The neuron and its structure
The basic structural and functional unit of the nervous system is the neuron (neuron). Its structure includes the cell body — cell body — and processes: the axon (axon) and dendrites (dendrites). The axon may be covered by a myelin sheath — myelin sheath.
Based on the number and characteristics of their processes, neurons are classified into the following types:
- unipolar neurons — unipolar;
- bipolar neurons — bipolar;
- multipolar neurons — multipolar;
- pseudounipolar neurons — pseudounipolar.
Peripheral nervous system: nerves and plexuses
Nerves are divided into spinal nerves (spinal nerves) and cranial nerves (cranial nerves). Spinal nerves form plexuses:
- cervical plexus — cervical plexus;
- brachial plexus — brachial plexus;
- lumbar plexus — lumbar plexus;
- sacral plexus — sacral plexus.
The intercostal nerves — intercostal nerves are distinguished separately. The verb to innervate is used to denote the area of innervation.
The twelve pairs of cranial nerves
- olfactory nerve — olfactory;
- optic nerve — optic;
- oculomotor nerve — oculomotor;
- trochlear nerve — trochlear;
- trigeminal nerve — trigeminal;
- abducens nerve — abducens;
- facial nerve — facial;
- vestibulocochlear nerve — vestibulocochlear;
- glossopharyngeal nerve — glossopharyngeal;
- vagus nerve — vagus;
- accessory nerve — accessory;
- hypoglossal nerve — hypoglossal.
Spinal cord: structure and terminology
The spinal cord in English is spinal cord. On a cross-section, grey and white matter are distinguished: grey matter represents clusters of neuronal cell bodies and proximal dendrites (neuronal cell bodies and proximal dendrites), while white matter is formed by myelinated axons (myelinated axons).
A spinal nerve is formed by the fusion of the anterior and posterior roots: anterior root and posterior root. In the grey matter, horns are distinguished:
- ventral horn — ventral horn;
- lateral horn — lateral horn;
- dorsal horn — dorsal horn.
The central canal runs through the center, containing cerebrospinal fluid (spinal fluid). The grey matter nuclei are subdivided into somatic motor nuclei, autonomic (visceral) motor nuclei, visceral sensory nuclei, and somatic sensory nuclei. Afferent sensory information enters through the posterior root (afferent sensory information), and efferent signals to muscles and glands leave through the anterior root (efferent signals to muscles and glands).
Brain: divisions and lobes
The brain is the brain. It consists of two hemispheres: the left hemisphere and right hemisphere. In each hemisphere, lobes are distinguished:
- frontal lobe — frontal;
- parietal lobe — parietal;
- temporal lobe — temporal;
- occipital lobe — occipital.
The brain also includes the cerebellum (cerebellum) and brain stem (brainstem). The brainstem includes the medulla oblongata (medulla oblongata), pons (pons), and midbrain (midbrain). Structures of the diencephalon include the thalamus, optic chiasm (optic chiasm), and the corpus callosum — the corpus callosum — is located above the thalamus.
Cortex, gyri, and sulci
The cerebral cortex is designated by the term cortex. Functionally, for example, visual cortex — the visual cortex in the occipital lobe, and auditory cortex — the auditory cortex, are distinguished.
The names of gyri (gyri) and sulci (sulci) in English follow the Latin model, but the adjective is placed first. Thus, the Latin gyrus temporalis superior becomes superior temporal gyrus. Similarly, the middle temporal gyrus (middle temporal gyrus) and inferior temporal gyrus (inferior temporal gyrus) are formed.
Applying terminology when reading articles
The acquired terminology allows for working with English-language sources. For example, the phrase grey matter atrophy manifests as volume loss and cortical thinning is translated as "атрофия серого вещества проявляется потерей объёма и истончением коры". The adjective cortical is derived from cortex. When describing the structure of grey matter, one encounters glial cells (glial cells) and extracellular space (extracellular space), and aging mechanisms are considered at the cellular and molecular levels.
Key points
- A neuron consists of a cell body, axon, and dendrites; the axon may be covered by a myelin sheath.
- Spinal plexuses: cervical, brachial, lumbar, sacral plexus.
- The 12 pairs of cranial nerves have standardized English names from the olfactory to the hypoglossal nerve.
- The spinal cord contains grey matter (neuronal cell bodies) and white matter (myelinated axons).
- Spinal nerve roots: anterior root — efferent, posterior root — afferent.
- The brain includes the hemispheres, four lobes, the cerebellum, and the brain stem (medulla oblongata, pons, midbrain).
- The names of gyri are structured according to the formula "adjective + gyrus", for example, superior temporal gyrus.
- Knowledge of terminology facilitates reading English-language scientific articles in neurology and neuroanatomy.