Lecture 2: Musculoskeletal System

Question 1

What is the largest organ of the integumentary system?

Answer 1

Skin

The skin is the body’s largest organ, playing a crucial role in protection and regulation.

Question 2

List the layers of the skin from superficial to deep.

Answer 2

• Epidermis
• Dermis
• Superficial fascia (Hypodermis)

These layers each have distinct functions and structures, contributing to the skin’s overall role.

Question 3

What is the composition of the superficial fascia (Hypodermis)?

Answer 3

Loose connective tissue & fat

This layer provides fat storage and varies in thickness across different parts of the body.

Question 4

What does the superficial fascia (Hypodermis) contain?

Answer 4

• Deepest parts of skin
• Glands
• Lymphatics
• Neurovascular structures

This layer is crucial for housing various important biological structures.

Question 5

What is deep fascia composed of?

Answer 5

Dense, organized connective tissue devoid of fat

Deep fascia plays a vital role in supporting and compartmentalizing muscles.

Question 6

Where is deep fascia found in relation to superficial fascia?

Answer 6

Deep to overlying superficial fascia

This positioning allows deep fascia to perform its supportive functions effectively.

Question 7

What is investing fascia?

Answer 7

Fascia that invests (surrounds/covers) muscles & neurovascular bundles

This type of fascia provides structural support and organization to muscle groups.

Question 8

What are intermuscular septa?

Answer 8

Structures that divide muscles into groups or compartments

They help to organize muscles functionally and mechanically.

Question 9

What are fascial planes?

Answer 9

Found between individual muscles

These planes facilitate movement and reduce friction between muscles.

Question 10

What is subserous fascia?

Answer 10

Fascia located between deep fascia & serous membranes

This layer plays a role in protecting internal organs and allowing for movement.

Question 11

What are retinacula?

Answer 11

Bands of thickened deep fascia that stabilize and hold tendons in place during movement

Retinacula are essential for proper tendon function and joint stability.

Question 12

What are the two regions of the skeletal system?

Answer 12

Axial skeleton and Appendicular skeleton

Axial skeleton includes the skull, vertebrae, ribs, and sternum. Appendicular skeleton includes limb elements such as pectoral and pelvic girdles.

Question 13

What components make up the skeletal system?

Answer 13

Cartilage and bone

Cartilage is avascular and semirigid, while bone is vascularized and rigid.

Question 14

What is cartilage?

Answer 14

Avascular, semirigid connective tissue that provides some flexibility

Cartilage is not innervated and has limited ability for repair.

Question 15

What type of cartilage covers articulating surfaces of bones in synovial joints?

Answer 15

Articular cartilage

Articular cartilage is a form of hyaline cartilage that reduces friction during movement.

Question 16

List the other forms of cartilage.

Answer 16

• Fibrocartilage
• Elastic cartilage

Fibrocartilage is found in intervertebral discs and pubic symphysis, while elastic cartilage is found in the epiglottis and pinna of the ear.

Question 17

What is bone?

Answer 17

Vascularized, rigid connective tissue

Bone is innervated and metabolically active, remodeling throughout life.

Question 18

What is the periosteum?

Answer 18

Dense fibrous connective tissue that surrounds bone

The periosteum nourishes bone, allows for remodeling, and serves as an anchor for muscle attachment.

Question 19

What are the functions of bone?

Answer 19

• Support and protection of body cavities and vital structures
• Provides scaffolding for muscle movement
• Mineral storage
• Houses bone marrow

Bone marrow produces red and white blood cells and platelets.

Question 20

What are the two types of bone based on material amount?

Answer 20

• Compact (cortical) bone
• Spongy (cancellous or trabecular) bone

Compact bone is dense and forms a thin outer layer, while spongy bone has a honeycomb appearance formed by trabeculae.

Question 21

Where is compact bone thicker?

Answer 21

In weightbearing bones/areas

An example is the shaft of the femur.

Question 22

Where is spongy bone prominent?

Answer 22

In vertebral bodies and long bone epiphyses

Spongy bone is characterized by its trabecular structure.

Question 23

What are long bones?

Answer 23

Tubular structures where length > width (e.g. femur, humerus, metacarpals)

Long bones have distinct features such as epiphysis, diaphysis, and medullary cavity.

Question 24

What is the epiphysis of long bones?

Answer 24

End cap of long bones containing trabecular bone covered by cortical bone

The epiphysis is crucial for joint articulation.

Question 25

Define diaphysis.

Answer 25

Body or shaft of bone consisting primarily of cortical bone ## Footnote The diaphysis is the long central part of a long bone.

Question 26

What is the medullary cavity?

Answer 26

Hollow space in center of long bones that stores bone marrow ## Footnote The medullary cavity plays a key role in blood cell production.

Question 27

What are short bones?

Answer 27

Cuboidal bones found in the wrist and ankles ## Footnote Short bones provide stability and support with little movement.

Question 28

Describe flat bones.

Answer 28

Consisting of two thin plates of cortical bone with trabecular bone in between (e.g. neurocranium, ribs, scapula) ## Footnote Flat bones serve protective functions and provide large areas for muscle attachment.

Question 29

What are irregular bones?

Answer 29

Grab bag of bones with various other shapes not listed above (e.g. vertebra, os coxae, bones of the face) ## Footnote Irregular bones are unique in shape and function.

Question 30

Define sesamoid bones.

Answer 30

Bones that develop in tendons that protect against wear and can improve performance via changing the angle of attachment ## Footnote An example of a sesamoid bone is the patella.

Question 31

What is a condyle?

Answer 31

Rounded area of articulation ## Footnote Condyles are often found at the ends of long bones.

Question 32

Define epicondyle.

Answer 32

Eminence superior to a condyle (G. epi = upon, over, above) ## Footnote Epicondyles serve as attachment points for ligaments and tendons.

Question 33

What is a crest in bone terminology?

Answer 33

Ridge of bone ## Footnote Crests are prominent features often serving as muscle attachment sites.

Question 34

Define line in bone markings.

Answer 34

Linear elevation ## Footnote Lines are less prominent than crests but still serve as muscle attachment points.

Question 35

What is a tuberosity/tubercle?

Answer 35

Raised eminence of bone typically serving as a site of muscle attachment ## Footnote These structures are important for muscle leverage.

Question 36

What is a malleolus?

Answer 36

Rounded prominence ## Footnote Malleoli are commonly found at the ends of the tibia and fibula.

Question 37

Define protuberance.

Answer 37

Low rounded projection ## Footnote Protuberances can serve various purposes, including muscle attachment.

Question 38

What is a trochanter?

Answer 38

Large blunt elevation on femur ## Footnote Trochanters are essential for muscle attachment on the thigh.

Question 39

Define process in bone terminology.

Answer 39

Projecting thorn-like extension ## Footnote Processes can serve various functions including muscle and ligament attachment.

Question 40

What is a facet?

Answer 40

Smooth, flat area of articulation ## Footnote Facets are critical for joint movement.

Question 41

Define foramen.

Answer 41

Hole through which a structure passes (e.g. neurovascular bundle) ## Footnote Foramina are essential for the passage of nerves and blood vessels.

Question 42

What is a fossa?

Answer 42

Shallow depression ## Footnote Fossae often serve as sites for articulation with other bones.

Question 43

Define notch.

Answer 43

Indentation on bone ## Footnote Notches can accommodate other structures or serve as points of articulation.

Question 44

What is bone ossification?

Answer 44

All bone develops from embryonic connective tissue called mesenchyme via one of two pathways ## Footnote Ossification is critical for bone formation and growth.

Question 45

What is intermembranous ossification?

Answer 45

Bone models consisting of mesenchymal cells develop osteoblasts (bone forming cells) which begin direct ossification ## Footnote Found in cranial vault, facial bones, most of the clavicle.

Question 46

Define endochondral ossification.

Answer 46

Mesenchymal cells first develop into chondroblasts (cartilage forming cells) that form a cartilaginous bone model with ossification occurring later at several points ## Footnote This process is common in long bone development.

Question 47

What is the primary ossification center?

Answer 47

Initiated by vascular periosteal bud along the diaphysis ## Footnote This center is crucial for the development of long bones.

Question 48

Define metaphysis.

Answer 48

Flared portion of the diaphysis near the epiphysis ## Footnote The metaphysis is involved in the growth of long bones.

Question 49

What are secondary ossification centers?

Answer 49

Initiated via epiphyseal arteries entering various parts of the epiphyses ## Footnote These centers contribute to the growth and shaping of bones.

Question 50

What are epiphysial plates?

Answer 50

Hyaline cartilage plates between the epiphysis and diaphysis allowing for longitudinal growth (i.e. lengthening) – forms epiphyseal line at fusion (cessation of growth) ## Footnote Epiphysial plates are critical for bone growth during childhood.

Question 51

What is a joint?

Answer 51

Point of articulation between two or more rigid components

Question 52

What are the three general types of joints?

Answer 52

* Fibrous joints * Cartilaginous joints * Synovial joints

Question 53

Define fibrous joints.

Answer 53

Articulating bones connected by fibrous tissue, membrane, or interosseous ligament

Question 54

What is a suture in terms of fibrous joints?

Answer 54

Often interlocking bones united by fibrous tissue (e.g. cranial sutures)

Question 55

What characterizes a syndesmosis joint?

Answer 55

United by a fibrous sheet or ligament – partially movable (e.g. interosseous membrane in forearm)

Question 56

What is a gomphosis joint?

Answer 56

Anchor tooth roots in an alveolus via short periodontal ligaments

Question 57

Define cartilaginous joints.

Answer 57

United via either hyaline cartilage or fibrocartilage

Question 58

What is a synchondrosis?

Answer 58

Primary cartilaginous joint united by hyaline cartilage (e.g. epiphysial plates)

Question 59

What is a symphysis?

Answer 59

Secondary cartilaginous joint united by fibrocartilage (e.g. intervertebral discs)

Question 60

What are synovial joints?

Answer 60

Most common type of joint consisting of a fibrous joint capsule lined with a synovial membrane

Question 61

What does the synovial cavity contain?

Answer 61

Synovial fluid which lubricates the articular cartilage covering the bones

Question 62

List the types of synovial joints.

Answer 62

* Pivot (e.g. atlanto-axial joint) * Ball and socket (e.g. hip joint) * Plane (e.g. acromioclavicular joint) * Hinge (e.g. elbow joint) * Saddle (thumb carpometacarpal joint) * Condyloid (metacarpophalangeal joint)

Question 63

Fill in the blank: A _______ joint allows for rotation around a single axis.

Answer 63

[pivot]

Question 64

True or False: Ball and socket joints allow for the most range of motion.

Answer 64

True

Question 65

Fill in the blank: The _______ joint is an example of a hinge joint.

Answer 65

[elbow]

Question 66

True or False: Fibrous joints are typically movable.

Answer 66

False

Question 67

What are the three types of muscles?

Answer 67

Smooth muscle, Cardiac muscle, Striated (skeletal) muscle ## Footnote These three types differ in structure, function, and control mechanisms.

Question 68

What is a key characteristic of smooth muscle?

Answer 68

Lack microscopic striations ## Footnote This feature distinguishes it from striated muscles.

Question 69

How is smooth muscle classified in terms of control?

Answer 69

Involuntary muscle (autonomic nervous system) ## Footnote It operates without conscious control.

Question 70

Where is smooth muscle typically located?

Answer 70

Walls of hollow organs, blood vessels, ducts, skin, and eye ## Footnote Examples include intestines and ureters.

Question 71

What is a defining feature of cardiac muscle?

Answer 71

Striated ## Footnote This striation is similar to that of skeletal muscle.

Question 72

What type of muscle is cardiac muscle classified as?

Answer 72

Involuntary muscle with specialized intrinsic conduction system ## Footnote This system is modulated by the autonomic nervous system.

Question 73

Where is cardiac muscle found?

Answer 73

In the heart ## Footnote It is essential for pumping blood.

Question 74

What is a defining characteristic of striated (skeletal) muscle?

Answer 74

Voluntary muscle (somatic nervous system) ## Footnote This allows for conscious control of movement.

Question 75

Where is striated (skeletal) muscle located?

Answer 75

Limbs, trunk, head, neck, etc. ## Footnote It is the most common type of muscle in the body.

Question 76

What are the two portions of striated muscle?

Answer 76

Fleshy contractile portion and noncontractile portion ## Footnote The fleshy part is often referred to as the head or belly, while the noncontractile part is a tendon or aponeurosis.

Question 77

In muscle anatomy, what is the fixed attachment site called?

Answer 77

Origin ## Footnote This is typically more proximal.

Question 78

What is the mobile attachment site of a muscle called?

Answer 78

Insertion ## Footnote This is generally more distal.

Question 79

How are skeletal muscles in the limbs organized?

Answer 79

Into muscle groups via fascial compartments ## Footnote These groups generally have similar actions, innervations, and attachments.

Question 80

What do many muscle names describe?

Answer 80

Size, length, depth, shape, form, attachment, function ## Footnote This nomenclature helps in identifying the muscles' characteristics.

Question 81

Give an example of a muscle named for its size.

Answer 81

Gluteus maximus muscle ## Footnote The name indicates it is the largest of the gluteal muscles.

Question 82

What does the name 'Palmaris longus' indicate about the muscle?

Answer 82

It is long and related to the palm ## Footnote The term 'longus' signifies its length.

Question 83

What does 'Flexor digitorum profundus' indicate about its depth?

Answer 83

It is a deep flexor of the digits ## Footnote 'Profund' means deep in Latin.

Question 84

What shape does the 'Piriformis muscle' refer to?

Answer 84

Pear-shaped ## Footnote 'Piri' in Latin translates to pear.

Question 85

What does 'Biceps femoris' mean in terms of muscle structure?

Answer 85

It has two heads of attachment on the femur ## Footnote 'Bi' means two in Latin.

Question 86

What does 'Levator scapulae' indicate about its function?

Answer 86

It is a lifter of the scapula ## Footnote 'Levator' is derived from the Latin word for lifter.

Question 87

True or False: If a muscle has an antithesis term, there is often a corresponding muscle named for it.

Answer 87

True ## Footnote For example, Flexor digitorum superficialis vs Flexor digitorum profundus.