Physiology Study Guide for Exam #1

FAHHHHH i actually hate the bicarbonate system

What is at least 1 possible cause of Eugene’s medical issues?

One possible cause of Eugene’s medical issues is alcohol poisoning or low blood sugar.

What information can be obtained from a CNC and blood chemistries?

electrolyte levels and vitamin levels????

What are homeostatic control systems and how can you apply this concept to a case study?

Homeostatic control systems are regulatory loops the body uses to keep an internal variable constant. you can use this in a case study to figure out whats wrong with the guy idfk

What are the 5 main goals of this class?

Reflect on how your understanding of physiology applies to your prior learning in other

disciplines and to your personal health care decisions.

 

Use the powerful general models of physiology (flux, mass balance, Le Chatelier's

principle, and homeostatic control systems) to make predictions about novel

physiological phenomena.

 

Provide mechanistic, causal explanations, that cross scales (e.g., molecule, cell, organ,

organism), for how physiological phenomena occur.

 

Describe the societal impacts of biological research on health equity issues and how

people from a variety of backgrounds have contributed to science.

 

Implement strategies for learning human physiology that are based on scientific

evidence and thus are active, collaborative, and effective.

What are your obligations as a student in this class?

idfk

Why will you be working in teams in this class? What did Driessan et al. (2024) suggest about group work?

Students that worked in teams performed 1 standard deviation higher (which is super significant) than students that did not work in teams.

How does laptop use and seating location correlate with student performance?

Laptop usage decreases student performance

Sitting father in the back decreases student performance

Where can you find information about the class? Where can you get help?

Info on the class can be found on the canvas syllabus

I can get help by emailing the profess or oscar or PFs ig????

How is “remembering” different than “applying”?

Remembering only requires you to recall information, but you need a much deeper understanding of the content to apply that knowledge in a new situation.

What is physiology and how does it differ from anatomy?

Physiology is the study of the body and how its parts function.

Anatomy is different as anatomy is the structure of the parts of the body and physiology focuses on the function.

Name and describe the hierarchical levels of organization. (from smallest to biggest)

1. Chemical level

2. Cell level (cytology)

3. Tissue level (histology)

4. Organ level

5. Organ system level

6. Organismal level

How do social factors influence your physiology? Is race a genetic or social contrsuct?

Social factors such as stress can influence your physiology. (idkf)

Race is a social construct, not genetic.

What is the vitamin D-folate hypothesis?

The vitamin D folate hypothesis is that UV light is needed for vitamin D production in the skin. (Vitamin D is important regulating calcium) But also UV light degrades folate (and folate is important for DNA synthesis, repair, and methylation)

so basically get UV light but not too much

Why are B vitamins important in the human body?

B vitamins are important because without them, brain cell death would occur.

What are ions? What are electrolytes? What is an anion and what is a cation?

Ions: atoms that carry a net electrical charge (neg or pos)

Electrolytes: substances that dissolve in water and separate into ions

Anion: negative ion

Cation: positive ion

Ion: Oxygen

Important?: no

Significance: a component of water and other compounds. essential for respiration

Ion: Carbon

Important?: no

Significance: found in all organic molecules

Ion: Hydrogen

Important?: YESSS

Significance: a component of water and most other compounds in the body

Ion: Nitrogen

Important?: no

Significance: found in proteins, nucleic acids, and in other organic compounds

Ion: Calcium

Important?: YESSS

Significance: found in bones and teeth, important for membrane functions, nerve impulses, muscle contraction, and blood clotting

Ion: Phosphorus

Important?: YESSS

Significance: found in bones and teeth, nucleic acids, and high-energy compounds

Ion: Potassium (bananas!!! yippee)

Important?: YESSSS

Significance: important for proper membrane function, nerve impulses, and muscle contraction

Ion: Sodium

Important: YESSSS

Significance: important for blood volume, membrane function, nerve impulses, and muscle contraction

Ion: Chlorine

Important?: YESSS

Significance: important for blood volume, membrane function, and water absorption

Ion: Magnesium

Important?: YESSS

Significance: a cofactor for many enzymes

Ion: Sulfur

Important?: no

Significance: found in many proteins

Ion: Iron

Important?: no

Significance: essential for oxygen transport and energy capture

Ion: Iodine

Important?: YESSS

Significance: a component of hormones of the thyroid gland

What is the difference between sodium atom (Na) vs sodium ion (Na+)? What is the difference between chlorine atom (Cl) and chlorine ion (Cl-)?

the sodium ion has one fewer electron compared to the atom

the chlorine ion has one more electron compared to the atom

What chemical properties and pH values define acids and bases?

Acids: substances that can release hydrogen ions (H+) Acid pH values are from 0-7 (not including 7).

Bases: substances that are proton(H+) acceptors. Base pH values are from 7-14 (not including 7)

Understand the pH scale. Why is 7.0 neutral? What is the relative acidity of different pH values?

The pH scale is a logarithmic scale measuring the concentration of hydrogen ions in a specific fluid.

a pH of 7.0 is neutral because at a pH of 7, the number of hydrogen ions (H+) and hydroxide ions (OH-) are exactly equal, cancelling out both of their powers and making it neutral.

pH 6 is 10x more acidic than pH 7

pH 5 is 100x more acidic than pH 7

and so on…

What is normal blood pH?

7.35-7.45

How does your body normally fix small deviations in pH?

Your body normally fixes small deviation in pH by using a buffer system.

Buffers are specific molecules that bind to hydrogen ions whenever the environment is too basic (pH drop) and release hydrogen ions whenever the environment is too basic (pH rise).

What are some common causes of acidosis (pH 7-7.35)?

Common Causes: Diarrhea and Breathing too little (hypo)

and kidney failure ig

What are some common causes of alkalosis (pH 7:45-7.8)?

Common Causes: Vomiting and breathing too fast (hyper)

Vomiting and its pH change

Parietal cells in the stomach produce HCl using the same bicarbonate buffer system. The H+ ions go into the stomach (it’s the acid in gastric juice) and the bicarbonate goes into the blood. And normally when you're done digesting food (that is now acidic) and it goes into the small intestine, the pancreas releases bicarbonate and therefore cancels the pH out. But when you vomit, the H+ gets lost in the thrown up stomach acid while the bicarbonate isnt used. This causes a decrease in the H+ and therefore increases pH (making it alkalosis). The equilibrium is shifted to the right to increase H+, so theres a crap ton of bicarbonate now. The kidneys pee out more bicarbonate to balance this out.

Lack of Glucose + Alcohol and pH change

When glucose is not available, adipose tissue (fat) and/or certain amino acids are broken down to provide energy. In that process, acidic ketones are also produced. Alcohol can also produce more of those acidic ketones by impairing the liver's ability to make glucose (making it necessary to break down adipose tissue). These acidic ketones make the body more acidic (acidosis). To fix this, the equilibrium shifts to the right, producing more hydrogen ions, increasing the pH and making eugene neutral.

Diarrhea and pH change

Normal pancreatic and intestinal secretions have a high concentration of bicarbonate because it helps neutralize food coming straight from the acidic stomach as it moves through the digestive system. When you have diarrhea, the food dosent stay in the colon long enough for the secretions to get reabsorbed into the body, so you basically lose a bunch of bicarbonate through pooping. This loss will cause the equilibrium to shift to the right, creating more bicarbonate, therefore making more hydrogen ions and making you acidic.

Breathing too fast and pH change

Breathing is your source of carbon dioxide, which is a key ingredient in the production of carbonic acid. When you breathe too fast, you expel a lot of carbon dioxide -> less carbonic acid -> more carbonic acid is being created -> less hydrogen ions -> being more basic

Breathing too little and pH change

 

When you hold your breath, you retain a lot more carbon dioxide -> more carbonic acid ->  equilibrium shifts to the right -> more hydrogen ions are produced -> more acidic

Kidney failure and pH change

Kidney failure is related to acidosis by the urinary system. We just learned that hydrogen ions are present in our pee, so another method of excreting hydrogen ions is by peeing. If we have kidney failure, our kidneys, the kidneys cannot pump hydrogen ions into our pee to be excreted. So that means the hydrogen ions stay in our body, decreasing our pH and making us acidic.

Renal System with acidic blood

When blood is too acidic: kidneys pump H+ ions into urine and pump bicarbonate into the blood. This fixes stuff because when the blood is acidic, there is too much H+ and not enough bicarbonate (as a lot of it was used up trying to turn into carbonic acid in an attempt to balance the pH). So the kidneys throw the extra H+ in the pee to get rid of it (increasing the pH) and pumps bicarbonate into the blood (to replenish the bicarbonate supply which increases the pH)

Renal system with basic blood

When blood is too basic: kidneys pump bicarbonate into urine and pump more H+ into the blood (less H+ is pumped into urine). This fixes stuff because when the blood is basic, there is not enough H+ (because it was used up in an attempt to balance out the buffer system) and too much bicarbonate. So the kidneys throw the extra bicarbonate into the pee to get rid of it (decreasing the pH) and pump more H+ into the blood (to replenish the H+ supply to make more acid, decreasing the pH)

Bicarbonate Buffer System

the CO2 and H2O side is RESPIRATORY SYSTEM

the bicarbonate and H+ side is RENAL SYSTEM (aka METABOLIC)

increase in CO2? equilibrium shifts to RIGHT

Decrease in CO2? equilibrium shifts to LEFT

Increase in bicarbonate? equilibrium shifts to LEFT

decrease in bicarbonate? equilibrium shifts to RIGHT

Notes:

if CO2 or bicarbonate is affected, shift equilibrium FIRST BEFORE determining acid/base state

if H+ is affected, shift equilibrium AFTER determining acid/base state

you can pee both acidic AND basic (pH 4.5 - 8)

pH to [H+]

pH = -log[H+]

[H+] = 10^-pH

pH + pOH = 14

6 Steps of the Digestion Process

1. Ingestion: food is placed in the mouth

2. Mechanical Processing: physical fragmentation of food into smaller pieces

3. Digestion: chemical breakdown of food

4. Secretion: movement of substances INTO the digestive tract (like the food)

5. Absorption: movement of substances OUT of the digestive tract and into the blood (like nutrients and stuff)

6. Excretion: removal of waste products

What are the main roles of the organs in the digestive system?

Liver: breaks down and builds up many biological molecules. produces bile

Gallbladder: stores and concentrates bile

Pancreas: produces digestive hormones (insulin, glucagon) and enzymes (protease, lipase, amylase). also releases bicarbonate which neutralizes stomach acid

Compare the roles of bile (salts) from the liver and pancreatic enzymes in digestion. Why are these introduced into the first part of the small intestine?

Bile salts: used to emulsify lipids. (Emulsify: break down into super small particles that are easier to digest. MECHANICAL BREAKDOWN)

Pancreas: releases 3 pancreatic enzymes: protease, lipase, and amylase.

• Protease = breaks bonds in carbohydrates

• Lipase = breaks bonds in lipids (Li = Li)

• Amylase = breaks bonds in proteins

All 4 of these components are introduced in the beginning of the small intestine so that they have time to break down the food and time for the nutrients to get absorbed before it enters the large intestine and turns into a useless dookie.

What health conditions are associated with pancreatitis and what are its effects?

Health Conditions: diabetes, obesity, and smoking

Effects: organ failure??? idfk

Risk Factors: gallstones, alcohol, high triglycerides

What are the main differences between MASH, MASLD, and cirrhosis?

Difference: if the liver is in MASH or MASLD state, the condition is reversible. if its cirrhosis, its irreversible

Another Difference: MASH (first stage)→ hepatocytes are bloated. MASLD (second stage) → hepatocytes are inflamed and dying. cirrhosis (last stage) → remnants of dead cells

Difference between bolus and chyme

A bolus is the ball of food formed by mechanical breakdown done in the mouth

Chyme is the semi-acidic liquid food formed in the stomach after lots of chemical breakdown

Difference between Mechanical and Chemical Breakdown of Food

Mechanical Breakdown: physically making the food into smaller particles. the chemical structure of the food is NOT changed (peristalsis, 3 stomach steps, emulsification)

Chemical Breakdown: the chemical structure of the food is changed and bonds are broken. (pepsin, enzymes, stomach acid)

How does peristalsis through the esophagus differ from propulsion, grinding, and retropulsion in the stomach?

smooth muscle does all of this btw

Peristalsis: in peristalsis (2 layers of muscle), circular muscles constrict esophagus behind the bolus while longitudinal muscles contract, lengthening food mass and pushing it forward towards the stomach.

Stomach: in the stomach (3 layers of muscle), there are 3 steps the stomach does for breakdown.

• First is propulsion, where peristalsis waves move from the fundus (the big portion of the stomach) to the pylorus (near the end of the stomach, near the pyloric sphincter).

• Next is grinding, where there are more vigorous peristalsis mixing action going on near the pylorus. At this time, the pyloric sphincter is opened a little bit to slowly let chyme into the duodenum of the small intestine.

• Lastly is retropulsion, where the sphincter closes, forcing most of the chyme/stomach acid contents back into the stomach.

I guess they differ because peristalsis just moves food while the 3 stomach actions actually break it down?

How does the structure of the small intestine increase absorption of nutrients?

The small intestines have structures called plicae (folds), villi, and microvilli. These structures all increase the surface area of the small intestine, allowing more of the small intestine to interact with the food and absorb nutrients.

How do secretions from other digestive organs affect digestion in the small intestine?

Bile salts (produced by the liver and stored/concentrated in the gallbladder) will affect digestion by emulsifying lipids.

Protease will help break down carbs, lipase will help break down lipids (L and L), and amylase will help break down proteins.

Pepsin (produced in the stomach) will heavily break down proteins but also breaks down carbs and lipids a little bit.

3 Main Macromolecules

Carbohydrates, Lipids, and Proteins

(we dont really talk aobut nucleic acids here)

(minerals: salts)

Metabolism and the Mass Balance Model

The mass balance model states that mass cannot be created or destroyed - only transformed. Basically, what goes in must come out or stay inside. This is related to metabolism because whatever is created (anabolism) must be destroyed (catabolism) or stay inside???? idfk

Liver and Glycogenesis/Glycogenolysis

Glucose (from yuor food) is absorbed in the intestine and taken to the liver through the bloodstream. There, glycogenesis can be performed, which is where an enzyme uses an anabolic process to combine glucose molecules into glycogen to store in the liver.

Then, whenever glucose is needed, another enzyme uses a catabolic process to break apart glycogen into multiple glucoses that travel into the bloodstream for cells to use.

Chemical Structure of Carbohydrates

Typical Ratio of Carbohydrates: C1 H2 O1

Glucose: C6 H12 O6

Effects of Cellulose and Why

An effect of eating a lot of cellulose (combined with a lot of water) is bulkier and softer dookies because humans lack the enzyme (cellulase) to digest cellulose so it just sits in our body (fiber) (bulkier poop) and it also absorbs water making softer poops

3D structures of glycogen, cellulose, and starch

Starch (2 types):

• Amylose: straight and linear part of starch

• Amylopectin: more branched/bent part of starch

Glycogen is HIGHLY branched

Branches make it super easy to break down the molecule into smaller parts (glucose).

Cellulose is linear but is connected to each other with hydrogen bonds, but since we dont have the enzyme cellulase to break those bonds apart, it stays together and we consider it fiber.

Importance of 3D structures of glycogen, cellulose, and starch and which complex carb is most rapidly catabolized by enzymes and why

The branches mean that glycogen can easily be broken down into glucose if I suddenly am burning thorugh my glucose supply. Starch is more linear compared to glycogen so it would take longer to break down into simple sugars (glucose). Cellulose cannot be broken down at all so its a very bad storage carbohydrate.

Glycogen is the complex carb that is the most rapidly catabolized by enzymes due to its many branches.

Difference between lacTOSE and lacTASE

Lactose: a milk sugar

Lactase: the enzyme that breaks down lactose

• Lactose can only be absorbed once it is broken down (catalyzed) by lactase. Lactase breaks down lactose into glucose and galactose

What type of carbohydrate is lactose?

disaccharide

Types of Carbohydrates

Monosaccharides (glucose, fructose, galactose): 1 ring carbs

• multiple hydroxyl groups (OH-)

Disaccharides (maltose, lactose, sucrose): 2 ring carbs

• formed by dehydration synthesis

Polysaccharides: multiple ring carbs

Salivary Amylase

produced in the salivary glands and breaks down starches (amylose and amylopectin)

Lactase Persistance, What led to human variation, and health equity issues

In areas where milk wasn’t needed for survival, there is more lactose intolerance.

In areas where milk was needed for survival and had a lot of health benefits, there is less lactose intolerance.

• natural selection type shift

Another factor for digestion differences is the ability to access milk easily

we should be calling people who can digest lactose “lactase persistence” people because majority of the world actually CANNOT digest lactose, so the people who can are in the minority and yet we call them “lactose intolerant”

National Dairy council sponsors research suggesting that health inequities can be attributed to cultural differences in milk consumption

Why Cell Membranes selectively permeable

Cell membranes are selectively permeable because of its hydrophobic heads on the phospholipids that form the cell membrane.

Because of the hydrophobic/non-polar qualities, hydrophilic/polar molecules cannot cross through the membrane because they repel.

Because its a membrane, large molecules cant go through the membrane

The substances that can travel through the membrane the easiest is small, nonpolar molecules.

Polar vs Non-Polar Bonds

Polar covalent bonds:

• atoms are sharing electrons UNEQUALLY

  • electrons are closer to the bigger nucleus

• causes the molecule to have slightly positive/negative sides

• often have bonds with oxygen and nitrogen

Nonpolar Covalent Bonds:

• atoms are sharing electrons EQUALLY

• nucleuses are equal size

• can cross the phospholipid bilayer

Active vs Passive vs Facilitated Transport

Passive Transport: the molecules are going from a high concentration to a low concentration

• Since this goes along with the natural forces of things trying to equalize themselves, this requires no energy

• Facilitated Transport: same change in concentration but the molecules cant cross the membrane by themselves (large/polar) so they need proteins to help

  • Channel Proteins (think of them like a tunnel)

  • Carrier Proteins (think of them like a gate)

Active Transport: the molecules are going from a low concentration to a high concentration

• Since this goes against with the natural forces of things trying to equalize themselves, this requires energy (ATP)

Carbohydrates after they’re broken down

Once carbohydrates get broken down, they go into the capillaries in the villi in the small intestine. They get there through facilitated diffusion using a carrier protein (gate) to get inside the cell, and then they do facilitated diffusion AGAIN to get into the capillaries.

Insulin and Glucose Transport

Insulin is produced in the pancreas and controls when glucose is transported into cells by binding to a receptor whenever cells need glucose to be transported inside of it.

Type 1 vs Type 2 Diabetes

Type 1 Diabetes: there is no insulin at all for the carrier proteins to open up and let the glucose in. This is because the immune system attacked all the insulin producing cells.

Type 2 Diabetes: there is so much insulin the carrier proteins are desensitized to it and wont open up for glucose anymore

Incretin Hormones and Insulin Release/Appetite

Incretin Hormones: GIP and GLP-1

• secreted from small intestine and travels to pancreas

They:

• make the body process insulin better

• increases production of insulin

• cause a slower release of glucose

• decreases appetite (feeling fuller → eating less → less glucose and insulin)

How and where are proteins broken down? What is produced by this breakdown? How are these substances transported into the blood?

Proteins are broken down into polypeptides in the stomach by pepsin.

Then, in the small intestine, trypsin, chymotrypsin, elastase, and carboxypeptidase (all enzymes created by the pancreas) all break down the polypeptides into short peptides and amino acids (monomers).

Amino acids are transported to the bloodstream using facilitated diffusion and cotransport.

How and where are lipids broken down? How are chemical and mechanical digestion used to break lipids into fatty acids and monoglycerides? Where do they go after they are broken down?

After lipids are emulsified by bile salts, lipids are chemically digested in the small intestine by pancreatic lipase and colipase into monoglycerides and fatty acids.

Once they are broken down, they travel through cells through facilitated diffusion and enter the LYMPHATIC SYSTEM (NOT THE BLOOD).

Flux

movement of a substance between compartments

Le Chatelier’s principle

if a chemical system at equilibrium experiences a change, than the equilibrium shifts to counteract the imposed change and a new equilibrium is created

How would changes in acidity affect different levels of organization?

Chemical level → basis for all other levels

Changes in acidity → changes protein structure which changes protein function → protein dosen’t work properly → nothing works properly anymore

Positive Feedback Loops

increases intensity of the stimulus away from baseline

eventually it reaches its limit and goes all the way back down to baseline

Negative Feedback Loops

decreases intensity of the stimulus towards the baseline

Health Equity

The attainment of the highest level of health for all people. We can work towards achieving it by valuing everyone equally  with focused ongoing societal efforts to address avoidable inequalities and injustices and the elimination of healthcare disparities"

Gastrin

a hormone that activates the gastric glands

HCl (hydrochloric acid)

converts pepsinogen into pepsin (an enzyme needed to break down protein)

Mucus

protects the lining of the stomach from stomach acid

Intrinsic Factor

only essential function of the stomach.

a glycoprotein needed for vitamin B12 absorption (which is necessary for DNA synthesis and hemoglobin synthesis)

Metabolism

all chemical reactions that occur in your body

Enzymes

proteins that act as catalysts for biological reactions

Many have ending with “-ase”. The enzymes used to break down macromolecules comes from the pancreas and small intestine.

Aquaporin

channels that let water go through