smc-5521-20-Bones/synovial joints

HMS, BM EQ-Bank 820

Explain how the structure of the pelvic girdle and hip joint contributes to its function in weight-bearing and movement. (5 marks)

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Sample Answer

The pelvic girdle consists of fused bones (ilium, ischium, pubis) forming a strong bowl shape. This fusion creates a rigid structure that effectively supports upper body weight. Because the bones are thick and dense, they can withstand compressive forces during standing and walking.
The bowl shape distributes weight evenly to both legs. As a result, forces are balanced during single-leg stance in walking. Multiple muscle attachment points on the pelvis enable powerful leg movements. Therefore, the structure serves dual functions of stability and movement.
The hip joint features a deep ball-and-socket design. The acetabulum (socket) is deep and surrounds much of the femoral head. This depth provides inherent stability while still allowing multi-directional movement.
Short, strong ligaments reinforce the joint. These structures prevent dislocation during weight-bearing while permitting the range of motion needed for locomotion. Consequently, the hip joint achieves an optimal balance between mobility for movement and stability for supporting body weight.

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Sample Answer

The pelvic girdle consists of fused bones (ilium, ischium, pubis) forming a strong bowl shape. This fusion creates a rigid structure that effectively supports upper body weight. Because the bones are thick and dense, they can withstand compressive forces during standing and walking.
The bowl shape distributes weight evenly to both legs. As a result, forces are balanced during single-leg stance in walking. Multiple muscle attachment points on the pelvis enable powerful leg movements. Therefore, the structure serves dual functions of stability and movement.
The hip joint features a deep ball-and-socket design. The acetabulum (socket) is deep and surrounds much of the femoral head. This depth provides inherent stability while still allowing multi-directional movement.
Short, strong ligaments reinforce the joint. These structures prevent dislocation during weight-bearing while permitting the range of motion needed for locomotion. Consequently, the hip joint achieves an optimal balance between mobility for movement and stability for supporting body weight.

HMS, BM EQ-Bank 819

Compare the structure and movement capabilities of ball-and-socket joints and gliding joints. (4 marks)

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Sample Answer

Similarities:

Both are synovial joints containing synovial fluid for lubrication.
Both have articular cartilage covering bone surfaces to reduce friction.

Differences:

Structure:
- Ball-and-socket joints feature a spherical head fitting into a deep cup-shaped socket.
- Whilst gliding joints have flat or slightly curved articulating surfaces.
Movement capabilities:
- Ball-and-socket joints allow flexion, extension, abduction, adduction, rotation and circumduction – movement in all planes.
- In contrast, gliding joints permit only sliding or gliding movements in one plane.
Examples and function:
- Hip and shoulder joints (ball-and-socket) provide maximum mobility for activities like throwing.
- Conversely, carpal and tarsal joints (gliding) offer limited motion but greater stability for weight-bearing.

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Sample Answer

Similarities:

Both are synovial joints containing synovial fluid for lubrication.
Both have articular cartilage covering bone surfaces to reduce friction.

Differences:

Structure:
- Ball-and-socket joints feature a spherical head fitting into a deep cup-shaped socket.
- Whilst gliding joints have flat or slightly curved articulating surfaces.
Movement capabilities:
- Ball-and-socket joints allow flexion, extension, abduction, adduction, rotation and circumduction – movement in all planes.
- In contrast, gliding joints permit only sliding or gliding movements in one plane.
Examples and function:
- Hip and shoulder joints (ball-and-socket) provide maximum mobility for activities like throwing.
- Conversely, carpal and tarsal joints (gliding) offer limited motion but greater stability for weight-bearing.

HMS, BM EQ-Bank 818

Describe the structure and function of the hinge joint in the knee. (3 marks)

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Sample Answer

Structure:

The knee is a hinge joint where the femur articulates with the tibia.
The patella sits anteriorly, protecting the joint.
Strong ligaments provide stability while articular cartilage covers bone surfaces.

Function:

Allows flexion and extension in one plane, enabling walking, running and squatting movements.
The hinge design provides stability during weight-bearing while restricting lateral movement.
Synovial fluid lubricates the joint for smooth motion.

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Sample Answer

Structure:

The knee is a hinge joint where the femur articulates with the tibia.
The patella sits anteriorly, protecting the joint.
Strong ligaments provide stability while articular cartilage covers bone surfaces.

Function:

Allows flexion and extension in one plane, enabling walking, running and squatting movements.
The hinge design provides stability during weight-bearing while restricting lateral movement.
Synovial fluid lubricates the joint for smooth motion.

HMS, BM EQ-Bank 817 MC

Which of the following correctly identifies the bones that form the elbow joint?

Humerus, radius and ulna
Radius, ulna and carpals
Scapula, humerus and radius
Humerus, radius and carpals

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\(A\)

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A is correct: The elbow joint consists of humerus, radius and ulna.

Other Options:

B and D are incorrect: Carpals are wrist bones
C is incorrect: Scapula is part of the shoulder joint

HMS, BM EQ-Bank 816 MC

A basketball player performs a jump shot. Which type of synovial joint in the shoulder allows for the full range of arm movement during this action?

Hinge joint
Pivot joint
Ball-and-socket joint
Condyloid joint

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\(C\)

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C is correct: Ball-and-socket joints allow multi-directional movement needed for jump shots.

Other Options:

A is incorrect: Hinge joints allow one plane movement only
B is incorrect: Pivot joints allow rotation only
D is incorrect: Condyloid joints lack full rotation capability

HMS, BM EQ-Bank 815 MC

Which of the following joints allows for rotation of the head?

Hinge joint
Pivot joint
Gliding joint
Saddle joint

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\(B\)

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B is correct: Pivot joints at the top of the spine allow head rotation.

Other Options:

A is incorrect: Hinge joints allow flexion/extension only, not rotation
C is incorrect: Gliding joints allow sliding movements, not rotation
D is incorrect: Saddle joints don’t allow rotation

HMS, BM EQ-Bank 20 MC

The diagram below shows bones labelled 1, 2, 3 and 4, of the upper limb.

Which row correctly lists the bones for 1, 2, 3 and 4?

\begin{align*}
\begin{array}{l}
\rule{0pt}{2.5ex} \ \rule[-1ex]{0pt}{0pt}& \\
\rule{0pt}{2.5ex}\textbf{A.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{B.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{C.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{D.}\rule[-1ex]{0pt}{0pt}\\
\end{array}
\begin{array}{|c|c|c|c|}
\hline
\rule{0pt}{2.5ex}\textbf{1}\rule[-1ex]{0pt}{0pt}& \textbf{2}& \textbf{3}& \textbf{4} \\
\hline
\rule{0pt}{2.5ex}\text{Scapula}\rule[-1ex]{0pt}{0pt}&\ \ \text{Humerus}\ \ &\text{Ulna}&\text{Phalanges}\\
\hline
\rule{0pt}{2.5ex}\text{Clavicle}\rule[-1ex]{0pt}{0pt}& \text{Ulna}&\quad \text{Radius}\quad &\text{Phalanges}\\
\hline
\rule{0pt}{2.5ex}\ \ \text{Humerus}\rule[-1ex]{0pt}{0pt}\ \ & \text{Radius} &\text{Ulna}&\text{Metacarpals} \\
\hline
\rule{0pt}{2.5ex}\text{Clavicle}\rule[-1ex]{0pt}{0pt}& \text{Humerus}&\text{Ulna}&\text{Metacarpals} \\
\hline
\end{array}
\end{align*}

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\(D\)

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D is correct:

1. Clavicle – long bone that attaches the shoulder girdle and the vertebral column.

2. Humerus – long bone in upper arm joining the elbow to the shoulder.

3. Ulna – longest bone in the forearm on the little finger side.

4. Metacarpals – long bones in hand between the carpals and phalanges

\(\Rightarrow D\)

HMS, BM EQ-Bank 19

Describe how the structural differences between the hip joint and shoulder joint reflect their contrasting functional requirements in human movement. (3 marks)

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Sample Answer

Hip joint:

Features a deep acetabulum (socket) that encloses most of the femoral head, with short, strong ligaments providing robust support. This stable structure reflects its primary function of weight-bearing during standing and locomotion.

Shoulder joint:

Has a shallow glenoid cavity with loose joint capsule and longer ligaments. This flexible structure allows extensive multi-directional movement required for reaching, throwing, and overhead activities.

Structural Differences:

These directly match functional needs: stability for weight-bearing (hip) versus mobility for upper limb activities (shoulder).

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Sample Answer

Hip joint:

Features a deep acetabulum (socket) that encloses most of the femoral head, with short, strong ligaments providing robust support. This stable structure reflects its primary function of weight-bearing during standing and locomotion.

Shoulder joint:

Has a shallow glenoid cavity with loose joint capsule and longer ligaments. This flexible structure allows extensive multi-directional movement required for reaching, throwing, and overhead activities.

Structural Differences:

These directly match functional needs: stability for weight-bearing (hip) versus mobility for upper limb activities (shoulder).

HMS, BM EQ-Bank 18

Using an example from the shoulder girdle, explain how the arrangement of bones and joints allows for effective throwing movements. (3 marks)

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The shoulder girdle’s ball-and-socket joint connects the rounded head of the humerus to the shallow glenoid cavity of the scapula. This arrangement creates extensive mobility through multi-directional movement.
During the wind-up, the shoulder extends and externally rotates, which allows the arm to move behind the body. This backward positioning stores elastic energy in anterior muscles.
In the forward phase, the shallow socket permits rapid shoulder flexion and internal rotation. Combined with the scapula’s mobility on the ribcage, this generates maximum throwing velocity through an extended range of motion.

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The shoulder girdle’s ball-and-socket joint connects the rounded head of the humerus to the shallow glenoid cavity of the scapula. This arrangement creates extensive mobility through multi-directional movement.
During the wind-up, the shoulder extends and externally rotates, which allows the arm to move behind the body. This backward positioning stores elastic energy in anterior muscles.
In the forward phase, the shallow socket permits rapid shoulder flexion and internal rotation. Combined with the scapula’s mobility on the ribcage, this generates maximum throwing velocity through an extended range of motion.

HMS, BM EQ-Bank 17

Outline THREE types of synovial joints in the human body and provide an example of where each is located. (3 marks)

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Sample Answer – ANY 3 of the following

Hinge joint: Allows flexion and extension in one plane only. Located at the elbow and knee.
Ball-and-socket joint: Permits movement in all planes including rotation. Found at the shoulder and hip.
Pivot joint: Enables rotational movement around a single axis. Located between the atlas and axis vertebrae in the neck.
Gliding joint: Permits movement in two planes (flexion/extension and abduction/adduction). Located at the wrist between radius and carpals.
Condyloid joint: Allows flexion and extension in one plane only. Located at the elbow and knee.
Saddle joint: Allows movement in two planes but no rotation. Found at the base of the thumb.

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Sample Answer – ANY 3 of the following

Hinge joint: Allows flexion and extension in one plane only. Located at the elbow and knee.
Ball-and-socket joint: Permits movement in all planes including rotation. Found at the shoulder and hip.
Pivot joint: Enables rotational movement around a single axis. Located between the atlas and axis vertebrae in the neck.
Gliding joint: Permits movement in two planes (flexion/extension and abduction/adduction). Located at the wrist between radius and carpals.
Condyloid joint: Allows flexion and extension in one plane only. Located at the elbow and knee.
Saddle joint: Allows movement in two planes but no rotation. Found at the base of the thumb.