Harris Lecture 6 notes (1 per page)(1)-1

Harris Lecture 6 notes (1 per page)(1)-1 - All structures...

Info icon This preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
1 1 All structures need maintenance Once cells and tissues are formed they continually regenerate This can occur at the level of molecular turnover or cellular turnover
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 2 Some tissues contain the same cells for the life of the organism, but the molecular components of these cells do turn over -typically cells with very specialized architecture e.g. auditory hair cells or photoreceptor cells Other tissues renew their cells rapidly -typically cells exposed to harsh environments or activities e.g. skin cells, gut cells or blood cells Other tissues are between these extremes
Image of page 2
3 3 The specialized architecture of auditory hair cells in the organ of Corti
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4 4 This architecture functions to convert sound waves in nerve impulses (it allows us to hear) Sound waves cause stereocilia atop hair cells to tilt With tilting, tethers pull open ion channels on neighbouring stereocilia (this initiate a nerve impulse)
Image of page 4
5 5 This architecture functions to convert sound waves in nerve impulses (it allows us to hear) Sound waves cause stereocilia atop hair cells to tilt With tilting, tethers pull open ion channels on neighbouring stereocilia (this initiate a nerve impulse)
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
6 6 In mammals, these cells do not re-grow when lost Their loss from disease, toxins or extreme noise leads to permanent > (Remarkably, other vertebrates can replace these cells)
Image of page 6
7 7 Despite their stable overall structure, the hair cells and their stereocilia are very dynamic at the molecular level Actin cytoskeleton in a inner hair cell stereocilia bundle (adult mouse, width of picture 10 μm) www.uni-goettingen.de The stereo cilia are filled and supported by actin This actin undergoes continually polarized > How can such dynamic machinery maintain the specific architecture of the stereocilia for the lifetime of the animal?
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
8 8 Their architecture converts light waves into nerve impulses Human photoreceptor cells are another permanent cell type with a specific architecture.
Image of page 8
9 9 The overall photoreceptor cells are permanent, but do they turn over at the molecular level?
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern