Week 1 Flashcards
The presence of Type I collagen in the matrix indicates that the cartilage sample is most likely from
A. Epiglottis
B. Trachea
C. The nose
D. Intervertebral disc
Bonus: what other tissue has a high proportion of Type I collagen?
D. Intervertebral disc
Type I collagen indicates fibrous cartilage.
Bonus: also present in bone
218a Cartilage Histology
4. Describe the molecular components of the cartilage matrix.
The densest bone is found on the [outside/inside] layers of bone.
Outside - cortical bone - Haversian systems
219a Bone Histology 2. Describe the basic histologic structure of bone and distinguish between compact/lamellar and trabecular bone (MKS1a)
A child’s x-ray of the elbow shows ossification of the radial head but not the medial epicondyle.
The child is between:
A. 1-3 years B. 3-5 years C. 5-7 years D. 7-9 years E. 9-11 years F. 11+ years
B. 3-5 years
The mnemonic of the order of appearance of the individual ossification centers is C-R-I-T-O-E: Capitellum, 1yo Radial head, 3yo Internal (medial) epicondyle, 5yo Trochlea, 7yo Olecranon, 9yo External (lateral) epicondyle. 11yo
219a Bone Histology
6. Describe when ossification centers appear and fuse (MKS1a)
A 58 yo former typist comes to you with worsening hand pain. She is worst in the morning, better in the evening. Both her hands hurt, and are sometimes swollen at the joints. She also plays guitar, and has found making the chords with her left hand harder than using her fingers to strum. She keeps her nails painted because they are “ugly”. Her heels often also hurt and are swollen in the morning, but they get better when she rubs them down and starts walking around.
You run some tests and expect to find: A. RF and CCP B. ANA and anti-Sm C. Rash and CCP D. Joint space narrowing on x-ray
Answer:
Psoriatic arthritis, hinted at by inflammatory presentation (worse in morning, better with use/at the end of the day), swelling, fingernail changes, and Achilles enthesitis
C. Rash and CCP
Of note: if you said A for rheumatoid arthritis, this is the second highest in the DDx.
220a Joint Pain / Rheum
2. Use location and symmetry of a musculoskeletal problem to help distinguish
rheumatoid arthritis, psoriatic arthritis, and osteoarthritis?
3. List some autoantibodies in rheumatic diseases along with their disease associations
The longissimus is innervated by the [dorsal/ventral] rami of the spinal nerve.
This defines it as an [extrinsic/intrinsic] back muscle
Answer:
Dorsal rami, intrinsic
3. The intrinsic muscles of the back are the epaxial muscles which develop from the epimere of the myotome and
are innervated by dorsal rami of TSN. They maintain upright posture, and extend, bend, and rotate the head,
neck, back, and torso
221a Anatomy of the Back
4. Explain the relationship between development, innervation, and function of the extrinsic and intrinsic muscles of the back.
A patient with a rotator cuff has trouble lifting their right arm out to the side and over their head, and must use the left arm to lift it to 90 degrees before they can lift it the rest of the way.
They have most likely injured the:
A. Subscapularis
B. Supraspinatus
C. Infraspinatus
D. Teres minor
B. Supraspinatus
Abduction, typically linked to first 30 degrees of abduction (from 0-30) before the deltoid assist kicks in.
222a Anatomy/Organization of Upper Limb
2. Know the location, function, and innervation of the major muscles of the shoulder and arm. Approach this by
organizing the muscles into developmental (eg, compartments) or functional ( eg, rotator cuff) groups.
During an exciting game of croquet, a player gets struck in the back of the knee. On x-ray, there is no fracture, yet the player can no longer stand on their toes.
The injured nerve is in which compartment of the leg?
A. Anterior
B. Lateral
C. Posterior (Deep & Superficial)
C. Posterior
Tibial nerve injury, indicated by inability to stand on toes and location of original injury.
223a Anatomy/Organization of Lower Limb
1. Know the location, function, and innervation of the major muscles of the thigh, leg, and foot. Approach this by organizing the muscles into compartments of functional groups
One major contributor to the spring-like function of muscles is based on:
A. Number of motor neuron action potentials
B. Number of attached x-bridges due to filament overlap
C. Number of attached x-bridges due to speed of movement vs speed of myosin ATPase
B. Force-length (F-L): alteration in filament overlap as a consequence of different limb positions (i.e. muscle
lengths) alters # of attached x-bridges (FIG 4) (also often referred to as the length-tension (L-T) function).
F-L function: an elastic spring: stiffness is an increase in force for an increase in length.
224a Muscle Physiology & Mechanics
2. Describe basic mechanical properties of our musculoskeleltal system, especially its springlike behavior
A 55 yo formerly obese woman presents to your clinic with 6 months of right knee pain. 10 years ago, she lost 100lbs by running, and has been an avid runner ever since. Her knee pain is better in the morning, and worsens throughout the day. Her grandmother had rheumatoid arthritis, and her mother was a seamstress but had to retire “due to her finger joints getting bumpy”. When you ask “anything else”, she adds that her left hip has started to ache at the end of long runs.
You run some tests and expect to find: A. RF and CCP B. ANA and anti-Sm C. Rash and CCP D. Joint space narrowing on x-ray
D. Joint space narrowing on x-ray
Osteoarthritis, monoarticular, history of joint load and overuse.
225a Osteoarthritis
2. Compare the symptoms and physical exam features of a person who has osteoarthritis from those of a person
who has rheumatoid arthritis, when these features are presented in the format of a clinical vignette.
