All High School Biology Resources
Example Questions
Example Question #1 : Understanding Types Of Nervous Tissue
What support cell is responsible for myelinating the axons found in the peripheral nervous system?
Ependymal cells
Astrocytes
Schwann cells
Oligodendrocytes
Schwann cells
There are two types of cells responsible for myelinating axons in the nervous system: oligodendrocytes and Schwann cells. They only differ by the division of the nervous system in which they are found. Oligodendrocytes myelinate axons in the central nervous system, while Schwann cells myelinate axons in the peripheral nervous system.
Ependymal cells and astrocytes are other types of neuroglia. Ependymal cells secrete cerebrospinal fluid (CSF) into the central nervous system. Astrocytes play a key role in creating the blood-brain barrier in the central nervous system.
Example Question #1 : Nervous Tissue
Which of these is not a part of the cerebrum?
The occipital lobe
Broca's area
The primary sensory cortex
The thalamus
The hippocampus
The thalamus
The cerebrum is the portion of the brain above the middle of the brain, or diencephalon. The thalamus is a part of the diencephalon, and it is intimately associated with motor behaviors, such as walking or flying (in birds). The cerebrum is divides into four lobes based on location and function. The frontal lobe contains the motor cortex and pre-frontal cortex, as well as Broca's area. It is associated with thought and higher brain function. The parietal lobe contains the sensory cortex and processes tactile input. The temporal lobe contains the hippocampus and auditory cortex. The occipital lobe contains the visual cortex.
Example Question #3 : Understanding Types Of Nervous Tissue
What type of nervous cell is used to phagocytose pathogens and debris in the central nervous system?
Oligodendrocytes
Schwann cells
Astrocytes
Microglia
Microglia
Nervous tissue contains a variety of support cells in order to preserve the neurons in the brain, known as glial cells. Microglia are similar to monocytes, a type of white blood cell. They are used to remove debris and pathogens from the central nervous system.
Schwann cells, oligodendrocytes, and astrocytes are all part of the neural glia. Schwann cells produce myelin around the axons of neurons in the peripheral nervous system, while oligodendrocytes produce myelin for the axons of neurons in the central nervous system. Astrocytes around found in the central nervous system and help create the blood-brain barrier.
Example Question #4 : Understanding Types Of Nervous Tissue
Which of the following types of tissue is not an element in the neuron-to-muscle pathway?
Connective neurons
Sensory neurons
Effectors
Association neurons
Motor neurons
Connective neurons
Sensory neurons respond to stimuli, such as pain. Association neurons receive signals from the sensory neurons and, on the basis of that input, activate motor neurons. Motor neurons activate muscles or glands. Effectors are the muscles or glands that perform the response directed by the nervous system.
Connective tissue consists of bone, cartilage, blood, and fat and is not involved in this process. Connective neurons is a misnomer. Interneurons, however, can be used to relay signals between sensory and motor neurons in the spinal cord.
Example Question #971 : High School Biology
What part of a neuron is considered white matter?
Axon
Dendrite
Synapse
Cell body
Synaptic bud
Axon
White matter is white due to the myelin sheath. Since the myelin sheath only covers the axon, neural tissue that is referred to as white matter is only located on a neuron's axon. Grey matter actually refers to the cell body due to its grayish appearance. Accordingly, one neuron is actually part of both the white and the gray matter in the nervous system.
Example Question #1 : Understanding Properties Of Nervous Tissue
Which of the following occurs in synaptic transmission?
Only a small potential is generated in the post-synaptic neuron
The action potential depolarizes the end of the pre-synaptic neuron
All of these events occur during synaptic transmission
The membranes of synaptic vesicles fuse with the cell membrane of the pre-synaptic neuron
Neurotransmitter chemicals diffuse across the synaptic cleft
All of these events occur during synaptic transmission
As the action potential depolarizes the pre-synaptic terminal button, calcium enters the region and causes the vesicles (full of neurotransmitter) to fuse their membranes with the membrane of the neuron, leading to rapid release of their chemical content outside of the cell. The neurotransmitters must diffuse across the synaptic cleft in order to cause a post-synaptic effect. Typically, many, many excitatory inputs must summate to cause depolarization of the post-synaptic neuron. Each individual stimulus is generally well below threshold, and the post-synaptic neuron will only generate an action potential with several stimuli at once.
Example Question #2 : Understanding Properties Of Nervous Tissue
When an action potential reaches the axon of a neuron, what is the first event to occur?
Extracellular potassium rushes into the cytoplasm
Intracellular sodium rushes out of the cytoplasm
Extracellular sodium rushes into the cytoplasm
Intracellular potassium rushes out of the cytoplasm
Calcium rushes into the cytoplasm
Extracellular sodium rushes into the cytoplasm
At rest, the neuron will have large amounts of sodium outside the cell and large amounts of potassium inside the cell. When an action potential reaches the axon of the neuron, it opens voltage-gated sodium channels. Sodium immediately rushes through these channels to enter the cell, flowing from high sodium concentration to low sodium concentration. This event is known as depolarization.
Later in the action potential, potassium channels will open and potassium will rush out of the cell along its concentration gradient. This is part of the action potential leads to hyperpolarization.
Example Question #3 : Understanding Properties Of Nervous Tissue
What is the purpose of the nodes of Ranvier?
They allow the transport of proteins along the axon
They allow a way from neurons to communicate with each other, via connecting nodes
They provide support and protection to the axon
They allow neurons to recieve oxygen
They allow the action potential to skip over sections of the axon
They allow the action potential to skip over sections of the axon
A fatty substance called myelin wraps arounds the axon of a neuron, forming an insulating layer called the myelin sheath. Gaps in the myelin coating create small openings, called the nodes of Ranvier, where the cell membrane is exposed. During an action potential, the electrical signal is able to jump from on node to the next, skipping portions of the axon. This speeds up the conduction of the action potential signal. Instead of travelling in a constant wave down the axon, the signal can jump or bounce past segments of it. This process is known as saltatory conduction.
Many neurological diseases and disorders arise from the degeneration of the myelin sheath, slowing the propagation of action potentials and hindering neural functionality.
Example Question #4 : Understanding Properties Of Nervous Tissue
What do function do glial cells facilitate?
They send and receive nerve impulses
They amplify neural impulses
They detect malfunctioning nerve impulses
They increase the speed of nerve impulses
They produce neural impulses
They increase the speed of nerve impulses
Glial cells are cells that make up nervous tissue and provide support, protection, and nutrients for the neurons in the brain and nervous system. While neurons are the cells responsible for actually generating, sending, and receiving neural impulses, glial cells are capable of enhancing the speed at which these impulses can be transmitted. In particular, Schwann cells and oligodendrocytes provide myelin sheaths to neurons. Myelin acts as an insulator and helps the action potential travel more quickly down the neural axon.
Example Question #5 : Understanding Properties Of Nervous Tissue
Into what structure does a neuron release neurotransmitters?
Nodes of Ranvier
Soma
Synaptic cleft
Axon
Dendrite
Synaptic cleft
Neurotransmitters are released from the axon terminal into the synaptic cleft.
Neurons are essential for transmitting signals, but do so without actually touching one another. The space between neurons is known as the synaptic cleft, or synapse. When a signal reaches the end of one neuron at the axon terminal, it causes neurotransmitters to be released from vesicles. The neurotransmitter molecules travel to the dendrites of the next neuron, which receives the signal and passes it down the next axon.
The soma is the cell body of the neuron, which synthesizes proteins and integrates incoming signals. Nodes of Ranvier are regions along myelinated axons that allow for faster action potential conduction.