respiratory and digestive system descriptions quiz 6

lumen

a cavity or hole inside of a tube, blood vessel or hollow organ. blood flows through the ____ of the blood vessel

acini

small, ball shaped cluster of secretory cells surrounding ducts

duct

a tubular structure transports secretions of gland. ____ are comprised of a single cubiodal epithelium, doughnut pattern

lobes

large, roundish projection of divisions of organs. ___ can be seen with the naked eye.

lobules

small divisons of the cells in an organ, forming a functional unit. ____ usually require a microscope to be seen

general alimentary canal

the stomac, small intestine, and large intestine have a similar general structure. 4 layers of tissue called tunics,

serosa

very thin tunic made of simple squamous epithelium that surrounds the outside of the organ. difficult to see bc of how thin it is but always is there.

muscularis externa

lies immediately inside the serosa, comprise of at least 2 layers of smooth muscle - outer layer longitudinal, inner layer circulatory. helps peristalsis (wave like movement to help food through.) one layer the nuclei is like cigars, the other is round

submucosa

next to muscularis externa, rather empty looking tunica, scattered nucli, a few wavy collagen fibers and sometimes glanduar tissue

mucosa

closest to lumen, has 3 sub layers

muscularis mucosa

first sub layer of mucosa, thin layer of smooth muscle, dark pink band.

lamina propria

a loose matrix of cells and ground tissue, middle layer

epithelium

protects the organ from what is insid the lumen, closest sub layer to lumen.

order of tunicas, including sublayers. Outside → Inside.

serosa>muscularis externa>submucosa>mecosa(muscularis mucosa>lamina propia>epithelium)