Bio 141 - Exam 3 (Chapter 9) |23 Questions and
Answers
Define a joint or articulation - -A joint, or articulation, is the place of contact b/t bones, b/t
bone and cartilage, or b/t bones and teeth.
-Name and describe the composition of the three different structural classifications of
joints. - -Joints are classified by both their structural characteristics and the movement
they allow. Structurally, they are categorized on whether a space occurs b/t the articulating
bones and the type of connective tissue that binds the articulating surface of the bones:
- Fibrous Joints have no joint cavity and occur where bones are held together by dense
regular (fibrous) connective tissue. (Ex: Articulation b/t radius and ulna, b/t ribia and
fibula.)
- Cartilaginous Joints have no joint cavity and occur where bones are joined by cartilage.
(Ex: Intervertebral disc articulations)
- Synovial Joints have a fluid-filled joint cavity that separates the articulating surface of the
bones. The articulating surfaces are enclosed w/in a connective tissue capsule, and the
bones are attached to each other by various ligaments. (Ex: Hip joint)
-Name and describe the amount of movement of the four functional classifications of joints
- -Functional classification address the extend of movement a joint allows.
- A synarthrosis is an immobile joint.
- An amphiarthrosis is a slightly mobile joint.
- A diarthrosis is a freely mobile joint. (All synovial joints are diarthroses.)
-Explain the three types of fibrous joints, using examples. - -- Gomphosis: a "peg in a
socket." The only one in the human body is the teeth in the periodontal membrane.
Classified as a synarthrosis.
- Sutures: immobile fibrous joints found only b/t certain skull bones. They have distinct,
interlocking edges that increase strenght and descrease the number of fractures at these
articulations. Classified as synarthrosis.
- Syndesmoses are fibrous joints in which articulating bones are joined by long strands of
dense regular connective tissues only. They allow for slight mobility, so are classified as
amphiarthroses. (Found b/t the radius and ulna and the tibia and fibula.)
-Explain the two types of cartilaginous joints using examples - -- Synchondrosis - an
articulation in which bones are joined by hyaline cartilage. (All are immobile and classified
as synarthroses.) (Ex: The costochondral joint, b/t each rib and its respective costal
caritlage is a synchondrosis.)
, - A symphysis has a pad of fibrocartilage b/t the articulating bones. It resists compression
and tension stressors and acts as a resilient shock absorber. Classified as amphiarthroses.
(Ex: The pubic symphysis, which becomes more mobile in pregnant females to allow the
fetus to pass through the birth canal.) (Ex2: Intervertebral discs.
-Name the seven basic features common to all synovial joints. (Refer to Figure 9.4) - --
Articular capsule
- Joint cavity
- Synovial fluid
- Articular cartilage
- Ligaments
- Nerves
- Blood Vessels
-Explain the composition and three functions of synovial fluid - -Synovial fluid is a viscous,
oily substance located w/in a synovial joint. It is produced by both the synovial membrane
cells and filtrate formed from blood plasma. It has three functions:
1. Lubricate the articular cartilage on the surface of articulating bones
2. Nourish the articular cartilage's chondrocytes. (It must be circulated continuously to
provide nutrients and remove waste.)
3. Act as a shock absorber, distributing stress and force evenly across the articular surface
when pressure in the joint increases.
-Briefly explain the functions of the following accessory structures of synovial joints:
- Bursae
- Tendon Sheath
- Fat pads - -- Bursae: fibrous, sac-like structures that contain synovial fluid and are lined
internally by a synovial membrance. They are associated w/ most synovial joints and are
where bones, ligaments, muscles, skin, or tendons overlie each other and rub together.
- Tendon sheath: an elongated bursa that wraps around a tendon where there may be
excessive friction. Particularly common in confined spaces of the wrist and ankle.
- Fat pads: the "packing material" of the joint; distributed along the periphery of a synovial
joint.
-State the three types of movement possible at a synovil joint with respect to the three
perpendicular planes / axes - -Movement of a bone at a synovial joint is best descrbied w/
respect to the three intersecting perpendicular planes:
- A uniaxial joint has bones that move in only one plane or axis.
- A biaxial joint has bones that move in two planes or axes.
- A multiaxial (or triaxial) joint has bones that move in mujltiple planes or axes.
Answers
Define a joint or articulation - -A joint, or articulation, is the place of contact b/t bones, b/t
bone and cartilage, or b/t bones and teeth.
-Name and describe the composition of the three different structural classifications of
joints. - -Joints are classified by both their structural characteristics and the movement
they allow. Structurally, they are categorized on whether a space occurs b/t the articulating
bones and the type of connective tissue that binds the articulating surface of the bones:
- Fibrous Joints have no joint cavity and occur where bones are held together by dense
regular (fibrous) connective tissue. (Ex: Articulation b/t radius and ulna, b/t ribia and
fibula.)
- Cartilaginous Joints have no joint cavity and occur where bones are joined by cartilage.
(Ex: Intervertebral disc articulations)
- Synovial Joints have a fluid-filled joint cavity that separates the articulating surface of the
bones. The articulating surfaces are enclosed w/in a connective tissue capsule, and the
bones are attached to each other by various ligaments. (Ex: Hip joint)
-Name and describe the amount of movement of the four functional classifications of joints
- -Functional classification address the extend of movement a joint allows.
- A synarthrosis is an immobile joint.
- An amphiarthrosis is a slightly mobile joint.
- A diarthrosis is a freely mobile joint. (All synovial joints are diarthroses.)
-Explain the three types of fibrous joints, using examples. - -- Gomphosis: a "peg in a
socket." The only one in the human body is the teeth in the periodontal membrane.
Classified as a synarthrosis.
- Sutures: immobile fibrous joints found only b/t certain skull bones. They have distinct,
interlocking edges that increase strenght and descrease the number of fractures at these
articulations. Classified as synarthrosis.
- Syndesmoses are fibrous joints in which articulating bones are joined by long strands of
dense regular connective tissues only. They allow for slight mobility, so are classified as
amphiarthroses. (Found b/t the radius and ulna and the tibia and fibula.)
-Explain the two types of cartilaginous joints using examples - -- Synchondrosis - an
articulation in which bones are joined by hyaline cartilage. (All are immobile and classified
as synarthroses.) (Ex: The costochondral joint, b/t each rib and its respective costal
caritlage is a synchondrosis.)
, - A symphysis has a pad of fibrocartilage b/t the articulating bones. It resists compression
and tension stressors and acts as a resilient shock absorber. Classified as amphiarthroses.
(Ex: The pubic symphysis, which becomes more mobile in pregnant females to allow the
fetus to pass through the birth canal.) (Ex2: Intervertebral discs.
-Name the seven basic features common to all synovial joints. (Refer to Figure 9.4) - --
Articular capsule
- Joint cavity
- Synovial fluid
- Articular cartilage
- Ligaments
- Nerves
- Blood Vessels
-Explain the composition and three functions of synovial fluid - -Synovial fluid is a viscous,
oily substance located w/in a synovial joint. It is produced by both the synovial membrane
cells and filtrate formed from blood plasma. It has three functions:
1. Lubricate the articular cartilage on the surface of articulating bones
2. Nourish the articular cartilage's chondrocytes. (It must be circulated continuously to
provide nutrients and remove waste.)
3. Act as a shock absorber, distributing stress and force evenly across the articular surface
when pressure in the joint increases.
-Briefly explain the functions of the following accessory structures of synovial joints:
- Bursae
- Tendon Sheath
- Fat pads - -- Bursae: fibrous, sac-like structures that contain synovial fluid and are lined
internally by a synovial membrance. They are associated w/ most synovial joints and are
where bones, ligaments, muscles, skin, or tendons overlie each other and rub together.
- Tendon sheath: an elongated bursa that wraps around a tendon where there may be
excessive friction. Particularly common in confined spaces of the wrist and ankle.
- Fat pads: the "packing material" of the joint; distributed along the periphery of a synovial
joint.
-State the three types of movement possible at a synovil joint with respect to the three
perpendicular planes / axes - -Movement of a bone at a synovial joint is best descrbied w/
respect to the three intersecting perpendicular planes:
- A uniaxial joint has bones that move in only one plane or axis.
- A biaxial joint has bones that move in two planes or axes.
- A multiaxial (or triaxial) joint has bones that move in mujltiple planes or axes.
