Lecture 16 Flashcards
Outline the ideas of integration, coordination and response, after having the sensory experience of looking + smelling sushi.
Integration :
- am I hungry?
- do I want sushi?
- do I want that much?
Coordination :
- prep for eating
- start craving something else
- thoughts of doing something else
Response :
- order some
- go to a different restaurant
- walk away
What makes up the central nervous system (CNS)? What cells make these parts up?
- brain (neurons + glia)
- spinal cord (neurons + glia)
What makes up the peripheral nervous system (PNS, including ENS)? What cells make these parts up?
Peripheral nerves and ganglia (neurons + glia)
What are neurons?
Nerve cells specialized for transmission of information. Has 4 morphological types.
What are glia?
Support for neurons. Has 5 basic types (4 in CNS, 1 in PNS), each with their own type.
What are the structural components of the neuron and their function? Draw it if you can.
Dendrites :
- receives input
- sends info to cell body
Cell body :
- contains nucleus + organelles (like other cells)
- sums the input from the dendrites
- highly dynamic, so has lots of rER to make proteins
Axon :
- carries electrical impulses
- may or may not be myelinated
Axon terminal :
- end of axon
- neurotransmitter released via vasicles
What do you call a group of cell bodies in the CNS?
Nucleus
What do you call a bundle of axons in the CNS?
Tract
What do you call a group of cell bodies in the cerebral cortex or spinal cord?
Grey matter
What do you call a bundle of axons in the cerebral cortex or spinal cord?
White matter
What do you call a group of cell bodies in the PNS?
Ganglion
What do you call a bundle of axons in the PNS?
Nerve
What parts of the neuron are a part of the input zone? What is their function?
- dendrites and cell body
- receive chemical signals from other neurons
What part of the neuron is a part of the summation zone? What is the function?
- axon hillock
- summation of the input
What part of the neuron is a part of the conduction zone? What is the function?
- axon
- carry electrical signals between brain areas, to and from spinal cord, or from peripheral sensory receptors and to effector cells
What part of the neuron is a part of the output zone?
- axon terminal
- contact with input zone of other neurons or effectors
- releases neurotransmitters = chemical signal
Majority of the brain is made of…
Glia
What are astrocytes?
- glia that supply nutrients to the neurons
- cover blood capillaries
- injury response, prevents more damage
What are microglia?
- glia that are immune cells of the CNS
- engulf microorganisms and debris
- get rid of malfunctioning + dead cells
What are ependymal cells?
- glia that lines fluid filled spaces of brain and spinal cord
- have cilia to move cerebrospinal fluid (CSF), fluid around brain and spinal cord with nutrients and waste
What are oligodendrocytes?
- glia that support nerve fibres
- unsheath them with myelin
What are schwann cells?
- glia only found in PNS
- support peripheral nerve fibres
- unsheath them with myelin
- similar to oligodendrocytes
What is the myelin sheath?
- lipid bilayer wrapped around axon
- insulates axon
- increases conduction velocity
- comes from oligodendrocytes in CNS
- comes from schwann cells in PNS
What is the structure of the myelin sheath?
- many layers of lipid bilayer
- multiple Schwann cells in a line
- nodes of Ranvier (gaps between myelin), increase conduction velocity
Briefly explain synapse.
- electrical -> chemical -> electrical
- synapse = junction between cells
What is a pre-synaptic neuron and its function?
- pre-synapse
- release neurotransmitter (chemical signal) from axon terminal
What is the synaptic cleft?
- space between axon terminal and dendrite/cell body of 2 neurons
- neurotransmitters diffuse through gap
What is a post-synaptic neuron and its purpose?
- after synapse
- contains receptors for neurotransmitter
What do we call information going into the brain in terms of the flow of information?
Afferent/ascending
What do we call information going out of the brain in terms of the flow of information?
Efferent/descending
