How Tissues are Made from Cells Flashcards
What is a somatic cell also known as?
Vegetal cell
How many chromosomes does a gamete have?
23
What is syngamy?
Where the pronuclei of an egg and sperm come together to form a new nucleus
What is a 16-cell zygote called?
Morula
What is the function of the zona pellucida?
The zona pellucida prevents polyspermy (no more sperm fertilise the egg following the first one)
What is a Morula?
A 16-cell zygote
The trilaminar disc comprises what 3 germ layers?
Ectoderm
Mesoderm
Endoderm
The inner cell mass and outer cell mass gives rise to the _____blast and ______blast
Inner cell mass = Epiblast
Outer cell mass = Hypoblast
The epiblast gives rise to what?
The 3 primary germ layers, ectoderm, endoderm, mesoderm
The hypoblast gives rise to what?
Extraembryonic endoderm
The trophoblast has what function and develops into what?
Provides nutrients to embryo, and develops into the placenta
The bilaminar disc comprises what?
Hypoblast and epiblast
What does the ectoderm differentiate into?
Nervous system, tooth enamel, epidermis
What does the mesoderm differentiate into?
Cardiac muscle, skeletal muscle, smooth muscle, RBCs
What does the endoderm differentiate into?
Lung cells, thyroid cells, pancreatic cells
What are the types of simple epithelia?
Simple squamous
Simple cuboidal
Simple columnar
What are the types of stratified epithelia?
Stratified squamous
Stratified cuboidal
Stratified transitional
What are the types of pseudostratified epithelia?
Pseudostratified columnar
What are the four main types of cell-cell junctions?
Tight junctions
Adherens junctions
Desmosomes & Hemidesmosomes
Gap junctions
Describe what cadherins are
Cadherins are transmembrane proteins, which form homodimers. They require Ca2+. There are three subtypes: E, N, P-Cadherin subtypes, and are found in Adherins junctions and in Desmosomes
At gap junctions, what proteins are found?
Connexins
Proteoglycans are found in the ECM. Why are they negatively charged?
So they attract positively charged Na+, which helps keep the ECM hydrated
Describe the structure of Collagen Type 1
Accounts for 90% of all Collagen. Is a tropohelix of a1, a1, and a2 subunits. Has a high Glycine content (every 3rd residue)
Describe what Oesteogenesis Imperfecta is
A genetic condition also known as “Brittle bone disease”, mutation in COL1A1 or COL1A2 genes. Symptoms include brittle bones, blue schlera, hearing loss etc.
Describe the biochemical structure of Elastin
Rich in hydrophobic amino acids such as Glycine / Proline - with no hydroxylation
Describe the structure of Integrins
Dimer of alpha subunit and beta subunit, with an RGD motif
What is the difference between loose connective tissue and dense connective tissue?
Loose connective tissue has less collagen fibres than dense
An epithelial cell cancer is known as,.?
Carcinoma
A mesenchymal cell cancer is known as..?
Sarcoma
A haematopoetic cell cancer is known as…?
Leukemia / Lymphoma
A neural cell cancer is known as..?
Glioma / Neuroblastoma
As we age, what changes occur to collagen and elastin?
Collagen cross linking increases
Elastin is lost
