Biology Chapter 9 Fibrous Joints

Questions and Answers

What type of connective tissue connects articulating bones in fibrous joints?

Dense regular connective tissue

What is the primary function of fibrous joints?

To hold together two bones

What are the three types of fibrous joints?

Gomphoses, sutures, and syndesmoses

What is a gomphosis, and where is it located in the human body?

A gomphosis is a synarthrosis between a tooth and the jaw, located in the articulations of the roots of individual teeth with the alveolar processes of the mandible and the maxillae Signup and view all the answers

What holds a tooth firmly in place in a gomphosis?

Fibrous periodontal membranes Signup and view all the answers

Why are orthodontic braces painful and take so long to correctly position the teeth?

Because of the architecture of the gomphosis, which normally prevents movement between the tooth and the jaw Signup and view all the answers

What type of joint is a syndesmosis functionally classified as?

An amphiarthrosis Signup and view all the answers

What is the main difference between a gomphosis and a suture?

Location, with gomphoses found in teeth sockets and sutures found between skull bones Signup and view all the answers

Describe the relationship between osteoblasts and osteoclasts in the alveolar process.

Osteoblasts build new bone, while osteoclasts resorb old bone, together facilitating the remodeling of the alveolar process. Signup and view all the answers

What is a gomphosis, and where is it primarily found in the body?

A gomphosis is a type of fibrous joint specifically found between teeth and their sockets in the jaw. Signup and view all the answers

Explain the functional classification of sutures and their role in skull development.

Sutures are classified as synarthroses, meaning they are immobile joints that allow the skull to grow as the brain increases in size. Signup and view all the answers

What changes do sutures undergo in older adults?

In older adults, the dense regular connective tissue in sutures becomes ossified, leading to the fusion of skull bones. Signup and view all the answers

What structural features define syndesmoses and their locations?

Syndesmoses are fibrous joints connected by long strands of dense regular connective tissue, found between the radius and ulna, and between the tibia and fibula. Signup and view all the answers

What type of movement is permitted by syndesmoses?

Syndesmoses permit slight mobility, classified functionally as amphiarthroses. Signup and view all the answers

Describe the interosseous membrane's role in syndesmoses.

The interosseous membrane connects the shafts of two articulating bones, allowing them to pivot slightly relative to each other. Signup and view all the answers

How does the composition of sutures contribute to their functionality?

Sutures are composed of dense regular connective tissue with interlocking edges that enhance stability and allow for skull growth. Signup and view all the answers

Study Notes

Fibrous Joints

Articulating bones in fibrous joints are connected by dense regular connective tissue.
Fibrous joints have no joint cavity, thus, they lack a space between the articulating bones.
Most fibrous joints are immobile or at most only slightly mobile; their primary function is to hold together two bones.
Examples of fibrous joints include the articulations of the teeth in their sockets, sutures between skull bones, and articulations between either the radius and ulna or the tibia and fibula.

Gomphoses

A gomphosis is a synarthrosis (immobile joint) between a tooth and the jaw.
Gomphoses resemble a "peg in a socket".
The only gomphoses in the human body are the articulations of the roots of individual teeth with the alveolar processes (sockets) of the mandible and the maxillae.
A tooth is held firmly in place by fibrous periodontal (per′ē-ō-don′tăl; peri = around, odous = tooth) membranes.
This joint is immobile and thus is functionally classified as a synarthrosis.

Sutures

Sutures are fibrous joints found only between certain bones of the skull.
Sutures are functionally classified as synarthroses, since they are immobile joints.
Sutures have distinct, interlocking, usually irregular edges that both increase their stability and decrease the number of fractures at these articulations.
Sutures permit the skull to grow (by new bone being deposited at these sutures) as the brain increases in size during childhood.
In an older adult, the dense regular connective tissue in the suture becomes ossified, fusing the skull bones together.

Syndesmoses

Syndesmoses are fibrous joints in which articulating bones are joined by long strands of dense regular connective tissue only.
Because syndesmoses allow for slight mobility, they are classified functionally as amphiarthroses.
Syndesmoses are found both between the radius and ulna and between the tibia and fibula.
The shafts of the two articulating bones are bound by a broad, ligamentous sheet called an interosseous membrane (or interosseous ligament).
The interosseous membrane provides a pivot where the radius and ulna (or the tibia and fibula) can move relative to one another.