THE MUSCULOSKELETAL SYSTEM

Question 1

The musculoskeletal system is

Answer 1

Consists of three major components that provide form, support, stability and movement to the body. There are:

1. Bones.
2. Muscles.
3. Connective tissues.

The musculoskeletal system main function is to produce movement and motion to the body. Body
movement takes place along axes.

Question 2

Axes

Answer 2

There are three types of axes that the body is divided into:

• Transverse (horizontal) plane
• Coronal (Frontal) plane
• Sagittal plane

Question 3

Transverse(horizontal) plane

Answer 3

Divides the body into cranial and caudal.

• Cranial – the upper portion of the body (superior head).
• Caudal – the lower portion of the body (inferior-tail).

Question 4

Coronal(frontal) plane

Answer 4

divides the body into Dorsal and Ventral.

• Dorsal – the posterior portion of the body (back).
• Ventral – the anterior portion of the body (front).

Question 5

Sagittal plane

Answer 5

Divides the body into sinister and dexter. Can also be divided into medial and lateral.

• Sinister – left portion of the body.
• Dexter – right portion of the body.
• Medial – meaning approximate to the middle of the body.
• Lateral – approximate to the side of the body.

Question 6

Bones are

Answer 6

rigid organ that is part of the skeleton. The bone is in constant change. Meaning, it is being destroyed and rebuild constantly. This process is done by:
* Osteoclasts (destroy the bone).
* Osteoblast (build the bone).
There are 206 bones in the human body.

• Due to its constant chance, a bone will change its entire structure in approximately every seven
  years.

Question 7

Muscles are

Answer 7

Soft tissues that produce contraction in order to create force and motion. In movement, the muscles are divided into that parts that work together:

• Agonist muscle – the muscle that contacts (for instance biceps).
• Antagonist muscle – the muscle that relaxes while the antagonist contracts (for the example above, triceps).

Question 8

Tendons are

Answer 8

Dense connective tissue that connects muscle to bones. Transmit tension from the
muscle to the bone to produce movement and motion.

Question 9

Joints are

Answer 9

location at which two or more bones make contact. Constructed to allow movements and
stability.

Question 10

Ligaments are

Answer 10

Tough connectives tissue that connects bones to bones. There by giving stability and
support to the joints by holding the bones in place

Question 11

Fascia is

Answer 11

A connective tissue fibber that usually made out of collagen. They are providing stability and are forming sheets under the skin to enclose or separate muscles from other internal organs.

Question 12

Types of bones

Answer 12

There are 5 types of bones:

• Long bones
• Short bones
• Flat bones
• Irregular bones
• Sesamoid bones

Question 13

Long bones

Answer 13

Bones that are longer more than they are wide. They are subjective to most of the louds during day activities. They are crucial for skeletal mobility and they support the body’s weight. Example of bones: Tibia, femur, fibula, and humerus.

Question 14

Short

Answer 14

Long as they are wide. Primarily function is to provide support, stability and little or to no movements. Example of bones: tarsals (5 bones in the foot) and carpals (9bomes).

Question 15

Flat

Answer 15

Fond at the surface of muscle attachments and their principle idea is to increase surface formuscles contact to provide extra protection for organs. Example of bones: shoulder blade, scapula,
sternum and cranium.

Question 16

Irregular

Answer 16

Vary in shape and structure and therefore do not fit into any other category. They often
have a fairly complex shape, which helps protect internal organs. Example of bones: pubis, ilium,
and ischium

Question 17

Sesamoid

Answer 17

Bones that embedded in tendons. These small, round bones are commonly found in
the tendons of the hands, knees, and feet. Sesamoid bones function to protect tendons from stress
and wear. Example of bones: The patella (kneecap).

Question 18

Bone functions:

Answer 18

1. Provide body form.
2. Protection for body organs
3. Production of blood cells
4. Stores minerals and lipids; mostly calcium.
5. Provide leverage and movement

Question 19

Joints

Answer 19

Joints are, as side before, the location at which two or more bones make contact. They can construct to
allow movement and stability. There are 340 joints in the body.

Question 20

Classifications of joints types:

Answer 20

1.*Structure: Fibrous.
*Function:Synatrosis – not moving joint (like in the
skull)

2.*Structure: Collagenous.
*Function: Amphiarthrosis - Partial and little
movement for shock absorption.

3. *Structure: Synovial.
   
   • Function: Diarthrosis – moving joints.

Question 21

Types of moments by joints:

Answer 21

1. Flexion and extension – flexion is lowering the angle in the joint. Meaning, bringing the bone closer to the muscle. Extension is the opposite. Meaning, increasing the angle in the joint, and bringing the bone away from the agonist muscle.
2. Abduction and adduction – adduction is moving the bone closer toward the medial part of the
   body, while abduction is moving the bone away, to the lateral part.
3. Circumduction – movement in a circle.
4. Rotation – partial rotation (not full cycles)

Question 22

Types of joints:

Answer 22

1. Hinge – allows only one part of motion (flexion/extension).
2. Pivot – allows rotation around itself (like in the neck)
3. Condyloid – allow flexion/extension, abduction/adduction and circulation. Usually in the wrist
   (carpal bones).
4. Gliding – allows gliding movements. Usually located in the carpal joints and bones.
5. Saddle – allows flexion/extension, abduction/adduction and circulation. Usually in the thumb.
6. Ball and socket – allows all types of movements.

Question 23

Major joints in the body:

Answer 23

• Elbow
• knee
• Ankle
• Neck
• Carpal
• Wrist/M.C.P
• Thumb
• Shoulder
• Hip

Question 24

Major joint - Elbow

Answer 24

Type: Hinge

Movement: Flexion/Extension

Bones: Humerus, ulnar, radial

Muscle: Biceps and triceps

Question 25

Major joint - knee

Answer 25

Type: Hinge Movement: Flexion/Extension Bones: Femur, tibia, fibula, pattela Muscle: Quadriceps, hamstrings

Question 26

Major joint - Ankle

Answer 26

Type: Hinge Movement: Flexion/Extension or Dorsiflexion/Plantarflexion Bones: tibia, fibula, tarsals Muscle: Gastrocnemius, soleus.

Question 27

Major joint - Neck

Answer 27

Type: Pivot Movement: Rotation Bones: C1, C2 Muscle: Splenius capitis, sternocleidomastoid trapezius and levator scapulae.

Question 28

Major joint - Carpal

Answer 28

Type: Gliding/Plane Movement: Gliding Bones: Carpal, Tarsal, Spine Muscle: Pronator quadratus and lumbricals.

Question 29

Major joint - Wrist/M.C.P

Answer 29

Type: Condyloid Movement: Flexion/Extension, Rotation (supination/Pronation), Add/Abd (ulnar deviation/Radial deviation). Bones: Carpal, Ulnar, Radius, Phalanges, Meta-Tarsal Muscle: Palmaris brevis and lumbricals.

Question 30

Major joint - Thumb

Answer 30

Type: Saddle Movement: Flexion/Extension, Rotation Add/Abd, Circumduction Bones: Carpal, Meta-carpal Muscle:1st Doral interosseous and pollicis brevises (adductor, flexor abductor and opponens).

Question 31

Major joint - Shoulder

Answer 31

Type: Ball-socket Movement: Flexion/Extension, Rotation Add/Abd, Circumduction. Bones: Humerus, Scapula. Muscle: Deltoid, Pectoralis(major/minor), Latissimus dorsi.

Question 32

Major joint - Hip

Answer 32

Type: Ball socket Movement: Flexion/Extension, Rotation Add/Abd, Circumduction. Bones: Femur, pelvis(ilium ,ischium, pubis). Muscle: Gluteus Maximus, Adductor femoris, Tensor facia latea.

Question 33

The Trunk (Torso)

Answer 33

The trunk is the centre of the body, and it consist: 1. The thoracic cavity – contains the lungs and the heart. 2. The Diaphragm – a muscle that separates the cavities and participate in respiratory activities. 3. The abdominal cavity – contains organs of the urinary and digestive systems.

Question 34

The thoracic cavity

Answer 34

Divided into four part: *Anterior – contains the sternum and the rib cage. Both the ribs and the sternum are made of bones and cartilage. The sternum has very little cartilage that turns into bone with age. * Posterior – contains the thoracic vertebrae (part of the spine), the scapula and rib cage (posterior part). * Superior – contains the clavicle bone. * Inferior – contains the diaphragm

Question 35

The abdominal cavity:

Answer 35

Divided into four part: *Superior – contains the diaphragm. * Inferior – contains pelvic floor. * Anterior – contains muscle wall, connective tissues and abdominal muscles. * Posterior – contains the lumbar vertebrae (part of the spine).

Question 36

The Ribs

Answer 36

The ribs are a structure of bones in the upper chest. There are 12 pairs of ribs in the rib cage. The ribs main functions are: 1. Support – they are big and strong, therefore they can support the weight of the torso and maintain the upper body structure. 2. Protection – due to their strength, size and durability, they provide lots of protection to the organs in the thoracic cavity (lungs and heart). 3. Respiration – with the help of the diaphragm, abdominal and intercostal muscles, the ribs can change their position to allow inhalation and exhalation.

Question 37

The ribs are classified and divided into three parts:

Answer 37

1. True ribs – ribs that are directly connected to the sternum (ribs no. 1-7). 2. False ribs – ribs that are not directly connected to the sternum (ribs no. 8-12). 3. Floating ribs – ribs that are connected to the vertebrae (spine) only (ribs no. 11-12). Floating ribs are part of the false ribs.

Question 38

The Vertebrae (Spine)

Answer 38

The spine is made of 33 individual bones stacked one on top of the other. This spinal column provides the main support for the body, allowing it to stand upright, bend, and twist, while protecting the spinal cord from injury. Strong muscles and bones, flexible tendons and ligaments, and sensitive nerves contribute to a healthy spine. Yet, any of these structures affected by strain, injury, or disease can cause pain.

Question 39

The vertebral column has four main functions:

Answer 39

* Protection – encloses and protects the spinal cord within the spinal canal. * Support – carries the weight of the body above the pelvis. * Axis – forms the central axis of the body. * Movement – has roles in both posture and movement.

Question 40

The vertebrae are divided into 5 segments:

Answer 40

1. Cervical vertebrae – contains disks number: 𝐶1 − 𝐶7. * The first disk (𝐶1) is called the atlas. 2. Thoracic vertebrae – contains disks number: 𝑇1−𝑇12. 3. Lumber vertebrae – contains disks number: 𝐿1 − 𝐿7. 4. Sacral vertebrae – contains disks number: 𝑆1 − 𝑆5 (5 fused parts). 5. Coccygeal vertebrae – contains the Coccyx (4 fused parts).

Question 41

The spine has 4 curves:

Answer 41

Cervical curve (neck) Thoracic/kyphotic curve (mid back) Lumber curve (lower back) Sacral curvature

Question 42

Cervical curve (neck)

Answer 42

Located in the neck area and contains the first seven vertebrae of yourspine. It begins directly below the skull at the atlas vertebrae and ends above the thoracic spine. A healthy cervical curve resembles a wide, backward “C” shape. The ideal cervical curve is approximately 42 degrees when standing upright.

Question 43

Thoracic/kyphotic curve (mid back)

Answer 43

It is made up of 12 vertebrae, and it is located below the top 7 vertebrae of the cervical spine and above the lumbar spine. These vertebrae connect to your ribs and form part of the back wall of the thorax (the ribcage area between the neck and the diaphragm). The curve of the thoracic spine is a “C” shape with the opening of the “C” in the front (unlike the cervical curve).

Question 44

Lumber curve (lower back)

Answer 44

This area usually has 5 vertebrae. However, sometimes people are born with 6 vertebrae in the lumbar region. The base of your spine (called the sacrum) is a group of specialized vertebrae that connects the spine to the pelvis. When one of the bones forms as a vertebra rather than part of the sacrum, it is called a transitional (or sixth) vertebra. This occurrence is not dangerous and does not appear to have any serious side effects. The lumbar spine is shaped like a backward “C”, just like the cervical spine.

Question 45

Sacral curvature

Answer 45

Sacral curvature (SC), represented by the angle between the first and the last sacral vertebrae, is a feature that differentiates the human pelvis from that of other animals. It is in a “C” shape

Question 46

Important to remember about the spine

Answer 46

* Backwards “C” shape is called lordotic, while regular “C” shape is called kyphotic. * The body loses 2% of its bone mass per year after menopause.