GD FIRST TIMERS CORE 2: Bones 2 (A-F)

An osteon is how long:

Osteons are like logs in that they have rings. The log-like osteons grow side-by-side with each other in bones.

Giant Sequoia trees may have a thousand rings or more, but the maximum amount of rings that an osteon has is about 200.

The tube (C is pointing to one layer of it) that has concentric circles (rings) which are protruding out from the rest of the tubes is:

Osteons are about as wide as a cat’s whisker.

One lamellae layer in bone (a ring) is 7-8 inches wide which is about as wide as a red blood cell.

Lamellae means “thin layer”. A tree ring has what can be called lamellae and so does a gecko’s foot. The dark “lamellae rings” of wood are the winter growth of the wood.

Mushroom “gills” (The straight lines below) are where spores are made. The are also called lamellae.

A mushroom spore has all the mushroom DNA in it to make a new mushroom fungus.

Mushroom gill lamellae (the straight lines above) increase the surface area to make leaves for the fungus.

Fish gill lamellae (secondary) stand up straight. The blood flow in them runs the opposite direction to the water flow coming in through the gills.

A tuna fish can weigh up to 1500 pounds!

What covers the gills to protect them is the skin layer called the popacitum.

A nudibranch sea slug has very unusual gills. They are located in the slime-secreting “foot” that it slides on.