midbrain

Examples of midbrain in the following topics:

• Midbrain

  • The midbrain plays a major role in both wakefulness and regulation of homeostasis.
  • The nuclei of cranial nerves III and IV are located in the tegmentum portion of the midbrain.
  • The midbrain is the smallest region in the brain and helps to relay information for vision and hearing.
  • The cerebral peduncles are located on either side of the midbrain and are its most anterior part, acting as the connectors between the rest of the midbrain and the thalamic nuclei.
  • Brainstem anatomy showing the location of the midbrain in relation to the midbrain, pons, medulla, basilar artery, and vertebral arteries.

• Development of the Human Brain

  • The human brain is split up into three major layers: the hindbrain, the midbrain, and the forebrain.
  • The midbrain makes up part of the brain stem.
  • All sensory and motor information that travels between the forebrain and the spinal cord passes through the midbrain, making it a relay station for the central nervous system.

• Functions of the Brain Stem

  • The three components of the brainstem are the medulla oblongata, midbrain, and pons.
  • The midbrain (mesencephalon) is associated with vision, hearing, motor control, sleep and wake cycles, alertness, and temperature regulation.
  • The pons (part of metencephalon) lies between the medulla oblongata and the midbrain.
  • Structures of the brainstem are depicted on these diagrams, including the midbrain, pons, medulla, basilar artery, and vertebral arteries.

• Lower-Level Structures

  • With the exception of the spinal cord, these structures are largely located within the hindbrain, diencephalon (or interbrain), and midbrain.
  • The pons connects the medulla oblongata with the midbrain region, and also relays signals from the forebrain to the cerebellum.
  • The midbrain is located between the hindbrain and forebrain, but it is actually part of the brain stem.
  • Dorsal regions of the midbrain are involved in sensory information circuits.
  • The substantia nigra, a part of the brain that plays a role in reward, addiction, and movement (due to its high levels of dopaminergic neurons) is located in the midbrain.

• Pons

  • It is above the medulla, below the midbrain, and anterior to the cerebellum.
  • These connect the cerebellum to the pons and midbrain.
  • $$Structure of the brainstem showing the location of the pons in relation to the midbrain and medulla.

• The Central Nervous System (CNS)

  • It consists of the midbrain, pons, and medulla.
  • The midbrain is found in between the hindbrain and the forebrain.

• Thalamus

  • The thalamus (derived from the Greek meaning "inner chamber") is a midline symmetrical structure within the brain, situated between the cerebral cortex and midbrain.
  • Similarly, the medial geniculate nucleus acts as a key auditory relay between the inferior colliculus of the midbrain and the primary auditory cortex.

• Organization of Motor Neuron Pathways

  • The axons of these cells pass from the cerebral cortex to the midbrain and the medulla oblongata.
  • The midbrain nuclei include four motor tracts that send upper motor neuronal axons down the spinal cord to lower motor neurons.

• Brain: Midbrain and Brain Stem

  • It consists of the midbrain, medulla oblongata, and the pons.

• Biology of Emotion

  • Other parts of the limbic system include the olfactory bulbs, anterior nuclei, fornix, column of fornix, mammillary body, septum pellucidum, habenular commissure, cingulate gyrus, parahippocampal gyrus, limbic cortex, and limbic midbrain areas.
  • The reticular activating system (RAS) is a network of neurons that runs through the core of the hindbrain and into the midbrain and forebrain.
  • The RAS is made up of the midbrain reticular formation, the mesencephalic nucleus (mesencephalon), the thalamic intralaminar nucleus (centromedian nucleus), the dorsal hypothalamus, and the tegmentum.