10th Class Biology Chapter 13 Notes | Get Now
10th Class Biology Chapter 13 Notes cover the topic of Support and Movement, one of the most important chapters in the SSC-II Biology syllabus. This chapter explains how the human skeleton provides structure, protection, and the ability to move. Students preparing for board exams often search for these notes because the chapter includes definitions, diagrams, and numerical facts that are frequently tested in MCQs and short questions.
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These 10th Class Biology Chapter 13 Notes are designed to simplify difficult concepts like cartilage, bone structure, joints, and muscle action so students can revise quickly before exams.
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Why Support and Movement Matters
Every organism with a larger body size needs a support system to hold its shape and mass together. This is especially true for animals living on land, where gravity constantly pulls the body down. Without a skeleton, movement, posture, and protection of internal organs would not be possible.
Movement itself is divided into two types:
- Movement of body parts (like bending an arm)
- Locomotion (moving the whole body from one place to another)
What Is a Skeleton?
A skeleton is the framework of hard, articulated structures that gives physical support, provides attachment points for muscles, and protects the internal organs of the body.
The skeleton performs three major functions:
- Physical support
- Attachment for skeletal muscles
- Protection for the body’s internal organs
There are two main types of skeletons found in animals:
- Endoskeleton – located inside the body (example: humans)
- Exoskeleton – located outside the body (example: arthropods)
Students looking for more comparison-based content can check [internal link] for related biology chapter notes.
Cartilage and Bone in 10th Class Biology Chapter 13 Notes
This section of the 10th Class Biology Chapter 13 Notes explains the two main connective tissues that make up the skeleton: cartilage and bone.
Cartilage
Cartilage is a dense, clear, blue-white connective tissue that is less strong than bone. Its cells are called chondrocytes, and each one sits inside a fluid-filled space known as a lacuna. Blood vessels do not enter cartilage tissue.
There are three types of cartilage:
- Hyaline Cartilage – strong yet flexible, found in the nose, larynx, trachea, and bronchial tubes
- Elastic Cartilage – similar to hyaline but has elastic fibers, found in the epiglottis and pinna
- Fibrous Cartilage – tough and less flexible, found in intervertebral discs
Bone
Bone is the hardest connective tissue in the human body. It has two main regions:
- Compact bone – the hard outer layer
- Spongy bone – the soft, porous interior that contains blood vessels and bone marrow
The bone matrix contains collagen, calcium, and phosphate. Mature bone cells are called osteocytes.
Babies are born with about 300 soft bones, and many of these fuse together as the body grows, leaving the adult skeleton with 206 hard bones.
Bones perform several key functions:
- Movement
- Support
- Protection
- Storage of minerals
- Production of red and white blood cells
Human Skeleton Structure
According to 10th Class Biology Chapter 13 Notes, the 206 bones of the adult human skeleton are organized into two divisions: the axial skeleton and the appendicular skeleton.
Axial Skeleton
The axial skeleton contains 80 bones located in the head and trunk. It has five parts:
- Skull – 22 bones (8 cranial and 14 facial)
- Middle Ear Ossicles – 6 bones total (3 in each ear)
- Hyoid Bone – one bone in the neck
- Vertebral Column – 33 bones (vertebrae)
- Chest – made up of the sternum and 24 ribs (12 pairs)
Appendicular Skeleton
The appendicular skeleton has 126 bones and includes:
- Pectoral girdle – 4 bones
- Arms – 6 bones
- Hands – 56 bones
- Pelvic girdle – 2 bones
- Legs – 8 bones
- Feet – 56 bones
Joints Explained in 10th Class Biology Chapter 13 Notes
A joint is the location where two or more bones meet. Joints allow movement and provide mechanical support to the skeleton. They are classified based on how much movement they allow.
Types of Joints
1. Immovable (Fixed) Joints
These allow no movement at all. Example: joints between the skull bones.
2. Slightly Movable Joints
These permit only slight movement. Example: joints between the vertebrae.
3. Movable Joints
These allow a wide range of motion and include:
- Hinge joints – move back and forth in one plane, like the knee and elbow
- Ball-and-socket joints – allow movement in all directions, like the hip and shoulder
Tendons, Ligaments, and Muscle Action
Tendons and ligaments are connective tissues made of tightly packed collagen fibers, but they serve different purposes.
- Tendons attach muscles to bones. When a muscle contracts, the tendon pulls the bone and creates movement.
- Ligaments join one bone to another at a joint and prevent dislocation.
Antagonistic Muscle Pairs
Muscles can only pull or contract — they cannot push. This is why skeletal muscles work in antagonistic pairs, where one muscle contracts while the other relaxes.
At the elbow joint, biceps and triceps form a classic antagonistic pair:
- Biceps is the flexor muscle; it bends the elbow (flexion)
- Triceps is the extensor muscle; it straightens the elbow (extension)
The fixed end of a muscle is called the origin, while the movable end is called the insertion.
Common Skeletal Disorders
This part of the 10th Class Biology Chapter 13 Notes covers two disorders often asked in exams: osteoporosis and arthritis.
Osteoporosis
Osteoporosis is a bone disease common in old age, especially in women. It causes decreased bone density due to loss of calcium and phosphorus. Common causes include:
- Malnutrition
- Lack of protein and vitamin C
- Lack of physical activity
- Deficiency of estrogen hormone
Arthritis
Arthritis means inflammation of the joints, causing pain and stiffness. It commonly affects weight-bearing joints like the hip and ankle. Types include:
- Osteoarthritis – caused by cartilage degeneration
- Rheumatoid arthritis – inflammation of joint membranes, with symptoms like fatigue and fever
- Gout – caused by uric acid crystal buildup, often in the toe joints
For more chapter-wise revision material, students can also explore [internal link] to strengthen their exam preparation.
Contribution of Andreas Vesalius
Andreas Vesalius (1514–1564) was born in Brussels, Belgium. He is honored as the founder of modern anatomical studies. Through dissection of human bodies, he made major discoveries and published a book containing the most accurate depictions of the human skeleton and muscles known at that time.
FAQs
Q1. What topics are covered in 10th Class Biology Chapter 13 Notes?
These notes cover support and movement, including skeleton types, cartilage, bone structure, joints, tendons, ligaments, muscle action, and disorders like osteoporosis and arthritis.
Q2. How many bones are in the adult human skeleton?
The adult human skeleton has 206 bones. Babies are born with about 300 softer bones, many of which fuse together during growth into childhood and adolescence.
Q3. What is the difference between the axial and appendicular skeleton?
The axial skeleton includes the skull, vertebral column, and ribs (80 bones), while the appendicular skeleton includes the arms, hands, legs, feet, and girdles (126 bones).
Q4. Why can muscles only pull and not push?
Muscles contract by shortening their fibers, which creates a pulling force. They cannot lengthen actively to push, which is why they work in antagonistic pairs like biceps and triceps.
Q5. What is the main cause of osteoporosis?
Osteoporosis is mainly caused by decreased bone density from calcium and phosphorus loss, often linked to low estrogen levels, poor nutrition, and lack of physical activity in older age.
Q6. Where can I find complete 10th Class Biology Chapter 13 Notes for exam preparation?
Complete notes with MCQs, short questions, and long questions are available on TaleemWorld.com, covering every topic from this chapter in an easy-to-understand format for board exam preparation.