Module 8: The Nervous System Flashcards
Hypoxia
The medical condition in which there is an inadequate oxygen supply to the brain.
Ischemia
A lack of blood supply to the brain.
Hypoglycemia
A condition in which glucose levels in the blood have become so low that the brain cannot function properly.
What are the two basic types of stroke?
Ischemic and hemorrhagic stroke.
What happens in an ischemic stroke?
A blood clot cuts off the blood supply to part of the brain.
What happens in a hemorrhagic stroke?
A blood vessel in the brain bursts, the blood supply to the neurons is interrupted, and the neurons are bathed in blood chemicals toxic to them, killing large numbers of neurons.
What does the acronym FAST refer to?
It refers to the steps that should be taken to recognize a stroke. F: Face
A: Arms S: Speech T: Time
What are some of the basic nutrients the brain needs?
It needs glucose, B vitamins and minerals, and essential fat.
What are B vitamins and minerals used for in the brain?
It allows the neurons’ mitochondria to produce ATP efficiently.
What is essential fat used for in the brain?
The neuroglia use the fat to make myelin.
Gray matter
Collections of neuron cell bodies and their associated neuroglia.
White matter
Bundles of parallel axons and their coverings.
What does MRI stand for?
Magnetic resonance imaging
Midsagittal section
A slice down the center of the brain that splits it into equal left and right halves.
What three sections can the brainstem be split into?
The medulla oblongata, the pons, and the midbrain.
Decussation
The anatomical crossing over of neurons from left to right.
Where does decussation typically take place?
The medulla oblongata.
What is the name of the groups of gray matter in the medulla, and what is their function?
They are called nuclei, and they act as control centers for the body’s vital functions.
Vital functions
Those functions of the body necessary for life.
The vasomotor area
The area in the medulla that controls the dilation or constriction of blood vessels throughout the body. It is a vital blood pressure control mechanism.
Foramen magnum
The opening at the base of the skull through which the spinal cord and brain are connected.
Why can a sudden blow to the head be fatal?
Swelling of the brain causes the medulla to be pushed through the foramen magnum, damaging the medulla, which controls the vital functions of the body.
What is the function of the pons?
The pons forms a bridge between the medulla and the upper brain stem. It also has several nuclei that relay messages between the cerebrum and the cerebellum.
How does the pons work with the medulla?
The pons and medulla have nuclei which work together to enable the body to switch from breathing in (inspiration) to breathing out (expiration).
What are the functions of the nuclei on the midbrain?
The nuclei control hearing, sight, and reflexes that cause you to turn toward the source of a sudden sound or sudden sight. The midbrain also contains nerve pathways that connect the brain stem to the upper parts of the brain.
What do the nuclei called reticular formation do?
They receive information from various afferent nerves, especially those of the face. They play a major role in determining the cycle of sleeping and waking.
Reticular activating system
The nuclei distributed throughout the brain stem called reticular formation and their interconnections.
What are the two major components of the diencephalon?
The thalamus and the hypothalamus.
Intermediate mass
The small cylinder that links the two sides of the thalamus.
What are the functions of the thalamus?
The thalamus is a major relay station and affects mood and body movements, especially those related to strong emotions such as fear and anger.
Where do afferent axons synapse with other neurons in the brain?
The thalamus.
What is the function of the hypothalamus?
It regulates the pituitary gland is involved in the functions of the autonomic nervous system, and controls the body temperature.
How does the hypothalamus regulate the pituitary gland?
It regulates the pituitary gland through neural connections and its own hormones.
Why is the pituitary gland often called the master endocrine gland?
It secretes many hormones that affect diverse functions such as metabolism, reproduction, urination, and response to stress.
What are the basic functions of the cerebrum?
It deals with higher-level brain functions, interprets signals sent from the sensory receptors to the body, reasoning, and memory.
Cortex
The outer surface of the cerebrum that is composed of gray matter that is deeply folded.
Gyri
The folds of the cerebrum’s cortex.
Sulci
The grooves between the gyri of the cortex.
What are the functions of the cerebellum?
The cerebellum controls functions that occur without conscious thought, subconscious motor functions, equilibrium, sequencing of muscle contractions, muscle preset, and dampening.
Equilibrium
Balance, or the constant state of control the muscles are in to maintain a certain position.
Sequencing of muscle contractions
The precise timing and sequencing of muscular actions that must occur for an action to be performed correctly.
Muscle preset
A predetermined correct amount of contraction to perform a task.
Dampening
The inhibition of motor neurons that prevents the limbs from swinging.
What is the function of the corpus callosum?
It allows the left and right halves of the cerebrum to communicate with each other.
What divides the cerebrum into two hemispheres?
The longitudinal fissure.
What functions is the temporal lobe involved in?
Hearing, smell, memory, and abstract thought.
What functions is the frontal lobe involved in?
Motor function, smell, mood, emotions, foresight, and memory.
What functions is the occipital lobe involved in?
It receives and integrates visual sensory information.
What functions is the parietal lobe involved in?
All sensory information except smell, vision, and hearing. It receives information from receptors of touch from the entire surface of the body.
What functions is the primary somatic sensory area involved in?
It receives generalized sensory input from all over the body.
How does the primary somatic sensory area know which area of the body a signal came from?
There is a little area on the primary somatic sensory area that corresponds to almost every part of the body’s surface. The primary somatic sensory area localizes the sensations that come from the body.
What functions is the somatic sensory association area involved in?
It determines the meaning of a sensation and has a sensory memory to refer to.
What functions is the visual cortex involved in?
It receives the action potentials from the optic nerves that are attached to the eyes. Action potentials are interpreted to give the basics of vision: shape, color, and size.
What functions is the visual association area involved in?
Action potentials from the visual cortex pass to the visual association area, which then compares the image with past experience.