Thyroid &Parathyroid

Question 1

The L&R thyroid gland are joined together by

Answer 1

Isthium

Question 2

The isthmus covers the ___, ___&___ tracheal ring

Answer 2

2,3&4

Question 3

The gland is surrounded by
a facial sheath derived

Answer 3

from
the pretracheal layer of the
deep cervical fascia

Question 4

Each lobe is pear shape,
with its apex directed
upward as far as the
oblique line of the thyroid
cartilage; its base lies at
the_____ ring

Answer 4

4
th or 5th tracheal

Question 5

The 3rd thyroid lobe is often called___&
Is attaches 4rm ____ to ____ and is more to d left
The attachment is made by

Answer 5

Pyramidal lobe
Sup. Isthmus to hyoid bone
Levator glandulae thyroidae

Question 6

connection to the hyoid bone represent a remnant of a structure called the ______

Answer 6

thyroglossal duct.

Question 7

Relation of theThyroid Gland
Ant. Lat.
Pst
Mid.

Answer 7

Sternothyroid, Sternohyoid, Sup. Belly of omohyoid, SCM
Pst. Carotid sheath
Mid-above. Pharynx and larynx
Mid. Below. Trachea & oesophagus
Cricothyroid M& Ex. Laryngeal N

Question 8

The pst. Border of the thyroid gland is related to

Answer 8

Sup&inf parathyroid gland
Anastomosis between the sup. &inf. Thyroid artery

Question 9

Q: Where does the superior thyroid artery originate from?

Answer 9

A: The superior thyroid artery originates from the external carotid artery.

Question 10

What’s the blood supply to the thyroid

Answer 10

Sup. Thyroid artery
Inf. Thyroid artery
Thyroidea ima artery

Question 11

Where does the inferior thyroid artery originate from?

Answer 11

A: The inferior thyroid artery originates from the thyrocervical trunk, which is a branch of the subclavian artery.

Question 12

What important nerve crosses in relation to the inferior thyroid artery?

Answer 12

A: The recurrent laryngeal nerve crosses either in front or behind the inferior thyroid artery.

Question 13

What path does the inferior thyroid artery follow behind the thyroid gland? A: The inferior thyroid artery ascends behind the gland to the level of the cricoid cartilage, then curves medially behind the carotid sheath. It reaches the posterior aspect of the gland and descends downward.

Question 14

What are the veins of the thyroid vein and what do they drain into?

Answer 14

1-Superior thyroid vein = internal jugular vein
2- Middle thyroid vein = internal jugular vein
3- Inferior thyroid
vein = left brachiocephalic vein

Question 15

The thyroid gland are enclosed in the facial capsule

Question 16

Location of the sup & inf. Parathyroid gland

Answer 16

Sup= middle of the thyroid
Inf. = inf pole

Question 17

What is the lymph drainage of the thyroid and parathyroid which are the same

Answer 17

Lymph nodes:
 Deep cervical & paratracheal
lymph nodes

Question 18

The nerve supply of the parathyroid gland

Answer 18

 Nerve supply: Superior & middle cervical
sympathetic ganglia

Question 19

How does the thyroid gland develop?

Answer 19

A: The thyroid gland develops from the endoderm of the floor of the primitive pharynx, specifically at the junction of the anterior two-thirds and posterior one-third of the tongue (foramen cecum). It descends downward in the neck as the tongue grows, positioned anterior to the developing hyoid bone and laryngeal cartilages.

Question 20

What is the thyroglossal duct?

Answer 20

A: The thyroglossal duct is a narrow tube that connects the developing thyroid gland to the developing tongue. It allows the thyroid gland to descend in the neck during development.

Question 21

What happens to the thyroglossal duct as the thyroid gland develops?

Answer 21

A: The thyroglossal duct undergoes fibrosis and degeneration as the thyroid gland matures. The upper end of the duct may persist in the dorsum of the tongue as the foramen cecum. In some individuals, the distal part of the duct may persist and form a pyramidal lobe of the thyroid gland.

Question 22

The pyramidal lobe is attached to the hyoid and isthmus ny

Answer 22

This lobe can be attached to the hyoid bone by fibrous or smooth muscle called Levator thyroidae glandulae.

Question 23

@ what week/day does the thyroid gland begin to take it’s shape and position and the thyroglosal duct begin to degenerate

Answer 23

7th week/ 50 days

Question 24

By the____ week the sup. &inf. parathyroid gland develops from

Answer 24

6th week
Dorsal part of the 4th pharyngeal pouch= Sup.
Dorsal part of the 3rd pharyngeal pouch = Inf.

Question 25

The ventral part of the third pharyngeal pouch forms the ______ an important part of the immune system.
The ventral part of the fourth pouch forms a structure known as the ______&

Answer 25

primordium of the thymus gland,
Ultimopharyngeal body/ hymus

Question 26

As the thymus primordium develops, it descends downward into the ______

Answer 26

thorax behind the sternum in the superior mediastinum

Question 27

Goiter may compress what structures
The goiter maybe able to move

Answer 27

compress the trachea, esophagus & rec laryngeal n.
Pst. Inf. Mid but not sup. Due to attachment of sternohyoid and sternothyroid M

Question 28

I’m thyrodectomy the pst. Part of each lobe is spared die to?

Answer 28

To protect the sup. & recurrent laryngeal nerve and to spare the parathyroid gland

Question 29

____ runs along with the sup. Thyroid artery and may cause horsiness of voice if ligated
____ runs along the inferior thyroid artery and it’s ligation may cause

Answer 29

External laryngeal nerve
Recurrent laryngeal nerve
Impaired breathing and speech