Which of the following apply to fibronectins? Please select all that apply.

a) They are disulphide linked dimers, with each polypeptide composed of a number of binding domains joined together by short flexible segments.

b) They have an essential role in linking the extracellular matrix to its underlying cells.

c) Like integrins, fibronectins are directly connected to the cytoskeleton.

d) They participate in 'inside out' and 'outside in' signalling mechanisms.

#Question id: 11186

#Unit 7. System Physiology – Animal

Refer to the following graph of an action potential to answer the question. The membrane potential is closest to the equilibrium potential for potassium at label ________.

#Question id: 11187

#Unit 7. System Physiology – Animal

Refer to the following graph of an action potential to answer the question.

The membrane's permeability to sodium ions is greatest at label ________.

#Question id: 11188

#Unit 7. System Physiology – Animal

Refer to the following graph of an action potential to answer the question.

The minimum graded depolarization needed to operate the voltage-gated sodium and potassium channels is indicated by the label ________.

#Question id: 11189

#Unit 7. System Physiology – Animal

Refer to the following graph of an action potential to answer the question.

At label ________, the cell is not hyperpolarized; however, repolarization is in progress, as the sodium channels are inactivated or becoming inactivated, and many potassium channels have opened.

#Question id: 11190

#Unit 7. System Physiology – Animal

For a neuron with an initial membrane potential at -70 mV, an increase in the movement of potassium ions out of that neuron's cytoplasm would result in the ________.

#Question id: 11191

#Unit 7. System Physiology – Animal

Opening all of the sodium channels on an otherwise typical neuron, with all other ion channels closed (which is an admittedly artificial setting), should move its membrane potential to ________.