Anatomy Flashcards
Describe the transverse plane
It is a horizontal plane that cuts you in half at the belly button approx.
Describe the Sagittal Plane
Vertical plane that is in line with your butt crack
Describe the Frontal Plane
Vertical plane that is parallel to collar bones
What is abduction?
Moving your leg or arm away from you
What is adduction?
Moving your leg or arm towards you
Describe synarthrodial joints
Joint that connects bones by fibrous tissue and allows little or no movement (ex. connections between different parts of the skull) (can think of these joints as sutures)
Describe amphiarthrodial joints
Joint that allows small amount of motion (ex. vertebrae)
Describe diarthrodial joints
Diarthrodial or synovial joints are the main joints about which movements occur, which includes the majority of joints in the body. These are either uniaxial, biaxial, or multiaxial joints.
In which direction do antero-posterior rotations typically occur?
In line with the frontal plane. ie. moving your arm away from your body sideways
In which direction do medio-lateral rotations typically occur?
In line with the sagittal plane. ie. Swinging your leg back and forth at the hip
What are the two distinct phases for each limb?
1) Stance
2) Swing
What are the parts of the stance phase?
1) Initial contact
2) Loading Response
3) Midstance
4) Terminal Distance
5) Pre-swing
6) Toe-off
What is the loading response and % of stride?
Sole of foot comes in contact with the ground (10-15%)
What is the midstance and % of stride?
Tibia rotates over the stationary foot (15-30%)
What is the terminal stance and % of stride?
Weight is shifted to the forefoot (30-45%)
What is the pre-swing and % of stride?
Weight is shifted onto other limb in preparation for swing phase (45-60%)
What are the periods of the swing phase and associated percentages?
1) Initial Swing (60-73%)
2) Mid-swing (73-87%)
3) Terminal Swing (87-100%)
What is the most accepted model of gait mechanics?
Inverted pendulum model
Why does it cost energy to walk?
- We must transition from one pendulum-like step to the next
- Have to redirect CM upward into the next pendulum
What is the froude number?
Ratio of centripetal force over the gravitational force (v^2/gL)
How much mechanical energy is conserved in human walking?
60-70%
In human walking, how do gravitational force and centripetal force relate?
Gravitational force must >= centripetal force
When should the walk to run transition occur?
Transition at less than but close to efficiency overlap point
What is the purpose of articular cartilage?
- Load transmission
- Stress transmission
- low friction contact
What are the three different zones in cartilage?
Articular surface 1) Superficial zone 2) Middle Zone 3) Deep Zone Tidemark
What happens to the orientation of the collagen fibres as you go deeper in the cartilage?
Collagen fibres go from horizontal to vertical and the uniaxial strain modulus (MPa) increases
What do the collagen fibres and proteoglycan matrix retain?
- Collagen fibres retain proteoglycans
- Proteoglycan matrix retains fluid
What are the charges on the proteoglycan matrix, collagen fibres, and interstitial fluid?
proteoglycan matrix = negative
interstitial fluid = positive
collagen fibres = neutral
What are the structural functions of the proteoglycan matrix, collagen fibres, and interstitial fluid?
proteoglycan matrix = compression
interstitial fluid = compression
collagen fibres = shear,tension
What blocks the binding sites on the actin, and when does this occur?
Tropomyosin, and when the muscle is relaxed.
What needs to occur for the binding sites to be exposed?
Calcium ions needs to bind with Troponin on the actin which pulls the Tropomyosin off of the binding sites.
How does the muscle contract through actin and myosin?
Actin is the thin filament that surrounds the myosin.
Myosin uses ATP to attach to actin at binding sites and pull it, causing muscle contraction.
What are the three regions of force-length relationship?
Ascending limb, Plateau region, descending limb
What is the centre of mass equation from Fred’s notes?
R_g = 1/m∫(ρ*r dV)
What is the total linear momentum density from Fred’s Notes?
P = ∫(ρ*v dV)
What is the total angular momentum density from Fred’s Notes?
Lo = ∫(r x ρ*v dV)
After expanding the total angular momentum density equation, what is the fourth term equal to?
Tensor of inertia
What does the total angular momentum simplify to if the local reference frame P coincides with the centre of mass G?
L_o = R_g x (mv_g) + J_gω
What is the tensor of inertia in matrix notation?
J_p = ∫ (ρ[(ξ_pξ_p)δ_ij - ξ_iξ_j])dV
What are the simplified equations for linear and angular momentum?
Linear: P = mv_g
Angular: L_o = r_g x (mv_g) + J_g*ω
Provide the equation that constitutes the simplest way to measure experimentally the moment of inertia of a rigid body.
J_g = ( [ T^2mgl ] / [ 4π^2 ] ) - ml^2
What are the Cardan angles sometimes named?
Tait-Bryan angles
How do you find the transformation of a second order tensor A with rotation matrix Q?
A’ = [Q]^T [A] [Q]
What is passive rotation?
old basis vectors rotated by orthogonal tensor Q into new basis
{v}’ = [Q]^T {v}
What is active rotation?
Basis vectors remain unchanged, the vector is transformed into a new vector:
{w} = [Q] {v}
Important features of articular cartilage modelling?
multiphasic: solid, fluid, ions
microstructured: cells, PGs, collagen fibres
anisotropic: direction-dependence
inhomogeneous: location-dependence
non-linear: under large deformations
What is the first approximation of articular cartilage modelling?
biphasic: solid, fluid non-structured: regular continuum isotropic: rotation-invariant homogeneous: translation-invariant linear: small displacements
What does the confined compression test measure?
Measures properties in one direction, and location dependence:
inhomogeneity
What does the unconfined compression test measure?
To measure properties in different directions:
anisotropy
What is the interstitial fluid in cartilage for?
nutrient transport
(tissue is avascular!)
What do the 11 DLT parameters depend on?
u'_ci = camera geometry x_ci = camera position D_ij = camera orientation
