somesthetic cortex

Examples of somesthetic cortex in the following topics:

• Mapping the Primary Somatosensory Area

  • A cortical homunculus is a pictorial representation of the anatomical divisions of the primary motor cortex and the primary somatosensory cortex; it is the portion of the human brain directly responsible for the movement and exchange of sensory and motor information of the body.
  • Each one shows a representation of how much of its respective cortex innervates certain body parts.
  • The primary somesthetic cortex (sensory) pertains to the signals within the postcentral gyrus coming from the thalamus, and the primary motor cortex pertains to signals within the precentral gyrus coming from the premotor area of the frontal lobes.
  • Typically, the area of the body corresponds to a point on the primary somatosensory cortex (postcentral gyrus).
  • Areas such as the appendages, digits, and face can draw their sensory locations upon the somatosensory cortex.

• Motor Areas

  • The motor areas of the brain are located in both hemispheres of the cortex.
  • Premotor cortex: Located anterior to the primary motor cortex and responsible for some aspects of motor control.
  • Posterior parietal cortex – Guides planned movements, spatial reasoning, and attention.
  • Various experiments examining the motor cortex map showed that each point in motor cortex influences a range of muscles and joints, indicating significant overlapping in the map.
  • $$Topography of the human motor cortex, including the premotor cortex, SMA, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex.

• Neural Mechanisms (Cortex)

  • The primary motor cortex is the neural center for voluntary respiratory control.
  • More broadly, the motor cortex is responsible for initiating any voluntary muscular movement.
  • Different parts of the cerebral cortex control different forms of voluntary respiration.
  • Topography of the primary motor cortex, on an outline drawing of the human brain.
  • Each part of the primary motor cortex controls a different part of the body.

• Sensory Areas

  • Most sensory information is routed to the cerebral cortex via the thalamus.
  • The cortex is commonly described as composed of three parts: sensory, motor, and association areas.
  • The primary somatosensory cortex, located across the central sulcus and behind the primary motor cortex, is configured to generally correspond with the arrangement of nearby motor cells related to specific body parts.
  • For example, the right primary somatosensory cortex receives information from the left limbs, and the right visual cortex receives information from the left eye.
  • Similarly, there is a tonotopic map in the primary auditory cortex and a somatotopic map in the primary sensory cortex.

• Internal Anatomy of the Kidneys

  • The renal cortex is a space between the medulla and the outer capsule.
  • Erythropotein, a hormone necessary for the synthesis of new red blood cells, is also produced in the renal cortex.
  • At one end of each nephron, in the cortex of the kidney, is a cup-shaped structure called the Bowman's capsule.
  • The kidney is made up of three main areas: the outer cortex, a medulla in the middle, and the renal pelvis.
  • Distinguish between the cortex and medulla in the internal anatomy of the kidney

• The Brain

  • As a rule, the smaller the cerebrum, the less convoluted the cortex.
  • The cortex of a rat or mouse is almost completely smooth.
  • The cortex of a dolphin or whale, on the other hand, is more convoluted than the cortex of a human.
  • The left and right hemispheres of the cerebral cortex are nearly symmetrical.
  • The division into lobes does not actually arise from the structure of the cortex itself.

• Adrenal Cortex

  • The adrenal cortex is devoted to the synthesis of corticosteroid and androgen hormones.
  • The adrenal cortex comprises three zones, or layers: Zona glomerulosa (outer), Zona fasciculata and Zona reticularis.
  • Androstenedione (Andro): an androgenic steroid produced by the testes, adrenal cortex, and ovaries.
  • The layers of the adrenal cortex are shown in this figure.
  • Differentiate among the zones (and hormones produced) of the adrenal cortex

• Overview of the Cerebrum

  • The cortex is composed of two hemispheres, right and left, separated by a large sulcus.
  • Damage to motor areas of cortex can lead to certain types of motor neuron disease.
  • Speech and language are mainly attributed to parts of the cerebral cortex.
  • The cerebral cortex is the outer layer depicted in dark violet.
  • Notice the folded structure of the cortex: the "valleys" of the cortex are known as sulci.

• Limbic System

  • The limbic system makes up the inner border of the cortex and is vital for emotion, motivation, and memory.
  • It includes the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex, and fornix, and supports a variety of functions including emotion, behavior, motivation, long-term memory, and olfaction.
  • The term "limbic" comes from the Latin limbus, for "border" or "edge," because the limbic system forms the inner border of the cortex.
  • Amygdala: Involved in signaling the cortex of motivationally-significant stimuli, such as those related to reward and fear, and in social functions, such as mating.
  • The limbic system is also tightly connected to the prefrontal cortex.

• Cerebral Lobes

  • The cortex is divided into four main lobes: frontal, parietal, occipital, temporal.
  • The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex.
  • For example, it comprises the somatosensory cortex and the dorsal stream of the visual system.
  • The two occipital lobes are the smallest of the four paired lobes in the human cerebral cortex.
  • The superior temporal gyrus includes an area where auditory signals from the ear first reach the cerebral cortex and are processed by the primary auditory cortex in the left temporal lobe.