Trivia Flashcards
A bone is classified as this shape when it does not fit any other mold.
Irregular
A cell that builds bone matrix has this in common with a cell that helps form skeletal muscles.
-blast in its name
A hair follicle, skeletal muscle, and long bone are all considered this.
Organs
(Comprised of 2 or more tissue types)
A muscle cell and neuron share this key property.
Excitable - communicate information rapidly, over long distances through the cell using changes in membrane potential
A person damages their articular cartilage and later feels pain. Where is this pain likely coming from?
Bone
(Cartilage does not have nerves)
An action potential is initiated following the depolarization of this location. (Can you answer for both of our electrically excitable cells?)
Motor end plate (muscles)
Axon hillock (nerves)
Balance between these is key to maintaining bone density.
Osteoblast and osteoclast activity
Central canals blood vessels must reach. To do so, they much pass through these.
Perforating canals
Cross-bridges cycle, yet the muscle does not shorten. Why?
Tension does not exceed load, could also be that the muscle is overstretched to the point where there is 0 overlap
(no overlap = no shortening)
Extracellular matrix that is made by osteoblasts, is not quite bone matrix, but is almost bone matrix is called by this name.
Osteoid
For a muscle to relax, this must be undone.
Cross bridge needs to detach
Could also talk about removing calcium from the cytosol, change in tropomyosin position, breaking down the acetylcholine
I die when my surroundings calcify. What am i?
Chondrocyte
(die by this mechanism in endochondral ossification)
If this is unavailable, a skeletal muscle cannot shorten.
ATP or active sites on actin
May also put calcium, signal from motor neuron
If this replaces a damaged tissue, the original function will be lost.
Scar tissue
(Fibrous dense connective tissue)
In the absence of hairs, a person may have trouble detecting this.
Debris or insects
Lifting a heavy object? Expect to recruit more of these to accomplish the job.
Motor units
Muscle or neuron it matters not, depolarization always involves the movement of this.
Sodium ions
(Across the membrane and into the cell)
No matter the bone, this forms its outside.
Perimysium (most superficial part of the bone)
Some might describe skeletal muscle as a bundle of bundles of fibers. What wraps the bundles?
Epimysium (surrounds all the bundles/everything)
OR perimysium (what surrounds an individual bundle of fibers)
The arrector pili muscles provides the “push” that this needs to get to the surface of the skin
Sebum
The contraction of these cells when you are nervous makes you sweat.
Myoepithelial cells
(Myo - part of the name implies contraction)
The secretions of these glands are tied to body odor.
Apocrine sweat glands
(Bacteria feed on these secretions and produce body odor)
The word “power” in power stroke refers to this.
(Hint it is not ATP hydrolysis)
Myosin (part of thick filament) pulling actin (part of thin filament) - pulling = tension
These make a cell “attractive” to both Na+ and K+
Protein anions
This helps you dilute out and wash away things that come into contact with your skin.
Sweat
This increases when a muscle shortens.
Zone of overlap / degree of overlap between thick and thin filaments
This is how excitation gets coupled to contraction in a muscle.
Depolarization of t tubules leads to opening of calcium channels so that calcium can diffuse into the cytosol, bind troponin, and troponin can move tropomyosin to uncover that active sites on actin
This makes hair and nails tougher than our skin.
Hard keratin
(as opposed to soft keratin)
This must be exceeded to create movement.
Load
(Force that opposes movement)
This refers to a change in membrane potential that can vary in magnitude.
Graded
(Graded = levels = can be variable)
To build bone without this is to all but guarantee a break.
Collagen
Trapped in the matrix, these let osteocytes survive.
Canaliculi
What is something that is not part of the skeletal system, yet also serves functions such as protecting organs and storing nutrients?
Skeletal muscles
What structure is seen in compact but not spongy bone?
Osteons, central canals, different arrangements of the lamellae (spongy just has very few layers that are irregularly arranged)
When just the endosteum and periosteum are involved, a bone can only grow in this way.
In width or thickness (appositional growth), but not in length
Where no net stress is applied to long bone, you find this instead of bone tissue.
Empty spaces that can be filled with marrow
(E.g. medullary cavity)
