Welcome to my blog! Here I plan to post information on things I'm studying and working on.
Neuroscience Exploring the Brain Ch4
Define membrane potential (Vm) and sodium equilibrium potential (Ena). Which of these, if any, changes during the course of an action potential?
Membrane potential (Vm) is the voltage across the neuronal membrane at any moment. Sodium equilibrium potential (Ena) is the electrical potential difference that exactly balances the sodium concentration gradient. The membrane potential changes during an action potential.
What ions carry the early inward and late outward currents during the action potential?
Na+ ions rush into the cell in the rising phase and K+ ions rush out in the falling phase.
Why is the action potential referred to as "all-or-none"?
Action potentials don't occur unless a threshold is crossed.
Some voltage-gated K+ channels are known as delayed rectifiers because of the timing of their opening during an action potential. What would happen if these channels took much longer than normal to open?
It would delay the neuron's return to the resting membrane potential and any further action potentials.
Imagine we have labeled tetrodotoxin (TTX) so that it can be seen with a microscope. If we wash this TTX on to a neuron, what parts of the cell would you expect to be labeled? What would be the consequence of applying TTX to this neuron?
Sodium channels would be labeled. A neuron washed with TTX will have all action potentials blocked.
How does action potential conduction velocity vary with axonal diameter? Why?
If the axon is wide the conduction velocity will be high.
C++ In One Hour A Day Lesson 10
Below are the review questions and my answers for lesson 10 of
C++ In One Hour A Day. I want some base class members to be accessible to the derived class but not outside the class hierarchy. What access specifier do I use?
If I pass an object of the derived class as an argument to a function that takes a parameter of the base class by value, what happens?
The object is sliced, meaning only the methods of the base class will remain.
Which one should I favor? Private inheritance or composition?
Private inheritance works best for situations in which a derived class only needs 1 instance of the base class.
How does the
using keyword help me in an inheritance hierarchy?
It allows access to hidden base class methods.
A class Derived inherits private from class Base. Another class SubDerived inherits public from class Derived. Can SubDerived access public members of class Base?
No. All members of class Base are private to class SubDerived.
Neuroscience Exploring the Brain Ch3
What two functions do proteins in the neuronal membrane perform to establish and maintain the resting membrane potential?
Proteins in the membrane separate cytosol from extracellular fluid and channels provide selective permiability of different ions.
On which side of the neuronal membrane are Na+ ions more abundant?
When the membrane is at the potassium equilibrium potential, in which direction is there a net movement of potassium ions?
There is no net movement of potassium ions at the equilibrium potential.
There is a much greater K+ concentration inside the cell than outside. Why, then, is the resting membrane potential negative?
Negatively charged ions are left inside the cell during diffusion of K+.
When the brain is deprived of oxygren, the mitochodria within neurons cease producing ATP. What effect would this have on the membrane potential? Why?
The membrane potential would gain a positive charge as ATP is used to trasport Na+ and Ca2+ out of the cell.
C++ In One Hour A Day Lesson 9
Below are the review questions and my answers for lesson 9 of
C++ In One Hour A Day. When I create an instance of a class using new, where is the class created?
My class has a raw pointer int* that contains a dynamically allocated array of integers. Does sizeof report different sizes depending on the number of integers in the dynamic array?
No. The size of the pointer is unaffected.
All my class members are private and my class does not contain any declared friend class or function. Who can access these members?
Only methods from that class.
Can one class member method invoke another?
What is a constructor good for?
Setting up default values and constants.
What is a destructor good for?
Freeing system memory from a program.
Neuroscience Exploring the Brain Ch2
State the neuroscience doctrine in a single sentence. To whom is this insight credited?
Neurons adhere to cell theory and communicate by contact, not continuity. A histologist and artist from the early 20th century named Cajal.
Which parts of a neuron are shown by a Golgi stain that are not shown by a Nissl stain?
The soma (cell body) and the neurites.
What are three physical characteristics that distinguish axons from dendrites?
Axons are much longer than dendrites.
Dendrites generally taper to a fine point.
There's normally a single axon and multiple dendrites.
Which of the following structures are unique to neurons and which are not? Nucleus, mitochondria, rouch ER, synaptic vesicle, golgi apparatus
Synaptic vesicles are unique to neurons.
Colchicine is a drug that causes microtubules to break apart (deploymerize). What effect would this drug have on anterograde transport? What would happen in the axon terminal?
Without microtubules anterograde transport cannot occur. This will starve the axon and cause Wallerian degeneration.
Classify the cortical pyrimidal cell based on (a) the number of nuerites, (b) the presence or absence of dendritic spines, (c) connections, and (d) axon length.
(c) Golgi type 1
What is myelin? What does it do? Which cells provide it in the central nervous system?
An insulating wrap around axons. Speeds the propogation of nerve impulses. Oligodendroglial cells.
C++ In One Hour A Day Lesson 8
Below are the review questions and my answers for lesson 8 of
C++ In One Hour A Day. Why can't you assign a const reference to a non-const refernce?
Const variables and references cannot be modified once declared.
Are new and delete functions?
What is the nature of the value contained in a pointer variable?
Pointers store memory addresses.
What operator would you use to access the data pointed to by a pointer?
The dereference operator (*).
Neuroscience Exploring the Brain Ch1
What are brain ventricles, and what functions have been ascribed to them over the years?
During the roman empire, a physician named Gulen believed the brain ventricles were used to pump fluid around the body and make it move.
What experiment did Bell Perform to show that the nerves of the body contain a mixture of sensory and motor fibers?
He severed the connection of ventrical roots and dorsal roots, which nerve fibers divide into at the spinal cord, sepparately then observed the loss of muscle control and feeling respectively.
What did flourens' experiements suggest were the functions of the cerebrum and the cerebellum?
The cerebellum plays a role in the coordination of movement. The cerebrum is involved in sensation and perception.
What is the meaning of the term 'animal model'?
Animals/animal tissue used in an experiment.
A region of the cerebrum is now called Broca's area. What function do you think this region performs and why?
Speech production. Broca is famous for studying a man who could understand language but not speak.
What are the different levels of analysis in neuroscience research? What types of question do researchers ask at each level?
"How do certain molecules give rise to cellular function?"
"How do neurons perform computations?"
"How do different neural circuits analyze sensory information, form perceptions of the external world, make decisions, and execute movements?"
"How do neural systems work together to produce integrated behaviors?"
"How do functions of the mind manifest from the brain?"
What are the steps in the scientific process?
C++ In One Hour A Day Lesson 7
Below are the review questions and my answers for lesson 7 of
C++ In One Hour A Day. What is the scope of variables declared in a function's prototype?
Function variables are accessible within their functions.
What is the nature of the value passed to this function?: int Func(int &someNumber);
&someNumber is a reference to a variable which can be updated and returned to by the function.
I have a function that invokes itself. What is such a function called?
I have declared two functions, both with the same name and return type but different parameter lists. What are these called?
Does the stack pointer point to the top, middle, or bottom of the stack?
C++ In One Hour A Day Lesson 1
Below are the review questions and my answers for lesson 1 of
C++ In One Hour A Day. What is the difference between an interpreter and a compiler?
An interpreter runs source code directly and a compiler converts source code to a stand alone application.
What does the linker do?
Combines object files and dependencies into an executable file.
What are the steps in the normal development cycle?
Writing a program
Compiling to object files
Link output to compilation
How does the C++11 standard better support multicore CPUs?
Multithreading was introduced in C++11
C++ In One Hour A Day Lesson 4
Below are the review questions and my answers for lesson 4 of
C++ In One Hour A Day. Check the array MyNumbers in listing 4.1. What are the indexes of the first and last elements in that array?
If you need to allow the user to input strings, would you use C-style strings?
No, using the C++ standard library strings is a safer ad simpler way.
How many characters are in '\0' as seen by the compiler?
'\0' and other escape characters are interpreted as single characters.
You forgot to end your C-style string with a null terminator. What happens when you use it?
Depending on how it's used, this could crash a program or display incorrect data.
See the declaration of vector in listing 4.4 and try composing a dynamic array that contains elements of the type char.