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Interesting Notes for Curious Students to Get High Marks

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Interesting Notes for Curious Students to Get High Marks

CHAPTER 13: Support and Movement

Understand The Concept

1. What are the main components of the axial skeleton and the appendicular skeleton of humans?

Axial Skeleton

The axial skeleton consists of the bones that form the central axis of the body. It includes:

  • Skull: Protects the brain and forms the structure of the face.
  • Vertebral Column (Spine): Supports the body and protects the spinal cord.
  • Rib Cage: Protects the heart and lungs.
  • Sternum (Breastbone): Connects the ribs in the front.

Appendicular Skeleton

The appendicular skeleton includes the bones of the limbs and the girdles (shoulder and pelvic) that attach them to the axial skeleton. It consists of:

  • Pectoral Girdle: Includes the scapula (shoulder blade) and clavicle (collarbone).
  • Upper Limbs: Includes the humerus (upper arm), radius and ulna (forearm), carpals (wrist bones), metacarpals (hand bones), and phalanges (finger bones).
  • Pelvic Girdle: Includes the hip bones.
  • Lower Limbs: Includes the femur (thigh bone), patella (kneecap), tibia and fibula (lower leg bones), tarsals (ankle bones), metatarsals (foot bones), and phalanges (toe bones).

2. Describe the types of joints and give examples.

Fibrous Joints

These joints are held together by fibrous connective tissue and allow little or no movement. Example:

  • Sutures in the skull.

Cartilaginous Joints

These joints are connected entirely by cartilage and allow more movement than fibrous joints but less than synovial joints. Example:

  • Intervertebral discs in the spine.

Synovial Joints

These joints have a synovial cavity filled with fluid, allowing for a wide range of movements. Examples include:

  • Hinge Joints: Like the elbow and knee, allowing bending and straightening.
  • Ball-and-Socket Joints: Like the shoulder and hip, allowing movement in many directions.
  • Pivot Joints: Like the neck, allowing rotation.
  • Gliding Joints: Like those in the wrists and ankles, allowing sliding movements.
  • Saddle Joints: Like the thumb joint, allowing movement back and forth and side to side.
  • Condyloid Joints: Like the wrist, allowing movement but no rotation.

3. What are ligaments and tendons? What function do they perform?

Ligaments

Ligaments are tough, elastic bands of connective tissue that connect bones to other bones at joints. They provide stability and support to joints, preventing excessive movements that could cause injury.

Tendons

Tendons are strong, fibrous connective tissues that attach muscles to bones. They transmit the force generated by muscles to the bones, enabling movement.

4. Explain antagonism in muscle action, selecting biceps and triceps as an example.

Muscles often work in pairs to create movement. This is called antagonism, where one muscle contracts while the other relaxes.

Biceps and Triceps Example:

  • Biceps: Located at the front of the upper arm, this muscle bends the elbow (flexion).
  • Triceps: Located at the back of the upper arm, this muscle straightens the elbow (extension).

When you want to bend your elbow, your biceps contracts (shortens) while your triceps relaxes. Conversely, when you want to straighten your elbow, your triceps contract while your biceps relax. This coordinated action allows for smooth and controlled movements.

1. What are the main components of the axial skeleton and the appendicular skeleton of humans?

Axial Skeleton

The axial skeleton consists of the bones that form the central axis of the body. It includes:

  • Skull: Protects the brain and forms the structure of the face.
  • Vertebral Column (Spine): Supports the body and protects the spinal cord.
  • Rib Cage: Protects the heart and lungs.
  • Sternum (Breastbone): Connects the ribs in the front.

Appendicular Skeleton

The appendicular skeleton includes the bones of the limbs and the girdles (shoulder and pelvic) that attach them to the axial skeleton. It consists of:

  • Pectoral Girdle: Includes the scapula (shoulder blade) and clavicle (collarbone).
  • Upper Limbs: Includes the humerus (upper arm), radius and ulna (forearm), carpals (wrist bones), metacarpals (hand bones), and phalanges (finger bones).
  • Pelvic Girdle: Includes the hip bones.
  • Lower Limbs: Includes the femur (thigh bone), patella (kneecap), tibia and fibula (lower leg bones), tarsals (ankle bones), metatarsals (foot bones), and phalanges (toe bones).

2. Describe the types of joints and give examples.

Fibrous Joints

These joints are held together by fibrous connective tissue and allow little or no movement. Example:

  • Sutures in the skull.

Cartilaginous Joints

These joints are connected entirely by cartilage and allow more movement than fibrous joints but less than synovial joints. Example:

  • Intervertebral discs in the spine.

Synovial Joints

These joints have a synovial cavity filled with fluid, allowing for a wide range of movements. Examples include:

  • Hinge Joints: Like the elbow and knee, allowing bending and straightening.
  • Ball-and-Socket Joints: Like the shoulder and hip, allowing movement in many directions.
  • Pivot Joints: Like the neck, allowing rotation.
  • Gliding Joints: Like those in the wrists and ankles, allowing sliding movements.
  • Saddle Joints: Like the thumb joint, allowing movement back and forth and side to side.
  • Condyloid Joints: Like the wrist, allowing movement but no rotation.

3. What are ligaments and tendons? What function do they perform?

Ligaments

Ligaments are tough, elastic bands of connective tissue that connect bones to other bones at joints. They provide stability and support to joints, preventing excessive movements that could cause injury.

Tendons

Tendons are strong, fibrous connective tissues that attach muscles to bones. They transmit the force generated by muscles to the bones, enabling movement.

4. Explain antagonism in muscle action, selecting biceps and triceps as an example.

Muscles often work in pairs to create movement. This is called antagonism, where one muscle contracts while the other relaxes.

Biceps and Triceps Example:

  • Biceps: Located at the front of the upper arm, this muscle bends the elbow (flexion).
  • Triceps: Located at the back of the upper arm, this muscle straightens the elbow (extension).

When you want to bend your elbow, your biceps contracts (shortens) while your triceps relaxes. Conversely, when you want to straighten your elbow, your triceps contract while your biceps relax. This coordinated action allows for smooth and controlled movements.

Short Question

1. What are the main components of the axial skeleton and the appendicular skeleton of humans?

Axial Skeleton

The axial skeleton consists of the bones that form the central axis of the body. It includes:

  • Skull: Protects the brain and forms the structure of the face.
  • Vertebral Column (Spine): Supports the body and protects the spinal cord.
  • Rib Cage: Protects the heart and lungs.
  • Sternum (Breastbone): Connects the ribs in the front.

Appendicular Skeleton

The appendicular skeleton includes the bones of the limbs and

SHORT QUESTIONS 1. Differentiate between cartilage and bone. 2. What is the role of skeleton in support and movement? 3. How would you differentiate between osteoporosis and arthritis? 4. Label the biceps and triceps in the following diagrams and also mention their contracted or relaxed states.[act as an expert and write the question answers]ChatGPT

Sure! Here are the short questions along with their answers:

1. Differentiate between cartilage and bone.

Cartilage:

  • Composition: Made of a flexible, rubbery matrix of collagen and elastic fibers.
  • Function: Provides cushioning and flexibility in joints; forms structures like the ear and nose.
  • Blood Supply: Avascular (lacks blood vessels), so it heals more slowly.
  • Location: Found in joints, rib cage, ear, nose, throat, and between intervertebral discs.

Bone:

  • Composition: Composed of a hard, rigid matrix of collagen fibers and calcium salts.
  • Function: Provides structural support, protects organs, stores minerals, and enables movement through muscle attachment.
  • Blood Supply: Vascular (rich in blood vessels), so it heals relatively faster.
  • Location: Makes up the entire skeleton of the body.

2. What is the role of the skeleton in support and movement?

The skeleton provides structural support and shape to the body, protecting internal organs such as the brain, heart, and lungs. It also facilitates movement by serving as an attachment point for muscles. When muscles contract, they pull on bones, moving joints.

3. How would you differentiate between osteoporosis and arthritis?

Osteoporosis:

  • Definition: A condition characterized by weakened bones that are more prone to fractures.
  • Cause: Caused by a decrease in bone density, often due to aging, hormonal changes, or deficiency in calcium or vitamin D.
  • Symptoms: Increased risk of fractures, bone pain, and a decrease in height over time due to vertebral compression.

Arthritis:

  • Definition: Inflammation of the joints, causing pain and stiffness.
  • Cause: Can be due to autoimmune diseases (e.g., rheumatoid arthritis), wear and tear (e.g., osteoarthritis), infections, or metabolic abnormalities.
  • Symptoms: Joint pain, swelling, stiffness, and decreased range of motion.

4. Label the biceps and triceps in the following diagrams and also mention their contracted or relaxed states.

(Since I can’t provide or interact with actual diagrams here, I’ll explain how to identify and label the biceps and triceps along with their states.)

  • Biceps: Located at the front of the upper arm. When the elbow is bent, the biceps are contracted. When the elbow is straight, the biceps are relaxed.
  • Triceps: Located at the back of the upper arm. When the elbow is straight, the triceps are contracted. When the elbow is bent, the triceps are relaxed.

In a diagram of the arm:

  • Label “Biceps” on the front side of the upper arm.
  • Label “Triceps” on the back side of the upper arm.
  • If the arm is shown bending at the elbow, label the biceps as “Contracted” and the triceps as “Relaxed.”
  • If the arm is shown straightening at the elbow, label the biceps as “Relaxed” and the triceps as “Contracted.”

These explanations and labeling help in understanding the roles and interactions of muscles in movement.

References

  1.  Musculoskeletal+System at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
  2.  Mooar, Pekka (2007). “Muscles”. Merck Manual. Archived from the original on 10 November 2011. Retrieved 12 November 2008.
  3.  Jump up to:a b Kahn, Cynthia; Scott Line (2008). Musculoskeletal System Introduction: Introduction. New Jersey, US: Merck & Co., Inc.
  4.  Jump up to:a b Applegate, Edith; Kent Van De Graaff. “The Skeletal System”. Archived from the original on 3 June 2010. Retrieved 3 January 2009.
  5.  Engelbert, Phillis; Carol DeKane Nagel (2009). “The Human Body / How Many Bones Are In The Human Body?”. U·X·L Science Fact Finder. eNotes.com, Inc. Retrieved 24 January 2009.
  6.  Jump up to:a b c Gary, Farr (25 June 2002). “The Musculoskeletal System”. Archived from the original on 29 November 2014. Retrieved 18 November 2008.
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