Karteikarten
physiology chapter 6
Karten in diesem Stapel (29)
- 1depolarizationmore negative
- 2repolarizationreturn to resting membrane potential
- 3hyperpolarizationmore positive
- 4insulin secretion- from beta cells in pancreas
- allows uptake of glucose (activates GLUT 4)
- dependent on the integration of transporters, ion channels and exocytosis - 5steps in insulin secretion1. glucose enters cell through GLUT Transporters
2. Increased glucose metabolism leads to increased ATP
3. More ATP causes ATP-gated K+ channels top close
4. K+ remains in cell to lead to membrane depolarization
5. depolarization leads to voltage-gated Ca2+ channels opening
6. Ca2+ influx is signal for insulin-filled vesicles to merge with membrane
7. secretion of insulin - 6Intercellular communication1. direct communication
2. indirect communications
3. local communications
4. Long distance communication - 7direct communication- signal can travel directly from one cell to another via gap junctions
- 8indirect communications- chemical messengers
- endocrine, autocrine, paracrine and synaptic - 9CAMS- cell adhesion molecules
- mostly in immune system
- Transfers signals in both directions - 10gap junctions- form direct cytoplasmic connection with adjacent cells
- 11local communication- chemical signals
- 12Autocrine cells- act on the same cells that secrete them (auto= self)
- 13paracrine cells- secreted by one cell and diffuse to adjacent cells (para = near)
- 14long distance communicationhormones are secreted into the blood, act on distant target cells
- neurotransmitters are secreted by neurons that diffuse to the cell target
- - 15amplifiers- enzymes are attached on the cell membrane, create a larger output of the signal
- 16cell response- metabolic enzymes
- gene activity
- membrane transport proteins - 174 categories of membrane receptors- receptor channel
- G protein-couples receptor
- catalytic receptors (receptor enzyme, receptor in nucleus) - 18receptor channels- ligand binding open or closes the channel
-most rapid - 19G protein coupled receptos- Ligand binding to a G protein coupled receptor opens an ion channel or alters enzyme activity
- 20receptor enzyme- ligand binding to a receptor enzyme activates intracellular enzyme
- 21receptor in nucleusligand binding to integrin receptors alters enzymes or the cytoskeleton
- 22when G proteins are activated:open ion channels in the membrane
or
alter enzyme activity on the cytoplasmic side of the membrane - 23Tyrosine Kinase (TK) receptortransfers a phosphate group from ATP to tyrosine (an amino acid) of a protein
- signal molecule binds to surface receptor ->
Tyrosine kinase on cytoplasmic side
->
Phosphorylated protein - 24agonist- activates the receptor but not the specific molecule
- - 25antagonist- blocks receptor activity, no response
- 26Modulated cellular responsesdownregulation, upregulation
- 27down regulation- decreased number of receptors
- cell is less responsive
- can occur in response to chronic exposure to higher concentration of signal molecule - 28upregulation- increased number of receptors
- cell is more responsive
- can occur in response to chronic exposure to lower concentration of signal molecule - 29reflex pathwaystimulus -> sensor -> input signal -> integrating center -> output signal -> target -> response
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- Physiology Karteikarten am physiology chapter 6, erstellt von Kevin Floyd am 15/10/2019.
- Erstellt von
- Kevin Floyd
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