Animal structure Flashcards
(31 cards)
Why can’t humans sit in water and absorb it through their skin?
The keratin interwoven into the skin traps oils in the holes in the mesh. Because water and oil are insoluble in one another, water cannot diffuse through.
However, fat soluble things can get in! Ex. poison oak.
What are the four type of tissue?
- epithelial
- nervous
- muscle
- connective
What is simple epithelium?
Epithelium that is one cell layer thick
What is stratified epithelium?
Epithelium that has two or more layers.
What do squamous epithelial cells look like? Give a location example.
Flat cells with no geometric shape.
Found in the lungs & blood vessels (easy diffusion)
What do cuboidal epithelial cells look like?
Shaped like cubes.
Found in the kidney tubules
What do columnar epithelial cells look like?
Taller than they are wide.
Found in the intestine.
What do Pseudostratified Columnar epithelial cells look like?
Appear stratified, but actually all of the cells are attached to the basement membrane (but not all reach the apical surface)
Found in the lining of the respiratory tract
What is a gland? What type of tissue are they made of?
Glands produce metabolic products and secrete those into ducts or body fluid including the blood.
These are composed of epithelial tissue.
What are exocrine glands?
These glands secrete products through ducts directly to the target.
Ex. Sweat, saliva, tears
What are endocrine glands?
These glands secrete products into the blood for transport to their destination.
Ex. thyroid, pituitary
What is the difference between exocrine glands and endocrine glands?
Exocrine glands transport products through ducts directly to the target.
Endocrine glands transport products through blood to get to the target.
What is the most diverse tissue type in the animal body?
Connective tissue
What germ layer does connective tissue arise from?
The mesoderm
What are the two BROAD types of connective tissue?
Proper & Special
What cell secretes the extracellular matrix in connective tissue?
Fibroblasts
What are the two type of fibers that support the extra cellular matrix in connective tissue? What is their function?
Elastin fibers
- makes the tissue elastic
Collagen fibers
-helps in support
What is loose connective tissue?
Tissue that has cells scattered within a matrix that contains a large amount of ground substance.
Found between the skin and organs to act as a shock absorber.
What type of tissue is adipose tissue.
Fat is stored in adipose tissue, a type of loose connective tissue.
Globules increase or decrease in size, not in number, when we gain or lose weight
What is dense connective tissue?
This has less ground substance and has more tightly packed collagen.
What are the two type of dense connective tissue?
Regular
- the collagen fibers line up in parallel
ex. tendons and ligaments
Irregular
- different orientations of collagen
ex. covers muscles, nerves, and bones
What is cartilage? Where is it found? What are the cells called?
A special type of firm and flexible connective tissue that does not stretch.
It’s found in joints, the outer ear, the larynx, and the nose.
Cells = chondrocytes
What is bone? Where is it found? What are the cells called?
A special type of connective tissue composed of calcium phosphate crystals.
It’s found in most of the skeleton.
Cells = osteocytes
What is ossification and what type of cells carry this out?
Ossification is the process by which cartilage is replaces by bone. This is achieved by bone forming cells called osteoblasts.
