Locomotion Flashcards
What is the function of the musculoskeletal system?
What are its components?
The musculoskeletal system allows movement and interaction with our environment.
Its components are:
- Bones
- Joints
- Muscles
List the functions of bones, joints and muscles
Bones:
- Structural support
- Protection
- Calcium store
- Haematopoiesis (parts of the bone invovlved in RBC production)
Joints
- Facilitate movement: (they dont generate movement)
- Allow growth
- Stability
Muscles
- Generate movement
- Generate heat
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Label the diagram
List the characteristics of the outer cortex and inner medulla
Outer cortex
- Compact (cortical) bone
- Dense
- Strong
- Heavy
Inner medulla
- Spongy (trabecular/cancellous) bone
- Light
- Weaker
- More porous
What is the function of the medulla (and which specific bones are involved in this)?
- The medulla MAY contain bone marrow
- In some bones the marrow is the site of hematopoiesis: RBC and WBC protection
- skull
- vertebrae
- Sternum
- ribs
- hip bone
- in the proximal cancellous ends of the long bones femur and humerus
Label the diagram
Describe the bone’s neurovascular supply
Periosteum (fibrous connective tissue “sleeve”):
- Vascularised: has neurovascular bundles in it - vein, artery, nerve, lymphatics
- Supplies the compact bone around the outside of the bone (not spongy bone)
- It is very well innervated, very sensitive to sensation: during fractures most of the pain is actually from the periosteum tearing
Nutrient vessels (nutrient artery & vein). Supplies medullary cavity:
- Bone marrow
- Spongy bone
- Deep compact bone
Label the diagram
NB. Epiphysis and epiphyseal growth plate conected. Metaphysis comes after
Metaphysis = neck of bone
Diaphysis = shaft of bone
How do long bones develop? Name and describe the process
Long bones develop via endochondral ossification:
- process in which an initial small, hyaline cartilage version of the bone grows and turns into bone (ossifies)
- begins to ossify via 2 ossification centers – the primary ossification centre in the diaphysis and the secondary ossificaiton cenre in the epiphysis
- Epiphyseal growth plate remains hyaline cartilage as long as the bone continues to grow - this is where most of the growth of the bone occurs
- Once you reach your ultimate height, the growth plates fuse
What is the difference between tendons and ligaments?
Tendon = connective tissue that connects muscle to bone
Ligament = connective tissue connecting two bones
Label the different types of bone with examples
What are the 2 divisions of the skeleton?
Label them and their constituent parts
What is the seeming exception?
The sacrum is part of axial skeleton, but technically also part of the pelvic girldle (appendicular).
The axial classiciation overrides the appendicular
NOTE:
- coccyx not included in axial skeleton
- Appendicular = upper and lower limbs and the girdles that attach them
How many vertebra do we have? What are their subdivisions?
How many curvatures does our vertebral column have?
Label them
What causes their development?
Every adult has 4 curves intheir vertebral column
The curves that are the same as the fetus – primary curvature
Secondary curvature = develops as a result of bipedalism and weight bearing
Where are spinal nerves found?
What kind of joint occurs between the articular processes of vertebrae?
What can it be affected by?
In the intervertebral foraminae (which form between adjacent vertebrae - only appear when the vertebrae are stacked together)
Vertebral facets (on processes) joined by:
- Facet joint: synovial plane joint
- Between inferior/superior articular processes of 2 adjacent vertebrae
- Affected by arthritis
Which part of the body do the spinal nerves supply?
How do they connect with that body part and with the spinal cord?
The spinal nerves supply the soma (body wall)
They connect with the soma via anterior and posterior rami (branches)
They connect with the spinal cord via roots and rootlets
What is a common feature/characteristic identifying feature of cervical vertebrae?
Why is this feature in place?
Are there any exceptions?
Any vertebra with little holes in the transverse processes (in each transverse process) = cervical vertebrae: has transverse foramen
Transverse foraminae are for the passage of vertebral arteries
Except C7 = transverse foraminae much smaller since only smaller veins go through them. Sometimes missing in C7
Which are the atypical cervical vertebrae?
Name them and describe their features
C1, C2, C7 = completely atypical
C1 - Atlas:
- does not have a body
- does not have a spinous process
- has a posterior arch and an anterior arch instead
C2 - Axis:
- has an odontoid process which projects superiorly from body (has stolen C1’s body)
C7:
- vertebrae prominens - long spinous process
- first palpable spinous process in 70% of people: palpated in the midline of the posterior aspect of the neck
- small or missing transverse processes: for passage of small veins instead of arteries
Identify the bone
C7: vertebrae prominens
Identify the bone
C1: Atlas
Identify the bone
C2: Axis
What are the two girdles of the body? What are their functions?
The two girdles of the body are:
Pectoral girdle (2 scapulas and 2 clavicles): attaches upper limb to trunk
Pelvic girdle (Sacrum and 2 hip bones): attaches lower limb to trunk
Label the diagram
What does meta mean?
Meta = beyond or after
What are the two parts of the skull?
What is their dividing line and where does it run?
The two parts of the skull are
Neurocranium: bones of the cranial vault
Viscerocranium: bones of the facial skeleton
They are divided by the base of the skull (most inferior part of the neurocranium), which runs from superior to the orbits to inferior to the ears
What are the 3 types of muscle?
Describe their characteristics
- Skeletal Muscle
- Striated: actin & myosin filaments in sarcomere
- Voluntary
- Function: Mainly skeletal movements
- Cardiac Muscle
- Striated: actin & mysoin filaments in sarcomere
- Involuntary
- Function: Heart beating
- Smooth Muscle
- Unstriated: does not need to contract
- Tube
- Function: viscera
What are the descending units of skeletal muscle?
- Skeletal muscle
- Muscle fascicle (bundle of muscle fibres)
- Muscle fibre (bundle of myofibrils)
- Myofibril (bundle of myfilaments)
- Myofilaments (bundle of sarcomeres)
- Sarcomeres: Z line of actin to next Z line of actin
- Actin filaments: thin (light stripe)
- Myosin filaments: thick (dark stripe)
What is straining of skeletal muscle?
What does grade 3 strain indicate?
Strained = tearing some of the fibers
3 is the most severe: ruptured = completely torn
What are the types of skeletal muscle? List with examples
- Sphincter muscles: circular e.g. orbicularis oris
- Quadrate: 4-sided or square looking e.g. abdominus rectus
- Fusiform: spindle shaped (big belly that tapers on either end) e.g. biceps brachii
- Pennate: feather-like e.g. deltoid
- Flat with aponeurosis: flattened tendon instead of tube-shaped e.g. external oblique
What determines skeletal muscle contractility and range of motion?
Length of the muscle
longer muscle fibres:
- greater potential range of shortening
- greater potential range of movement produced at joint
Describe skeletal muscle attachment to bone
What is the exception?
Muscles attach to bone by tendons (usually)
usually at least 2 points of attachment to bone
- the “origin(s)” on one side of a joint: usually more proximal to the body (not always the case)
- the “insertion(s)” on the other side: usually more distal (not always the case)
- Muscles have to cross a joint to be able to move it by contraction
Tendons (connective tissue) usually connect muscle to bone. One area where this is not the case is the face.
Muscles of facial expression
Attach from bone to skin and soft tissue (of the superficial fascia)
What is the function of facial muscles?
- Muscles of facial expression allow for communication without words: Convey emotion
- protect entrance into the body
Where are skeletal muscles found?
How are they compartmentalized?
What is the exception?
skeletal muscles usually found deep to deep fascia
- deep fascia: tough fibrous connective tissue covering
- deep fascia separates muscle into different compartments by forming intermuscular septae
Facial muscles are an exception (not deep to deep fascia)
Label the diagram with the characteristic of each layer
Are the muscles that perform reflexes skeletal or smooth?
Do we have control over reflexes?
Where do muscles transition between types?
muscles that perform the protective reflexes of coughing, sneezing, gagging, swallowing & vomiting are all skeletal muscles of the proximal respiratory/alimentary tracts
NB We don’t have control of reflexes, but generally have control over the muscles that perform reflexes
- approximate level of transition to smooth muscle: around C6 (the trachea & the middle third of the oesophagus)
- Upper 3rd of oesophagus = skeletal muscle
- Lower 3rd = smooth muscle
- Middle 3rd = both, transition zone
- approximate level of transition back to skeletal muscle: the perineum
muscles that control micturition & defecation are skeletal muscles
What are the different types of joints?
Describe their compromise profile
Different types and subtypes of joints
- Fibrous
- Cartilaginous
- Synovial
Each is a compromise between mobility and stability:
- Fibrous is more stable and less mobile
- Cartilaginous is in the middle
- Synovial is less stable and more mobile
What are the subtypes of fibrous joints?
Give examples
Fibrous joints:
- Generally limited mobility
- Quite stable
Types
1. Syndesmoses
- Unites bones with fibrous sheet/fibrous membrane
- Quite stable
- Partially movable
- e.g. interosseous membranes: a fibrous sheet between fibula and tibia
2. Sutures
- Between bones of skull
- Interlocking: Highly stable
- Can sometimes completely fuse together so we don’t even see joint anymore
- e.g. coronal suture
3. Gomphosis
- Dento alveolar syndesmosis
- Very little movement
- Peridontal ligament: is a gomphotic joint - attaches tooth to the alveolar bone in which it sits
What are the types of cartilaginous joints?
Describe them with examples
1. Primary cartilaginous
- Synchondroses: bones joined by hyaline cartilage
- e.g. long bone epiphyseal growth plate
- permit growth in length of bone
- Growth until ossification and fusion
2. Secondary cartilaginous
- Symphyses: fibrocartilaginous fusion between two bones
- Fibrocartilage very strong
- Slightly movable individually (we get big movements collectively across little movements of individual vertebra)
- e.g. intervertebral discs
What is a disadvantage of cartilaginous joints?
Since slightly less stable/with a bit more mobility than fibrous joints, both types of cartilaginous joints (primary and secondary) can ‘slip’ (generally backwards)
e.g.
primary – slipped femoral epiphysis
secondary – slipped disc
What are the different types of synovial joints?
- Ball and socket
- Pivot
- Hinge
- Plane
- Saddle
- Condyloid
Label the diagram
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