Biol. 210 Study Guide Exam 4 Notes

Biol. 210 Study Guide: Exam 4 Study Notes

Overview of Exam 4 Content

  • Focus on the following content areas for Exam 4:
      - Endocrine System (refer to Unit 3 Study Guide for relevant terms and concepts)
      - Digestive System (Chapter 24)
      - Urinary System (Chapter 26)

  • Exam Date: Thursday, April 23.

Digestive System (Chapter 24)

Key Terms

  • Mastication: The process of chewing food into smaller pieces to facilitate swallowing.

  • Micturition: The act of urinating; the process by which urine is expelled from the bladder.

  • Deglutition: The act of swallowing; involves moving food from the mouth through the pharynx and into the esophagus.

  • Defecation: The elimination of waste from the digestive tract via the anus.

  • Peritoneal cavity: The space within the abdomen that houses various organs; consists of a parietal and visceral peritoneum.

  • Retroperitoneal: Refers to organs located behind the peritoneum (e.g., kidneys, pancreas).

  • Ascites: Accumulation of fluid in the peritoneal cavity.

  • Bolus: A mass of chewed food that is ready to be swallowed.

  • Salivary amylase: Enzyme in saliva that begins the digestion of starches.

  • Lingual lipase: Enzyme secreted by glands in the tongue that begins the digestion of lipids.

  • Chyme: Semi-fluid mass of partially digested food that moves from the stomach to the small intestine.

  • Gastric emptying: The process by which food exits the stomach and enters the duodenum.

  • Emulsification: The process by which fatty substances are mixed with bile salts to facilitate digestion and absorption.

  • Segmentations: Rhythmic contractions of the intestines that mix and propel contents through the digestive tract.

  • Haustra: Pouches or sac-like structures formed by the contractions of the circular muscles in the colon.

  • Lipoproteins: Molecules composed of lipids and proteins that transport fats through the bloodstream.

  • Micelles: Aggregates of lipids that facilitate the absorption of lipids in the intestine.

  • Chylomicrons: Lipoprotein particles that transport dietary lipids from the intestines to other locations in the body.

  • MMC (Migrating Motor Complex): A pattern of electromechanical activity observed in the gastrointestinal tract during fasting.

  • MALT (Mucosa-associated Lymphoid Tissue): A type of lymphoid tissue found in mucosal surfaces, playing a role in the immune response.

  • 3 Extrinsic Reflexes of GI Tract:
      - Gastrocolic reflex: Stimulates contraction of the colon in response to food intake.
      - Gastroileal reflex: Stimulates the emptying of the ileum into the cecum after eating.
      - Enterogastric reflex: Inhibits gastric motility and secretion in response to the presence of chyme in the duodenum.

Concepts

  • 6 Processes (Functions) of Digestion:
      - Ingestion, Propulsion, Mechanical Digestion, Chemical Digestion, Absorption, Defecation.
      - Reference: Fig. 24.2 for visual representation.

  • Enteric Nervous System: The complex network of nerves within the gastrointestinal tract.
      - Plexuses: Located between the layers of the GI tract musculature; control gastrointestinal motility, secretions, and blood flow.

  • Peritoneum: Two layers surrounding the abdominal organs;
      - Visceral peritoneum: Covers the organs.
      - Parietal peritoneum: Lines the abdominal wall.

  • Folds of the Peritoneum:
      - Include the mesentery, mesocolon, falciform ligament, greater omentum, and lesser omentum, each associated with specific organs. Refer to Fig. 24.5.

  • Major Salivary Glands:
      - Parotid, submandibular, and sublingual glands; their locations are shown in Fig. 24.7.

  • Oral Cavity: The mouth where digestion begins.
      - Salivation: Controlled by the autonomic nervous system, activated by the sight, smell, or thought of food.
      - Salivary enzymes: Salivary amylase (digests starches) and lingual lipase (digests fats).

  • Pharynx Divisions: Includes nasopharynx, oropharynx, and laryngopharynx as previously covered in Chapter 23, Fig. 23.2.

  • Deglutition Stages:
      - Steps include the oral phase (voluntary), pharyngeal phase (involuntary), and esophageal phase (involuntary). Details found in Section 24.8.

  • Stomach Structure:
      - Includes the fundus, body, and pylorus, each with 3 muscularis layers: longitudinal, circular, and oblique (refer to 2 slides).

  • Glands and Cells of the Stomach:
      - Important cell types include mucous cells, parietal cells (secrete HCl), and chief cells (secrete pepsinogen); details available in Figs. 24.13 and Table 24.3.

  • Digestion Process: Refer to power points and Section 24.9 for digestion mechanics following stomach anatomy.

  • Pancreas Anatomy: Focus on exocrine functions such as secretion of pancreatic juices containing digestive enzymes.
      - Pancreatic Acini vs. Islets: Acini produce digestive enzymes, while islets produce hormones (insulin, glucagon). Refer to Tables 24.4 and 24.5 for enzyme details.

Biliary System

  • Bile Flow: Path from liver to gall bladder and its functions outlined in Fig. 24.16.

  • Hepatocyte Functions: Includes bile production, detoxification, synthesis of plasma proteins, etc.

  • Gall Bladder Function: Stores and concentrates bile.

  • Liver Functions:
      - Carbohydrate metabolism, lipid metabolism, protein metabolism, drug and hormone processing, bilirubin excretion, bile salt synthesis, phagocytosis, and vitamin D activation.

Small Intestine

  • Structure and Function: Composed of duodenum, jejunum, and ileum, responsible for most enzymatic digestion and nutrient absorption.

  • Plicae Circulares, Villi, and Microvilli: Structures that increase surface area for absorption in the small intestine; refer to Figs. 24.20 and 24.21.

  • Digestion of Macromolecules:
      - Processes for carbohydrates, proteins, lipids, and nucleic acids demonstrated with supplementary material reflecting Fig. 24.22.

Large Intestine

  • Regions and Functions: Ascending, transverse, descending, and sigmoid colon play roles in water absorption and feces formation; refer to Figs. 24.24 and 24.25.

  • Chemical Digestion: Discusses lipid transport mechanisms such as chylomicrons and micelles, and lacteal functions.

  • Formation of Feces: Processes related to mechanical and chemical digestion in the large intestine discussed in Table 24.6.

  • Defecation Reflex: Coordinated action resulting in the expulsion of feces.

  • Diarrhea and Constipation Causes: Physiological terms and conditions affecting normal bowel movements.

  • Digestive Hormones: Major hormones controlling digestion outlined in Table 24.8.

Urinary System (Chapter 26)

Key Terms

  • Renal Cortex: The outer layer of the kidney.

  • Renal Medulla: The innermost part of the kidney containing renal pyramids.

  • Parenchyma: Functional tissue of the kidney involved in urine production.

  • Nephron: The functional unit of the kidney responsible for forming urine.

  • Glomerular Filtrate: Fluid that enters the nephron's tubule after filtration at the glomerulus.

  • Macula Densa: Specialized cells that detect sodium concentration in the distal convoluted tubule.

  • Juxtaglomerular Cells: Cells that release renin in response to low blood pressure.

  • Juxtaglomerular Apparatus (JGA): Structure important for the regulation of blood pressure.

  • Glomerular Filtration Rate (GFR): The rate at which blood is filtered through the glomeruli.

  • Reabsorption and Secretion: Processes by which substances are returned to the blood or removed from it.

  • Aquaporins: Water channel proteins facilitating water reabsorption.

  • Urinalysis: Laboratory examination of urine for medical diagnosis.

  • Electrolytes: Charged particles essential for various body functions, including nerve conduction and muscle contraction.

  • Thirst Center: Area of the brain that regulates thirst and fluid intake.

  • Albuminuria: Presence of albumin in urine, indicating possible kidney damage.

  • Ketonuria: Presence of ketones in urine, often associated with diabetes.

  • Renal Calculi: Kidney stones formed from mineral buildup.

  • Glucosuria: Presence of glucose in urine, indicating hyperglycemia or diabetes.

Concepts

  • Kidney Functions: Overview of primary functions including filtration, reabsorption, and secretion; depicted in 2 slides.

  • Kidney Anatomy: External and internal structures of kidneys must be known.

  • Filtration Membrane Components:
      - Composed of glomerular capillary endothelium, basement membrane, and podocytes.

  • Forces in Glomerular Filtration: Distinction between forces favoring and opposing filtration.

  • Renal Physiology Basics: Detail the three main processes of urine formation: filtration, reabsorption, secretion.

  • GFR Norms: Normal glomerular filtration rates in males and females, with emphasis on the difference between filtrate and excreted urine amounts post-reabsorption.

  • Glomerulus and Capsule Cells: Identification of cell types, layers, and their roles in filtration.

  • Filtration Membrane's Role: Components that allow filtration and molecules that are restricted from passing.

  • Glomerular Filtration Rate Significance: Implications of GFR values being too high or too low regarding kidney function.

  • Factors Affecting GFR: Understanding renal autoregulation, neural regulation, and hormonal regulation relative to GFR control.

  • Reabsorption and Secretion Slides: Details on how substances are reabsorbed and secreted throughout the nephron.

  • Nephron Permeability: Identification of nephron segments that are permeable or impermeable to water.

  • Reabsorption Sites: Specific substances reabsorbed at different nephron sections such as the proximal convoluted tubule and loops of Henle.

  • Renin/Aldosterone System: Mechanism of how this system regulates blood volume and pressure illustrated in endocrine chapter figure.

  • Antidiuretic Hormone (ADH): Understanding how it operates to limit water loss.

  • Atrial Natriuretic Peptide: Mechanism controlling blood volume by reducing reabsorption of sodium.

  • Calcium Regulation: Role of parathyroid hormone in preventing calcium loss.

  • Urine Concentration: Processes that lead to the formation of dilute vs. concentrated urine.

  • Urinalysis Tests: Overview of relevant tests including blood urea nitrogen and plasma creatinine measurements.

  • Urine Prevention Mechanisms: Mechanisms preventing the backflow of urine from the bladder to ureters.

  • Trigone Function: Understanding the trigone area of the bladder and its significance in urine storage.

  • Micturition Reflex: Overview of the anatomy and physiology behind the urination reflex.

  • Electrolyte Homeostasis: The role of electrolytes in maintaining bodily fluid balance discussed in Chapter 27.

  • Hormones for Na+ and Cl- Regulation: Key hormones regarding sodium and chloride reabsorption affecting fluid homeostasis mentioned across Chapters 26 and 27.

  • Urination Anatomy: Structures in male and female bodies involved in the urination process; reference materials provided at the end of chapter power points.