Musculoskeletal Anatomy Flashcards
(38 cards)
1
Q
Role of Skeletal System?
A
SPMPS:
STABILITY - Consists of 206 bones, forming a framework, which the softer tissues
and organs of the body are attached
PROTECTION - Vital organs are protected by the skeletal system
MOVEMENT - Bodily movement is carried out by the interaction of the muscular and
skeletal systems
PRODUCTION - Blood cells are produced by the marrow located in some bone
STORAGE - Bones serve as a storage area for minerals such as calcium and phosphorus
2
Q
Function of Skeletal system?
A
- Enables movement for locomotion
- Provides physical support (framework)
- Provides protection for internal organs
- Acts as a reservoir for minerals
- Blood cell formation
3
Q
Axial Skeleton
A
- 80 Bones
- Forms point of attachment for
appendicular skeleton; Houses vital
organs - Divided into five regions: Skull (22), Cranial Bones (8), Facial Bones (14), Auditory Ossicles (6), Hyoid Bone (Located in neck, 1), Vertebral Column (26), Thoracic Cage (25) - Sternum (1) Ribs (24
4
Q
Appendicular Skeleton
A
- 126 Bones
- Function = Movement and Manipulation
- Divided into six major regions: Shoulder/Pectoral Girdles (4), Arm and Forearm (6), Hands (58), Pelvis (2), Thigh and leg (8), Feet (48)
5
Q
Structure of skeletal system
A
- Rigid, hard structure
- Bone (osseous) tissue
- Two types of bone tissue: Compact (cortical) bone =
80% of skeleton, Cancellous or
spongy bone - High compressive
strength = Pushing - Poor tensile strength= Pulling
- Very low shear stress strength =Twisting
6
Q
Two forms of bony tissue
A
Cancellous bone lies
deep to the compact bone. Collagen fibres laid down in plates called lamellae, quite widely spaced
Compact (cortical) bone forms the outer layer of a bone. Collagen fibres closely packed make it dense
7
Q
Bone Classification
A
5 types
- long
- short
- flat
- irregular
- sesamoid
8
Q
Long bones
A
- Found in the limbs
- Consist of a shaft (diaphysis) and two expanded ends
(epiphysis) - epiphysial ends are covered in articular cartilage as it articulates with other joints/bones
Structure of long bone:
- Diaphysis
- Epiphyses
- Periosteum
- Endosteum
9
Q
Short bones
A
- Found in the wrist
(carpal bones) and
part of the foot
(tarsal bones) - They are mainly
composed of trabecular bone with a thin outer crust of compact bone
10
Q
Flat bones
A
- Thin and curved
- Include bones of the skull
vault and the ribs - They consist of two layers
of compact bone enclosing
trabecular bone
11
Q
Irregular bones
A
- Bones which fit none of the other categories
- They consist of a thin layer of compact bone surrounding trabecular bone
- E.g. Vertebrae and many skull/face bones
12
Q
Sesamoid bones
A
- Found in tendons, e.g. Patella
- Small seed shaped
bones which develop
in vulnerable tendons - Prevents friction where a tendon passes over a
bone
13
Q
Articulations
A
- Articulations (Joints) of Bone
- Arthrology = the scientific study of joints
- Synovial = fluid/cavity identified by the presence of thick fluid providing lubrication and cushioning
- Fibrous Tissue = connective tissue, high tensile strength
14
Q
Joint classifications
A
- The structural classification of joints:
1) Fibrous joints
2) Cartilaginous joints
3) Synovial joints - The functional classification of joints:
1) Synarthrosis
2) Amphiarthrosis
3) Diarthrosis - The same joint can have a functional and structural
classification - Structural = based on the absence or presence of a space between the articulating bones called a
synovial cavity and the type of connective tissue that binds the bones together - Fibrous
- Cartilaginous
- Synovial
15
Q
Functional Classifications
A
- Functional Classifications are based upon the degree of movement allowed by an articulation
1) Synarthosis – immovable joint
2) Amphiathrosis – slightly movable
3) Diathrosis – freely movable
16
Q
Joints (Fibrous Joints)
A
- Lack a synovial cavity
- The articulating bones are
held very closely together
by dense irregular
connective tissue - Fibrous joints permit little
or no movement - Three types of fibrous
joints
1) Sutures
2) Syndesmoses
3) Gomphoses
17
Q
Joints (Cartilaginous Joints)
A
- Lacks a synovial cavity
- Allows little or no movement
- Joint is tightly connected by cartilage
- Two types of cartilaginous
joints: - Synchondroses
- Connecting tissue is hyaline cartilage
- Epiphyseal (growth) plate
- Symphyses
- Slightly movable joint
- Ends of the articulating bones are covered with
hyaline cartilage, but a disc of fibrocartilage connects the bones - Pubic symphysis
- Between the anterior
surfaces of the hip bones - Intervertebral joints between the vertebrae
18
Q
Diarthrosis (Freely moveable) Joints
A
- A freely mobile joint is classified as a diarthrosis
- Provide the majority of body movements.
- Most diarthrotic joints are found in the appendicular skeleton and thus give the limbs a wide range of motion.
- Divided into three categories, based on the number of axes of
motion provided by each.
1) uniaxial (for movement in one plane)
2) biaxial (for movement in two planes)
3) multiaxial joints (for movement in all
three anatomical planes)
19
Q
Features of Joints (Synovial Joints)
A
- Synovial cavity allows a joint to be freely movable
- Ligaments hold bones
together in a synovial joint - Articular Capsule
- Synovial Fluid
20
Q
Features of Joints (Synovial Joints)
A
- Accessory Ligaments and
Articular Discs - Menisci
- Bursae
- Tendon sheaths
21
Q
Types of Diarthrosis Joints
A
- Gliding (plane) Joint = joint has flat articulating surfaces that are slightly curved and may be either ovoid or sellar
- Multidirectional, but no rotation around an axis
- Hinge Joint = the convex surface of one bone fits into the concave
surface of the other - Movement is usually flexion and extension
- Hyperextension
- Pivot Joint- a rounded or
pointed surface of one bone articulates within a ring formed partly by bone and partly by ligament - Movement is primarily rotation, movement of a bone around its axis
- e.g. wrist
- Condyloid/Ellipsoid Joint-
oval shaped articulating
surface of one bone fits into a depression of another bone - Movement is side-to-side and back-and-forth
- e.g. Flexion/extension and adduction/abduction
- Saddle Joint = the articular surface of one bone is saddle-shaped
and the articular surface of the other is shaped like the legs of a rider sitting in a saddle - e.g. side-to-side and back-and-forth
- Ball and Socket = a ball like surface of one bone fitted into a cuplike depression of another bone
- e.g. hips, shoulders
22
Q
Types of muscle
A
- Smooth Involuntary muscle; controlled by the autonomic nervous system
- Located in the walls of blood vessels and throughout internal organs
- Cardiac Controlled by the autonomic nervous and endocrine systems
- Located only in the heart
- Skeletal Voluntary muscle; controlled consciously by the somatic nervous system
- More than 600 different skeletal muscles located throughout the body
23
Q
General Properties of Muscle Tissue
A
- Contractility: ability of a muscle to shorten with force
- Excitability: capacity of muscle to respond to a stimulus (usually from nerves)
- Extensibility: muscle can be stretched beyond normal resting length and still be able to contract
- Elasticity: ability of muscle to recoil to original resting length after stretched
24
Q
Naming Skeletal Muscles
A
- Muscles are named
according to 7 criteria:
1) Location
2) Size
3) Number of origins
4) Origin and insertion
5) Shape
6) Orientation of fasciculi
(direction of muscle fibres)
7) Action
25
Location
Structure near which muscle is found
26
Size
Relative Size of Muscle:
1) Maximus = largest
2) Medius = middle
3) Minimus = smallest
4) Longus = longest
5) Brevis = short
6) Tertius = third
27
Origin and Insertion
- The origin is the attachment site that doesn't move during
contraction
- The insertion is the attachment site that does move when the muscle contracts
- One end of the muscle is fixed in its position, while the other end moves during contraction
28
Number of Origins
- Biceps = Two
- Triceps = Three
- Quadriceps = Four
29
Shape
Relative Shape of the Muscle:
- DELTOID = triangular shape
- TRAPEZIUS = trapezoid shape
- SERRATUS = saw-toothed
- RHOMBOIDEUS = rhomboid shape
- TERES = round
30
Action
- FLEXOR: Decrease angle at a joint
- EXTENSOR: Increase angle at a joint
- ABDUCTOR: Move bone away from midline
- ADDUCTOR: Move bone toward midline
- LEVATOR: Produce upward movement
- DEPRESSOR: Produce downward movement
- SUPINATOR: Turn palm upward/anterior
- PRONATOR: Turn palm
downward/posterior
31
Contribution to movement
- Prime mover (agonist) major role in a specific movement
- Assistant movers: similar to prime mover but less significant
- Antagonists: act in direct opposition to agonist
- Co-contraction: of agonist and antagonist can be desirable
- Stabilizers (fixators): muscles that contract to control the position of a bone
- Synergists: act simultaneously with one or more muscles to enable the agonist to produce the correct movement
32
Direction/Orientation of Muscle Fibers
- Relative to the Midline
- RECTUS = parallel to the
midline
- TRANSVERSE = perpendicular to midline
- OBLIQUE = diagonal to
midline
33
Muscle Shapes
- Fusiform = muscle belly is wider than at tendons
- Pennate = many types, but the key characteristic is fibres running diagonally between tendons
34
Types of Muscle
Contractions
- Isometric: no change in
length but tension
increases
- Isotonic: change in length
but tension constant
35
Muscle Fibers Types
- Slow-twitch (type I): Contract more slowly, smaller in diameter, better blood supply, more mitochondria, more fatigue-resistant than
fast-twitch, large amount of myoglobin
- Fast-twitch (type II): Respond rapidly to nervous stimulation, contain myosin that can break down ATP more rapidly than that in Type
I, less blood supply, fewer and smaller mitochondria than slow-twitch. Comes in oxidative and glycolytic forms
36
Parts of a Muscle
Sarcolemma
sarcoplasm
Transverse tubules
Sarcoplasmic reticulum
Myofibrils
Myofilaments
Sarcomere
37
Sarcomeres
- Regions of sarcomere:
- A bands
- I bands
- H zone
- M line
38
Actin (Thin) and Myosin (Thick) Myofilaments
- Many elongated
myosin molecules
shaped like golf clubs
- Two strands of fibrous (F) actin form a double helix
- Tropomyosin
- Troponin
