Cartilaginous Joints Explained: Synchondroses And Their Functions

Cartilaginous Joints Explained: Synchondroses And Their Functions

Question 1. Primary cartilaginous joint
Answer:

• Primary cartilaginous joints are also known as synchondroses
• These bones are connected by hyaline cartilage
• Sometimes occur between ossification centres
• This cartilage may ossify with age
• Such joints allow only a little movement such as in spine and ribs.

Question 2. Histology of thyroid gland
Answer:

• Thyroid gland is covered by fibrous capsule
• Septa extends from capsule into gland substance and divides it into lobules
• Each lobule is made up of follicles
• Follicle has a cavity filled with colloid
• Each follicle consists of:

1. 1. Cells
      1. Follicular cells
         • They line the follicle
         • Secretes T3 &T4 hormones
         • They vary in shape according to their activity
      2. C cells or parafollicular cells
         • They are polyhedral in shape
         • Present between follicular cells and basement membrane and between the follicles
   2. Connective tissue stroma
      • It surrounds the follicles
      • Contains capillary plexus, lymphatic capillaries and sympathetic nerves