Cells and Body Systems - Exam Notes

Body Systems

Overview

  • There are multiple body systems that make up our body including:
    • Skeletal
    • Respiratory
    • Lymphatic
    • Urinary
    • Muscular
    • Nervous
    • Digestive
    • Endocrine
    • Cardio-vascular
    • Reproductive

Interesting Facts

  • The heart beats about 3 billion times in the average person's lifetime.
  • A newborn baby has 350 bones, while a fully-grown adult has 206.
  • Blood is a liquid organ.
  • The surface area of the lungs is approximately the same size as a tennis court.
  • Food will get to your stomach even if you're standing on your head.
  • Skin is the largest body organ.

Big Ideas

  • How do different systems in the human body work together to keep us healthy, and what happens when one of these systems isn't functioning properly?
  • How do the parts of a cell work together to keep living things organized?
  • How does our body move things in and out of the cell, and why is this important?

Digestive System

  • Path of food:
    1. Food enters the mouth.
    2. Goes down the esophagus.
    3. Then to the stomach, where pepsin helps digestion.
    4. Then to the small intestines.
    5. Then the large intestine.
    6. To the rectum and out through the anus.
  • These are the organs that food directly passes through.
  • Function: To break down and process food into energy to help our bodies grow and eliminate solid wastes we don't need.
  • Ingestion: Process of putting large food molecules into the mouth.
  • Digestion: Process of breaking up large macromolecules (carbohydrate, protein, fat) into smaller micronutrients (glucose, amino acid, glycerol & fatty acid) to be used in the body.
  • Absorption: Process of taking in the nutrients from the digestive tract into the blood stream.
  • Egestion: Process of eliminating undigestible waste from the body.
Types of Digestion
  • Mechanical Digestion:
    • Physical break down of food.
    • No enzymes are involved.
    • Involves mouth, teeth, and stomach muscles.
    • Begins with physical chewing.
  • Chemical Digestion:
    • Breaks food into chemical components.
    • Involves enzymes and acids.
    • Involves salivary glands, stomach, pancreas, and intestines.
    • Begins with saliva in the mouth.
  • Both Mechanical & Chemical Digestion:
    • Occur in the digestive tract.
    • Aim to breakdown food into nutrients.
    • Essential for nutrient absorption.
    • Work together in digestion.
Digestive System Chemicals
  • Amylase: An enzyme in our saliva in our mouth, where it begins the chemical process of digestion.
  • Pepsin: An enzyme produced in the stomach to help break down food.
Digestive System Accessory Organs
  • Pancreas, Liver & Gall Bladder aid in chemical digestion.
Lessons Learned (Digestive System)

  • Complete Digestive Tract:

    • Ingestion -> Digestion -> Absorption -> Egestion
    • Mouth -> Esophagus -> Stomach -> Small Intestine -> Large Intestine -> Rectum -> Anus

  • Additional Organs:

    • Liver (Gall Bladder), Pancreas

  • Ingestion:

    • Putting food into the body through the mouth

  • Digestion:

    • Breaking large macromolecules into small molecules

    • Mechanical – mouth (teeth, tongue), stomach (churning), liver bile (fat droplets) Food is cut up into smaller pieces to increase surface area

    • Chemical – mouth (salivary amylase), stomach (pepsin), small intestine/pancreas (pancreatic juice) Once cut up, chemical enzymes can break chemical bonds to make even smaller molecules

      STARCH−>sugar−>glucoseSTARCH -> sugar -> glucose

      PROTEIN−>peptide−>aminoacidPROTEIN -> peptide -> amino acid

      FAT -> small fat -> glycerol & fatty acid

  • Absorption:

    • Moving small digested molecules into the blood stream
    • Villi cells (increase surface area) in the small intestine absorb nutrients into the blood stream
    • Water is absorbed to create a solid stool in the large intestine

  • Egestion:

    • Storing then eliminating undigested food waste
    • Undigested waste is eliminated from the digestive tract

Respiratory System

  • Breathing in/Inhalation: Oxygen is taken in / breathed in.
  • Breathing out/Exhalation: Carbon dioxide is excreted / breathed out.
  • Pathway of air:
    1. Mouth cavity / nasal cavity
    2. To trachea
    3. To bronchi (singular: bronchus)
    4. To bronchiole
    5. To alveoli (singular: alveolus)
  • What is the role of the epiglottis?
    • When you swallow.
Testing for CO2CO_2
  • Hydrogencarbonate indicator is used to measure carbon dioxide levels.
  • It is red in equilibrium with atmospheric air.
  • It becomes more orange/yellow with increased carbon dioxide levels.
  • It changes from red through magenta to deep purple as carbon dioxide is removed.
  • Alveoli
    • Interface between circulatory system and respiratory system.
    • O2O_2 moves from alveoli sac to capillary.
    • CO2CO_2 moves from capillary to alveoli sac.
    • Diffusion: Movement of MOLECULES from an area of HIGH concentration to an area of LOW concentration.
    • Why does O<em>2O<em>2 move into and CO</em>2CO</em>2 move out of the alveoli?
  • How does air move in and out of our body?
    • The diaphragm muscles and rib muscles help to draw in air when they contract.
Lessons Learned (Respiratory System)

  • Complete respiratory system

    • nasal cavity -> soft palate -> larynx -> trachea -> bronchus(i) -> bronchiole(s) -> alveolus(i) ; diaphragm muscle, rib cage, intercostal muscles

  • Inhalation:

    • O2O_2 is breathed in… diaphragm contracts (pulls down) -> intercostal muscles contract -> rib cage rises, expands -> lungs inflate -> air pulled in through nasal cavity

  • Exhalation:

    • CO2CO_2 is breathed out… diaphragm relaxes (domes up) -> intercostal muscles relax -> rib cage lowers, inwards -> lungs deflate -> air is pushed out through nasal cavity

  • Change in breathing rate

    • Breathing rate increases when O2O_2 demand increases for respiration OR
    • when CO<em>2CO<em>2 concentration increases as build up of CO</em>2CO</em>2 can create acid and lower the pH of the body fluids
    • e.g. during exercise and muscle contraction

Circulatory System

  • Components: Heart, blood vessels, blood.
  • Carries food and gases around the body and removes wastes.
  • Blood vessels: arteries, veins, and capillaries (smallest blood vessels).
  • Arteries: carry blood away from the heart.
    • They carry O2O_2 from the heart to the rest of the body (oxygenated blood).
  • Veins: carry blood back to the heart.
    • They carry CO2CO_2 from the body to the heart (deoxygenated blood).
  • Capillaries: branch into tissue cells.
    • Here, materials are exchanged (O<em>2O<em>2 into cells and CO</em>2CO</em>2 into capillaries).
Structure of the Heart
  • Heart has 4 chambers: right atrium, left atrium, right ventricle, left ventricle.
    • Right Atrium: receives blood from all parts of the body. Blood is high in carbon dioxide and low in oxygen.
    • Left Atrium: receives blood from the lungs. Blood is high in oxygen and low in carbon dioxide.
    • Right Ventricle: pumps blood to the lungs. Blood is high in carbon dioxide and low in oxygen.
    • Left Ventricle: pumps blood to all parts of the body except the lungs. Blood is high in oxygen and low in carbon dioxide.
  • Atria and ventricles are separated by valves.
  • Blood Vessels
    • Veins carry blood to the heart
    • Arteries carry blood away from the heart
Blood Vessel Structures
  • Artery:
    • Away from the heart
    • Made of thick muscle tissue to be strong enough to withstand pressure of blood pumping
  • Vein:
    • Towards the heart
    • Made of thinner muscle tissues; Has valves to prevent blood from flowing backwards
  • Capillary:
    • Made of only thin epithelial tissue- only 1 cell thick
Components of Blood
  • Plasma:
    1. water
    2. soluble substances
      • proteins
      • nutrients
      • waste
      • gases
      • hormones
      • antibodies
  • Blood cells (about 45% by volume), Plasma (about 55% by volume
  • Red blood cells
  • White blood cells and Platelets
Lessons Learned (Circulatory System)

  • Complete CIRCULATORY system

    • heart -> artery -> capillary -> vein -> heart… Double circulation: 1. to the body 2. to the lungs heart -> body -> heart -> lung -> heart…

  • The Heart (left : oxygenated; right : deoxygenated; top : atrium; bottom: ventricle)

    • vena cava -> right atrium -> right ventricle -> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> left ventricle -> aorta

  • Arteries, Capillaries, Veins

    • Arteries carry oxygenated blood from the heart to the body
      • Arteries: muscular to withstand pressure from heart and small space to increase pressure of flow
    • Capillaries in the tissues, where exchange happens
      • Capillaries: smallest vessels, only one cell thick, allows diffusion and osmosis to happen easily between blood stream and cells
    • Veins carry deoxygenated blood from the body to the heart
      • Veins: thin wall, more space for flow under low pressure, valves to prevent backflow

  • Blood: RBC (carry O2O_2), WBC (immune system), platelet (blood clotting), plasma (dissolving)

  • Change in heart rate

    • Same as breathing (pump more O<em>2O<em>2 into the body or pump more CO</em>2CO</em>2 out of the body)

System Interactions

  • Respiratory and Circulatory Systems:
    • Among the tissues of the lung, these two systems come in closest contact.
    • Blood brings nutrients and oxygen all throughout the body. It takes away wastes and carbon dioxide
  • Circulatory and Digestive Systems:
    • Food is digested and in absorbable form in the small intestines.
    • Fingerlike projections called villi are present in small intestines to increase surface area for absorption.
    • Inside each villus are blood capillaries.
    • The blood carries absorbed food from the digestive system and takes them around the body to all cells.
  • Digestive and other systems:
    • Digests nutrients the body needs to survive.
    • The body gets rid of waste it no longer needs.

Shiga Toxins

Digestive System
  • Stephanie Ingred's initial symptoms are diarrhea and nausea.
  • This is due to the presence of Shiga toxins, which can significantly impact the digestive system in several ways, including:
    • Is she the only victim of Shiga toxin exposure?
Respiratory System

Shiga toxins can also affect the respiratory system in some ways:

  • Inflammation
    • Toxins can cause inflammation in the body, potentially affecting the respiratory system, leading to symptoms like coughing or difficulty breathing.
  • Immune Response
    • The body's response to infections from Shiga toxin-producing bacteria can lead to respiratory issues, such as pneumonia or other lung problems.
  • Complications from HUS
    • Severe cases of Hemolytic Uremic Syndrome (HUS) may lead to lung complications, causing fluid buildup or respiratory distress.
  • Indirect Effects
    • Poor kidney function due to toxins can cause electrolyte and fluid imbalances, affecting breathing and overall respiratory health.
Circulatory System

Shiga toxins can also affect the circulatory system in some ways:

  • Damage to Blood Vessels
    • Harms blood vessel cells, causing leakage of fluids and proteins.
  • Hemolytic Uremic Syndrome (HUS)
    • A serious condition with symptoms like anemia (low red blood cells), low platelets (increased bleeding), and kidney damage.
  • Small Blood Clots
    • Causes tiny clots in blood vessels, particularly in the kidneys, blocking blood flow and increasing damage.
  • Inflammation
    • Triggers the body's defense response, leading to further harm to blood vessels and organs.
  • Shock
    • Can result from reduced blood flow and oxygen to vital organs, requiring urgent medical attention.

Key Questions and Concepts

  • How do the parts of a cell work together to keep living things organized?
    • Key words: cell organelles, cell, tissue, organ, organ system, organism
  • How does our body move things in and out of cells, and why is this important?
    • Key words: cell, diffusion, osmosis, semi-permeable membrane, concentration, swell, shrink
  • How do different systems in the human body work together to keep us healthy, and what happens when one of these systems isn't functioning properly?
    • Key words: digestive, respiratory, circulatory, urinary, nervous system