BY 264 Spring 2025 Study Outline - Midterm Study Guide
BY 264 Spring 2025 Study Outline - Midterm Lab Notes
Lab 1: Compound Microscope and Neuron Anatomy
Different Parts of a Compound Microscope
Objective Lenses: Multiple lenses for varying magnification levels.
Eyepiece (Ocular Lens): Lens the viewer looks through, typically 10x magnification.
Stage: Platform where the slide is placed for viewing.
Coarse Focus Knob: Used for initial focusing of the specimen.
Fine Focus Knob: Used for precise focusing after using the coarse adjustment.
Illuminator: Light source to illuminate the specimen.
Base: Support structure for the microscope.
Calculation of Total Magnification
Formula: ext{Total Magnification} = ext{Eyepiece Magnification} imes ext{Objective Lens Magnification}.
Example: If eyepiece = 10x and objective = 40x, then total magnification = 10 imes 40 = 400x.
Parts of a Neuron (Identify from model)
Cell Body: Contains the nucleus and organelles.
Nucleus: Stores genetic material.
Nucleolus: Produces ribosomes.
Dendrite: Receives signals from other neurons.
Axon Hillock: Connects the cell body to the axon and initiates action potentials.
Axon: Transmits impulses away from the cell body.
Myelin Sheath: Insulates the axon to increase transmission speed.
Schwann Cells: Form myelin in the peripheral nervous system.
Oligodendrocytes: Form myelin in the central nervous system.
Nodes of Ranvier: Gaps in myelin sheath for faster signal conduction.
Axon Terminal: Releases neurotransmitters to communicate with other neurons.
Types of Neurons
Unipolar Neuron: Single process extending from the cell body, primarily found in sensory neurons of the peripheral nervous system.
Bipolar Neuron: Two processes (one axon, one dendrite), found in sensory organs like the retina.
Multipolar Neuron: Multiple dendrites and one axon, common in motor neurons and central nervous system.
Microscopic Appearance of Neurons
Important structures to identify:
Dendrite: Short, branching projections.
Axon: Long projection that transmits impulses.
Cell Body: Central part with a large nucleus.
Nucleus: Darkly stained area in the cell body.
Waste Disposal Protocols
Black Trashcan: For regular waste.
Beige Trashcan: For general materials (e.g., paper, plastics).
Sharps Container (Red): For all sharp objects like needles and blades.
Lab Dress Code
Proper lab attire required: closed-toe shoes, lab coats, safety goggles.
Lab 2: Sheep Brain Dissection and Cranial Nerves
Anatomical Structures from Sheep Brain Dissection
Identified key regions of the sheep brain during dissection.
Functions of Cranial Nerves
Focus on Olfactory and Optic nerves:
Olfactory Nerve: Responsible for the sense of smell.
Optic Nerve: Related to vision.
Optic Nerve: Distinct “U” shape.
Optic Tract: Distinct INCORRECT orientation with an upside-down “U” shape.
Optic Chiasm: The crossover point of the optic nerves.
Parts of the Human Brain Model
Familiarize with the various sections of the human brain model.
Different Lobes of the Brain
Frontal Lobe: Associated with executive functions, decision-making.
Temporal Lobe: Involved in processing auditory information and memory.
Parietal Lobe: Integrates sensory information and spatial awareness.
Occipital Lobe: Responsible for visual processing.
Lab 3: EEG Equipment and Brain Activities
Parts of EEG Equipment Used
BIOPAC Unit: Main device for recording EEG signals.
Leads: Cables connecting electrodes, NOT wires.
Electrodes: Sensors placed on the scalp to detect electrical activity.
Standard Deviation of Brain Waves
Understanding measured ranges for different brain wave types.
Human Conditions Related to Brain Waves
Different brain states correspond to specific wave types:
Awake & Alert: Beta waves (high frequency).
Awake & Relaxed: Alpha waves (medium frequency).
Deep Sleep: Delta waves (low frequency).
Microscopic Structures of a Spinal Cord Slide
Identifying diagram:
“V” shape indicates the ventral side; important in distinguishing dorsal and ventral structures.
White vs Gray Matter
White Matter: Consists of myelinated axons; lighter in color on models.
Gray Matter: Contains neuronal cell bodies and unmyelinated axons; darker in color.
Lab 4: Nerve Plexuses and Reflexes
Identifying Different Nerve Plexuses
Color-coded yellow nerves on human models:
Brachial Plexus: Network of nerves supplying the upper limb.
Lumbar Plexus: Supplies the lower back and legs.
Sacral Plexus: Supplies the pelvis and lower limbs.
Vertebral/Spinal Regions of Nerve Plexuses
Brachial Plexus: Originates from the thoracic region.
Lumbar Plexus: Originates from the lumbar region.
Sacral Plexus: Originates from the sacral region.
Mnemonic: “BREAKFAST @ 7, LUNCH @ 12, DINNER @ 5??” signifies the sequence of plexus origins.
Identifying Nerves in Cat Dissection
Specific nerves to identify in cat's arm and leg:
Ulnar Nerve (brachial plexus).
Median/Medial Nerve (brachial plexus).
Radial Nerve (brachial plexus).
Femoral Nerve (lumbar plexus).
Saphenous Nerve (lumbar plexus).
Sciatic Nerve (sacral plexus).
Common Fibular Nerve (sacral plexus; runs to the OUTSIDE of knee).
Tibial Nerve (sacral plexus; runs to the INSIDE of knee).
Equipment for Triggering Reflexes
Reflex Hammer: Used to elicit and assess reflex responses.
Listing Human Reflexes
Common reflexes:
Patellar Reflex (knee jerk).
Calcaneal Reflex (ankle jerk).
Lab 5: Eye and Ear Anatomy
Anatomical Structures from Cow Eye Dissection
Important features to identify:
Tapetum Lucidum: Iridescent layer for night vision, visible in some animals.
Choroid Coat: Dark, pigmented layer; located posterior of the eye.
Retina: Covers the tapetum lucidum and the choroid (beige in color); anchored to the fibrous tunic at the blind spot.
Anatomical Structures on Ear Model
Identify various components of the ear model discussed.
Microscopic Structures of a Retina Slide
Important structures to identify:
Choroid: Provides nutrients to the retina.
Nuclei of Rods and Cones: Photoreceptor cells (PCR) crucial for vision.
Nuclei of Bipolar Cells: Relay signals from rods and cones to ganglion cells.
Nuclei of Ganglion Cells: Final layer of retina; their axons form the optic nerve.
Identifying Structures on Eye Model
Familiarize with the eye model's key anatomical parts.
Diagnostic Tests Conducted by Eye Doctors
Disorders for which tests may be performed:
Astigmatism: Irregular curvature of the eye.
Colorblindness: Inability to distinguish certain colors.
Visual Acuity: Measure clarity of vision.
Utilized diagnostic tests in lab:
Otoscope: Used to examine the ear, particularly for conditions like otitis media.