Neuroanatomia Flashcards
Qual a organização do sistema nervoso?
The central nervous system (CNS) consists of the brain and spinal cord. The peripheral nervous system (PNS) is made up of the peripheral nerves and muscles they innervate. Microscopically, the CNS includes mainly cell bodies of neurons along with their axons which are covered by a thick myelin sheath; areas of the CNS that are made up of cell bodies are termed grey matter, named after their color on fresh sections. Large collections of cell bodies in the CNS are termed nuclei. Areas of the CNS that consist mainly of myelinated axons are termed white matter. Organized bundles of axons that share a common function or destination are termed tracts. In the PNS, collections of cell bodies are termed ganglia and bundles of axons are simply peripheral nerves.
Quais as divisões dos lobos cerebrais?
The cerebral cortex can be divided into a number of functional lobes. The division between the frontal and parietal lobe is particularly important; the central sulcus divides the two lobes and separates the precentral gyrus from the postcentral gyrus. The precentral gyrus includes the cell bodies of those neurons that serve as the origin of the corticospinal tract and is alternatively termed the primary motor cortex. The postcentral gyrus includes, in contrast, the primary sensory cortex. Both the motor and sensory cortices are organized to contain representations of each part of the body; this homunculus is key to understanding the distribution of weakness or sensory loss that results from specific lesions of the brain.
Qual o papel do talamo no SNC?
The thalamus is the largest set of nuclei in the nervous system. Positioned on either side of the third ventricle, the thalami act as an integration center for cognitive and motor pathways and as a relay for various types of sensory information (vision, audition, touch, position sense, pain, temperature).
Qual o papel do cerebelo?
The cerebellum sits under the brain in the posterior fossa. Its function is to receive and integrate sensory information from the brain and spinal cord and coordinate movements and balance smoothly.
Qual o papel dos nucleos da base?
The basal ganglia are composed of nuclei involved in processing motor information. Disorders affecting these nuclei can lead to involuntary movements such as in Parkinson’s disease.
Qual a anatomia do sistema motor?
There are a variety of motor systems in the nervous system, but the most important and relevant to clinical neurology is the corticospinal tract. It is important to learn the course of this pathway throughout the brain and spinal cord. A two neuron system is required to move any muscle of the body. The first neuron (termed the “upper motor neuron”) originates with its cell body in the precentral gyrus and sends axons down the corticospinal tract in the brain and spinal cord before forming a synapse on a second neuron (termed the “lower motor neuron”) whose cell body resides in the anterior horn of the spinal cord and whose axons form peripheral nerves which directly innervate the muscle. You will learn during the course how to use the clinical neurologic examination to localize a patient’s weakness to lesions affecting the upper or lower motor neuron.
Quais as principais vias sensitivas?
In contrast to the single most important motor system, there are two major sensory pathways mediating sensation from the body to the brain. The posterior column pathway mediates vibration and proprioception from the body while the spinothalamic pathway (also termed the anterolateral pathway) mediates pain and temperature information.
Qual a anatomia das meninges?
Three layers of connective tissue surround the central nervous system and separate it from the skull and vertebral column. From the outside, these layers are the dura mater, the arachnoid, and the pia mater. The dura consists of a thick, fibrous layer of connective tissue that is fused to the inner surface of the skull.
Como é a vascularização do sistema nervoso central?
The arterial blood supply to the brain can be divided into the anterior circulation, arising from the paired carotid arteries and the posterior circulation arising from the paired vertebral arteries. The terminal branches of the anterior circulation are formed on each side when the internal carotid artery bifurcates into the anterior cerebral artery (ACA) and middle cerebral artery (MCA) supplying blood to most of the cerebral hemispheres. The posterior circulation is formed when the paired vertebral arteries join to form the basilar artery which then in turn gives off two terminal posterior cerebral arteries (PCAs). The anterior and posterior circulations are connected through an anastomotic ring termed the circle of Willis.
