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Lecture Exam 2 Flashcards

1
Q

What are the main functions of the respiratory system?

A

Gas exchange

Vocalization

Olfaction

Acid-base balance

ACE conversion / BP

Pressure Gradient establishment

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2
Q

Name the structures/pathway in order from the mouth/nose to the lungs

A

nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli

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3
Q

What does the conducting division of the respiratory system consist of?

(Structure and function)

A

Those passages that serve only for airflow, essentially from the nostrils through the major bronchioles

  • Upper respiratory tract
    • Structure:
      • Mouth, pharynx, epiglottis
    • Function:
      • Airflow
      • Warm, cleanse, and humidify air
      • Olfaction
  • Lower respiratory tract
    • Structure:
      • Glottis, larynx, trachea, bronchi
    • Function:
      • Airflow and cleansing
      • “Mucous elevator”
      • Vocalization
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4
Q

What are the respiratory division structures consist of and what are their functions?

A
  • Bronchioles
    • smooth muscle
  • Alveoli
    • Site of gas exchange
    • Cellular specialization
      • Squamous (Type 1) Cells = ~95% of cell
        • Diffusion
      • Great (Type 2) cells = ~5% of cell
        • Repair and surfactant production
        • Wandering macrophages
    • Respiratory membrane
      • Squamous (Type 1) cell
      • Basement membrane
      • Capillary endothelial cell
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5
Q

Explain the details of the respiratory membrane

Include:

  1. Squamous alveolar cell
  2. Shared basement membrane
  3. Capillary endothelial cell
A
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6
Q

What are the inspiratory and expiratory muscles?

A

Inspiratory muscles:

  • Diaphragm
  • External intercostals

Expiratory muscles:

  • Internal intercostals
  • Abdominal muscles
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7
Q

Name and describe the neural control centers for the respiratory control and what they impact

A

Control of skeletal muscles

  • Medulla
    • Ventral Respiratory Group (VRG)
      • Active in bursts during quiet breathing
      • Control activity of phrenic and intercostal nerve
      • primary generator of respiratory rhythm
  • Dorsal Respiratory Group (DRG)
    • Receives sensory input
    • Modifies activity of the VRG
    • Breathing is adapted to varying conditions
  • PONS
    • Pontine respiratory group (PRG)
      • Modifies activity of VRG and DRG
      • Receives input from high brain centers
        • eg. hypothalamus, limbic system, and cerebral cortex
        • Adapts to sleeping, exercise, vocalization and emotional response changes
  • Neural Output
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8
Q

Explain the types of stimuli and sensors (Who controls the control centers?)

A
  • Central Chemoreceptors
    • Medulla oblongata - brainstem neurons
      • respond to changes in pH of cerebrospinal fluid
    • “Stimulating” stimuli:
      • Increase CO2 (hypercapnia) or decrease pH of CSF
  • Peripheral Chemoreceptors
    • Carotid and aortic bodies
      • respond to O2 and CO2 content of the blood and pH
    • Stimulating stimuli:
      • Decrease PO2, Increase CO2, or Decrease pH in blood
  • Stretch Receptors
    • Found in smooth muscle of the bronchi and bronchioles and in the visceral pleura
      • Respond to inflation of lungs and signal the DrG by way of vagus nerves
    • Hering-Breuer reflexes (excessive inflation triggers this reflex)
      • Inflation reflex
      • Deflation reflex
      • Prevent damage due to overexpansion or collapse
  • Irritant Receptors
    • Detection of irritating chemicals / gases
      • Trachea receptors trigger coughing
      • Nose and pharynx receptors trigger sneezing
  • Voluntary Control
    • Required for vocalization and swimming
    • Neural bypass of respiratory centers under control of cerebral cortex
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9
Q

What is the fluid flow directly proportional to?

A

F = delta P / R

Where:

F = flow

Delta P = change in pressure

R = resistance

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10
Q

What is the pressure that drives respiration, explain

A

atmospheric (barometric) pressure

the weight of the air above us

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11
Q

Explain Boyle’s law

A

at constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume

P1V1 = P2V2

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12
Q

Explain how the pressure difference in the lungs and chest cavity are impacted during the respiration cycle

A
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13
Q

Explain the breathing mechanistic gas physics, ie. ideal gas law

A

PV = nRT

(Boyle’s law)

P = pressure

V = volume

n = # of gas molecules

R = gas constant

T = temperature

Pressure and volume are inversely proportional

Air moves from high to low pressure

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14
Q

Explain the respiratory pressure changes during the respiration cycle

A
  • Atmospheric Pressure
    • Air pushing down
    • 760 mm Hg (at sea level)
    • Since it doesn’t change, set to zero
  • Intrapulmonary Pressure
    • Internal pressure in the lungs (in alveoli)
    • Changes due to lung volume
      • Normally -1 to +1 (relative to Patm)
        • -1 = greater volume in lung
        • +1 = lower volume in lung
  • Respiratory Cycle
    • Inspiration
      • Increase in lung volume = decreased intrapulmonary pressure
      • Air flows in
  • Intrapleural pressure
    • Pressure in pleural space
    • A ‘sucking’ force!
    • Based on elastic pull inwards vs. adhesion outwards
    • Varies during respiratory cycle
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15
Q

What are the factors that enhance pressure in the lungs?

A

Volume changes, most substantial effect

Adhesion of lung to pleural wall

Elasticity of the lungs and chest wall

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16
Q

Explain the factors enhancing resistance in the lungs

A
  • Airway diameter
    • Bronchoconstriction
      • Histamine, PSNS
        • for people with allergic response, this is how it is treated
    • Bronchodialation
      • Epinephrine, SNS
      • beta 2 agonists
        • in puffers for people with asthma
  • Pulmonary compliance
    • Surfactant decreases surface tension
      • very easy to fill up under normal circumstances, but as you get older the elasticity decreases
    • Prevents collapse
      • amphiphilic molecules that disrupts and prevents collapse
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17
Q

Explain alveolar ventilation, like breaths per minute for a normal adult and for a child

A

Adult normal = 12 / min

Children = 18 - 20 / min

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18
Q

Explain how to calculate the respiratory minute volume (VE)

A

Respiratory minute volume (VE) = F x Vt

where: F = breaths per minute, Vt = title volume

Normally 12 breaths/min x 500 ml/breath = 6 L/min

Variable by delta F or delta Vt

Up to 200 L/min

If your VE = 6.0 L/min, how many breaths per minute are you taking?

  • cannot answer because you do not have the title volume (Vt)
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19
Q

Explain the alveolar ventilation (VA) and how to calculate it

A

Volume of ‘fresh’ air getting to alveoli

  • Automic dead space (VD)
    • Air ‘left’ in conducting zone
      • Only one way in and out, so the air mixes and that wish why you must subtract out the dead space when calculating the alveolarventilation
    • ~150 ml per breath
  • VA = f ( Vt - Vd)
    • VA = alveolar ventilation
    • Vt = title volume
    • VD = Automic dead space
  • ex: VA = 12 bpm x (500 ml - 150 ml) = 4.2 L/min
    • only about 2/3 of the air we breath is fresh
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20
Q

What are the anatomical dead space implications?

  1. If VE stays constant (6.0 L/min), but F goes down, what happens to VA
  2. how many breaths before VA = 0 L/min when VE = 6.0 L/min
A
  1. If F goes up and VE is held constant, VA would also go up
  2. Any amount of breaths over 40, is just replacing dead space air, that is why people pass out when you have panic attacks
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21
Q

Explain the spirometry trend and components

A
  • Tidal Volume
    • Volume of air during normal (quiet) breathing cycle (eupnea)
    • ~500 ml
  • Inspiratory Reserve Volume
    • Volume that can be inspired (over tidal) with maximum effort
    • Hyperpnea
      • 1500 - 500 ml
  • Expiratory Reserve Volume
    • Volume that can be expelled (after tidal) with maximum effort
      • 500 - 1000 ml
  • Residual Volume
    • Volume of air that remains in the lung, even after maximum exhalation
      • Not normally measurable
      • 900 - 1200 ml
      • Due to surfactant, intrapleural pressure
  • Minimal volume (after collapse)
    • 30 - 120 ml
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22
Q

Explain how each of the following are determined and if you can measure them

  1. Total Lung Capacity
  2. Inspiratory Capacity (IC)
  3. Vital Capacity (VC)
  4. Functional Residual Capacity
A

VT = Tital Volume

IRV = Inspiratory Reserve Volume

ERV = Expiratory Reserve Volume

Vres = Residual Volume

  1. Total Lung Capacity = VT + IRV + ERV + Vres
    • No, cannot measure Vres
  2. Inspiratory Capacity (IC) = VT + IRV
    • Yes, can measure
  3. Vital Capacity (VC) = VT + IRV + ERV
    • Yes, can measure
  4. Functional Residual Capacity = ERV + Vres
    • No, cannot measure Vres
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23
Q

Explain an overview of gas exchange?

A
  1. Gas diffuses down its own concentration gradient
    • usually talk in partial pressure gradient
  2. The structure of the respiratory memebrane is well adapted for the exchange of O2 and CO2
  3. Hemoglobin carries both O2 and CO2
    • Must have an affinity to oxygen but also needs to be able to dump it off
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24
Q

Explain the physics behind gas movement

A
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25
Q

Explain what makes up air and the details of partial pressure and dalton’s law

A
  • What is air?
    • Mixture: N2, O2, H2O, CO2, other
    • Partial Pressure = % air X air pressure
    • Dalton’s Law: PN2 + PO2 + PCO2 + PH2O = 760 mm Hg
      • PO2 = 760 mm Hg (21%) = 160 mm Hg
      • PCO2 ​= 760 mm Hg (0.04%) = 0.3mm Hg
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26
Q

Explain Henry’s Law

A

Amount of gas in a solution: is directly proportional to its partial pressure

  • Henry’s Law
    • And depends upon the solubility of the gas
    • CO2 is more soluble in water than O2
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27
Q

Explain alveolar gas exchange

A

Respiratory Efficiency

  • Large partial pressure gradient
  • Short distance
  • High permeability
  • Large surface area
  • Greater blood flow around higher alveolar O2 levels and vice versa
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28
Q

Explain the oxygen hemoglobin saturation curve and the overall transport of Oxygen

A

Transport: O2

  • Hemoglobin:
    • Hb + O2 -><- HbO2
  • Hemoglobin saturation
    • % of heme units bound to O2

Transport based on the partial pressures in the blood and tissue as to where it is dropped

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29
Q

Explain the partial pressure differences in the circulatory system and how it impacts the respiratory system

A
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30
Q

Explain Alveolar capillary diffusion with CO2 and O2

A
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31
Q

Explain the Hemoglobin saturation curve impact with a change in pH

A
  • Decreased acidity causes more O2 release
  • (decreased affinity
  • Bohr effect
    • eg due to metabolism
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32
Q

Explain the hemoglobin saturation curve impact with a change in temperature

A
  • Increased temperature causes more O2 release (decreased affinity)
  • again, due to metabolism
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33
Q

Explain CO2 transport type

A
  • Bicarbonate Ions / carbonic acid
    • ~90% of CO2 transported
    • CO2 + H2O -><- H2CO3 -><- H+ + HCO3-
    • Catalyzed by carbonic anhydrase
      • converts the chemical reaction (no ATP)
    • Exchanged for Cl- (chloride shift) = simporter
  • Bound to Hemoglobin
    • ~5% of CO2, about 20% of the exchanged CO2
    • CO2 + Hb -><- HbCO2
    • Carbonimohemoglobin - attraction to CO2
  • Dissolved Gas
    • ~5% of CO2, because CO2 is water soluble
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34
Q

Explain the systemic gas exchange process

A
  • Unloading of oxygen
    • Diffusion (100 -> 40 mm Hg)
  • Loading of carbon dioxide
    • Diffusion (46 -> 40 mm Hg)

Facilitating this shift is where bicarbonate ions are exchanged for Cl- ions

We load our tissue with tissues to allow for it to metabolize and produce energy for the cells

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35
Q

Explain a summary of respiratory control

A
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36
Q

Explain a summary of neural control of breathing

A
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37
Q

Explain Hemoglobin Saturation and curve

A

Arterial blood:

  • PO2 = 100 mm Hg
  • 98.5% saturated (hemoglobin not perfect)

Venous blood:

  • PO2 = 40 mm Hg
  • 75% saturated

Curve due to change in shape with O2 binding

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38
Q

Explain the positive feedback

A

Implications:

  • Good saturation throughout normal body conditions
  • Self-regulating system:
    • As blood PO2 falls, more O2 is released
    • Say, due to increased metabolism
    • Oxygen stored even in venous blood
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39
Q

Explain RBC Metabolism

A
  • 2, 3 BPG
    • Produced by RBCs
    • High altitude, anemia
    • Decreases O2 affinity
    • Curve shift?
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40
Q

Explain Fetal Hemoglobin shift

A
  • Higher affinity for O2 Overall
  • Steep slope means more sensitive O2 release
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41
Q

What are the overall functions of the digestive system?

A

Ingestion

Digestion (mechanical and chemical)

Absorption

Compaction

Defecation

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42
Q

What are the main conditions that affect hemoglobin saturation?

A
  1. PO2 of blood
  2. Blood pH
  3. Temperature
  4. RBC metabolism
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43
Q

What is oxyhemoglobin (HbO2)?

A

if one or more molecules of O2 are bound to hemoglobin, the compound is called oxyhemoglobin

Whereas hemoglobin with no oxygen bound = deoxyhemoglobin

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44
Q

A blood pH > 7.45 is called _____ and can be caused by a CO2 deficiency called _____

A

alkalosis, hypocapnia

  • alkalosis = pH > 7
  • Hypocapnia = most common cause of alkalosis, Pco2 < 37 mm Hg
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45
Q

What is the most common cause of acidosis?

A

Hypercapnia

Pco2 > 43 mm Hg

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46
Q

What is the thing that catalyzes the equation to make bicarbonate?

A

carbonic anhydrase

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47
Q

Name each of the accessory organs of the digestive tract and describe the function

A
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48
Q

Describe how the overall digestive system processes are accomplished

A
  • Secretions
    • By accessory glands
  • Motility
    • Skeletal muscles
    • Smooth muscles
      • Multi unit
      • Visceral (single unit)
      • Peristalsis = one direction
      • Segmentation = bidirectional mixing
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49
Q

Describe the smooth muscles of the digestive system

A
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50
Q

Describe the overall digestive system histology

A
  • Four layers:
    • Mucosa
      • Muscous membrane
      • Lamina propria
    • Submucosa
    • Muscularis externa
    • Serosa
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51
Q

Describe the cellular level digestive system histology

A

Four layers:

  • Mucosa
    • Muscous membrane
    • Lamina propria
  • Submucosa
  • Muscularis externa
  • Serosa
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52
Q

what is the esophagus, stomach and intestine nervous system network called and what does it do?

A

enteric nervous system

regulates digestive tract motility, secretion and blood flow

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53
Q

Explain the types of control of the digestive system

A
  • Neural (long)
    • Sympathetic/parasympathetic division
      • carry sensory signals from the digestive tract to the brainstem and motor commands back to the digestive tract (vagus nerves)
  • Neural (short)
    • Enteric nervous system
      • stretching or chemical stimulation of the digestive tract acts through the myenteric plexus to stimulate contraction
  • Hormones
    • ​gastrin and secretin
  • Local mechanisms, reflexes
    • ​​secretions = histamine and prostaglandins
      • ​stimulate movement
54
Q

Name the functions of the tongue

A

Manipulation

Sensation

Production of lingual lipase

(is a skeletal muscle)

55
Q

What are the glands that make up your mouth region?

A

Parotid, sublingual, submandibular

56
Q

What is the composition of saliva?

A

water, buffers, antibodies, amylase, mucin, urea

57
Q

Explain salivary control

A
  • Medulla oblongata (MO) salivary center (salivatory nuclei)
    • Parasympathetic stimulation: lots of watery saliva
    • Sympathetic inhibition: little, viscous saliva
  • Response to stimuli
    • Smell, taste or thought of food
58
Q

Describe the pharynx

A
  • Shared passageway (esophagus and trachea)
  • Oropharynx
  • Laryngopharynx
59
Q

Explain the basics of the esophagus

A

muscular tube

Superior and inferior esophageal sphincters

60
Q

Explain the phases of swallowing

A
  • Voluntary oral phase
    • During chewing, tongue collects food and presses against palate and collects in oropharynx
  • Involuntary pharyngeal phase
    • vocal folds and nasal cavity close to prevent food from going in the wrong place
  • Esophageal phase
    • wave of involuntary peristalsis
61
Q

What are the structures that make up the Lower GI Tract?

A

Stomach

Accessory Glands

Small intestine

Digestive Hormonal Regulation

62
Q

Explain the cell in the stomach that specializes in cell replacement?

A

Stem cells

63
Q

Explain the cell in the stomach that specializes in cell protection?

A

Mucous cell

64
Q

Explain the cell in the stomach that specializes in the secretion of HCl, intrinsic factor, ghrelin?

A

Parietal cells

65
Q

Explain the cell in the stomach that specializes in the secretion of pepsinogen?

A

chief cells

66
Q

Explain the cell in the stomach that specializes in the secretion of chemical messengers?

A

Enteroendocrine cells

67
Q

Explain a summary of the cellular specialization in the stomach

A

Stem cells: Replacement

Mucous cells: protection

Parietal cells: HCl, intrinsic factor, ghrelin

Chief cells: pepsinogen

Enteroendocrine cells: chemical messengers

68
Q

Explain the volume and types of gastric secretion

A

produce 2 to 3 L of gastric juice per day

  • HCl
    • Mechanism:
      • CO2 + H2O -> H2CO3 -> HCO3- + H+
      • H+ / K+ pump
      • Chloride shift
      • Alkaline tide
    • Functions:
      • Antibacerial action
      • Protein denaturation
      • Cell wall breakdown
      • Pepsin activation
  • Enzymes
    • Pepsinogen to pepsin (protein digestion)
    • Gastric lipase (Fats)
  • Intrinsic factor (Vitamin B12 absorption)
  • Chemical messengers
69
Q

explain the gastric function in the stomach

A
  • Distention stimulates churning
  • Gastric emptying through pyloric sphincter
    • (~3 ml per squirt)
  • Time in stomach varies
  • Digestion: proteins and fats
  • Absorption: not much
70
Q

Explain the cellular anatomy of the stomach

71
Q

What are the three stages that make up the gastric activity?

A
  1. Cephalic phase
  2. Gastric phase
  3. Intestinal phase
72
Q

Explain the cephalic phase of gastric functional regulation

A
  • Cephalic Phase: (PREP PHASE)
    • Stimulus: Sight, smell, taste of food
    • Hypothalamus -> vagus nerve -> enteric NS
    • Response: Gastric juice secretion, gastrin release
73
Q

Explain the gastric phase of gastric functional regulation

A
  • Gastric: WORK
    • Stimuli: Distention, pH increase, Undigested proteins
    • Response: Increased gastric juice secretion, gastrin release, increased churning
74
Q

Explain the intestinal phase of gastric functional regulation

A
  • Intestinal Phase: (CONTROL)
    • Stimuli: Chyme in SI, pH decrease, Undigested nutrients
    • Response: Hormone release, suppress gastric activity
75
Q

Explain the summary of hormones in the lower GI track

76
Q

Explain the liver overall anatomical structures, histology, and physiology

A
  • Anatomical overview:
    • Four lobes
    • Hepatic portal vein
    • Hepatic artery
  • Liver histology:
    • Lobules
      • Blood and bile vessels
    • Kupffer cells (in sinusoids)
      • Macrophages (remove bacteria and debris from blood)
  • Liver Physiology
    • Liver digestive function: bile production (fat emulsifier)
77
Q

What is the function of the gallbladder?

A

storage of bile, release under control of CCK

78
Q

Explain the general anatomy of the pancreas

A

Pancreatic ducts

Ampulla of Vader (hepatopancreatic)

Sphicter of Oddi

79
Q

Explain the histology of the pancreas

A
  • Endocrine
    • Islets of Langerhans
      • Insulin and glucagon - sugar level balance
  • Exocrin
    • Acini cells: secrete pancreatic juice
      • Neutralization
80
Q

Explain the pancreatic physiological exocrine secretions

A
  • Exocrine secretions (Secretions that cut up carbohydrates, lipids and protein)
    • Enzymes (CCK controlled)
      • All nutrient classes
        • PSN (ACh from parasympathetic system), CCK regulate secretions
    • Bicarbonate (Secretion controlled)

Regulation of secretion:

  • ACh
    • ​stimulates pancreatic acini to secrete their enzymes during cephalic phase
  • CCK
    • ​response to fat in small intestine, stimulates pancreatic acini to secrete enzymes.
    • Gallbladder release
  • Secretin
    • ​response to acidity of chyme = neutralize
81
Q

Explain the primary digestion and absorption of the small intestines, sections and surface area adaptations

A

Primary site of digestion and absorption

  • Accepts secretions of the liver and pancreas
  • Three sections:
    • Duodenum, jejunum, ileum
    • Ileocecal valve
  • Surface area adaptations
    • Plicae (circular folds)
    • Villi
    • Microvilli
82
Q

Explain the histology of the small intestines

A
  • Extensive capillary beds (absorbs everything but fat)
    • Lacteal
    • Duodenal (Brunner’s) glands
      • Glands in the submucosa, mucus and alkaline secretions
      • Mucus production
    • Intestinal glands (crypts of Leiberkuhn)
      • Brush boarder enzme production
83
Q

Explain the intestinal motility

A
  • Weak peristaltic waves:
    • Local (myenteric) control
  • Gastroenteric reflex:
    • Whole intestine motility
  • Gastroileal reflex:
    • Relaxation of ileocecal valve
84
Q

Explain the gastrin digestive hormonal regulation feedback loop

A
  • Stimulus
    • Food sensation (senses and distention)
  • Sensors/CC:
    • G cells in gastric pits
      • direct and interic stimulation (vagus nerve)
  • Effectors:
    • Gastric secretory cells
    • gastric smooth muscle
    • pyloric sphincter
  • Response:
    • Increased gastric activity and motility
85
Q

Explain the CCK digestive hormonal regulation feedback loop

A
  • Stimulus
    • Lipid chyme in intestine (high fats)
  • Sensors/CC:
    • SI enteroendocrin cells
  • Response:
    • Gastric glands inhibited
    • stimulates release in pancrease and gallbladder
    • decreased hunger (CNS)
86
Q

Explain the Secretin digestive hormonal regulation feedback loop

A
  • Stimulus:
    • Acid chyme in intestine
  • Sensor:
    • SI enteroendocrine cells
  • Response:
    • Pancreatic buffers and bile production/secretion
    • Gastric glands inhibited
    • Gastric motility inhibited (pyloric sphincter)
87
Q

Explain the GIP (Glucose-dependent insulinotropic peptide) digestive hormonal regulation feedback loop

A
  • Stimulus:
    • Glucose hyperosmolarity
  • Sensor:
    • SI enteroendocrine cells
  • Effectors/response:
    • Islets of Langerhans - insulin secretion
88
Q

Explain the VIP (Vasoactive intestinal peptide) digestive hormonal regulation feedback loop

A
  • Stimulus:
    • Distention of pylorus
  • Sensors/CC:
    • SI enteroendocrine cells
  • Effectors/Response:
    • Intestinal glands - increased secretion
    • Vasodilation of intestinal vessels
    • Gastric glands inhibited
89
Q

Explain hydrolysis

A

water comes in, splits a molecule and results with a combining of one molecule with an OH and another with an H

90
Q

Explain carbohydrate digestion enzymes and products

A
  • Major enzymes:
    • Salivary and pancreatic amylase (SUGARS)
  • Products:
    • Maltose (disaccaride)
    • Limit dextrins (due to branching)
    • Further digestion
      • Intestinal brush boarder enzymes

Sucrase: Sucrose -> fructose + glucose

Maltase: Maltose -> 2 glucose

Lactase: Lactose -> galactose + glucose

91
Q

Explain carbohydrate absorption

A
  • Lumen -> blood
    • Glucose and galactose:
      • Na+ cotransport across apical membrane (SGLT transporters)
      • Facilitated diffusion across basolateral
      • Solvent drag (because glucose is highly soluble)
    • Fructose
      • Facilitated diffusion
92
Q

Explain the types of protein digestion

A
  • Endopeptidases
    • Breaks interior amino acid bonds
  • Expeptidases
    • Cleaves at ends (pac-man style)
  • Zymogens
    • Produced in an inactive form
93
Q

Explain protein digestion in the stomach

A
  • Pepsin (endopeptidase)
    • Produced as pepsinogen
    • Secreted by chief cells
    • Activated by acidity of stomach
94
Q

Explain protein digestion in the small intestine

A
  • Pancreatic proteases
    • Trypsin (endo)
    • Chymotrypsin (endo)
    • Carboxypeptidase (exo)
  • Brush boarder proteases
    • Aminopeptidase (exo)
    • Dipeptidase (endo)
    • Enterokinase (activator)
      • turns on trypsin
95
Q

Explain protein absorption

A
  • Apical membrane
    • Amino acids
      • Na+ cotransport
  • Dipeptides, tripeptides
    • Active cotransport
    • Broken down further inside cell
      • infants can bring more into cell
  • Basolateral membrane
    • Facilitated diffusion
      • Lots of carrier proteins to allow things into the cell
96
Q

Explain lipid digestion and lipid packaging

A
  • Issues:
    • Hydrophobic
    • Tendency to aggregate
  • Bile (emulsification)
  • Lipases:
    • Lingual
    • Pancreatic
      • works on surface area, takes long time
  • Lipase activity
    • Triglycerides -> monoglyceride + 2 fatty acids
  • Micelle
    • Absorbable lipid / bile salt complex
  • Lipid packaging
    • Chylomicrons
      • Triglyceride /cholesterol assemblies
97
Q

Explain lipid absorption

A
  • Diffusion
  • Reassembly
  • Golgi chylomicron packaging
  • exocytosis
  • lacteal entry
98
Q

Name and describe other nondigested things in the small intestine

A
  • Vitamins
    • Fat soluble (A, D, E, K) absorbed with fats
    • Water soluble via diffusion
    • B12 -> intinsic factor
      • Greatly enhances the absorption of Vitamin B12
  • Minerals
    • Channel - mediated diffusion
      • Na+, K+, Cl-, HCO3-
    • Active transport
      • Na+, Ca2+, Mg2+, Fe2+
    • Cotransport
      • Na+
  • Water absorption
    • Two liters consumed, but 7 liters enter GI tract
      • Secretions: salivary, gastric, etc.
    • Passive:
      • Driven by osmotic gradient
      • “water follows salt”
99
Q

What are the functions of the large intestine

A

water absorption

Vitamin absorption

Production and elimination of feces

100
Q

Explain the histology of the large intestine

A
  • Lack of villi
  • No enzyme production
  • Numerous goblet cells (mucus producing)
101
Q

Explain the physiology and reflex of the large intestine

A
  • Absorption
    • Water ~1 L daily
    • Bacteria produced vitamins:
      • K, biotin, B5
  • Movement
    • Haustral churning
    • Mass movements
    • Defication relex
102
Q

Explain the long term and short term appetite regulation

A
  • Short-term regulation
    • Ghrelin
      • Secreted by parietal cells when empty
      • Stimulates feeding centers of hypothalamus
    • Peptide YY and CCK
      • Secreted by enteroendocrine cells when chyme enters small intestine
      • Inhibit feeding centers of hypothalamus
  • Long-term Regulation
    • Leptin
      • Secreted by adipose tissue when fat stores are ‘high’
      • Stimulates satiety center (set point)
    • Insulin
      • Inhibits feeding center (high blood glucose)
103
Q

Explain calories

A
  • Usable energy sources when oxidized
    • Fats: 9 kcal/g
    • Carbs and proteins: 4 kcal/g
104
Q

What are the macronutrients

A
  1. Carbohydrates
  2. Fiber
  3. Lipids
  4. Protein
105
Q

Explain the macronutrient carbohydrate and the dietary sources

Stored, energy source, regulation, dietary source

A
  • Carbohydrates:
    • 440 g stored: 434 g muscles, 100 g liver, 15-20 plasma
    • Neurons and RBC exclusive energy source
    • Regulated by insulin and glucagon
    • Dietary sources:
      • Starches
      • sugars
106
Q

Explain the fiber macronutrient

A

cellulose

RDA 30 g/daily

107
Q

Explain an overview of the Lipid macronutrient

A
  • 15 - 25% of body weight
  • 80 - 90 % energy requirement
  • RDA < 30% calories from fat
108
Q

What are the types of lipid transport?

A
  • Lipoproteins
    • Protein + lipid transport
  • Chylomicrons
    • small particle like micelle
  • VLDL
    • very low density lipoprotein
  • IDL
  • LDL
  • HDL
109
Q

Explain the exogenous lipid pathway

A

Dietary source

  • Digestive tract
    • -> lymphatic system
    • -> circulatory system
    • -> tisues via lipoprotien lipase action
    • Bypasses hepatic portal system
  • Chylomicron fate
  • Lipoprotein lipase
    • Break down chylomicrons for fatty acid absorption
110
Q

Explain the endogenous lipid pathway

A

Liver source

Liver -> VLDL -> IDL -> Tissue

  • Chylomicron enters liver
  • VLDLs formed -> circulation
  • Muscles and fat cells absorb triglycerides
  • teturn to liver as IDL
111
Q

Explain cholesterol transport of lipids

A
  • Low-density lipoprotien (LDL) formed
  • Triglycerides removed
  • Cholesterol added
  • Released into circulation
    • LDLs are cholesterol “deliveries”
  • LDLs absorbed by tissues and broken down
  • Excess cholesterol is released
  • Absorbed by HDLs

Problem: if ICF cholesterol levels are high, LDLs NOT absorbed

  • Statins decrease cholesterol production in liver
112
Q

Explain protein macronutrient

A

RDA 0.37 x body weight (lb) in grams

Essential and inessential proteins

113
Q

Name and describe the micronutrients

A
  • Minerals
    • Function:
      • Bones
      • Molecular structure
      • Electrolytes (Na+, K+, Ca2+, Cl-)
  • Vitamins
    • 13 essential organic compounds
    • Metabolic constituents or precursors
    • Fat soluble
      • A, D, E, K
    • Water soluble
      • B-complex (8), C
114
Q

Explain the difference between catabolism and anabolism

A
  • Catabolism:
    • Exergonic
    • Energy yielding
  • Anabolism:
    • Endergonic
    • Energy requiring
115
Q

Explain cellular energetic (redox cycles), name and describe details of each cycle

A
  • Citric acid cycle:
    • NADH and FADH2
    • Acetyl CoA -> 3 NADH + 1 FADH2 + 2 CO2 + 1 ATP
  • Oxidative phosphorylation: (electron transport chain)
    • ATP Production
    • NADH / FADH2 oxidized -> H2O produced
    • Energy lost to create the H+ gradient to allow for H+ to diffuse down ATP synthase and make ATP
116
Q

Name and state anabolic or catabolic to the types of carbohydrate metabolsm

A
  1. Glycolysis (catabolic)
  2. Gluconeogenesis (anabolic)
  3. Glycogenlysis (catabolic)
  4. Glycogenesis (anabolic)
117
Q

Explain Glycolysis carbohydrate metabolism

A
  • Anaerobic in cytosol
  • Glucose -> 2 pyruvate + 2 NADH + 2 ATP
  • (if O2 present) Pyruvate -> acetyl CoA + CO2
  • (If not) Pyruvate -> lactate
118
Q

Explain gluconeogenesis carbohydrate metabolism

A
  • Anabolic
  • Glucose synthesis (ATP Required!)
  • Precursors:
    • Pyruvate
    • Ketogenic amino acid
    • Glycerol
    • Lactate (cori cycle)
119
Q

Explain glycogenolysis carbohydrate metabolism

A
  • catabolic
  • Glycogen -> glucose
  • Glucagon and epinephrine stimulated (fight or flight response)
  • Occurs in skeletal muscle and liver
120
Q

Explain glycogenesis carbohydrate metabolism

A
  • anabolic
  • Glucose -> glycogen (stimulated by insulin)
  • Medium term energy storage
121
Q

Explain lipid metabolsms catabolic process

A

LIPOLYSIS

  • Triglycerides -> fatty acids
  • Beta - oxidation
    • Fatty acids -> acetyl CoA (51 ATP per 6C)
    • Excess -> acetone
122
Q

Explain lipid metabolsms anabolic process

A

Lipogenesis

  • Acetyl CoA -> fatty acids (glycolysis) -> glycerol -> triglycerides
  • Because of the accumulation of ATP, does not go into mitochondria and the fat builds
123
Q

Explain the types of protein catabolism metabolism

A
  • Transamination:
    • Amino acid + keto acid -> new amino acid + new keto acid
    • then enters citric acid cycle
  • Deamination:
    • Amino acid -> keto acid + ammonium ion
      • Urea cycle
    • If do not have any glucose or fats
124
Q

Explain protein anabolism metabolism

A

Amination or transamination of keto acids

(stick an amino group onto it, requires NRG)

125
Q

Explain the nutrient metabolism summary

126
Q

Explain the overall metabolism summary

127
Q

Explain the absorptive state (after a meal)

Major process, primary fuel, controlling hormones

A
  • Anabolism favored: Storing energy
  • Building and storing (anabolic activities)
  • Primary fuel: glucose
  • Controlling hormone: insulin, enterohomones
    • GRP and CCK also impact because food is being stored
128
Q

Explain the absortive state (after a meal) pathway

129
Q

Explain the postabsorptive state (between meals/starvation)

Major process, primary fuel, controlling hormones

A
  • Catabolism: releasing energy
  • Fuel source: mostly fatty acids
  • Controlling hormones: Glucagon, epinephrine, growth hormone, glucocorticoids
130
Q

Explain the post absorptive state pathway

131
Q

Explain the metabolic rate

A
  • Basal metabolic rate (BMR)
    • Just enough energy to maintain vital function
  • Caloric intake (Mifflin estimate)
    • P=[10 x m (kg) + 6.25 x h (cm) - 5.0 x age + s] kcal/day
    • s = +5 males, -161 females
  • Does not take into account exercise, lean body mass
132
Q

Explain thermoregulation

A
  • Heat transfer
    • Convection
    • Radiation
    • Evaporation
    • Conduction
  • Control:
    • Hypothalamus

BIOH 211 (5 decks)

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