and and p lecture 19

Vaccination Effects

• Post-vaccination may cause discomfort for a few days.

Cartilage Reinforcement

• Important areas: Larynx (voice box), trachea, and bronchi (two main branches).

Bohr Effect

• Refers to how temperature affects the affinity of hemoglobin for oxygen but is separate from the general physiological processes in the body.

• Key components of this effect involve the globin part of hemoglobin, while the heme part remains unchanged across various respiratory pigments.

Weekly Online Quizzes

• Quiz 9 is currently open for participation.

• Quiz 10 will be activated after class; emails should be sent if access issues arise.

• Quiz 12 may replace quiz 11 for better exam preparation despite scheduling limitations.

Cell Membrane Transport

• Main principle: All solutes must be dissolved in an aqueous medium to transport across cell membranes.

• The body functions in a water-based environment (extracellular and intracellular).

Compartmentalization

• Essential for creating distinct physiological spaces:

  • Examples include gastrointestinal system compartments and respiratory structures.

• Cell membranes separate compartments, maintaining gradient differences crucial for processes like digestion and metabolism.

Importance of Surface Area

• Increasing surface area is crucial for absorption and secretion processes, similar to structures like villi in the small intestine.

• Model illustrated by a piece of material resembling a sponge, showcasing the role of increasing surface area to enhance nutrient absorption.

Small Intestine Functions

• Location for actual digestion and nutrient absorption; major enzymes are secreted here.

• Enzymes like pancreatic juice and bile help neutralize stomach acid and aid in fat digestion.

• Nutrient rich chime enters, where intestinal juices mix to help digest food.

Liver Function

• Produces bile, essential for fat digestion, and acts as a detoxifying organ.

• It stores blood, nutrients, and vitamins (A, B12, K), synthesizes proteins, and regulates blood sugar levels through insulin and glucagon.

• The liver processes and regulates many hormones, cleaning out excess from circulation.

Gastrointestinal Timing

• Process from consumption to digestion in the stomach (4 hours) and small intestine (6 hours) before moving to colon (12-24 hours), depending on content.

Accessory Organ Functions

• The gallbladder serves as a bile reservoir while the pancreas secretes digestive enzymes and bicarbonate to neutralize stomach acid in the duodenum.

Large Intestine Structure

• Responsible for final absorption of water and solid waste formation.

• Composed of the cecum, colon (ascending, transverse, descending, sigmoid), rectum, and anal canal.

• Limited digestion occurs here; bacterial fermentation breaks down some indigestible substances.

Microbial Health in the Gut

• Diverse populations of bacteria are crucial for health; they assist in fermenting certain carbohydrates and synthesizing vitamins.

• Maintaining a balance of these microbes is vital for preventing potential illnesses.

Digestive Enzymes

• Hydrolysis via digestive enzymes breaks down food components including proteins (into amino acids), fats (into fatty acids), and carbohydrates (into simple sugars).

• Important to understand the mechanisms of fibers (for example, cellulose) that we cannot digest directly; microbiota helps in fermenting these.

Regulation of Digestion

• Autonomic nervous system governs digestive processes based on food intake signaling.

Final Thoughts for Examination Preparation

• Emphasize understanding the structures and functions of organs involved in digestion and metabolism for successful exam performance.