline:
 Activity 1 The facilitator will explain the student's Gross anatomy of Parathyroid Gland
 Activity 2 The facilitator will ask the students to make a labeled diagram of the Histology of Parathyroid
Gland
 Activity 3 The facilitator will ask the students a few Multiple Choice Questions related to it with
flashcards.

8. Recommended Books
 Students assessment: MCQs, Flashcards, Diagrams labeling.
 Learning resources: Langman’s T.W. Sadler, Laiq Hussain Siddiqui, Snell Clinical Anatomy,
Netter’s Atlas, BD Chaurasia’s Human anatomy, Internet sources links.

9. Thyroid Gland

10. Thyroid Gland
 Named after the Thyroid cartilage
 (Greek: Shield shaped)
 Largest endocrine gland
 Location: Anterior neck region
 2 Lateral lobes connected by isthmus
 Secretes:
1. Tetra-iodo-thyronine (Thyroxine)
2. Tri-ido-thyronine
3. Calcitonin
Location of thyroid gland

11. Gross Anatomy of
Parathyroid Gland
 GROSS FEATURES OF PARATHYROID GLAND.
 HISTOLOGICAL FEATURES OF PARATHYROID GLAND
 BLOOD & NERVE SUPPLY OF PARATHYROID GLAND.

12. Parathyroid Gland
 Small flattened, oval (6 mm long in diameter)
 4 on Posterior surface of each lobe of the
thyroid gland, lying within its fascial capsule
 Superior & Inferior Parathyroid glands
 External to Thyroid capsule
 Hormone it opposes: Calcitonin (regulates
Ca+2 ions into blood & Bones)
 Function: maintain body calcium &
phosphate level so nervous & muscular
system function properly by secreting
parathyroid Hormone (Para-thormone)

13. Location and Description
1. Two Superior Parathyroid Glands: 1 cm superior to the point of
entry of inferior thyroid arteries into thyroid gland.
 More constant in position
 Usually at the level of inferior border of cricoid cartilage.
2. Two Inferior Parathyroid Glands:1 cm inferior to arterial entry
point
 Various positions
 Usually near inferior poles of thyroid gland
 or within fascial sheath, embedded in thyroid substance, or
outside the fascial sheath.
 Sometimes, they are found some distance caudal to thyroid
gland, in association with the inferior thyroid veins
 they may even reside in the superior mediastinum in the thorax.

14. Blood & Nerve supply of
Parathyroid gland.
 GROSS FEATURES OF PARATHYROID GLAND.
 HISTOLOGICAL FEATURES OF PARATHYROID GLAND
 BLOOD & NERVE SUPPLY OF PARATHYROID GLAND.

15. Blood Supply & Lymphatic Drainage
 Arterial Blood Supply:
a. Superior Parathyroid Gland = Inferior thyroid artery
b. Inferior Parathyroid Gland= Ascending branch of inferior thyroid arteries (arise from
thyrocervical trunk i.e. sub-clavian artery) & thyroid ima artery
c. Laryngeal, Tracheal & Esophageal arteries
 Venous drainage: is into: (drain into thyroid plexus of veins of thyroid gland)
a. Superior & Middle thyroid vein: drains into Internal Jugular vein
b. Inferior thyroid vein: drains into Brachiocephalic Vein
 Lymphatic Drainage: into
a. Deep Cervical Lymph Nodes
b. Para Tracheal Lymph Nodes

19. Neurovasculature
 Nerves: derived from thyroid branches
of cervical (sympathetic) ganglia
 they are vasomotor rather than
secretomotor
 Hormonally regulated, Parathormone
(PTH)
 controls metabolism of phosphorus &
calcium in blood. targets skeleton,
kidneys, intestine.

22. Developmental Embryology of Parathyroid
Gland
 Superior: 4 pharyngeal pouch
 Inferior: 3 pharyngeal pouch

23. Clinical Correlation

24. DiGeorge Syndrome

25. Ectopic Parathyroid Gland
• Abnormal
number of
parathyroi
d gland

26. Inadvertent Removal of Parathyroid Glands

27. Histological features of
Parathyroid gland
 GROSS FEATURES OF PARATHYROID GLAND.
 HISTOLOGICAL FEATURES OF PARATHYROID GLAND
 BLOOD & NERVE SUPPLY OF PARATHYROID GLAND.

28. Histology of the Endocrine System
Hormone delivery
 Pituitary (hypophysis)
– Anterior pituitary
– Posterior pituitary
 Adrenal gland (suprarenal)
– Adrenal cortex
– Adrenal medulla
 Thyroid gland
– Follicles
– Parafollicular cells
 Parathyroid gland
Considered in other lectures:
– Endocrine pancreas
– Male
– Female
– Enteroendocrine

29. Para-Thyroid Gland
 Connective tissue capsule
 Septa divide parenchymal cells (Cluster anastomosing cords)
into:
1. Chief Cells or Principal Cells
2. Oxyphil Cells
 Stroma
 Reticular Fibers
 Capillaries Fenestrated Capillaries
 Fat Cells (Increase with age, Elder 60-70% glandular mass)

31. No. Chief Cells (Principal Cells) Oxyphil Cells (stain-loving)
1. More numerous cells Less numerous cells
2. Small Polygonal cells Large cells
3. Round & central nucleus Single, small Cluster
4. Vesicular, Pale stain
5. Acidophilic cytoplasm Abundant cytoplasm, lightly stained=Acidophilic
(Increased mitochondria)
6. Glycogen granules
7. Lipid droplets
8. Lipofuscin pigments
9. Secretory Granules No secretory granules
10. Hormone: Secretes Parathyroid Hormone (PTH)=
Para-thormone
11. Function:
1. Increase Ca+2 : Stimulating Bone resorption
Increase renal excretion of Ca+2 by Kidney
tubules.
2. Lowers serum phosphate
Function: Unknown
Believed they are chief cells which has reached
non secretory stage

32. Fat cell
Oxyphil cell cluster, LM

33. Parathyroid gland (mostly chief cells) , low power LM
Blood vessel

34. Parathyroid, chief cells, one oxyphil (arrow), LM
Fat cell

35. Parathyroid capillary bed,
corrosion vascular cast, SEM

37. 1. Calcium: PTH increase blood calcium level by stimulating Osteoblast indirectly activating
osteoclasts to breakdown bone and release Calcium. PTH increases Gastro-intestinal
calcium absorption by activating Vit. D and promotes calcium conservation (resorption) by
Kidney.
2. Phosphate: PTH regulates serum phosphate conc. Via kidney. It is an inhibitor of proximal
tubular reabsorption of phosphorus through activation of Vit. D, Hence absorption of
Phosphate increased.
 Hyper- Parathyroidism:
 Bone Pain & Tenderness
 Dehydration
 Renal disease
 Hypo- Parathyroidism:
 Genetic condition

38. Thank You
ANY QUESTIONS?