Exam 3 Study Guide - BISC-230

Lecture 12: The Chemical Senses
Vocabulary and Concepts

  • Olfaction

    • Cribiform Plate: Thin bone structure through which olfactory nerve fibers pass.
    • Olfactory Nerve (Cranial Nerve I): Carries signals from the olfactory epithelium to the olfactory bulb.
    • Olfactory Bulb: Processes information about odors.
    • Olfactory Epithelium: Tissue in the nasal cavity where olfactory receptor cells are located.
    • Olfactory Receptor Cells: Bipolar neurons detecting odorants.
    • Odorants: Chemicals that can be detected by the olfactory system.
    • Odorant Receptors: Proteins on olfactory receptor cells that bind specific odorants.
    • Combinatorial Coding: Mechanism by which different combinations of odorants activate different receptors to produce a unique smell.
    • Glomerulus: A structure in the olfactory bulb where olfactory receptor cells converge based on the receptor type.
    • Central Olfactory Targets:
    • Limbic Structures: Regions involved in emotions and memory (e.g., Piriform Cortex, Amygdala).
    • Memory Structures: Support memory processing (e.g., Entorhinal Cortex).
    • Vomeronasal Organ (VNO): Structure involved in detecting pheromones in animals.
    • Pheromones: Chemical signals that affect social and reproductive behaviors among animals.

  • Gustation

    • Papillae: Structures on the tongue that contain taste buds.
    • Circumvallate: Largest, located at the back of the tongue.
    • Fungiform: Mushroom-shaped, found on the front and sides of the tongue.
    • Foliate: Located on the sides of the tongue.
    • Filiform: Provide texture sensation but do not contain taste buds.
    • Taste Modalities (Tastants):
    • Sweet: Associated with sugars.
    • Salty: Related to sodium ions.
    • Sour: Related to acids.
    • Bitter: Associated with toxic substances.
    • Umami: Savory taste, related to amino acids.
    • Taste Receptors:
    • T1Rs: Detect sweet and umami.
    • T2Rs: Detect bitter.
    • Labeled Line Hypothesis: Theory stating that specific pathways are designated for specific tastes without overlapping.
Lecture 13: The Visual System (Part 1)
Eye Anatomy
  • Lens: Focuses light onto the retina.
  • Ciliary Body and Muscles: Adjust tension for focusing the lens.
  • Optic Disc (Blind Spot): Point where the optic nerve exits; lacks photoreceptors.
  • Optic Nerve: Transmits visual information to the brain.
  • Retina: Contains photoreceptors (rods and cones).
    • Rods: Responsible for night vision, high sensitivity but low acuity.
    • Cones: Responsible for color vision and detail, high acuity but low sensitivity.
Lecture 14: The Visual System (Part 2)
Visual Processing
  • Primary Visual Cortex (V1): Processes visual information; has specific layer functions.
  • Higher Visual Processing Pathways:
    • Dorsal Pathway (Magnocellular): Handles spatial awareness and motion.
    • Ventral Pathway (Parvocellular): Focuses on object recognition.
Visual Field Deficits
  • Complete Vision Loss: Loss of vision in one eye due to optic nerve damage.
  • Bitemporal Hemianopia: Loss of temporal visual fields due to optic chiasm damage.
  • Homonymous Hemianopia: Loss of same side visual fields due to LGN damage.
Lecture 15: The Autonomic Nervous System
  • Autonomic Nervous System (ANS): Manages involuntary functions; divided into sympathetic and parasympathetic branches.
    • Sympathetic Branch: Prepares body for stress (fight or flight); uses norepinephrine.
    • Parasympathetic Branch: Relaxes body (rest and digest); uses acetylcholine.
Key Reflexes
  • Pupillary Light Reflex: Adjusts pupil size based on light intensity.
  • Micturition Control: Complex interaction between the sympathetic and parasympathetic systems for bladder control.