exam 1 chapters 1-6 Flashcards
What did Hippocrates believe
brain was not only involved in sensation but was also the seat of intelligence
What did Aristotle believe
the heart was center of intellect and that it was a radiator for cooling blood that was overheated by the seething heart (brain has large cooling capacity)
What is Trepanation
process of boring holes into skulls with aim to cure, not kill
(May have been used to treat headaches or mental disorders)
What were the Nineteenth-Century Views of the Brain
- Injury to the brain can disrupt sensations, movement, and thought and can cause death
- The brain communicates with the body via the nerves
- The brain has different identifiable parts, which probably perform different functions
- The brain operates like a machine and follows the laws of nature
What is the experimental ablation
method
parts of the brain are systematically destroyed to determine their function
What is phrenology
Correlating structure of head with personality traits was called
What did Flourens believe?
cerebrum acted as a whole and all regions of the cerebrum participate equally in all cerebral functions
Why did Cajal and Golgis ideas contradict?
golgi thought neurites of different cells were fused together to form a continuous network whereas cajal thought neurites of different neurons are not continuous with each other and communicate by contact, not continuity
The Neuron Doctrine in a Single Sentence
The neuron doctrine is the concept that neurons are discrete, autonomous units that communicate with each other via synapses, and this insight is credited to Santiago Ramón y Cajal.
Which parts of a neuron are shown by a Golgi stain that are not shown by a Nissl stain?
A Golgi stain shows the cell body, dendrites, and axons of neurons
A Nissl stain primarily reveals cell bodies by staining the RNA-rich regions
What are three physical characteristics that distinguish axons from dendrites?
Length: Axons can be much longer than dendrites, extending over great distances from the cell body.
Branching Pattern: Dendrites typically branch profusely and in complex patterns near the cell body, whereas axons may branch but usually do so at greater distances from the cell body.
Function: Axons are primarily involved in transmitting electrical signals away from the neuron’s cell body, while dendrites receive signals from other neurons.
Of the following structures, state which ones are unique to neurons and which are not: nucleus, mitochondria, rough ER, synaptic vesicle, Golgi apparatus.
Nucleus: Not unique to neurons; found in all eukaryotic cells.
Mitochondria: Not unique to neurons; found in nearly all eukaryotic cells.
Rough ER: Not unique to neurons; found in many eukaryotic cells.
Synaptic Vesicle: Unique to neurons; these are specialized vesicles that store neurotransmitters for release at the synapse.
Golgi Apparatus: Not unique to neurons; found in many eukaryotic cells.
What are the steps by which the information in the DNA of the nucleus directs the synthesis of a membrane-associated protein molecule?
Transcription: The process starts in the nucleus where DNA’s genetic information is transcribed into messenger RNA (mRNA).
RNA Processing: The mRNA is spliced and modified to become mature mRNA.
Translation: The mRNA travels to the ribosomes, often bound to the rough ER, where it is translated into a polypeptide chain.
Protein Modification: The polypeptide chain is modified and folded into its functional form; for membrane-associated proteins, this involves insertion into the rough ER membrane.
Transport: The protein is transported via vesicles to the Golgi apparatus for further modification, then directed to its final destination, such as the cell membrane.
Colchicine is a drug that causes microtubules to break apart (depolymerize). What effect would this drug have on anterograde transport? What would happen in the axon terminal?
Colchicine would depolymerize microtubules, which are essential for transporting materials from the cell body to the axon terminal. In the axon terminal, this disruption could lead to a shortage of necessary components (like neurotransmitters and membrane proteins), impairing the neuron’s ability to communicate with other neurons.
Classify the cortical pyramidal cell based on (1) the number of neurites, (2) the presence or absence of dendritic spines, (3) connections, and (4) axon length.
Number of Neurites: Multiple (one axon and several dendrites).
Presence or Absence of Dendritic Spines: Presence.
Connections: Excitatory connections to other neurons.
Axon Length: Long, can extend from the cortex to other parts of the brain or spinal cord.
Knowledge of genes uniquely expressed in a particular category of neurons can be used to understand how those neurons function. Give one example of how you could use genetic information to study a category of neuron.
Genetic information can identify specific markers or proteins that are unique to a category of neurons. For example, by identifying a gene that codes for a unique neurotransmitter or receptor found only in certain neurons, researchers can use this genetic marker to trace the pathways, connections, and functions of these neurons within the nervous system.
Principles of Chemical Synaptic
Transmission
Basic Steps
1. Neurotransmitter synthesis
2. Load neurotransmitter into synaptic vesicles
3. Vesicles fuse to presynaptic terminal
4. Neurotransmitter spills into synaptic cleft
5. Binds to postsynaptic receptors
6. Biochemical/Electrical response elicited in postsynaptic cell
7. Removal of neurotransmitter from synaptic cleft
On which side of the neuronal membrane are Na ions more abundant?
Sodium ions (Na+) are more abundant outside the neuron
When the membrane is at the potassium equilibrium potential, in which direction (in or out) is there a net movement of potassium ions?
there is no net movement of potassium ions when the membrane is at the potassium equilibrium potential
There is a much greater K concentration inside the cell than outside. Why, then, is the resting membrane potential negative?
Even though there’s more potassium inside, the resting membrane potential is negative because of the differential permeability of the neuronal membrane to different ions and the work of the sodium-potassium pump
When the brain is deprived of oxygen, the mitochondria within neurons cease producing ATP. What effect would this have on the membrane potential? Why?
The membrane potential would become less negative (depolarize) and eventually the cell could not maintain its resting membrane potential
rising phase
characterized by a rapid depolarization of the membrane
orthodromic conduction
action potentials conduct only in one direction, from the soma to the axon terminal
What are brain ventricles, and what functions have been ascribed to them over the ages?
Brain ventricles are fluid-filled spaces inside the brain
- ventricles contain cerebrospinal fluid (CSF), which cushions the brain, provides nutrients, and removes waste.
What experiment did Bell perform to show that the nerves of the body contain a mixture of sensory and motor fibers?
he observed that cutting specific nerves in animals led to loss of muscle movement but not sensation, while cutting other nerves led to loss of sensation but not movement. This led him to conclude that some nerves are responsible for sending signals to muscles (motor fibers) and others for conveying sensations to the brain (sensory fibers).
What did Flourens’ experiments suggest were the functions of the cerebrum and the cerebellum?
the cerebrum (the largest part of the brain) is involved in sensory and cognitive processes, such as processing sensory information and higher brain functions. His experiments on the cerebellum suggested that it plays a crucial role in coordinating and regulating muscle movements, not in cognition or sensation.
A region of the cerebrum is now called Broca’s area. What function do you think this region performs, and why?
Broca’s area is involved in language processing, specifically in speech production and the processing of language syntax. This conclusion comes from studies of patients with damage to this area who had difficulties forming coherent sentences or speaking fluently, a condition known as Broca’s aphasia, indicating its crucial role in generating and understanding language.
Descartes believed in?
a dualistic interaction via the pineal gland, not a hydraulic mechanism
what are the Brain ventricle functions
BV= FCU PRONU REWA
Fluid cushions
provides nutrients
removes waste
definition: Immunocytochemistry
method for viewing the location of specific molecules, including proteins, in sections of brain tissue
definition: In Situ Hybridization:
method for localizing specific mRNA transcripts for proteins
