CNS 1: Brain Anatomy and Functions

CNS 1: Brain

• The brain is comprised of the cerebrum, cerebellum, and brainstem.
• Objectives include labeling brain parts and defining their functions, differentiating between cerebellum, cerebrum, and brainstem.

Brain Overview

• Cerebrum: Divided into lobes (frontal, parietal, occipital, temporal).
• Frontal Lobe: Motor functions, executive functions, thinking, smell, speech, emotions.
• Parietal Lobe: Sensory processing, perception, language.
• Occipital Lobe: Visual interpretation.
• Temporal Lobe: Hearing, taste, language comprehension, emotional processing.
• Insula: Gustatory and sensorimotor processing, risk-reward behavior, autonomic functions, pain pathways, auditory and vestibular functions.
• Cerebellum: Coordinates motor and sensory information; vital for balance and posture.
• Brain Stem: Midbrain, pons, and medulla oblongata.
  • Midbrain: Sensory and motor information relay station.
  • Pons: Information relay station, breathing.
  • Medulla Oblongata: Regulation of heart rate, blood pressure, breathing, coughing, sneezing, swallowing, and vomiting.
• Diencephalon: Thalamus, hypothalamus, pineal body, and pituitary gland.
  • Thalamus: Relays and processes information to cerebrum.
  • Hypothalamus: Regulates hormones, temperature, H2O levels, thirst, emotions, and pituitary gland.
  • Pineal Body: Body clock; produces melatonin.
  • Pituitary Gland: Hormones.
• Important Gyri to Know: Precentral and Postcentral Gyri.
  • Precentral Gyrus: Primary motor cortex.
  • Postcentral Gyrus: Primary sensory cortex.
• Important Brain Areas: Substantia Nigra (in basal ganglia, produces dopamine, role in movement), Broca's Area (nonfluent speech), Wernicke's Area (language comprehension deficits).

Important Brain Areas

• Substantia Nigra: Located in basal ganglia, produces dopamine (movement).
• Pineal Gland: Produces melatonin.
• Pituitary Gland: Hormones (endocrine function).
• Broca's Area: Nonfluent speech (frontal cortex).
• Wernicke's Area: Language comprehension deficits (temporal lobe).

Blood Supply

• Vertebral Artery: Supplies spinal cord and medulla.
• Basilar Artery: Supplies pons, cerebellum, midbrain, etc.
• Internal Carotid Artery: Supplies frontal and parietal lobes, lateral hemisphere.

CVA Presentations

• ACA: Personality changes, contralateral hemiplegia and hemisensory loss.
• MCA: Contralateral homonymous hemianopia, hemiplegia, hemisensory loss, language impairment.
• PCA: Neglect, thalamic syndrome possible, vision and eye issues.

Collateral Circulation

• Network to provide alternate pathways for blood flow.

Blood Brain Barrier

• Tightly joined epithelial cells control passage; only small, fat-soluble molecules naturally pass; active transport is necessary for water-soluble substances like glucose and amino acids.

Cerebral Spinal Fluid

• Regulates extracellular content and provides protection.
• Formed in the ventricles, circulates to the subarachnoid space, and is absorbed into venous circulation.

CSF: Ventricles and Layers

• Choroid Plexus: Secretes cerebrospinal fluid (CSF) within the ventricles.
• Meninges: Dura Mater, Arachnoid, Pia Mater.

Limbic System

• Involved in behavioral and emotional responses, including survival behaviours (feeding, reproduction, caring for young).
• Located in the thalamus, hypothalamus, basal ganglia, hippocampus, amygdala.
  • Hippocampus: Memories.
  • Amygdala: Emotional Response.

Corpus Callosum

• Connects right and left hemispheres.
• Left hemisphere typically associated with language; right hemisphere typically associated with attention, memory, reasoning, problem-solving.