Brain Anatomy and Lobes Quiz

False (B)

<p>False (B)</p> Signup and view all the answers

<p>Coordination of voluntary movements.</p> Signup and view all the answers

<p>mamillary body</p> Signup and view all the answers

<p>It controls involuntary functions such as heart rate and digestion.</p> Signup and view all the answers

<p>III (Oculomotor)</p> Signup and view all the answers

<p>Rostral = Towards the front of the brain Caudal = Towards the back of the brain Dorsal = Towards the top of the brain Ventral = Towards the bottom of the brain</p> Signup and view all the answers

<p>Third ventricle (C)</p> Signup and view all the answers

<p>Olfactory nerve = I Optic nerve = II Oculomotor nerve = III Trochlear nerve = IV</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Trigeminal nerve (C)</p> Signup and view all the answers

<p>Superior colliculus</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Vestibulocochlear nerve (VIII)</p> Signup and view all the answers

<p>corpus callosum</p> Signup and view all the answers

<p>Lateral ventricle → Third ventricle → Fourth ventricle (B)</p> Signup and view all the answers

<p>Pituitary</p> Signup and view all the answers

<p>Facial sensation and motor functions (D)</p> Signup and view all the answers

<p>Increased Na+ permeability (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>-70 mV</p> Signup and view all the answers

<p>less excitable</p> Signup and view all the answers

<p>Na+/K+ pump (A)</p> Signup and view all the answers

<p>Depolarization = Increase in membrane potential due to Na+ influx Repolarization = Return to resting membrane potential due to K+ efflux Refractory Period = Time after an action potential when a neuron is less excitable Hyperpolarization = Membrane potential becomes more negative than resting potential</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Voltage-gated channels</p> Signup and view all the answers

<p>flow</p> Signup and view all the answers

<p>Depolarization must exceed the threshold of about -55 mV (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Na+</p> Signup and view all the answers

<p>repolarization</p> Signup and view all the answers

<p>Depolarization = The membrane potential moves toward a more positive value. Repolarization = The membrane potential returns to resting levels. Hyperpolarization = The membrane potential becomes more negative than resting. Absolute Refractory Period = No new action potential can be generated, regardless of stimulus strength.</p> Signup and view all the answers

<p>It occurs when K+ ions exit the cell. (C)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>-55 mV</p> Signup and view all the answers

<p>hyperpolarization</p> Signup and view all the answers

<p>Repolarization (D)</p> Signup and view all the answers

The cerebellum is located at the back of the brain, below the cerebrum.

Protective membranes surrounding the brain and spinal cord.

Channels that collect blood drained from the brain.

Cerebrospinal fluid circulates through the brain and spinal cord.

C-shaped chambers on both sides of the brain with CSF.

Produces CSF (cerebrospinal fluid).

Connects the 3rd and 4th ventricles of the brain.

A ventricle located between the cerebrum and cerebellum, containing CSF.

The spinal cord, protected by the meninges, extends from the brain down the vertebrae.

Nerves connected directly to the brain, I-XII

Controls eye movement, pupil constriction, and eyelid elevation.

Controls sensations in the face, scalp, and teeth; also involved in chewing.

Brain region controlling body temperature, hunger, thirst, and sleep.

Region of the brain coordinating movement, posture, and balance.

Largest part of the brain; responsible for higher-level functions (thinking, language, memory).

Point where optic nerves from each eye cross over.

Small endocrine gland in the brain; produces melatonin.

Large bundle of nerve fibers connecting the two cerebral hemispheres.

The uneven charge across the plasma membrane of a cell, caused by different ion concentrations inside and outside the cell.

The transmembrane potential of a cell when it's not actively sending signals, typically around -70mV.

Membrane channels that are always open, allowing ions to pass through passively.

Membrane channels that open or close in response to specific stimuli.

Channels that open or close when they bind specific chemicals, like neurotransmitters.

Channels that open or close in response to changes in the membrane potential.

It actively pumps 3 sodium ions (Na+) out of the cell for every 2 potassium ions (K+) it pumps in.

The axon conducts nerve impulses away from the cell body to the axon terminals.

Short, branched extensions of a neuron that receive signals from other neurons.

The cell body contains the nucleus and other organelles of the neuron, and integrates incoming signals.

The three main types of stimuli that can open ion channels are mechanical, chemical, and electrical. Mechanical stimuli include things like touch, pressure, and vibration. Chemical stimuli involve the binding of a chemical messenger, such as a neurotransmitter, to a receptor on the channel. Electrical stimuli occur when changes in the membrane potential cause the channel to open.

Depolarization is a change in the membrane potential of a cell, making it less negative (more positive) compared to the resting membrane potential. It occurs when positive ions, like sodium (Na+), enter the cell through open channels.

The magnitude of depolarization is directly proportional to the strength of the stimulus. A stronger stimulus opens more ion channels, allowing more ions to flow in and resulting in a larger change in the membrane potential.

An action potential is a rapid, short-lived change in membrane potential that travels along the entire length of an excitable membrane. It is a brief reversal of the membrane potential, going from negative to positive and back to negative.

The threshold potential is the minimum level of depolarization required to trigger an action potential. If the membrane potential does not reach this critical value, an action potential will not be generated.

The all-or-none principle states that an action potential either occurs completely or not at all. There is no partial action potential. Once the threshold is reached, the action potential will proceed to completion.

The three stages of an action potential are depolarization, repolarization, and hyperpolarization. Depolarization is the initial increase in membrane potential, repolarization is the return to the resting membrane potential, and hyperpolarization is a temporary dip below the resting potential.

The refractory period is a brief time after an action potential during which the membrane is less responsive to further stimulation. It helps to prevent backward propagation of action potentials.

Continuous propagation occurs in unmyelinated axons, where the action potential travels along the membrane in a step-by-step manner. Saltatory propagation occurs in myelinated axons, where the action potential jumps from one node of Ranvier to the next, speeding up the process.

The speed of action potential propagation is directly proportional to the diameter of the axon. Larger axons have lower resistance, allowing the action potential to travel faster.