Hello again everyone! its matt from kenhub, and in this tutorial, we will be discussing the thyroid cartilage. The larynx is the most superior part of the respiratory tract and the voice box of the human body. It surrounds and protects the vocal cords as well as the entrance to the trachea preventing food particles or fluids from entering the lungs. The cartilages of the larynx make up its skeleton. The thyroid cartilage is the largest of the laryngeal cartilages and partially encloses the other cartilages. You can see the thyroid cartilage.
Highlighted in green on both of these images. on the left side, we see it from a lateral view and, on the right image, you can see the thyroid cartilage from a posterior view with the open pharyngeal muscles. The thyroid cartilage is the largest of the laryngeal cartilages and it is made of two smooth laminae of which the two lower thirds fuse in the midline while most of the superior third remains unfused and creates the laryngeal notch. The thyroid cartilage makes the wellknown.
Adam’s apple due to the laryngeal prominence caused by the fused laminae. the cartilaginous superior and inferior horns are created by the projections of the posterior, superior and inferior borders of the cartilage respectively. The thyrohyoid membrane connects the entire superior aspect of the cartilage to the hyoid bone. Other important structures of the thyroid worth mentioning on this tutorial include the superior thyroid notch which is located on the upper portion of the thyroid cartilage.
While the inferior thyroid notch is a shallow notch found at its lower margin as seen here. The superior and inferior thyroid tubercles are small lateral prominences on the outside of the thyroid lamina located at the upper and lower ends of the oblique line respectively. This tutorial is more fun than reading a textbook, right? If you want more tutorials, interactive quizzes, articles, and an atlas of human anatomy, click on the Take me to Kenhub button. It is time to say goodbye to your old textbooks and say hello to your new anatomy learning.
Neck Anatomy Organisation of the Neck Part 1
So this is a tutorial on the organization of the neck. i’m going to talk a little bit about the anatomical triangles of the neck, the anterior and posterior triangles. And then I’ll go on to talk about the fascial compartments. I’ll also talk a little bit about the different structures that pass through the anatomical triangles, but I’ll go on to more detail on other tutorials on this. So we’re looking at an anterior view of the neck. You can see this thin muscle here. This.
Is the platysma muscle. this is contained in the superficial fascia of the neck. so I’ll get rid of these and show you the different triangles. If I just zoom a little bit more, I got rid of the platysma muscle, which lies in the superficial fascia and then you can see this big muscle here, which runs from the mastoid process down to attach onto the sternum and also onto the clavicle. So it’s got two attachments, a sternal and a clavicular attachment, then it’s also attached to the mastoid process.
Up here. so this is the sternocleidomastoid muscle named because of its attachments. The anterior triangle of the neck is defined by few boundaries the inferior border of the mandible forms the superior border of the triangle, the midline forms the medial border and the anterior border of the sternocleidomastoid muscle forms the lateral border of the triangle. So the triangle is this here, the midline, inferior surface of the mandible. So you’ve got the inferior surface of the mandible forming the superior border. You’ve.
Got the anterior border of the sternocleidomastoid forming the lateral border and the midline of the neck which runs right down here forms the medial border. So that’s the anterior triangle of the neck. So as you can see here, there are several structures which run in the anterior triangle of the neck. I won’t go into huge detail on what these are, but I’ll just quickly go through them.
You can see this bone here. this is the hyoid bone. this bone is important because it forms the attachment for many muscles which make up the floor of the mouth and it provides attachments for the tongue muscles and it’s involved in swallowing. So this is the hyoid bone here. Muscles above it are called the suprahyoid muscles and these run in the anterior triangle. And you’ve got these muscles below the hyoid bone, so these are the infrahyoid muscles.
These infrahyoid muscles are also called strap muscles because of their appearance. i guess they look like a strap, so these are the strap muscles. Below the strap muscles, we’ve got the thyroid gland. We’ve got the larynx here and the trachea. We’ve also got the parathyroid glands behind the thyroid. And then also, you’ve got these vessels, which obviously run in the anterior triangle. You’ve got the common carotid and its branches, so the external and internal carotid. You’ve.
Got the internal jugular vein running through the anterior triangle. and then you’ve also got nerves. So for instance, the vagus nerve and recurrent laryngeal nerves run through the anterior triangle. That’s the anterior triangle. Just to recap, it’s formed by the anterior border of the sternocleidomastoid, the inferior margin of the mandible and the midline of the neck. So the posterior triangle lies just behind the anterior triangle. It’s formed by the.
Posterior border of the sternocleidomastoid, the middle portion of the clavicle and the anterior border of the trapezius muscle, this big muscle at the back (the big, powerful muscle there). The apex of the posterior triangle is this bit of occipital bone just behind the mastoid process here. You can see the triangle formed by the anterior margin of the trapezius, the middle portion of the clavicle and then the posterior border of the sternocleidomastoid.