The musculoskeletal system includes bones, cartilage, ligaments, tendons and connective tissues. It provides structure and support for the body, allows for movement via bones and muscles, and protects internal organs. There are over 200 bones in the human body that can be categorized as long bones, short bones, flat bones, irregular bones, or sesamoid bones. Joints such as synovial joints allow for movement between bones. Ligaments and tendons connect muscles to bones to facilitate movement. The three types of muscles are skeletal, smooth and cardiac muscle.

1. Musculoskeletal System
Palash Kumar Laskar
RN, MSN (incourse)
RADIX ACADEMY

2. Definitions
• Musculoskeletal system includes bones, cartilage,
ligaments, tendons and connective tissues.
• It gives the body its shape, allows movement,
support body's weight, maintain posture, makes blood
cells, provides protection for organs and stores
minerals.
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3. Body Movements

6. Bones
• A bone is a single section of a skeleton, made of very hard tissue.
• A specialized form of dense connective tissue consisting of bone
cells (osteocytes) embedded in a nonliving matrix; osseous tissue.
• Bone matrix is made of calcium carbonate, calcium phosphate, and
collagen fibers.
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7. The Axial Skeleton
• The axial skeleton forms
the vertical, central axis
of the body and includes
all bones of the head,
neck, chest, and back.

8. Bones of the Skull
• Frontal – forms the forehead
• Parietal – the upper lateral sides of the cranium
• Occipital – the posterior skull and base of the cranial cavity
• Temporal – the lower lateral sides of the cranium
• Sphenoid -the ‘keystone’ bone that forms part of the base of
skull and eye sockets
• Ethmoid – forms part of the nose and orbit and base of cranium
• Auditory ossicles – the small bones of the middle ear
• External auditory meatus – the external opening of ear and
temporal bone

9. Bones of the Face
• Zygomatic – the cheekbone
• Maxillary – the upper jaw and hard palate
• Palatine – the lateral walls of the nose
• Lacrimal – the walls of the orbit
• Inferior conchae – the lower lateral wall of the nasal cavity
• Vomer – the separates the left and right nasal cavity
• Mandible – the lower jaw bone (The only movable bone of
the skull)
• Hyoid – the bone located between the mandible and larynx,
not connected to other bones
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10. Bones of the Vertebral Column
• The vertebral column is curved, with two primary curvatures
(thoracic and sacrococcygeal curves) and two secondary
curvatures (cervical and lumbar curves).
• Types of Vertebrae
• Cervical – C1 to C7 – the first 7 vertebrae in the neck region
• Thoracic – T1 to T12 – the next 12 vertebrae that forms the
outward curvature of the spine
• Lumbar – L1 to L5 – the next 5 vertebrae that forms the inner
curvature of spine
• Sacrum –S1-S5- the triangular-shaped bone at the base of the
spine
• Coccyx -3/4/5– the tailbone

11. Ribs
• There are 12 sets of ribs and can be divided as such:
• 7 true ribs as they are attached to the front of the sternum
• 3 false ribs as they are attached to the cartilage that joins the sternum
• 2 floating ribs as they are not attached to the front of the sternum
Sternum
• The sternum, also known as the breast bone, is divided into 3 parts:
• manubrium – the upper portion of the breast bone
• body – the middle portion of the breast bone
• xiphoid process – the lower portion of the breast bone and is made up
of cartilage
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12. The Appendicular Skeleton
• The appendicular skeleton includes all bones of the upper and lower limbs, plus the bones that attach each limb
to the axial skeleton. There are 126 bones in the appendicular skeleton of an adult.
Bones of the Pectoral Girdle:
• Scapula – the shoulder blades
• Clavicle – the collar bones. It connects the sternum to the scapula
• Acromion – the extension that forms the bony point of the shoulder
Bones of the Arm
• Homarus – the bone in upper arm
• Radius – the bone that runs thumb-side of the forearm
• Ulna – the bone that runs on the side of the little finger of the forearm
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13. Bones of the Wrist and Hand
• Carpals – the wrist bones
• Metacarpals – the bones in the palm of hand
• Phalanges – the finger and toe bones
Bones of the Pelvic Region
• The bones of the pelvic region protect the reproductive, urinary, and excretory organs.
• Pelvic girdle – the hip or coxal bone. It is formed by the fusion of three bones during adolescence
• Illium – the largest part of the hip bone
• Ischium – the lower portion of pelvic girdle
• Pubis – the anterior portion of pelvic girdle
• Pelvis – consists of four bones: the left and right hip bones as well as the sacrum and coccyx
• Acetabulum – the large socket in the pelvic bones that holds the head of the femur
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14. Bones of the Leg:
• Femur – the thigh bone and is also referred to the upper leg bone. It is
the longest and strongest bone in the human body
• Patella – the knee cap
• Tibia – the shin bone. It is a medial bone and the main weight-bearing
bone of the lower leg
• Fibula – the smaller of the lower leg bone
Bones of the Ankles and Feet:
• Tarsals – the ankle bones (7 total)
• Malleolus – the bony protrusions of the ankle bones
• Talus – the superior ankle bones
• Calcaneus – the heel bones
• Metatarsals – the foot bones
• Phalanges – the bones of the toes

15. Types of bones:
1.Sesamoid bones (4)- reinforce tendons
2.Short bones (24)- are cube shaped
3.Flat bones (36)- protect internal organs.
4.Irregular bones (48) have complex shapes
5.Long bones (90)- support weight and facilitate movement.
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21. Composition of bone
• By volume, bone consists of-
▪40% inorganic component (hydroxyapatite),
▪25% water and
▪35% organic component (proteins).
• 90% of the organic component are collagen type I and
the remaining 10% noncollagenous proteins.
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22. Types of bone cells

23. Bone formation
The process of bone formation is called osteogenesis or ossification. After progenitor
cells form osteoblastic lines, they proceed with three stages of development of cell
differentiation, called proliferation, maturation of matrix, and mineralization.

24. Joint
• A joint is a point where two bones make contact.
Types of joint
Histologically the three joints in the body are -
• Fibrous joint : a fixed joint where fibrous tissue comprised primarily of
collagen connects bone.
• Cartilaginous joint : the bones attach by hyaline cartilage or fibrocartilage.
• Synovial joint : Synovial joints are freely mobile (diarthroses) and are
considered the main functional joints of the body.
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25. Types of fibrous joints
Fibrous joints are usually immoveable (synarthroses) and have no joint
cavity. They are subdivided into-
• Sutures : Sutures are immobile joints in the cranium.
• Gomphoses : Gomphoses are the immobile joints between the teeth and
their sockets in the mandible and maxillae.
• Syndesmoses : Syndesmoses are slightly movable joints
(amphiarthroses). For example, the tibia connects to
the fibula, forming the middle tibiofibular joint, and
the ulna attaches to the radius, forming the middle
radio-ulnar joint.
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26. Types of cartilaginous joints
Depending on the type of cartilage involved, the joints are classified as-
• Primary cartilaginous joints :
▪ Primary cartilaginous joints, also known as synchondroses, only involve hyaline cartilage.
▪ These joints may be slightly mobile (amphiarthroses) or immobile (synarthroses).
▪ The joint between the epiphysis and diaphysis of growing long bones is an example.
• Secondary cartilaginous joints:
▪ The secondary cartilaginous joint, also known as symphysis, may involve either hyaline
or fibrocartilage.
▪ These joints are slightly mobile (amphiarthroses). A classic example is a pubic symphysis.

27. Types of synovial joint
Synovial joints are often classified by the type of movements they
permit. There are six such classifications:
• Hinge (elbow),
• Saddle (carpometacarpal joint),
• Planar (acromioclavicular joint),
• Pivot (atlantoaxial joint),
• Condyloid (metacarpophalangeal joint),
• Ball and socket (hip joint).
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29. Ligaments
• Ligaments are bands of tough elastic tissue around your joints. They
connect bone to bone, give joints support, and limit their movement. We
have ligaments around our knees, ankles, elbows, shoulders, and other
joints. Stretching or tearing them can make your joints unstable.
• Ligaments are like cords made of connective tissue, elastic fibers that are
somewhat stretchy, and collagen, a protein that binds tissues in human.
• The human body has more than 900 ligaments that help connect bones,
joints and organs and hold them in place.
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30. The knee has 4 major ligaments connect the thighbone (femur) to the shin bone
(tibia).
• Anterior cruciate ligament (ACL):
This ligament is in the center of the knee. It controls rotation and forward
movement of the shin bone.
• Posterior cruciate ligament (PCL):
This ligament is in the back of the knee. It controls backward movement of the
shin bone.
• Medial collateral ligament (MCL):
This ligament gives stability to the inner knee.
• Lateral collateral ligament (LCL):
• This ligament gives stability to the outer knee.

32. Functions of ligaments
• Allow the joint to move in the direction(s) it was meant to move.
• Hold bones together.
• Make sure that joints don’t twist.
• Stabilize muscles and bones.
• Strengthen joints.
• Prevent bones from dislocating.
• For example, your knee has four ligaments that keep it from moving side to side or
backward. Ligaments also hold the uterus in place in a woman’s pelvis. Additionally,
they connect the liver, intestine and stomach and hold them in place.
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33. Muscle
• Muscle is a band or bundle of fibrous tissue in a human or animal body that has the ability to
contract, producing movement in or maintaining the position of parts of the body.
• There are about 600 muscles in the human body.
• Glucose from carbohydrates in our diet fuels our muscles. To work properly, muscle tissue
also needs particular minerals, electrolytes and other dietary substances such as calcium,
magnesium, potassium and sodium.
• A range of problems can affect muscles – these are collectively known as myopathy. Muscle
disorders may cause weakness, pain or even paralysis.
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34. Types of muscles

35. Shapes of skeletal muscle
Skeletal muscles come in four main shapes, including:
• Spindle – wide through the middle and tapering at both ends, such as
the biceps on the front of the upper arm.
• Flat – like a sheet, such as the diaphragm that separates the chest from
the abdominal cavity.
• Triangular – wider at the bottom, tapered at the top, such as the deltoid
muscles of the shoulder.
• Circular – a ring-shape like a doughnut, such as the muscles that
surround the mouth, the pupils and the anus. These are also known as
sphincters.
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38. Functions of muscular system
• Mobility- walking, running, swimming, writing, speaking, facial expressions
• Stability
• Posture
• Circulation
• Respiration
• Digestion
• Urination
• Childbirth
• Vision
• Organ protection
• Temperature regulation

39. Questions
1. Tunica intima, tunica media, and tunica adventitia are the layers of-
a. Arteries and veins b. Intestines and esophagus c. Urethra and Uterus d. Testis
and Ovaries
2. Which of the following is not an example of smooth muscle-?
a. Skeletal muscle b. Esophagus c. Stomach d. Cardiac muscle
3. Most abundant tissue of human body is-
a. Skeletal muscle b. Bone c. Blood d. Nerve
4. Mashrafi Bin Mortuza the former captain of Bangladesh cricket team, was frequently suffered from
which of the following injury?
a. ACL injury b. Ankle sprain c. Finger sprain d. Shoulder dislocation
5. which kind of tendon injury is common occurred among people who works long time in computers?
a. Tennis elbow b. Golfer's elbow c. Wrist tendonitis d. Achilles tendonitis
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40. Questions
6. The smallest bone in wrist joint is-
a. Lunate b. Capitate c. scaphoid d. Trapezoid
7. The shoulder girdle consists of-
a. three bones b. a and c c. three joints d. None of these
8. The sciatic nerve is a combination of-
a. Two nerve roots b. Three nerve roots c. Four nerve roots d. Five nerve roots
9. Most abundant mineral in human body is-
a. Calcium b. Potassium c. Sodium d. Magnesium
10. Which of the following muscle is used to inject intramuscular injection in mid thigh?
a. Rectus femoris b. Gracilis c. Biceps femoris d. Vastus lateralis
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41. Questions
11. The largest muscle in human body is-
a. Gluteus maximus b. Gluteus Medius c. Gluteus Minimus d.
Latissimus dorsi
12. IM injection is administered in _ potential sites.
a. 3 b. 4 c. 5 d. 6
13. Which of the following is the smallest muscle of your body?
a. Soleus b. Stapedius c. Rhomboids d. Pectineus
14. The second smallest bone of human body is-
a. Stapes b. incus c. vomer d. Malleus
15.The natural process of bone formation is known as-
a. Ossification b. Hematopoiesis c. Fibrogenesis d.
Osteogenesis