Discussion 9 Flashcards
What are glial cells?
Support cells within the nervous system that act as ‘nerve glue’, holding neurons in place, supplying nutrients, acting as insulation around axons, and removing pathogens and dead neurons.
What are the 5 types of glial cells?
Ependymal cells, Astrocytes, Microglia, Oligodendroglia, and Schwann cells.
What do ependymal cells do?
Small, ovoid cells found in the walls of the ventricles that make and secrete cerebrospinal fluid.
If CSF is prevented from leaving the brain, hydrocephalus may result.
What is hydrocephalus?
A condition resulting from the buildup of pressure and swelling of the head due to excess cerebrospinal fluid.
What are astrocytes responsible for?
Providing structural support for neurons, transporting substances between neurons and capillaries, forming scar tissue, and dilating blood vessels to enhance brain activity.
What are microglia?
Cells that originate in the blood as an offshoot of the immune system, providing growth factors and cleaning up debris through phagocytosis.
What do oligodendroglia do?
Glial cells in the CNS that myelinate axons, preventing adjacent neurons from short-circuiting and helping to send information faster.
What are Schwann cells?
Glial cells in the peripheral nervous system that myelinate sensory and motor neurons.
What is the blood-brain barrier?
A protective partition between blood vessels and the brain formed by tight junctions that prevents toxins from entering the brain but also limits useful substances.
What is Multiple Sclerosis (MS)?
A degenerative nervous system disorder resulting from the loss of myelin around axons, affecting over 90,000 people in Canada, with a higher prevalence in women.
What are neurons?
Specialized cells that produce proteins and have a complex internal structure, including a semi-permeable membrane.
What is the structure of a cell membrane?
Composed of phospholipids with a hydrophilic head and a hydrophobic tail, controlling the passage of substances.
What is the nucleus?
The executive office of the cell that contains blueprints for protein production, including chromosomes and genes.
What is protein synthesis?
The process by which chromosomes change shape to expose different segments of DNA, allowing for the production of various proteins.
What is transcription?
The early phase of protein synthesis where DNA strands unwind and a complementary strand of messenger RNA (mRNA) is created.To begin making a protein, the appropriate gene segment of DNA strand unwinds to expose its bases. The exposed sequence of neuclitie bases on the DNA strand then serve as a template to attract free floating molecules called nucleotides. These nucleotides attach to the DNA to form a complementary strand of RNA. The single stranded nucleic acid molecule then detaches from the NDA and leaves the cell carrying its structure the code for protein synthesis
“copying the message passing it on
What is translation?
The later phase of protein synthesis where mRNA travels to the endoplasmic reticulum and is translated into a sequence of amino acids.When an mRNA molecule reaches the ER, it passes through a ribosome, where its genetic code is read. In this process of translation a particular sequence of nucleotide bases in the mRNA is transformed into a particular sequence of amino acids
What is a codon?
A sequence of three bases on mRNA that codes for a particular amino acid.
What is the flow of genetic information?
DNA is transcribed into mRNA, which is then translated into an amino acid chain to form a protein.
What are genes
segments of DNA that encode the synthesis of particular proteins
Genes are within chromosomes
Four types of nucleotides
Adenine binds with thymine and Guanine binds with cytosine
1. Adenine
Thymine
Guanine
Cytosine
endoplasmic reticulum
structures just outside the nucleus that contain ribosomes
Ribosomes are protein structures that act as catalyst for protein synthesis
