Week 4 Physiological Systems Flashcards
What are the different physiology models?
- Applied models
- August krogh models
- Evolutionary models
What are the recurring themes in animal physiology
1.its integrative biology (molecules → organisms
2. Form and function variation, both within and between animals
3. Alternative approaches to homeostasis
What type of cells promote communication?
Epithelial cells → transport something from one side to another
What do epithelial cells need to communicate?
- Strong connection
- Structural platform (basal lamina)
- Polarity
What are the different types of cell layers
- Cuboidal epithelium (circle)
- Simple squamous epithelium( small square)
- Simple columnar epithelium ( columns)
- Stratified squamous epithelium(2 type)
What are the different layers in a epithelial cell
Apical - closest to outside
Basal - closest to inside
Difference between regulating and remodelling
Regulation is changes existing in hardware
Remodelling (plasticity)is changes in hardware that may be irreversible(developmental plasticity) or reversible (acclimation, acclimatization)
Microevolution is…
With in species: artificial and natural selection
Macroevolution is…
Between species: fast and slow animals
What is acclimatization?
Reversible changes in physiology in response to a complex natural environment
What is acclimation?
Experimental approach determining now a single environmental factor contributes to a change seen in acclimatization
Define allostasis
Many things changing to keep one thing constant
What is the physiological process that all for regulation?
Conformers and regulators
What are conformers?
Allow internal conditions ro change with external conditions (tolerate change)
What are regulators?
Maintain relatively constant internal conditions regardless of external conditions (resist change)
What is only driven by the electrochemical gradient of what is transported
Passive transport
What requires an additional form of energy
Active transport
What does primary active transport need?
Uses ATP
What does secondary active transport use?
Another form of energy’s typically a favorable gradient of something else
What are the different gated channels?
Voltage, ligand, temperature, mechanically
How do solutes travel via primary active transport?
ATP hydrolysis provides the energy to eject solute from cytoplasm against its electrochemical gradient
How do molecules travel across membranes via secondary active transport?
One molecule drives the transport of another
What are the different ways molectues move via secondary active transport?
Exchangers (antiport) or co-transporters (symport)
Define exchangers (antiports)
More one molecule into the cell an another out of the cell
Define co-transporters (symports)
Move two molecules in the same direction
What are the different types of cell-cell communication?
Autocrine, parachrine , endocrine
Define autocrine
The cell signals itself
Define paracrire
Cell signals neighbouring cell
Define endocrine
Cell signals a different cell far away
What is the most important determinant of a hormone pathway?
Chemical nature of factor (solubility)
What solutes are hydrophilic?
Proteins/ peptides(insulin, glucagon, gonadotropins)
Amines ( catecholamins, dopamine)
Purines (adenosine)
What solutes are hydrophobic?
Aromatic amino acid derivatives (thyroxine)
Steroids (estrogen, VD, ecdysteroids)
Fatty acid derivatives( prostaglandins)
Gases (nitric oxide)
What are the steps of signaling pathways?
1.synthesis (hormone synthesized in endocrine gland)
2. Secretion (escapes tissues)
3. Transport ( travels to target)
4. Reception (binds)
5. Transduction (connects receptor to signaling events )
6.effectors (change in cell)
What is cell signalling essential for?
Homeostasis
What is a agonist?
Triggers same response as hormone
What’s an antagonist?
Prevent natural hormone from binding
What are tropic hormones?
Hormones that have the main job of regulating other hormones
What are the major glands for cell-cell communication
Hypothalamus /pituitary gland
What does the hypothalamus do?
Receives and sends out information
→ senses metabolic status
→ sends axons to pituitary
Function of the pituitary glands
Posteriors → collection of termini of axons from hypo
Function of adrenal glands
Kidney, secretes epinephrines in flight/fight responses(inner cortex) and secretes steroids (outer)
What are the 3 main filaments in the cytoskeleton?
1.microtublues
2. Intermediate
3. Actin
How does the cytosketon move?
Motor proteins use ATP to change their shape
→kinesin / dynein(one walks to pos, one to neg)
What 2 proteins block the place on actin where myosin binds
Tropomyosin( long thin protein )
Troponin (makes sure tropomyosin is in the right position)
Muscles that have sarconeres have a stripped appearance are…
Striated muscles
Why is myosin referred toa mechano-enzyme?
Its an enzyme because it breaks down ATP and as a result changes in shape
What is a hormone?
A chemical secreted in extracellular fluid, and circulates through blood and communicates regulatory messages (specific function)
What is neuroendocrine signaling?
Neurotransmitters diffusing into bloodstream and triggering response in target cells
Define negative feedback
Form of regulation in which response reduces initial stimulus (restores pre-existing state)
Define positive feedback
Form of regulation that reinforces a stimulus leading to a greater response ( amplifies both stimulus and response)
What is the role of the posterior pituitary gland
Acts as an extension of hypothalamus
→ stores hormones (adh/oxytocin )
What is the role of the anterior pituitary gland?
Is an endocrine gland that synthesizes and secretes hormones (prolactin)
Thick filaments
Myosin
Thin filaments
Actin
What is tropomyosin?
Protein that stretches over thin filament and blocks binding
What is troponin?
Globular protein that binds to the tropomyosin and keep in position
