NCM 101 Health Assessment - Neurologic System Anatomy: Cerebrum

Diencephalon

• Lies beneath the cerebral hemispheres and consists of the thalamus and hypothalamus.
• Thalamus: responsible for screening and directing sensory impulses to specific areas in the cerebral cortex.
• Hypothalamus: part of the autonomic nervous system, regulates body functions, including:
  • Water balance
  • Appetite
  • Vital signs
  • Sleep cycles
  • Pain perception
  • Emotional status

Brain Stem

• Located between the cerebral cortex and the spinal cord.
• Consists of mostly nerve fibers and has three parts:
  • Midbrain: serves as a relay center for ear and eye reflexes.
  • Pons: links the cerebellum to the cerebrum and the midbrain to the medulla.
  • Medulla oblongata: contains the nuclei for cranial nerves, regulates:
    • Respiratory function
    • Heart rate and force
    • Blood pressure

Spinal Cord

• Located in the vertebral canal and extends from the medulla oblongata to the first lumbar vertebra.
• Inner part of the cord has an H-shaped appearance and is made up of two pairs of columns (dorsal and ventral) consisting of gray matter.

Cerebrum

• Divided into the right and left cerebral hemispheres.
• Hemispheres are joined by the corpus callosum, responsible for communication between the hemispheres.
• Consists of aggregations of neuronal cell bodies, gray matter rims the surfaces of the cerebral hemispheres, forming the cerebral cortex.

Lobes of the Brain

• Four lobes: frontal, parietal, temporal, and occipital.
• Frontal lobe: directs voluntary, skeletal actions, influences communication, judgments, and behavior.
• Parietal lobe: interprets tactile sensations, including touch, pain, temperature, shapes, and two-point discrimination.
• Temporal lobe: receives and interprets impulses from the ear, responsible for interpreting auditory stimuli.
• Occipital lobe: influences the ability to read with understanding and is the primary visual receptor center.

Cerebellum

• Located behind the brain stem, has two hemispheres.
• Primary functions include:
  • Coordination and smoothing of voluntary movements
  • Maintenance of equilibrium
  • Maintenance of muscle tone

Assessment of Cranial Nerves

• I (olfactory nerve): assess olfactory function by asking the client to identify scented objects.
• II (optic nerve): assess vision using a Snellen chart, near vision, and visual fields.
• III (oculomotor), IV (trochlear), and VI (abducens): assess extraocular movements, pupillary response to light, and accommodation.
• V (trigeminal): assess motor function, sensory function, and facial sensations.