Exam 4 Student Learning Objectives
Understand-Remember-Describe
Chapter 41
* Difference between heterotroph and autotroph:
* Heterotrophs must obtain energy and nutrients from other organisms.
* Autotrophs synthesize their own food using light, water, carbon dioxide, or other chemicals.
* Classification and functions of essential nutrients required by humans:
* Amino acids: Humans require 8 essential amino acids from diet (9–10 in reality).
* Vitamins: Organic compounds vital for health, needed only in minute amounts.
* Electrolytes: Inorganic ions (Na+, K+, Cl-) vital for osmotic balance and cell function.
* Minerals: Inorganic substances like Ca, Fe, Mg; used as cofactors and structural materials.
* Structural and functional differences between incomplete and complete digestive systems:
* Incomplete digestive tracts: Single opening for ingestion and elimination (e.g., gastrovascular cavity).
* Complete digestive tracts: Separate mouth and anus, allowing continuous processing and compartmentalization.
* Structure and function of different digestive tract segments:
* Mouth: Mechanical breakdown and chemical digestion of carbohydrates and lipids.
* Esophagus: Conducts food to stomach via peristalsis.
* Stomach: Mechanical and chemical digestion of proteins; acid environment.
* Small intestine: Major site of enzymatic digestion and nutrient absorption.
* Large intestine: Water absorption and formation of feces.
* Structural features that increase surface area for absorption:
* Villi and microvilli in the small intestine greatly increase surface area for nutrient absorption.
* Functions of different organs/cells involved in digestion:
* Salivary glands: Produce amylase and mucins for carbohydrate digestion and lubrication.
* Tongue cells: Secrete lingual lipase to begin lipid digestion.
* Chief cells: Secrete pepsinogen (inactive form of pepsin).
* Parietal cells: Secrete HCl to lower pH in the stomach.
* Mucous cells: Secrete mucus to protect stomach lining.
* Pancreas: Secretes digestive enzymes and bicarbonate into the small intestine.
* Liver: Produces bile to emulsify fats.
* Gallbladder: Stores and secretes bile into the small intestine.
* Rumen and reticulum: hold symbiotic bacteria to digest cellulose
* Roles of digestive enzymes:
* Salivary amylase: Begins carbohydrate digestion in mouth.
* Lingual lipase: Begins lipid digestion in mouth.
* Pepsinogen: Secreted by chief cells; converted to pepsin in stomach acid.
* Pepsin: Active protease in stomach.
* Enterokinase: Activates trypsinogen to trypsin in the small intestine.
* Trypsinogen/Trypsin: Trypsin activates other proteases in the small intestine.
* Nucleases: Digest RNA and DNA.
* Pancreatic amylase: Continues carbohydrate digestion.
* Pancreatic lipase: Breaks down fats into monoglycerides and fatty acids.
* Location and enzymes involved in chemical digestion:
* Carbohydrates: Mouth (salivary amylase), small intestine (pancreatic amylase); absorbed via facilitated diffusion/cotransport.
* Proteins: Stomach (pepsin), small intestine (pancreatic proteases); absorbed via facilitated diffusion/cotransport.
* Nucleic acids: Small intestine (nucleases).
* Lipids: Mouth (lingual lipase), small intestine (pancreatic lipase, bile emulsification); absorbed via simple diffusion.
* Hormones influencing digestion:
* Secretin: Stimulates pancreas to release bicarbonate into the small intestine.
* Cholecystokinin (CCK): Stimulates pancreas to secrete digestive enzymes and liver/gallbladder to secrete bile.
* Gastrin: Stimulates secretion of HCl from parietal cells in the stomach.
* Role of insulin and glucagon in glucose homeostasis:
* Insulin: Lowers blood glucose by promoting glucose uptake into cells.
* Glucagon: Raises blood glucose by stimulating breakdown of glycogen.
* Diabetes Mellitus: sendrowski has diabetes
* Type I: No insulin production (autoimmune destruction of insulin cells).
* Type II: Insulin resistance in target cells.
Chapter 40
* Principles of osmoregulation and water/electrolyte movement:
* Osmoregulation: Control of water and solutes inside cells and tissues.
* Osmoconformers: Match external osmolarity (e.g., sponges, jellyfish).
* Osmoregulators: Actively regulate internal osmolarity (e.g., marine/freshwater fish, land animals).
* Source and form of nitrogenous waste:
* Ammonia: Highly toxic, excreted by aquatic animals.
* Urea: Less toxic, excreted by mammals and amphibians.
* Uric acid: Excreted as a paste by reptiles, birds, insects (saves water).
* Structure and function of shark rectal gland:
* Secretes concentrated salt solutions; removes excess NaCl via active transport using Na+/K+-ATPase.
* Adaptations of insects to minimize water loss:
* Cuticle: Waxy layer preventing water loss.
* Spiracles: Can close to reduce water loss.
* Malpighian tubules: Form pre-urine, reabsorb water and ions to form hyperosmotic urine.
* Structure and function of mammalian kidney:
* Renal corpuscle: Filters blood, forms pre-urine.
* Proximal tubule: Reabsorbs water, ions, and nutrients.
* Loop of Henle: Establishes osmotic gradient for water conservation.
* Distal tubule and collecting duct: Regulate water and ion balance under hormonal control.
Chapter 42
Describe:
* Fick’s Law of Diffusion:
* Rate of diffusion = k x Surface Area × (Partial Pressure Difference) / Distance.
* Rate of diffusion = k x A x (P2-P1/D)
* Partial pressure concept in gas exchange:
* Gases move from areas of high partial pressure to low partial pressure.
* Difference in oxygen transport in water vs. air:
* Water has lower oxygen content; aquatic animals must move more medium for same O2 amount.
* Structure/function of respiratory systems:
* Fish: Gills with countercurrent exchange to maximize O2 uptake.
* Mammals: Lungs with alveoli to maximize surface area.
* Birds: Air sacs and parabronchi enabling unidirectional flow and gas exchange during both inhalation and exhalation.
* Insects: Tracheae system with spiracles.
* Relation of respiratory structures to Fick’s Law variables:
* k: Solubility/temp (constant).
* A: Increased by alveoli, lamellae, or tracheal branching.
* (P2-P1): Increased by maintaining high O2/low CO2 gradients.
* D: Minimized with thin epithelial layers.
* Relationship between pCO2 and pH, and control of respiration:
* Increased CO2 decreases blood pH; sensed by medullary respiratory center to increase breathing rate.
* Role of hemoglobin in O2/CO2 transport:
* Binds and carries O2; buffers blood pH by binding H+; transports CO2 as bicarbonate.
* Interpret hemoglobin/oxygen binding curves:
* Sigmoid curve due to cooperative binding.
* Effects of pH and fetal Hb on O2 binding:
* Low pH and high temp → decreased affinity (Bohr shift).
* Fetal Hb has higher O2 affinity than adult Hb for effective transfer from mother.
* pCO2 and pO2 relationship in active tissues:
* High CO2 and low O2 promote O2 unloading from hemoglobin into tissues.
Apply-Analyze-Evaluate
Chapter 41
* Digestive system dysfunctions:
* Analyze how gallstones, diabetes, or liver failure impact digestion and nutrient homeostasis.
Chapter 40
* Kidney adaptations:
* Evaluate adaptations like the kangaroo rat's long Loop of Henle for extreme water conservation.
* Hormonal effects:
* Understand how aldosterone and ADH regulate water and ion reabsorption in response to dehydration or salt imbalance.
Chapter 42
* Fick’s Law applications:
* Analyze gas exchange adaptations (e.g., bird lungs, fish gills) based on maximizing diffusion rate.
* Co-current vs. Countercurrent flow systems:
* Countercurrent systems (like fish gills) maintain higher efficiency by preserving a strong partial pressure gradient along the entire exchange surface.