What is the dye color of hematoxylin?
Blue
What is the dye color of eosin?
Red
What is the charge of hematoxylin?
Positive
What is the charge of eosin?
Negative
What is the charge of the structures that hematoxylin stains?
Negative
What is the charge of the structures that eosin stains?
Positive
What is an example of a structure that hematoxylin stains?
Cell Nuclei - DNA
What is an example of a structure that eosin stains?
Most Cytoplasmic Proteins - Collagen
What is the approximate size of a red blood cell?
About 7 µm in diameter
What stains with the Wright-Giemsa stain?
Blood smears
What stains with the silver stain?
Fungi and reticulin fibers (Type III Collagen)
What stains with the periodic acid-Schiff (PAS) stain?
Sugars
What stains with the acid-fast stain?
M. tuberculosis organisms
Tissues are composed of what?
Cells and extracellular matrix
Organs are composed of what?
Parenchyma and Stroma
Describe the function of parenchyma.
The cells that perform the main functions of organs
Describe the main function of stroma.
Supporting tissue
In general, what happens during phase 1 of the embryonic period?
The formation of the bilaminar disk and the formation of the trilaminar disk (gastrulation)
How long is phase 1 of the embryonic period?
0-4 weeks
What happens during week 1 of the embryonic period?
The differentiation of morula into a blastocyst
What is the morula
A dense body of cells caused by division after fertilization
How does a blastocyst form?
Cells in the middle of the morula die due to a lack of nutrients, becoming hollow and forming a nutrition supply called the primary yolk sac
What is the embryoblast?
The inner cell mass in the blastocyst that gives rise to the embryo
What happens during week 2 of the embryonic period?
The formation of the bilaminar germ disk
What does the embryoblast form during week 2?
The Amniotic Cavity
What are the cells called within the amniotic cavity?
Epiblast
What are the cells called within the secondary yolk sac?
Hypoblast
What will the epiblast eventually become?
The baby
What will the hypoblast become?
Supporting structures, such as the placenta
In general, describe what happens during gastrulation.
The formation of the trilaminar disk
How does the primitive streak form?
A migration of epiblast cells to form a depression, ending with a primitive node about halfway up towards the rostral (head)
How does the endoderm form?
The epiblast cells migrate inward through the primitive streak and displace the cells of the underlying hypoblast layer
How does the mesoderm form?
Epiblast cells migrate inward through the primitive streak. They then invaginate to form a layer between the ectoderm and endoderm
What is the ectoderm?
The outer germ cell layer caused by the invagination of the mesoderm
In general, what happens during phase 2 of the embryonic period?
The formation of the neural tube, differentiation of the mesoderm, and folding of the embryo
How does the notochord form?
Indentation of the ectoderm that moves down the primitive node towards the head
What is the purpose of the notochord?
Signaling center for the three cell layers
How does the neural tube form?
Depression of neural plate (neural groove) and the rise/unity of the neural crest cells (neural fold)
What does the neural tube become?
The brain and spinal cord
What happens to the neural crest cells once the neural tube is formed?
They break off and rest between the neural tube/mesoderm and the ectoderm
What are the three types of mesoderm?
Paraxial, intermediate, and lateral plate (in respective order from closest to furthest from neural tube)
What structures are derived from the endoderm?
Lining of GI tract (Inner-body linings)
What structures are derived from the paraxial mesoderm?
The muscles and bones of the body (NOT the bones of the head)
What structures are derived from the intermediate mesoderm?
Urogenital system
What structures are derived from the lateral plate mesoderm?
Heart and Hematopoietic System
What structures are derived from the ectoderm?
Central Nervous System
What structures are derived from the neural crest cells?
The bones of the head
What happens to the endoderm during the folding of the embryo?
Edges migrate towards each other and meet to form the gut (moving away from ectoderm)
What happens to the mesoderm during the folding of the embryo?
Lateral plate mesoderm follows and surrounds the endoderm. Paraxial and Intermediate stay relatively still but more isolated from each other
What happens to the ectoderm during the folding of the embryo?
Lags behind. Reaches around gut and zips up front to form anterior body wall
What will the paraxial mesoderm around the neural tube form?
Somatomeres (muscles of the head and neck) and Somites (bones and muscles of the back)