Esdin LS 2 Lec 4 Sensory

Cilium stereocilia kinocilium stretch gated channels

Info iconThis preview shows page 1. Sign up to view the full content.

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

Unformatted text preview: top Basilar membrane Axons To auditory nerve very flexible 5 4/21/13 Hair Cell one stiff cilium Stereocilia Kinocilium Stretch gated channels hair cells release neurotransmitters forms synapses, hair cell + neuron Sensory neuron Hair Cell Tectorial membrane Stereocilia Hair cell Basilar membrane Cochlear nerve bending causes stretch gated channels to open 6 4/21/13 K+ depolarizes here in Act. Pot. repolarizes influx of K+ leads to depolarization Hair Cells At Rest Protein bridge K+ K+ K+ all the cilia moving in the same direction has to be in a sp. direction for gates to open K+ Stretch gated channels gradient potential: small wave but not called that, receptor potential small wave of depolarization no action potential opened by physical stretching Ca2+ NT Voltage gated calcium channels Hair Cells Depolarized K+ K+ K+ K+ movement towards K-cilium results in depolarization Stretch gated channels Protein bridge Ca2+ decides if the aggregate input is enough to fire an action potential; will send the APs down the auditory nerve Voltage gated Ca2+ calcium channels Ca2+ NT fuses w membrane, and released NT signals travel to the temporal lobe activated and mobilization of neurotransmitters occurs auditory nerve --> medulla --> thalamus --> auditory cortex 7 4/21/13 Hair Cells Hyperpolarized K+ K+ K+ K+ Stretch gated channels Protein bridge Voltage gated calcium channels NT Hair Cells •  When hair cells are stimulated, K+ influx occurs •  The depolarization leads to the activation of the voltage-gated Ca channels •  Ca2+ influx causes the release of glutamate which activates the afferent neurons 8 4/21/13 Hair Cells •  Movement of the stereocilia towards the kinocilium activates the stretch activated channels •  Movement of the stereocilia away from the kinocilium closes the stretch activated channels Neural Pathway of Hearing •  Cochlear nerve fibers synapse on neurons in the cochlear nuclei in the medulla oblongata medial geniculate nucleus •  The signal is then sent to the thalamus •  From the thalamus, the information travels to the auditory cortex of the temporal lobe 9 4/21/13 The Eyes •  Composed of an optical portion •  Focus the image on sensory cells •  Transform the image to the brain through series of action potential •  Have receptors that are sensitive to light photoreceptors Layers of the Eyes Fibrous Neural inner outer Vascular middle light needs to fall on neural layer to be able to...
View Full Document

This test prep was uploaded on 04/02/2014 for the course CHEM 14BL taught by Professor Pang during the Summer '07 term at UCLA.

Ask a homework question - tutors are online