Throughout history, the symbol of the skull and crossbones has served as a representation of mortality, likely owing to the fact that following death and decay, bones are the sole remnants. Many individuals perceive bones as inert, desiccated, and fragile. While these attributes accurately portray the bones of a preserved skeleton, the bones within a living human being are profoundly alive. Living bones exhibit strength and flexibility, serving as the primary components of the skeletal system.

1. BBA HM-201
Dr Madhurima Kundu

2.  In the musculoskeletal system, the muscular and skeletal systems work together to support and move the
body.
 The bones of the skeletal system serve to protect the body's organs, support the weight of the body, and give
the body shape.
 The muscles of the muscular system attach to these bones, pulling on them to allow for movement of the
body.
 The skeletal portion of the system serves as the main storage system for calcium and phosphorus. The
importance of this storage is to help regulate mineral balance in the bloodstream
 The skeleton also contains critical components of the hematopoietic (blood production) system. Located in
long bones are two distinctions of bone marrow: yellow and red. The yellow marrow has fatty connective
tissue and is found in the marrow cavity.
 The red marrow of some bones is an important site for hematopoeisis or blood cell production that replaces

3. Musculoskeletal system
The body system that provides support, stability, shape,
and movement to the body
Joint The point at which two (or more) bones meet.
Cartilage Soft connective tissue found between joints
Ligaments Connective tissue that attaches bone to bone at a joint
Tendons Connective tissue that attaches muscle to bone

4. The axial skeleton consists of:
• the skull, which protects the brain and supports facial structure
• the vertebral column (spine), which surrounds and protects the spinal cord and
support the head
• the thoracic (rib cage), which surrounds and protects the organs within the
chest (including heart and lungs)
The appendicular skeleton consists of:
• the pectoral girdle (shoulders):
• upper and lower limbs (arms and legs)
• the pelvic girdle (hip bones)

5. Cartilage acts as a shock
absorber to reduce friction.
Ligaments help stabilize the
joint, keeping it from moving
outside of its intended range of
motion.
Tendons connect the skeletal
system to the muscular system
by attaching muscle to bone.
When muscle contracts, the
tendon acts on the bone,
causing movement.

6.  Bones serve as rigid structures to the body and as shields to protect delicate internal organs.
 They provide housing for the bone marrow, where the blood cells are formed. Bones also maintain the body's
reservoir of calcium.
 Bones are made up of a framework of a protein called collagen, with a mineral called calcium phosphate that
makes the framework hard and strong. Bones store calcium and release some into the bloodstream when it's
needed by other parts of the body.
 Bones are made up of two types of bone tissues:
-Compact bone is the solid, hard outside part of the bone. It looks like ivory and is
extremely strong. Holes and channels run through it, carrying blood vessels and nerves.
-Cancellous bone, which looks like a sponge, is inside compact bone. It is made up of a
mesh-like network of tiny pieces of bone called trabeculae.

8. Functions of Bones:
 Support: Bones provide a framework for the attachment of muscles and other tissues.
 Protection: Bones such as the skull and rib cage protect internal organs from injury.
 Movement: Bones enable body movements by acting as levers and points of attachment for
muscles.
 Mineral storage: Bones serve as a reservoir for calcium and phosphorus, essential minerals for
various cellular activities throughout the body.
 Blood cell production: The production of blood cells, or hematopoiesis, occurs in the red
marrow found within the cavities of certain bones.
 Energy storage: Lipids, such as fats, stored in adipose cells of the yellow marrow serve as an
energy reservoir.

9. What are the different types of bone cells?
The different types of bone cells include the following:
•Osteoblast- Found within the bone, its function is to form new bone tissue.
•Osteoclast- A very large cell formed in bone marrow, its function is to absorb and remove unwanted tissue.
•Osteocyte- Found within the bone, its function is to help maintain bone as living tissue.
•Hematopoietic- Found in bone marrow, its function is to produce red blood cells, white blood cells, and
platelets.
Types of bone:
 Long bones are longer than they are wide and have a shaft and two ends. The diaphysis, or central shaft, contains
bone marrow in a marrow cavity. The rounded ends, the epiphyses, are covered with articular cartilage and are
filled with red bone marrow, which produces blood cells. For example- the femur, tibia, ulna, and radius.
 Short bones, or cuboidal bones, are bones that are the same width and length, giving them a cube-like shape. For
example, the bones of the wrist (carpals) and ankle (tarsals).

10. Flat bones are thin and relatively broad bones that are found where extensive protection of organs is
required or where broad surfaces of muscle attachment are required. Examples of flat bones are the
sternum (breast bone), ribs, scapulae (shoulder blades), and the roof of the skull.
Irregular bones are bones with complex shapes. These bones may have short, flat, notched, or ridged
surfaces. Examples of irregular bones are the vertebrae, hip bones, and several skull bones.
Sesamoid bones are small, flat bones and are shaped similarly to a sesame seed. The patellae are sesamoid
bones. Sesamoid bones develop inside tendons and may be found near joints at the knees, hands, and feet.

12.  There are 206 bones in the human skeleton, not
including teeth and sesamoid bones (small
bones found within cartilage):
• 80 axial bones. This includes the head, facial,
hyoid, auditory, trunk, ribs, and sternum.
• 126 appendicular bones. This includes arms,
shoulders, wrists, hands, legs, hips, ankles, and
feet.

13. MUSCLES
The body contains three types of muscle tissue: skeletal muscle, smooth muscle, and cardiac muscle.
Skeletal Muscle Smooth Muscle Cardiac Muscle
Skeletal muscle is voluntary and striated. These are the muscles that attach to bones and control conscious
movement.
Smooth muscle is involuntary and non-striated. It is found in the hollow organs of the body, such as the stomach,
intestines, and around blood vessels.
Cardiac muscle is involuntary and striated. It is found only in the heart and is specialized to help pump blood
throughout the body.

14. THE SKULL

15.  FRONTAL- 1 bone
Forehead
 PARIETAL- 2 bones
Upper sides and roof of skull
 TEMPORAL- 2 bones
Sides and base of skull
 ETHMOID- 1 bone
Part of eye orbit, nose and floor of
skull
 SPHENOID- 1 bone
Part of skull floor
 OCCIPITAL-1 bone
Back and base of skull
CRANIAL BONES

18. There are fourteen facial bones, all of which are paired, except for two:
•Zygomatic bones: 2
•Maxillae: 2
•Nasal bones: 2
•Lacrimal bones: 2
•Vomer: 1
•Palatine bones: 2
•Inferior conchae: 2
•Mandible: 1
FACIAL BONES

19. (7)
(12)
(5)
Cervical- 7 vertebrae (C1 to C7)- The first vertebra, C1 or Atlas articulates
with the two occipital condyles of the skull. It allows the maximum
movement of the neck. It is responsible for the ‘yes’ movement of the
head.- The C2 and C1 joints allow the ‘no’ movement of the head.
– It supports the weight of the head.
Thoracic- 12 vertebrae (T1 to T12)- Vertebrae of the thoracic region have
limited movement and provide support to the rib cage and protect the
lungs and heart. 12 pairs of rib bones articulate with the thoracic vertebrae
on the posterior side.
Lumbar- 5 lumbar (L1 to L5)- Lumbar vertebrae support the weight of the
body.- They are larger in size and help in carrying heavy objects.
Sacral- 1 (fused 5 vertebrae, S1 to S5)- The five sacral vertebrae are fused
together.- They connect the vertebral column to the hip bones and
form pelvic girdle along with them.
Coccygeal/Coccyx- 1 (fused tailbone)- The four bones of the coccyx region
fuse together to form the tailbone

20. Scapula
Clavicle BONES OF THORAX, PELVIS
and EXTREMITIES

21. JOINTS
• The joints are the places where two or more bones meet. This is also called as articulation.
• 3 types of joints:
i) Fixed joints or immovable joints or fibrous or synarthrosis (joints in skull, teeth in the bony socket)
ii) Slightly movable joints or amphiarthrosis or cartilaginous (joints between vertebrae, small bones of ankle
and wrist)
iii) Freely movable joints or diarthrosis or synovial (hip joint, elbow joint)

22. MOVEMENTS of JOINTS
Gliding movement- two flat surfaces move on each other.
Flexion – bending a joint. This occurs when the angle of a joint decreases. For example, the elbow flexes when
performing a biceps curl.
Extension – straightening a joint. This occurs when the angle of a joint increases, for example, at the elbow when
putting a shot
Abduction – movement away from the midline of the body. This occurs at the hip and shoulder joints during a jumping
jack movement.
Rotation – this is where the limb moves in a circular movement around a fixed joint towards or away from the midline
of the body. This occurs in the hip in golf while performing a drive shot
Adduction- movement towards the medial aspect of the body
Angular movement- described according to the direction in which the movement takes place.
Circumduction- combination of rotation and angular movements

23. Phase 1 Elbow Flexion
Humerus,
radius, ulna
Biceps,
triceps
Concentric
Phase 2 Elbow Extension
Humerus,
radius, ulna
Triceps,
biceps
Concentric
Joint
Type of
movement Bones Muscles
Muscle
contraction