Neurons, Synapses, Muscles, and Movement - QUIZ Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Explain the role of the sodium potassium pump in maintaining the resting potential of a neuron.

A
  • Pumps NA+ ions out of axon and potassium ions K+ in
  • Requires ATP for active transport
  • 3 sodium out every 2 potassium in
  • Results in charge differences, outside is positive relative to inside
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define resting potential

A
  • the difference in charge across the membrane when a neuron is not firing (-70mV)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Neuron at rest

A
  • Inside more negative due to more K+
  • Outside more positive due to more NA+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define Action potential

A

nerve impulse is generated and propagated (sent) down the axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain the events of a nerve impulse and how it is propagated down the axon.

A
  • Nerve impulse are action potentials propagated along axons of neurons
  • Resting potential is -70mV (maintained by NA+/K+ pumps)
  • More sodium outside than inside at rest
  • Action potential stimulates depolarization along axon
  • If threshold potential is reached, NA+ channels open and sodium ions diffuse inside
  • potassium channels open and K+ ions move out (causing re-polarization)
  • Myelination increases propagation speed (saltatory conduction)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Myelin sheath

A

increases the speed of the signal along axon - saltatory conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explain the steps of synaptic transmission

A
  • Nerve impulse arrives
  • Calcium channels open and calcium diffuses in
  • Structures containing neurotransmitter fuse with membrane
  • Neurotransmitter released by exocytosis into cleft and binds to receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain the steps involved in synaptic transmission (at the neuromuscular junction) when ACh (acetylcholine) is the neurotransmitter.

A

-ACh binds to receptor protein
- Causes change in tertiary structure of protein
- Diffusion of ions is then allowed
- Acetylcholinesterase breaks down acetylcholine into acetyl and choline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain neonicotinoid pesticides

A
  • They irreversibly bind with acetylcholine receptors on postsynaptic membrane
  • Enzymes cannot break down neonicotinoids
  • Synaptic transmission prevented
  • Causing paralysis / death (of insect)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain muscle contraction

A
  • Happens in sarcomeres located in myofibrils
  • Sarcomeres shorten during muscle contraction
  • Nerve impulses stimulate contraction
  • Calcium ions released into sarcoplasmic reticulum
  • Calcium bins to troponin
  • Troponin causes tropomyosin to expose binding sites on actin
  • ATP provides energy for myosin heads to bind with actin
  • Myosin filaments pull actin towards center of sarcomere
  • ATP causes binding to break
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain structure of skeletal muscle

A

Largest to smallest:
muscle, muscular bundle, muscle fiber, sarcolemma, myofibril, sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain structures / functions of the elbow joint

A

Biceps - contract for flexion
Triceps - contract for extension
Humorous - upper bone, leverage for upper elbow muscles
Cartilage - absorbs shock, allows bone to move smoothly
Synovial fluid - provides nutrients to cartilage; reduces friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

relative concentrations of sodium and potassium inside and outside of a neuron when it is “at rest”

A
  • Positive outside (more sodium)
  • Negative inside (more potassium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly