Anatomy Ch 7 Quiz 6.1

Neuroglia refers to the support cells in the central nervous system. These cells play a crucial role in supporting and protecting the neurons. They provide structural support, regulate the chemical environment, and help repair damaged neural tissue. Neuroglia include various types of cells such as astrocytes, oligodendrocytes, and microglia. Oligodendrocytes are responsible for producing myelin sheaths, which insulate and protect the axons of neurons. However, the term "neuroglia" encompasses all the support cells in the central nervous system, making it the correct answer.

Sally's inability to vocalize her words despite knowing what she wants to say suggests that there is a problem with the part of her brain responsible for speech production. Broca's area is a region in the frontal lobe of the brain that is involved in the production of speech and language comprehension. Damage to Broca's area can result in a condition called Broca's aphasia, where individuals have difficulty forming words and constructing sentences. Therefore, it is likely that Sally's brain injury has affected her Broca's area, leading to her inability to speak.

Myelinated fibers are covered in a white, fatty substance called myelin, which gives them a white appearance. These fibers are responsible for transmitting signals quickly and efficiently in the central nervous system. On the other hand, unmyelinated fibers lack this myelin sheath and appear gray. They are involved in slower transmission of signals and are found in areas such as the gray matter of the brain and spinal cord. Therefore, myelinated fibers form white matter while unmyelinated fibers form gray matter.

The correct answer is "brain and spinal cord." The central nervous system consists of the brain and spinal cord, which are responsible for processing and coordinating information received from the sensory organs and sending instructions to the rest of the body. The brain controls higher cognitive functions, while the spinal cord relays signals between the brain and the peripheral nervous system.

Dendrites are the correct answer because they are the part of a neuron that receives incoming stimuli from other neurons or sensory receptors. They are responsible for transmitting these signals towards the cell body of the neuron, where the information is further processed and integrated. Dendrites have numerous branches and extensions, which increase the surface area available for receiving signals and allow for communication between neurons. Schwann cells, neurolemmas, axons, and satellite cells are not involved in the reception of incoming stimuli.

Loss of muscle coordination, also known as ataxia, is caused by damage to the cerebellum. The cerebellum is responsible for coordinating voluntary movements, maintaining balance, and controlling muscle tone. When the cerebellum is damaged, it can lead to problems with coordination, balance, and fine motor skills. This can result in difficulties with walking, speaking, and performing tasks that require precise movements. Damage to other parts of the brain, such as the thalamus, hypothalamus, midbrain, or cerebrum, may cause various other neurological symptoms, but they do not specifically result in loss of muscle coordination.

The question is asking for the fibers that carry information from the skin, joints, and skeletal muscles to the central nervous system. The correct answer is "somatic sensory" because somatic sensory fibers are responsible for transmitting sensory information from the body's external environment, such as touch, pain, and temperature, to the central nervous system. These fibers are part of the somatic nervous system, which controls voluntary movements and receives sensory input from the body's external environment.

The correct sequence in connective tissue sheaths, going from outermost to innermost layer, is epineurium, perineurium, endoneurium. The epineurium is the outermost layer, providing protection and support to the entire nerve. The perineurium is the middle layer, forming a barrier and compartmentalizing the nerve fibers into fascicles. The endoneurium is the innermost layer, surrounding each individual nerve fiber and providing nourishment and support.

The correct answer is irritability and conductivity. Neurons are specialized cells that are responsible for transmitting electrical impulses in the nervous system. Irritability refers to the ability of neurons to respond to stimuli, whether internal or external, by generating electrical signals. Conductivity, on the other hand, refers to the ability of neurons to transmit these electrical signals from one part of the body to another. These two properties are essential for the proper functioning of the nervous system and the communication between different parts of the body.

The cell bodies of the sensory neurons of the spinal nerves are located in the dorsal root ganglia of the spinal cord. These ganglia are located just outside the spinal cord and contain the cell bodies of the sensory neurons. From the dorsal root ganglia, the sensory neurons transmit information from the peripheral tissues to the spinal cord and then to the brain for processing and interpretation. The other options mentioned (hypothalamus, ventral root ganglia, thalamus, sympathetic ganglia) are not the correct locations for the cell bodies of the sensory neurons of the spinal nerves.

The hypothalamus is responsible for controlling temperature, endocrine activity, metabolism, and thirst. It acts as a regulatory center for these functions by receiving information from various parts of the body and coordinating appropriate responses. For example, it can signal the body to release hormones to regulate body temperature or to release thirst signals when the body is dehydrated. The cerebrum is primarily involved in higher cognitive functions, the cerebellum is responsible for coordinating movement and balance, the medulla oblongata controls vital functions such as breathing and heart rate, and the thalamus is involved in sensory processing.

The sensory homunculus is a representation of the human body in the brain, specifically in the primary somatic sensory area. This area is responsible for processing sensory information from different parts of the body. The parietal lobe is known to be involved in sensory processing, including touch, temperature, and pain sensations. Therefore, it is logical to conclude that the sensory homunculus is located in the parietal lobe.

The corpora quadrigemina is a part of the brain stem that houses reflex centers for vision and hearing. It consists of four rounded elevations, two superior colliculi for visual reflexes, and two inferior colliculi for auditory reflexes. These reflex centers receive sensory information from the eyes and ears and coordinate appropriate responses, such as turning the head towards a sound or adjusting the position of the eyes to track a moving object.

Cerebrospinal fluid is reabsorbed into venous blood in the dural sinuses via the arachnoid villus. The arachnoid villi are finger-like projections of the arachnoid mater that protrude into the dural sinuses. They act as one-way valves, allowing the cerebrospinal fluid to flow from the subarachnoid space into the dural sinuses, where it can be reabsorbed into the bloodstream. This process helps regulate the pressure and composition of cerebrospinal fluid in the brain and spinal cord. The other options, such as the choroid plexus, cerebral aqueduct, pons, and hypothalamus, are not directly involved in the reabsorption of cerebrospinal fluid into venous blood.

Saltatory conduction refers to the rapid transmission of nerve impulses along myelinated neurons. The myelin sheath acts as an insulating layer, allowing the nerve impulse to "jump" from one node of Ranvier to the next, significantly increasing the speed of transmission. This process saves energy and ensures efficient communication between neurons.