Week 5 Neurons And Nervous System Flashcards
What was the first animal to arose from protist ancestor?
Choanoflagellates
What are the main benefits of multicellularity
→ lower surface areas to volume ratio affects flux in an out
→efficiency through divisor of labour via cell specialization
What does division of labour mean?
Cell specialization: cell divides up The responsibilities for survival amongst each other
Describe cell specialization in tissues and organs
Regions/faces can become dedicated to specific functions
What are the three models of cellular specialization
- Aggregation of “like” cells
- Division of responsibilities
- Dedicated functions
In intercellular connections what is the impact of a cell wall?
→resist cell volume changes
→can grow but not easily move
How does 1 genome have different cells?
Embryonic stem cells are omnipotent, become any type of cell
→individual cell can differentiate turning on/off suites of genes to express specific phenotype
What is a metamer?
Repeating subunits that appear in embryonic development
What is a tagma?
A collection of segments in embryonic development that permit formation of complex structures
What is cephalization?
Collection of tagmata that enables sensory and nervous processes to be concentrated toward the anterior
What are the animal evolution trends
-increase in size
- increase in complexity
- increase in specialization and regionalization
How do non-animal organisms more?
-cytoskeleton reorganization
- flagella and cilia
-osmotic pressure
What do neurons and myocytes have in common?
They are both post-mitotic cells which means they no longer divide
→not prone to cancer but also cannot repair themselves
Why do neurons have a complex cytoskeletal network?
- Structurally polarize
- have microtublules
- require constant movement
What does na-k-ATPase do?
Permits recovery of a resting membrane potential enabling the excitable cells to repeat action potentials
Can NKA be found in plants
No! Only in animals, plants vs h-atpase
How does activation of myocytes in skeletal muscle happen?
A neuron triggers an action potential that causes an increase in cast
How does activation of a cardiac muscle happen?
Myocyte communicates AP directly to another magocyte to cause increase in calcium
How does activation of smooth muscle happen?
Changes activation state with input from neurons, hormones and may or may not change calcium levels
Is contraction, shortening
No, the cell doesn’t necessarily contract as in get shorter
What do protein specific toxins do?
→ligand binds a protein, altering its behaviour
→ affects the functions of specific cells, typically neurons
→ affects physiological systems
How do organisms that make toxin avoid poisoning themselves?
→ Insensitive targets ( host differs in shape or lacks target centirly)
→avoidance (host maybe vulnerable to the toxin but its held in a diff compartments )
What are the proteins that regulate the process of neuronal function called?
Gene products - evolve to suit organisms structure/function
If a toxin activates/inactivales a neuromuscular protein, what happens?
Toxins can open channels, block it, change kinetics and effects may be reversible or not
