Class 10/22 bio notes
Anatomical Terminology and Body Cavities
The vertebrate body is organized into specialized organ systems, in which multiple distinct organs cooperate to carry out overarching physiological processes such as respiration, digestion, and circulation.
The mammalian body trunk is structurally divided into two primary anatomical cavities:
Dorsal Cavity: Encloses the central nervous system structures, specifically the brain and the spinal cord.
Ventral Cavity: The anterior cavity, which is further compartmentalized into:
Thoracic Cavity: Superior chamber housing the heart, lungs, esophagus, trachea, and bronchial tree.
Abdominal Cavity: Intermediate chamber housing the stomach, liver, intestines, spleen, and pancreas.
Pelvic Cavity: Inferior chamber located within the hip girdle that contains the internal reproductive organs and lower urinary structures.
Standard anatomical orientations and clinical examination positions include:
Dorsal View: Inspection directed toward the posterior or back aspect of the organism.
Ventral View: Inspection directed toward the anterior or abdominal aspect of the organism.
Lateral View: Inspection directed from the side, designated as either left lateral or right lateral.
Recumbency: Clinical and orthopedic term designating a patient lying down in a specified plane.
Supine Position: An orientation where the patient lies horizontally facing upward (ventral surface up, dorsal surface supported below), routinely utilized for radiologic evaluations () and magnetic resonance imaging ().
Comparative Animal Circulatory Systems
Primary Function: The circulatory system delivers a continuous supply of vital nutrients and oxygen () to peripheral cells while collecting and eliminating metabolic waste products and carbon dioxide ().
Organisms Lacking a Specialized Circulatory System:
Basal aquatic invertebrates—including sponges (Porifera), hydras (Cnidaria) residing on sea beds, and flatworms such as tapeworms (Platyhelminthes)—lack a true heart, capillaries, and blood vessels.
These organisms depend entirely on direct cellular diffusion between their body cells and the aqueous environment.
Open Circulatory Systems:
Characteristic of phyla Mollusca (such as snails) and Arthropoda (such as insects).
Circulating fluid is hemolymph (a composite of heme fluid and interstitial fluid), which lacks human-like red hemoglobin and is not continuously enclosed within walls of blood vessels.
Hemolymph is pumped by primitive contractile tubes directly into open internal spaces and hemocoel sinuses, bathing organs directly.
Closed Circulatory Systems:
Present in all vertebrates (referred to as the Cardiovascular System or ).
Blood remains strictly confined within a continuous, unbroken circuit of specialized muscular pumping chambers and blood vessels.
Anatomy and Structural Organization of the Heart
Morphology and Placement:
The vertebrate heart is a muscular, cone-shaped organ roughly equivalent in size to a closed human fist.
It sits within the ventral thoracic cavity directly posterior to the sternum (the central breastbone to which ribs attach), with its inferior pointed apex tilted obliquely toward the left side of the body.
Pericardial and Wall Layers:
Pericardium: A tough, protective external connective tissue sac or sheet enclosing the heart, containing specialized pericardial fluid in the intervening space to reduce mechanical friction during continuous contraction.
Epicardium: The outermost protective epithelial and connective tissue layer intimately adhering to the cardiac muscle.
Myocardium: The thickest, intermediate tunic of the cardiac wall; composed of striated, involuntary cardiac muscle fibers that generate pumping contractions.
Endocardium: The smooth, glistening endothelial layer lining the inner surfaces of all cardiac chambers and valve leaflets.
Internal Chamber Architecture:
The heart is divided internally by a thick muscular wall called the septum, which completely separates the right and left sides to prevent the mixing of deoxygenated and oxygenated blood.
The heart contains four distinct internal chambers:
Atria (singular: Atrium): Two superior, relatively thin-walled chambers that receive incoming blood returning from the body or lungs (Right Atrium and Left Atrium).
Ventricles: Two inferior, highly muscular chambers responsible for exerting high pressure to pump blood out into major arteries (Right Ventricle and Left Ventricle).
Cyanosis indicates severe tissue deoxygenation, where oxygen-starved blood imparts a dark or bluish coloration to tissues.
Coronary Circulation:
The myocardium cannot extract nutrients or gases directly from the blood coursing through the internal heart chambers.
Instead, the myocardium is nourished independently by the coronary arteries, which originate at the base of the aorta, branch across the myocardium, and deliver oxygenated blood strictly to heart tissue.
Deoxygenated myocardial blood is collected by the coronary veins, which route venous blood back into the cardiac circulation.
Vascular Network and Hemodynamics
Arteries:
Thick-walled, highly muscular, and resilient vessels that carry blood away from the ventricles under high hydrostatic pressure.
Arteries located closest to the heart (most notably the aorta) are highly compliant and elastic, allowing them to expand to accommodate the sudden stroke volume ejected during ventricular contraction and recoil during ventricular relaxation.
Arterioles:
Smaller arterial branch vessels that lead from large conduit arteries into peripheral microcirculatory beds.
Their smooth muscle walls are heavily innervated by the autonomic nervous system and modulated by endocrine hormonal signals.
The constriction (vasoconstriction) and widening (vasodilation) of arterioles modulate systemic vascular resistance and directly dictate systemic blood pressure.
Capillaries:
Microscopic, extremely thin-walled vessels composed of a single endothelial cell layer forming dense capillary beds.
Function as the exclusive operational sites of microvascular exchange: oxygen () and essential nutrients diffuse from arterial capillary blood into peripheral tissue cells, while cellular metabolic wastes and carbon dioxide () diffuse from tissues back into venous capillary blood.
Venules:
Microscopic vessels that collect deoxygenated, waste-laden blood emerging directly from capillary beds and funnel it into small systemic veins.
Veins:
Capacitance vessels that receive blood from venules and return deoxygenated blood toward the heart under comparatively low pressure.
All peripheral systemic veins ultimately merge into the great systemic veins:
Superior Vena Cava (Precava): Large conduit vein draining venous blood from the head, neck (including jugular connections), upper extremities, and thorax directly into the right atrium.
Inferior Vena Cava (Postcava): Large conduit vein collecting venous blood from the lower extremities, pelvic region, and abdominal viscera directly into the right atrium.
Pulmonary and Systemic Pathways of Blood Flow
Systemic Circuit Pathway:
Left ventricle contracts, ejecting oxygen-rich blood through the aortic semilunar valve into the systemic aorta.
Blood courses through large systemic arteries into arterioles and subsequently into tissue capillary beds.
Internal respiration occurs: is unloaded into metabolically active tissue cells, and is loaded into the blood.
Deoxygenated blood flows sequentially through venules, systemic veins, and the superior or inferior vena cava, entering the right atrium of the heart.
Pulmonary Circuit Pathway:
Blood in the right atrium passes through the right atrioventricular (tricuspid) valve into the right ventricle.
The right ventricle contracts, pumping blood across the pulmonary semilunar valve into the pulmonary trunk and pulmonary arteries.
Pulmonary arteries deliver deoxygenated blood to alveolar capillary networks in the lungs.
External respiration occurs: diffuses into alveolar air spaces (to be exhaled via bronchioles, bronchi, and the trachea), and inhaled atmospheric diffuses into alveolar capillaries.
Freshly oxygenated blood returns to the heart via four pulmonary veins that empty directly into the left atrium.
Blood passes across the left atrioventricular (bicuspid or mitral) valve into the left ventricle, completing the dual circulatory circuit.
The Pulmonary Inversion Rule:
Throughout the systemic circuit, all arteries transport oxygenated blood, and all veins transport deoxygenated blood.
The pulmonary circuit functions as the sole exception to this rule: the pulmonary arteries carry deoxygenated blood rich in to the lungs, while the pulmonary veins carry freshly oxygenated blood rich in from the lungs back to the left side of the heart.
Cardiac Valves and Unidirectional Flow Prevention:
Atrioventricular (AV) Valves:
Tricuspid Valve: Three-cusp valve located between the right atrium and right ventricle.
Bicuspid (Mitral) Valve: Two-cusp valve located between the left atrium and left ventricle.
Function: Close promptly during ventricular systole to prevent regurgitation or backflow of blood from the ventricles into the atria.
Semilunar (SL) Valves:
Pulmonary Semilunar Valve: Positioned between the right ventricle and the exit into the pulmonary artery.
Aortic Semilunar Valve: Positioned between the left ventricle and the exit into the aorta.
Function: Close abruptly at the onset of ventricular diastole, preventing blood in the great arteries from rushing back into the relaxing ventricles due to arterial back-pressure.
The Cardiac Cycle, Heart Sounds, and Electrical Conduction
Mechanical Phases of the Cycle:
Systole: The phase of rhythmic muscular contraction and pressure generation within heart chambers.
Diastole: The phase of rhythmic muscular relaxation and chamber filling with blood.
Sequential Cycle Timing:
Phase 1: Atrial systole contracts the atria to complete ventricular filling while the ventricles reside in ventricular diastole.
Phase 2: Ventricular systole contracts the ventricles to eject blood into the pulmonary and aortic trunks while the atria enter atrial diastole.
Phase 3: Total cardiac diastole occurs, during which all four cardiac chambers relax simultaneously to permit passive filling before the next cycle initiates.
Quantitative Cardiac Metrics:
Resting heart rate: Approximately .
Cardiac cycle duration: Each single heartbeat lasts approximately .
Daily contraction frequency: Approximately .
Lifespan cardiac work: Over an average human lifespan, a heart contracts roughly ( contractions).
Cardiac Output ():
Defined as the total volume of blood pumped by the left ventricle into the systemic circuit via the aorta over the course of one minute ( or liters per minute).
Acoustic Mechanics of Heart Sounds:
The classic "lub-dub" cardiac acoustic signature represents discrete valve closures:
First Sound ("Lub" or "Lock"): A longer, lower-pitched sound caused by vibrations within cardiac tissues when the atrioventricular valves (tricuspid and mitral) close at the onset of ventricular systole.
Second Sound ("Dub" or "Dump"): A shorter, sharper sound caused by vibrations when the semilunar valves (pulmonary and aortic) snap shut at the onset of ventricular diastole due to retrograde arterial back-pressure.
Heart Murmurs: Pathological swishing or abnormal acoustic sounds produced by turbulent blood flow caused by an incompetent, malformed, or stenotic valve failing to close completely, allowing retrograde blood leakage back into an upstream chamber.
Arterial Pulse:
A tangible pressure wave propagating through the arterial tree, generated when the high volume of blood ejected during ventricular systole expands the compliant aortic wall, which subsequently recoils.
Electrocardiography (ECG / EKG):
A non-invasive diagnostic recording of the aggregate electrical depolarization and repolarization changes occurring throughout the myocardium across each cardiac cycle.
Includes distinct wave deflections (P wave representing atrial depolarization; QRS complex representing ventricular depolarization; T wave representing ventricular repolarization).
ECG abnormalities reveal structural conduction defects, ischemic tissue regions, and cardiac arrest patterns such as asystole (complete cessation of electrical and mechanical cardiac activity, colloquially termed "flatlining").
Blood Pressure Dynamics and Clinical Classifications
Physiological Basis:
Blood Pressure (): The lateral hydrostatic force exerted by circulating blood per unit area against the inner endothelial walls of systemic arteries.
Systolic Blood Pressure (): The peak pressure generated within systemic arteries during left ventricular systole, when blood is actively forced into the aorta.
Diastolic Blood Pressure (): The baseline residual pressure retained in the arterial system during left ventricular diastole while the ventricles are relaxing and filling.
Instrumentation and Measurement Units: Measured clinically via a sphygmomanometer (manometer) and expressed in millimeters of mercury (), documented as .
Reference Ranges by Age Demographics:
Individuals under of age: Baseline averages around .
Individuals approaching of age: Normal averages around .
Individuals aged : Standard baseline is roughly .
Individuals aged : Systolic averages roughly .
Individuals aged : Systolic reaches roughly .
Middle-aged adults: Systolic values up to may be tolerated, but is functionally equivalent to and indicates emerging clinical pathology.
Older adults (e.g., of age): Due to age-related arterial wall stiffening, systolic measurements of are frequently observed.
Minimum Threshold: In mature individuals, a systolic blood pressure falling below indicates clinical hypotension.
Clinical Blood Pressure Staging:
Normal Blood Pressure: Systolic between and diastolic between (standard clinical baseline is ).
Elevated Blood Pressure: Systolic reading of with a diastolic reading under (regularly triggered transiently during physical exertion).
Hypertension Stage 1: Systolic reading between or a diastolic reading exceeding (ranging ).
Hypertension Stage 2: Systolic reading of or higher, or a diastolic reading of or higher.
Hypertensive Crisis / Emergency: Systolic pressure spiking into the range of . A reading of or greater demands immediate emergency medical intervention, as unmanaged arterial pressures at this tier provoke catastrophic vascular ruptures, heart attacks, or strokes.
Cardiovascular Pathology and Etiology
Epidemiology: Cardiovascular diseases () have maintained the status of the leading cause of mortality in the United States continuously since .
Etiological Risk Factors:
Diets high in saturated and trans fats (e.g., regular consumption of triple-patty fast-food burgers with cheese and deep-fried foods).
The consumption of foods prepared in degraded, rancid cooking oils, or traditional home-cooking practices where food items are immersed in excessive volumes of oil.
Diets containing excessive sodium intake, promoting systemic fluid retention and vascular volume expansion.
High intake of stimulants, notably excessive coffee and energy drinks (including sugar-free variants), which provoke autonomic tachycardia, peripheral tremors, and spikes in blood pressure.
Cigarette smoking and tobacco abuse.
Obesity, chronic psychological distress, and chronic kidney disease.
Hereditary and genetic factors: Individuals with parental histories of cardiovascular pathology or type 2 diabetes face heightened vulnerability regardless of baseline dietary parity.
Arteriosclerosis and Atherosclerosis:
Arteriosclerosis: Pathological loss of vascular compliance characterized by the stiffening and hardening of arterial walls.
Atherosclerosis: A specific form of arteriosclerosis characterized by the subendothelial accumulation of fatty plaques (composed of cholesterol, lipids, and cellular debris).
Plaques protrude directly into the arterial lumen, reducing the cross-sectional area, impeding laminar blood flow, and provoking chronic cardiac pain (angina pectoris).
Thrombus and Embolus Formation:
Thrombus: A stationary, pathological blood clot formed directly along the endothelial surface of a blood vessel wall, typically over an ulcerated atherosclerotic plaque.
Embolus: A dislodged, freely floating thrombus (or detached fragment) that travels through the systemic or pulmonary circulation until it lodges in a narrow arterial vessel, occluding downstream blood flow.
Deep Vein Thrombosis () via Sedentary Venous Stasis:
Caused by prolonged immobility and prolonged sitting without muscular pump activation.
Documented risk scenarios: Continuous driving for without rest breaks, transoceanic commercial flights of , and extreme sedentary sitting during continuous online video-streaming for .
Preventive protocols include periodic ambulation, stretching, and the application of graduated compression stockings.
Post-Traumatic Coagulation: Physical trauma from automotive accidents can induce subtle internal vascular injury or slow internal bleeding, producing delayed blood clots that prove fatal up to after the inciting accident.
Myocardial Infarction (Heart Attack):
Caused by an occlusive thrombosis or embolism within the coronary arteries that arrests nutrient and oxygen delivery to downstream myocardium.
Gross pathology: Deprived of perfusion, the affected cardiac tissue exhibits a pale, yellowish discoloration due to acute focal ischemia, distinct from normal healthy vascularized muscle.
Cerebrovascular Accident (Stroke):
Occurs when cerebral arterial perfusion is interrupted, causing acute cerebral hypoxia, regional cellular death, permanent focal paralysis, or death.
Clinical Warning Signs: Sudden monocular visual impairment (temporary blindness in one eye), focal sensory numbness or paresis of an upper extremity (arm or hand), severe dyspnea, or pain radiating across the chest and neck.
Pathological Classifications:
Ischemic Stroke: Occurs when a detached embolus or in-situ atherosclerotic thrombus occludes a cranial artery, terminating downstream cerebral oxygenation.
Hemorrhagic Stroke: Occurs when a weakened cranial blood vessel ruptures (such as an aneurysm blowout), causing intracranial bleeding, localized tissue ischemia, and severe mechanical compression of cerebral parenchyma.
Distinction from Heat Stroke:
Heat stroke is not a vascular cerebrovascular event.
It represents systemic thermoregulatory failure induced by profound hyperthermia and dehydration, characterized by extreme lethargy, cognitive confusion, and severe physical exhaustion.
Organization and Cellular Components of the Nervous System
Adaptive Significance: The nervous system functions as an integrative network that monitors both internal visceral states and external environmental stimuli, maintaining internal physiological homeostasis while enabling animals to forage, locate mates, and avoid threats.
Evolutionary Trends: Vertebrates exhibit significant cephalization and possess far higher quantities and densities of neurons than invertebrate taxa.
Cellular Constituents of Nervous Tissue:
Neurons: The fundamental structural and functional cells of nervous tissue; specialized to receive incoming sensory inputs, transmit bioelectrical signals to central integration centers, and convey outgoing motor instructions to peripheral effectors.
Neuroglia (Glial Cells): Abundant non-conductive accessory cells that surround neurons to provide physical scaffolding, metabolic nourishment, electrical insulation, and homeostatic maintenance.
Anatomy of a Multipolar Neuron:
Cell Body (Soma): The biosynthetic center containing the nucleus, cytoplasm, and standard metabolic organelles.
Dendrites: Short, extensively arborized cytoplasmic projections that receive incoming neurochemical and sensory signals and transmit graded potentials toward the soma.
Axon (Nerve Fiber): A singular, elongated cylindrical process that propagates all-or-none action potentials away from the cell body toward target cells.
Axon Terminals: Distal terminal branchings of the axon that release neurotransmitters across synaptic junctions to transmit signals to adjacent neurons or effector cells.
Nerves: Anatomical bundles composed of hundreds or thousands of individual axons traversing the peripheral nervous system.
Functional Neuron Classifications:
Motor Neurons (Efferent Neurons):
Exhibit a multipolar morphology (possessing numerous branching dendrites and a single long axon).
Transmit outgoing motor impulses from the central nervous system out to peripheral effector organs, triggering muscle fiber contractions or endocrine/exocrine glandular secretions.
Sensory Neurons (Afferent Neurons):
Pick up internal or external stimuli and transmit afferent impulses from peripheral sensory receptors toward the central nervous system.
Sensory receptors at their distal axonal ends range from naked, unencapsulated nerve endings in the skin to highly specialized sensory organs such as the eyes and inner ears.
Interneurons (Association Neurons):
Reside entirely within the boundaries of the central nervous system, interposed structurally between sensory and motor pathways.
Form intricate, highly integrated neural circuits responsible for central coordination, abstract reasoning, memory consolidation, and language processing.
Central and Peripheral Nervous System Architecture
Primary Structural Divisions:
Central Nervous System (): Composed of the brain and the spinal cord.
Peripheral Nervous System (): Composed of all cranial and spinal nerves and encapsulated neuronal cell body clusters (ganglia) lying outside the central nervous system axis; serves as the communication conduit linking central integration centers with peripheral effector sites (skeletal muscles, smooth muscle tunics, and secretory glands like the insulin-secreting pancreas).
Macroscopic Brain Regions:
Forebrain: Responsible for memory storage, cognitive learning, thirst regulation, core body temperature management, and sleep-wake cycles.
Midbrain: Coordinates visual reflexes, autonomic eye tracking movements, and involuntary visceral/endocrine processes.
Hindbrain: Composed of the pons, medulla oblongata, and cerebellum; regulates baseline involuntary homeostatic functions including respiratory drive, vasomotor tone, and complex motor coordination.
Protective Structures of the Central Nervous System:
Bony Encasement: The skull (cranium) encases and protects the brain; the vertebral column (spinal vertebrae) encloses the spinal cord.
Meninges: Three thin, delicate protective connective tissue sheets enveloping both the brain and the spinal cord; acute inflammation of these sheets is clinically designated as meningitis.
Cerebrospinal Fluid (): A clear, water-like fluid circulating within the subarachnoid space, cerebral ventricles, and central canal; provides physical buoyancy and acts as a liquid shock absorber to protect neural tissues from concussive trauma.
Spinal Cord Structure and Physiology:
A dense cylinder of nervous tissue enclosed within the vertebral canal, extending from the base of the hindbrain down to the level of the lower rib cage.
Primary Functions:
Acts as the primary integration center for automatic reflex arcs, coordinating rapid, involuntary somatic responses to sudden external stimuli.
Serves as the two-way bioelectrical conduction highway facilitating rapid communication between the brain and peripheral spinal nerves.
Three Cardinal Functions of the Central Nervous System:
Sensory Input Reception: Peripheral sensory receptors detect internal or external environmental fluctuations and transmit afferent impulses into the .
Integration: The processes, sums, compares, and interprets converging afferent signals to formulate appropriate physiological decisions.
Motor Output Generation: The transmits efferent electrical impulses to peripheral effectors (inducing skeletal muscle contraction or stimulating glandular secretion).
Questions & Discussion
Participant Age Demographics and Aging Norms:
Question / Discussion Point: What are the participants' ages relative to standard blood pressure targets, and is mobility impairment expected in mid-adulthood?
Discussion: Participants shared ages ranging from and to . Clarification was provided regarding age-stratified blood pressure tables: while elderly individuals around of age may normally display systolic readings of due to gradual loss of vascular elasticity, individuals aged should not expect premature mobility impairments requiring walking canes. Conversely, readings below in adults represent clinically abnormal hypotension.
Dietary Fats and Culinary Habits:
Question / Discussion Point: What are the cardiovascular implications of typical fast foods versus home cooking methods?
Discussion: The discussion contrasted commercial fast-food items (e.g., bacon cheeseburgers) and deep-fried fish or chicken prepared in repeatedly heated, rancid frying oils with air-frying methods (such as air-frying mackerel). Traditional high-volume oil immersion cooking methods where pools of oil float atop tomato stews were identified as dietary risk factors for accelerated atherosclerosis.
Stimulants and Commercial Energy Drinks:
Question / Discussion Point: How do commercial energy drinks impact cardiovascular stability in students?
Discussion: Participants noted that vending machines stock high-stimulant energy drinks (including sugar-free varieties). An attendee described an adverse reaction to a single energy drink characterized by acute tachycardia, severe trembling, and shaking, emphasizing that excessive stimulant intake exacerbates borderline hypertension.
Unusual Protein Ingestion:
Question / Discussion Point: What atypical animal tissues have been consumed across different cultural diets?
Discussion: Participants confirmed having consumed snails (mollusks), frog legs, alligator meat, and wild bush rats.
Sedentary Thromboembolism Case Studies:
Question / Discussion Point: What real-world scenarios provoke deep vein thrombosis and fatal embolisms?
Discussion: A case was described of an individual who developed an embolism at age immediately following a long vacation drive. Another account highlighted a live-streamer who engaged in continuous gaming for without standing and succumbed to an acute fatal pulmonary embolism. Preventive measures discussed included avoiding continuous driving for , walking down aisles during flights, and wearing graduated compression socks.
Delayed Post-Traumatic Mortality:
Question / Discussion Point: Why do some accident victims experience sudden death weeks after appearing uninjured?
Discussion: Traumatic vehicular accidents can create occult microvascular tears, slow internal hemorrhages, or stationary thrombi that remain asymptomatic initially; after approximately , the clot may dislodge as a fatal pulmonary or cerebral embolus.
Classification of Strokes and Heat Stroke:
Question / Discussion Point: Is there a third distinct category of stroke, and does heat stroke qualify as a true stroke?
Discussion: It was confirmed that there are only two true vascular stroke categories: ischemic and hemorrhagic. "Heat stroke" is not a vascular cerebrovascular accident, but rather an acute hyperthermic breakdown characterized by extreme thermal overload, severe dehydration, exhaustion, and cognitive dysfunction.
Terminology Clarification on Homeostasis:
Question / Discussion Point: Was the slide term "hemostasis" an error for biological balance?
Discussion: It was clarified that the intended concept was physiological equilibrium (homeostasis), noting that archaic texts occasionally conflated the roots, whereas hemostasis specifically refers to the arrest of bleeding.
Step-by-Step Pathway of Pulmonary Circulation:
Question / Discussion Point: Can the pathway of blood from tissue capillaries through the pulmonary reversal be reviewed step-by-step?
Discussion: A student requested a complete repetition of the pathway. The complete route was traced from peripheral capillaries into venules, systemic veins, superior and inferior vena cavae, right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, and pulmonary arteries. The reversal of standard vessel roles was reinforced: the pulmonary arteries carry deoxygenated blood into lung alveoli to exhale ; freshly inhaled enters pulmonary veins, passes into the left atrium, across the bicuspid (mitral) valve into the left ventricle, and traverses the aortic semilunar valve into the aorta for systemic delivery.
Laboratory Specimen Confirmation:
Question / Discussion Point: What biological specimen will be utilized during the upcoming central nervous system dissection laboratory?
Discussion: It was confirmed that preserved fetal pig specimens will be dissected to view gross brain morphology, the protective meningeal coverings, and the spinal cord.