EXAM #2 Review

Lab 6 Respiratory System

• Divisions and structures: Divisions of the respiratory system include the upper respiratory (e.g., nasal cavity, pharynx, larynx) and lower respiratory tracts (e.g., trachea, bronchi, lungs), responsible for air conduction and gas exchange.

• Epithelial lining: The respiratory epithelium varies, with ciliated pseudostratified columnar epithelium in large airways and simple squamous epithelium in alveoli for efficient gas exchange.

• Histological structures: Key features include alveolar sacs (where gas exchange occurs), bronchioles, and capillary networks facilitating oxygen and carbon dioxide transfer.

• Structures of the lungs: The lungs are divided into lobes; the right lung has three lobes (superior, middle, inferior) while the left lung has two lobes, also housing structures like bronchi and alveoli.

• Pathway of oxygen: Oxygen travels through the respiratory tract starting at the nasal cavity, passing through the pharynx, larynx, trachea, bronchi, and into the alveoli where gas exchange occurs.

• Processes of respiration: Involves four processes: pulmonary ventilation (breathing), external respiration (gas exchange between lungs and blood), internal respiration (gas exchange between blood and tissues), and cellular respiration (use of oxygen by cells).

• Mechanics of pulmonary ventilation: Relies on diaphragm and intercostal muscles to create pressure changes that allow air to enter (inhalation) and exit (exhalation) the thoracic cavity.

• Respiratory volumes and capacities: Includes measurements like tidal volume (air volume per breath), vital capacity (max air exhaled after max inhale), and residual volume (air remaining post-exhalation), often charted on a graph.

• Definitions: Respiratory volumes are specific quantities of air exchanged during breathing cycles, whereas capacities are combinations of these volumes indicating total lung capacity potential.

• Pulmonary disorders: Obstructive disorders (e.g., asthma) hinder airflow, while restrictive disorders (e.g., pulmonary fibrosis) limit lung expansion.

• Carbonic acid-bicarbonate buffer system: Critical for maintaining pH balance in blood by regulating levels of carbon dioxide, which reacts with water to form carbonic acid, dissociating into bicarbonate and hydrogen ions.

• Hyperventilation and hypoventilation: Hyperventilation can lead to lowered carbon dioxide levels and respiratory alkalosis, while hypoventilation results in elevated carbon dioxide and respiratory acidosis affecting blood pH.

• Fetal pig structures: Involves identifying and comparing anatomical structures of the fetal pig, such as heart and lungs, to human anatomy, illustrating similarities in structure and function.

Lab 7 Digestive System Anatomy

• Trace food through the digestive tract: The process starts with ingestion in the mouth, followed by mechanical and chemical digestion in the stomach and small intestine, then absorption of nutrients, and elimination through the large intestine and anus.

• Tunics of the alimentary canal: Composed of four layers: mucosa (innermost, for absorption), submucosa (containing blood vessels and nerves), muscularis (responsible for peristalsis), and serosa (outer protective layer).

• Tunics changes: The structure of tunics varies, reflecting their functions; for example, the mucosa becomes more complex as food moves towards areas needing heavy absorption.

• Muscularis layers in the stomach: Comprises three muscle layers—inner oblique, middle circular, and outer longitudinal—that facilitate the churning and mixing of stomach contents.

• Rugae, folds, villi, microvilli: Rugae are folds in the stomach lining, circular folds (plicae circulares) in the small intestine increase surface area for absorption, while villi and microvilli further enhance surface area for nutrient absorption.

• Digestive functions: Each section (mouth, stomach, intestine) has unique roles; for instance, the stomach acids begin protein digestion, while the small intestine focuses on nutrient absorption with help from accessory organs.

• Digestive secretions: Refers to saliva (contains enzymes for carbohydrate digestion), gastric juice (acidic, aids protein digestion), bile (fat emulsification), and pancreatic juice (completes digestion of macromolecules).

• Histological structures: Involves identifying various tissue arrangements and cell types across the digestive tract, differentiating between areas like the esophagus, stomach, and intestines based on their histology.

• Teeth identification: Understanding different types of teeth: incisors (cutting), canines (tearing), and molars (grinding), along with their dental formulas for both temporary (deciduous) and permanent teeth.

• Fetal pig anatomy: A comparative study where structures in the fetal pig are analyzed alongside human anatomy to highlight anatomical similarities and developmental processes.

Lab 8 Digestive System Physiology

• Functions of the digestive system: Encompasses processes of intake, breakdown (mechanical and chemical), movement along the tract, absorption of nutrients, and ultimate elimination of waste products from the body.

• Carbohydrate digestion: Initiated in the mouth by salivary amylase, continued in the small intestine where pancreatic enzymes act to break down carbohydrates into simple sugars.

• Lipid digestion: Begins in the stomach and is further emulsified by bile in the intestine, where pancreatic lipase breaks down fats into fatty acids and glycerol.

• Protein digestion: Starts in the stomach with pepsin and continues in the small intestine through proteases (e.g., trypsin) that further break proteins down into amino acids.

• pH impact on enzymes: Enzyme activity is pH-dependent, with each enzyme having an optimal range conducive to its function; deviations can significantly reduce efficacy.

• Benedict’s test: A colorimetric assay for reducing sugars; a color change after heating indicates the presence of monosaccharides or some disaccharides (positive result).

• IKI test: A starch test using iodine; a positive result changes the color of the solution to blue-black indicating starch presence.

• Lipid presence test: Conducted by placing a substance on paper; a positive result leaves a translucent stain indicating lipids.

• Protein presence test: Uses Biuret reagent; a positive reaction triggers a color change to purple, indicating protein presence in the sample.

• Bile: A digestive fluid produced in the liver; it emulsifies fats in the small intestine, facilitating their breakdown and absorption by enzymes.

Lab 9 Metabolism

• Metabolism: Refers to the sum of biochemical reactions within the body, including anabolism (building up molecules) and catabolism (breaking down molecules), crucial for energy production and material synthesis.

• Basal metabolic rate (BMR) factors: Influenced by factors such as age, sex, muscle mass, and hormonal levels; BMR signifies the energy expended at rest to maintain vital functions.

• Hypothalamic-pituitary-thyroid axis: A regulatory pathway controlling metabolism through thyroid hormones; it starts in the hypothalamus releasing TRH which stimulates the pituitary to release TSH, prompting the thyroid to release thyroxine (T4) and triiodothyronine (T3).

• Thyroid disorders: Conditions such as hyperthyroidism (excessive hormone production increasing metabolism) versus hypothyroidism (insufficient hormone production decreasing metabolism), each presenting distinct physiological symptoms.

• Oxygen consumption and BMR: Oxygen consumption reflects metabolic rate, often correlating with Basal Metabolic Rate; higher consumption typically indicates higher metabolic activity.

• BMR components: Analysis factors for BMR include body size (larger size often correlates with higher BMR), environmental temperature adaptations, and thyroid function impacts from hormones such as thyroxine and TSH, further influenced by metabolic disorders.