Lecture 3 - Excitable Membranes Flashcards

1
Q

What is the structure of the plasma membrane?

A

fluid mosaic model

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2
Q

What makes up the fluid mosaic model?

A

-phospholipid bilayer
-cholesterol
-transmembranal proteins

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3
Q

What is the polar section of a phospholipid?

A

polar hydrophilic head

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4
Q

What is the non-polar section of a phospholipid?

A

non-polar hydrophobic fatty acid chains (tail)

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5
Q

peripheral membrane protein
-where
-what looks like
-function

A

-inside membrane
-small not across the full membrane
-attachment + shape changes

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6
Q

integral membrane proteins
-where
-what looks like
-function

A

-across the full membrane
-channel, pump…
-transport + communication

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7
Q

cytoskeleton
-where
-what looks like
-function

A

-underneath the plasma membrane
-small, attached to other proteins
-anchors + receptors

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8
Q

carbohydrates
-specific name
-where
-what looks like
-function

A

-glycocalyx
-outside of the cell
-thin, looks like little trees
-cell-cell recognition

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9
Q

cholesterol
-where
-what looks like
-function

A

-embedded in the membrane
-it looks like a steroid structure
-stabilization

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10
Q

4 functions of the plasma membrane

A
  1. communication
  2. selective
  3. physical barrier
  4. cell recognition
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11
Q

6 functions of the plasma membrane proteins?

A
  1. enzyme activity
  2. transport
  3. receptors
  4. cell-cell recognition
  5. intracellular joining
  6. attach to ECM
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12
Q

3 types of junctions formed between cells

A
  1. desmosomes
  2. gap junctions
  3. tight junctions
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13
Q

tight junctions + where

A

-impermeable
-no random diffusion
+ blood-brain barrier

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14
Q

desmosomes + where

A

-attach
-anchor
-structure
+ cardiac muscle tissue, bladder tissue, and epithelia

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15
Q

gap junctions + where

A

-channel
-communicate
-specialize
+ all cells of solid tissue

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16
Q

how much of the brain is used to maintain the Na+/K+ ATPases pump?

A

40%

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17
Q

How is the electrochemical gradient challenged? (2)

A

1) slow leaking ions
2) stimulation of muscle

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18
Q

3 types of endocytosis

A

1) pinocytosis
2) receptor-mediated
3) phagocytosis

19
Q

what is the process of exocytosis?

A

t-snare on receptor + v-snare of vesicle attach on membrane to release outside

20
Q

what molecules can travel past the membrane by simple diffusion?

A

O2 + CO2 + fats + urea + alcohol

21
Q

state 5 features of facilitated diffusion

A

1) no ATP
2) specific
3) down conc. gradient
4) carrier saturation
5) can be inhibited

22
Q

what and where is the biosynthetic centre?

A
  • large spherical nucleus
    -glandular cytoplasms
23
Q

where is the term tract used?

A

nerve processes of the CNS

24
Q

where is the term nerve used?

A

nerve processes of the PNS

25
what are the 3 special features of an axon?
1) extreme longevity 2) amitotic 3) high metabolic rate
26
look at the drawing on the 2nd page + names 1-4 regions
1) receptive 2) initial segment 3) conducting 4) secretory
27
receptive region of the axon -the name of parts of the cell -function
-dendrites + cell body -receive graded potentials
28
initiail segment of the axon -name parts -function
-axon hillock -where the action potential is reached
29
conducting region of the axon -name parts -function
-axon + myelin sheath -propagate the electrical current down the axon
30
2 functional divisions of PNS
-sensory -motor
31
how is the sensory PNS divided?
-somatic (skin/skeletal) -visceral (visceral organs to the CNS)
32
how is the motor PNS divided?
-somatic (voluntary movement of muscles) -autonomic (self-regulated organs)
33
What are the 2 principal cell types of nervous tissue and their definitions?
1) neuroglia -small cells that wrap around axons 2) neurons -excitable cells that transmit signals
34
what is the 4 main neuroglia that supports the CNS neurons?
1) astrocytes 2) oligodendrocytes 3) microglial 4) ependymal
35
astrocytes -definition -function
-highly branched that connect at capillaries and synaptic endings -support, exchange, guide, control, respond, influence, process
36
microglial cells -definition -functions
-small cells that touch and monitor neurons -help injury + phagocytize bad stuff
37
ependymal cells -definition -functions
-forms permeable membrane between the CSF and tissues -layer the central cavities of the brain and spinal column
38
oligodendrocytes -definitions -functions
- a highly branched fatty cell that wraps around the CNS nerve fibres -for conduction of electrical impulses
39
What is the 2 major neuroglia in the PNS?
1) Schwann cells -surround nerve fibres 2) ganglion -surround neuron cell body
40
What is vital to the regeneration of damaged PN fibres?
Schwann cells
41
What do conduction velocities depend on? (2)
-axon diameter -myelin sheath
42
What is anterograde transport?
-transport away from the cell body toward the synapse =mitos + cytoskeleton, membrane parts, nervous tissue
43
what is retrograde transport?
-transport towards the cell body =