3/11 Excitable cells & Muscles

Question 1

excitable cell

Answer 1

a cell which can be electrically excited resulting in significant membrane depolarisation

Question 2

excitable cell can lead to?

Answer 2

Transmission of signal (neurons)
Contraction (myocytes)
Secretion (some endocrine cells)

Question 3

Channelopathies:

Answer 3

mutations in ion channels which result in pathologies

Question 4

3 functional types of neuron:

Answer 4

Sensory (afferent): Respond to stimuli +Send signals to spinal cord/brain
Motor (efferent): Produce an effect +Receive signals from brain & spinal cord
Interneurons (relay): Connect neurons to neurons

Question 5

Noiciception

Answer 5

detection of painful stimuli

Question 6

Proprioception

Answer 6

(the sense that lets us perceive the location, movement & action of parts of the body)

Question 7

Mechanosensation

Answer 7

(transduction of mechanical stimuli into neural signals- provides the basis for the senses of light touch, hearing, proprioception, and pain.)

Question 8

Skeletal muscle : striated/non? voluntary/involuntary?

Answer 8

striated
voluntary control

Question 9

smooth muscle : striated/non? voluntary/involuntary?

Answer 9

non-striated
involuntary control

Question 10

cardiac muscle : striated/non? voluntary/involuntary?

Answer 10

striated
involuntary control

Question 11

Striated muscles are made of functional unit called?

Answer 11

myofibril and functional unit of that is sarcomere

Question 12

why striated muscles appear striped?

Answer 12

repeating bands of the proteins actin & myosin (dark and light bands appear in alternate fashion)

Question 13

troponin promotes?

Answer 13

promotes muscle contraction

Question 14

tropomyosin blocks?

Answer 14

muscle contraction

Question 15

contractile process in smooth muscle

Answer 15

Ca2+ binds to calmodulin & allows it to interact & activate myosin light chain kinase MLCK–> catalyses phosphorylation of myosin–> results in contraction of muscle

Question 16

Hyperpolarisation makes membrane more negative so makes it harder to?

Answer 16

produce an action potential

Question 17

In the heart & smooth muscle, electrical stimulus can spread from myocyte to myocyte through?

Answer 17

specialised gap junctions