Bio 109 Ch 14 - SPRING24

Chapter 14: Brain & Cranial Nerves

Overview

• Focus on cranial nerves, brain anatomy, and functions for the upcoming test.

• Important to memorize cranial nerve names/roman numerals and functions (Table 14.1 on p.533).

Page 1: Brain Structure

• Cortex: Composed of gyri (ridges) and sulci (grooves).

• Notable lobes and fissures:

  • Frontal Lobe: Executive functions, movement.

  • Parietal Lobe: Sensory information processing.

  • Occipital Lobe: Vision.

  • Longitudinal Fissure: Divides cerebral hemispheres.

  • Central Sulcus: Separates frontal from parietal lobe.

Page 2: Brain Anatomy

• Brainstem: Regulates basic life functions.

• Cerebellum: Coordinates motor control and balance.

• Cerebrum: Large part for higher brain functions; divided into lobes.

  • Gyri: Folds of cerebral tissue.

  • Lateral Fissure: Separates temporal lobe from frontal and parietal lobes.

Page 3: Brain Features & Cadaver Photos

• Notable structures include:

  • Thalamus: Relay center.

  • Hypothalamus: Homeostasis, hormone control.

  • Cingulate Gyrus: Emotion regulation.

  • Corpus Callosum: Communicates between hemispheres.

• Reference pictures for anatomy on pp. 506, 508, 512.

Page 4: Cranial Nerves

• Cranial Nerves listed:

  • Optic nerve (II), Trochlear nerve (IV), Trigeminal nerve (V), etc.

  • Functions: Sensory and motor aspects of craniofacial functions.

• CNS development starts as a tube, forming hollow organs in adults.

Page 5: Brain Development

• Classification of brain regions:

  • Diencephalon: Thalamus, hypothalamus.

  • Mesencephalon: Midbrain structures.

  • Telencephalon: Cerebral hemispheres.

• Importance of embryonic development stages for understanding structure.

Page 6: Pons and Cerebellum

• Pons: Contains ascending and descending tracts, involved in several cranial nerve functions and sensory processing.

• Cerebellum: Key for balance, coordination, and newer roles in sensory processing.

• Cranial Nerve Nuclei: Key functions for sensory and motor processing tracked here.

Page 7: Midbrain Functions

• Midbrain: Key structures involved in sensory processing and motor control.

  • Substantia Nigra: Associated with movement control; degeneration leads to Parkinson’s disease.

  • Major functions in eye movement and visual reflexes (via superior and inferior colliculi).

Page 8: Reticular Formation & Thalamus

• Reticular Formation: Involved in alertness, attention, and autonomic functions (heart rate, sleep cycles).

• Thalamus: Major relay station for sensory information except olfactory signals; essential in sensory data filtering.

Page 9: Hypothalamus & Epithalamus

• Hypothalamus: Critical for hormone secretion, homeostasis, and emotional regulation.

• Epithalamus: Contains the pineal gland, involved in regulating circadian rhythms.

Page 10: Cerebral Hemispheres

• Left and right hemispheres connected by the Corpus Callosum.

• Association tracts facilitate inter-hemispheric communication for integrated brain function.

Page 11: Cerebral Cortex

• Cortical Surface: Composed of gray matter, approx. 3mm thick, housing 14-16 billion cells.

• Two main cell types:

  • Stellate cells: Multi-directional dendritic projections.

  • Pyramidal cells: Axon projects out of the area.

Page 12: The Limbic System

• Important for emotions, learning, and memory.

  • Structures include the Amygdala, Hippocampus, and Cingulate Gyrus.

  • Hippocampus: Vital for organizing memories; lesions can impair memory formation.

Page 13: Brain Wave Functionality

• Alpha, Beta, Theta, and Delta waves corresponding to different mental states (awake, drowsy, deep sleep).

Page 14: Cognition

• Involves mental processes: awareness, perception, memory.

  • Majority of the brain (75%) comprises association areas for sensory and motor integrations.

  • Brain lesions help understand different cognitive impairments in various lobes (e.g., neglect syndrome, agnosia).

Page 15: Emotion Regulation

• Prefrontal Cortex: Key area for emotional expression and decision-making.

• Emotions arise from hypothalamus and limbic system; behaviors shaped by reinforcement.

Page 16: Sensory Association Areas

• Specific areas interpret sensory input:

  • Somesthetic (parietal) for touch,

  • Visual (occipital) for sight,

  • Auditory (temporal) for sound recognition.

Page 17: Motor and Sensory Integration

• Functions of various regions covered including vocalization and sensory responses.

Page 18: Cerebellar Motor Pathways

• Pathways for proprioception and coordination from muscle/joint inputs to cerebellum.

Page 19: Hemispheric Functions

• Detailed functions and characteristics of the left vs. right hemispheres concerning language, emotions, and sensory processing.