module 6 Flashcards
What are the four general functions of the respiratory system?
- Air passageway (atmosphere & alveoli)
- Site for exchange (O2 and CO2)
- Detection of odor (olfactory receptor)
- Sound production (vocal cord vibration)
Structural organization of the respiratory system
Upper respiratory tract and lower respiratory tract
Upper respiratory system
- Nose
- Nasal cavity
- Pharynx
- Larynx
Lower respiratory system
- Trachea
- Bronchus
- Lungs
- Bronchiole/Bronchus
Functional organization of the respiratory system
Conducting zone and respiratory zone
Conducting zone
Bulk movement of air into and out of lungs: nose to terminal bronchiole
Conducting zone
Bulk movement of air into/out of the lungs (nose to terminal bronchioles)
Respiratory zone
Diffusion of gasses into/out of the body: respiratory bronchiole, alveolar duct, and alveoli
Respiratory zone
Diffusion of gasses (respiratory bronchiole, alveolar duct, and alveoli)
Bronchiole tree
- Highly branched system of air-conducting passages that originates at the main bronchi
- At each point, bronchi decrease in size but increase in number of passageways (& surface area for exchange)
Bronchiole tree
- Highly branched system of air-conducting passages that originate at the main bronchi
- At each point, decrease size but increase number of passageways and surface area
Bronchioles and alveoli
- Have a large surface area for gas exchange
- High capillary density where gas exchange occurs
- Vascular smooth muscle (regulates the diameter of bronchioles)
- Elastic fibers allow for stretch and recoil
- Connective tissue for support
Asthma
Episodes of bronchoconstriction; wheezing, coughing, shortness of breath, and excess mucus. Often caused by sensitivity to an airborne agent
Asthma treatments
- Inhaled steroids
- Bronchodialators
Alveoli
- Each lung contains 300 to 400 million
- Alveolar pores: openings provide collateral ventilation
- Surrounded by pulmonary capillaries
- Divided by interalveolar septum (contain elastic fibers)
What are the three types of found in the alveoli
- Alveolar type 1
- Alveolar type 2
- Alveolar macrophages
Alveolar type 1 cells
- Most abundant
- Make up the internal surface of the alveolus simple squamous
- Ideal for diffusion
Alveolar type 2 cells
- Less common and smaller
- Simple cuboidal
- Produce and secrete surfactant (reduces surface tension and prevents collapsing)
Alveolar macrophages
- Mobile scavengers
- Engulf foreign material, dust, bacteria, etc.
Respiratory membrane
- Thin, large surface area
- Ideal for diffuison of gasses
What three components of the respiratory membrane
- Capillary endothelium
- Basement membranes of capillary endothelium and alveolar epitheluim fused together
- Alveolar epithelium
Anatomy of the lungs
Apex, base, diaphragm, ribs, costal surface, mediastinal surface
Left lung
- 2 lobes divided by one fissure
- Smaller
- Cardiac impression on the medial surface
- Cardiac notch on the interior surface (heart development in the fetus)
Right lung
3 lobes diveded by three fissures, larger and wider
Hilum (lungs)
Bronchi, pulmonary vessels, autonomic nerves, lymph vessels pass through here
Pulmonary circulation
Blood from the right ventricle to pulmonary capillaries, gas exchange - back to LV
Bronchiole circulation
blood from the systemic circulation providing oxygen and nutrient to the tissues of the lungs
8 steps of pulmonary ventilation
- Air containing O2 is inhaled into alveoli
- O2 diffuses from alveoli into the blood of pulmonary capillary
- O2 is transported in blood to systemic cells of the body
- O2 diffuses from the blood of systemic capillaries to systemic cells
- CO2 diffuses from systemic cells into the blood of systemic capillaries
- CO2 is transported in the blood to the lungs
- CO2 diffuses from the blood into the pulmonary capillaries into alveoli
- Air containing CO2 is exhaled
Boyle’s Law- Relationship of pressure and volume
Constant temperature, the pressure of a gas decreases if the volume of the container decreases and vice versa
Volume and Pressure equation
(P1)(V1)=P2)(V2), P1 and V1 represent initial conditions and P2 and V2 are the changed conditions
What type of relationship to pressure and volume have?
Inverse
Air pressure gradient exits when force per unit area is…?
Greater in one place than another (high to low pressure)
The thoracic cavity and lungs are lined with what serous membrane called what?
Pleural cavity
Function of the pleura
Protects the lungs from abrasive forces, and allows lungs to adhere to the thoracic cavity (inhalation)
The pleural cavity is divided into what two sections?
Parietal pleura (outer) and Visceral pleura (inner)
Interpleural pressure
Pressure in the pleural cavity, lower
Intrapulmonary pressure
Pressure in the lungs, higher
Why does the interpulmonary pressure have to be higher than the intrapleural pressure?
It allows the lungs to stay inflated
What two factors help to keep the lungs inflated
Pleural cavity (fluid) and the difference in pressure
Quiet breathing
- Passive & unconscious process
- Involves the diaphragm and external intercostals
- Relatively small changes in thoracic cavity volume and intrapulmonary pressure
- Chest volume changes are not readily apparent
Volume change during inspiration
Thoracic cavity volume increases
Vertitical volume changes during inspiration
Increases due to contraction, diaphragm flattens
Lateral volume changes during inspiration
Increases as thoracic cavity widens as ribs elevate (external intercostals)
Anterior/posterior changes during inspiration
The inferior portion of the sternum moves anterior
What is the specific value of interpulmonary pressure (& atmospheric pressure) AT REST
760 mm Hg
What is the specific value of intrapleural pressure AT REST
756 mm Hg
Tidal volume
The amount of air inhaled and exhaled at rest
Inspiratory reserve volume
The extra volume of air that can be inhaled with maximal effort after reaching the end of normal inspiration
Expiratory reserve volume
The extra amount of air that can be exhaled with maximal effort after reaching normal expiration
Residual volume
The volume of air remaining in the lungs after expiratory reserve volume (maximum air that can move into and out of the lungs)
Vital capacity
The maximum amount of gas that can be expelled from the lungs after taking the deepest possible breath
Pathway of air through the respiratory system & functions
- Nasal cavity: transport, condition (humidity, ^temp, clean)
- Trachea: transport, clean
- Primary Bronchi: transport
- Bronchiole: transport
- Alveolar sac: diffusion of gases (O2 and CO2)
Pressure and flow realtionship
Direct, lager pressure = larger flow
Flow and resistance realtionship
Inverse, increased resistance = less flow
Flow equation
Flow = change in pressure/resistance
Resistance equation
R = (viscosity)(length)/radius^4
Less viscosity will do what do resistance
Decrease
What will increasing the length of the vessel do to resistance
Increase
What will increasing the vessel radius to do resistance
Decrease
If intrapulmonary pressure and intrapleural pressure are equal what will happen to air flow
There will be no air flow
What are the two muscles associated with quiet breathing?
Diaphram and intercostals
What is the specific value of intrapulmonary pressure during quiet inspiration (breath in)
758 mmHg
What is the specific value of intrapleural pressure during quiet inspiration (breath in)
754 mmHg
What is the exact value of intrapulmonary pressure during quiet expiration (breath out)
763 mmHg
What is the exact value of intrapleural pressure during quiet expiration (breath out)
756 mmHg
Tidal volume value- Quiet breathing
300-500 mL
Respiratory rate value - Quiet breathing
12-17 breaths/min
Minute ventilation & value - Quiet breathing
amount of air moving into and out of lungs (300mL, 3L)
Forced breathing requires additional
Muscles
Forced breathing causes greater change in what volume?
Thoracic cavity volume
Tidal volume value - Forced breathing
3000mL (500mL rest)
Respiratory rate value - Forced breathing
40 to 70 breaths per minute
Minute ventilation - Forced breathing
150 L/min to 200 L/min
Where is the control of breathing regulated?
Brainstem
Medulla - Control of breathing
Inspiration and expiration
Pons - Control of breathing
Rate and depth of breathing
Motor output of breathing
Diaphram and External intercostals
Sensory output of breathing
- Central chemoreceptors
- Peripheral chemoreceptors
Thermoreceptors =- Cental hypothalamus
- Peripheral skin
- Skeletal muscle
Where are the peripheral chemoreceptors located?
Aortic arch and carotid sinus
The chemo receptors detect what (independently)
changes in PCO2 and H+ (&PO2)
When the body is cold, breathing will be
less frequent and deeper
When the body is warm, breathing will be
frequent and shallow
What percent of the air is N2?
79.04%
What percent of the air is O2?
20.93%
What percent of the air is CO2
0.03%
Daltons law
Total air= PN2 + PO2 + PCO2
Partial pressure,
Individual pressure, tells how much of one substance will diffuse in alveoli
Oxygen content in the blood will go from ___mmHg to ___mmHg when pumped through body
150, 40
Partial pressure drives what?
Diffusion of gas from alveoli to blood and then from blood to muscle
Systemic circulation blood vessels
many long blood vessels
Systemic pressure and resistance
higher pressure (120/80, 93 mmHg) and high resistance
Pulmonary circulation blood vessels
many small vessels
Pulmonary circulation pressure and resistance
Low pressure (15 mmHg) and low resistance
Oxygen carrying capacity
20 mL O2/100mL blood (1L O2/5L blood)
What percent of O2 is bound to hemoglobin in RBC
> 98%
What percent of O2 is dissolved in the plasma
<2%
What does increase in pH do do hemoglobin saturation
Lower % saturation, more oxygen unloaded
What does a higher PCO2 do to hemoglobin saturation
Lower % saturation, more oxygen unloaded
What does a warmer blood temperature do to hemoglobin saturation
Lower % saturation, more oxygen unloaded
Effects of exercising muscle
Decreasing pH, increase in PCO2 and temperature, favor unloading oxygen
General functions of the urinary system
- Filters the blood and regulates blood volume
- Eliminates waste (urea, creatine)
- Regulates levels of ions (Na+, K+, Ca++, electrolytes)
- Regulate acid-base balance (H+, HCO3-)
- Eliminate biologically active compounds (hormones and drugs)
- Regulate blood pressure (fluid loss and # of RBCs)
Urea
Waste product of protein metabolism
Path of urine
- Kidney
- Renal pelvis (urine here)
- Ureter
- Urinary bladder
- Urethra
Kidneys are innervated by what nervous system
Autonomic NS
Role of sympathetic NS in kidneys
Blood vessel constriction/dilatation to regulate blood flow to kidneys
Role of parasympathetic NS in KIDNEYS
unknown
Role of parasympathetic NS in BLADDER
internal sphincter
Role of somatic NS in urination
external sphincter
Kidney stone
High concentration of calcium oxalate or uric acid form a solid structure, or stone
Nephron
The microscopic functional unit of a kidney, where the volume of urine is regulated
Glomerulus
tuft of capillaries
Afferent arteriole
blood flow into the glomerulus (towards), larger
Efferent arteriole
blood flowing out of the glomerulus (away), smaller
Proximal convoluted tubule
Tublue closer to the glomerulus, bundled/high surface area
Distal convoluted tubule
Tubule farther from glomerulus, bundled/high surface area
Glomerular filtration
The movement of substances from the blood within the glomerulus into the capsular space
What is the fluid in the glomerulus called
filtrate
Tubular reabsorption
The movement of substances from the tubular fluid back into the blood
Tubular secretion
The movement of substances from the blood into the tubular fluid
What are the three layers that make up the glomerular filtration membrane?
- Endothelium (blocks formed elements)
- Basement membrane (blocks large proteins)
- Filtration slits of the visceral layer (block small proteins)
What is included in filtrate?
Water, glucose, amino acids, ions, urea, some hormones, vitamins B and C, ketones, and a very small amount protiens
In what segment of the nephron does filtration occur?
Glomerulus
What happens in the PCT
- Reabsorption of nutrients, proteins, water, ions, etc into the blood
- Secretion of drugs, hormones, urea, waste
What happens in the nephron loop
Continuos reabsorption of water and ions (25% each)
what happens in the DCT
- Na+ reabsorption is regulated by aldosterone and ANP
- Water reabsorption regulated by aldosterone and ADH
- Amount of K+ secreted regulated by aldosterone
What does urine contain
Ion, water, nitrogenous waste, some hormones
What does urine NOT contain
Formed elements, nutrients, protein
What does the kidney excrete?
- Some hormones and drugs
- Urea (by-product of protien metabolism)
- Uric acid (a by-product of the breakdown of protiens)
- Creatinine
(we want to get rid of these things)
Antidiuretic hormone is released by what?
Anterior pituitary gland
What is the general function of antidiuretic hormone in the kidney?
Makes nephron more permeable to water
Exercise will cause ADH to ___
increase (& decrease UV)
Alcohol will cause ADH to ___
decrease (& increase UV)
Nightime will cause ADH to ___
increase (& decrease UV)
Atrial natriuretic peptide is released from where?
The heart (RA)
What impact would increased circulation hormone have on urine output
decreased urine volume
What is the general function of ANP?
Promote the loss of water (block water from leaving nephron and produce a larger urine volume)
What stimulates the release of ANP
Increased blood volume
ANP blocks the release of
__
ADH
Where is aldosterone released from?
Adrenal gland
What is the general function of Aldosterone in the kidney?
increased sodium absorption in the kidney which will increase osmolarity (ions, solute)
pH in urine
4.5-8
Specific gravity of urine (how much “stuff”)
1.0 (pure water )-1.03 (more solute)
Water content of urine
93%-97%
Color of urine
Pale yellow
Odor of urine
variable with composition
Bacterial content of urine
trace amounts
Amount of protein in urine
trace amounts (5-10 mg/dL)
How much blood should be in the urine
none
Glycosuria
abnormally high levels of glucose in the urine (diabetes)
Protienuria
Excess protein in the urine (kidney trauma, hypertension, physical exertion, etc)
Hematuria
erythrocytes in the urine (kidney/urinary tract trauma)
Erythropotien mechanism (feedback loop)
imbalance in normal O2 levels, kidneys release erythropoietin, erythropoietin stimulates red bone marrow, enhanced erythropotien increases RBC count, increases O2 carrying ability of blood
Micturition reflex
increased stretch of the detrusor muscle, activates PSNS, relaxes the internal urethral sphincter
What are the two categories of organs in the digestive system
GI tract (continuous hollow tube. breaks down and absorbs food) and accessory organs (some produce secretion into GI tract, assists in breakdown)
What are the GI tract organs
- Oral cavity
- Pharynx
- Esophagus
- Stomach
- Small and large intestine
What are the accessory organs
- Teeth
- Tounge
- Salvilary galnds
- Liver
- Galbladder
- Pancreas
Ingestion
introduction of food into the oral cavity, first step in digestion
Motility
the mixing and moving of material through the GI tract, involves voluntary and involuntary muscle contractions (all alone digestive tract)
Secretion
Process of producing and releasing substances that facilitate digestion. Produced by the accessory glands, salivary glands, liver, pancreas
Digestion
breakdown of ingested food into smaller components that can be absorbed from the GI tract
mechanical digestion
breakdown of food into smaller particles without changing the chemical composition
chemical digestion
involves specific enzymes that breakdown larger molecules into smaller ones
Absorbtion
involves membrane transport of ingested molecules (electrolytes, vitamins, minerals, water across epithelial membrane into the blood or lymph
Elimination
expulsion of ingestible components through the anal canal
What are the four general layers, tunics, of the GI tract
- Epithelium (secretion and absorption)
- Muscular (layers of smooth muscle, circular layer, and longitudinal layer)
- Mixing (back and forth motion, waves and segmentations)
- Propulsion (direction of movement, peristalsis)
Stretch receptors- nerve reflexes of the digestive system
detect stretch of GI tract wall
Chemoreceptors- nerve reflexes of the digestive system
monitor chemical contents in the lumen, reflexes (ANS or ENS) are initiated in response to receptor input
Short reflex - chemoreceptors
local reflex, only involves ENS, coordinate small segments of GI tract
Long reflex - chemoreceptors
involves sensory input to CNS and ANS output, coordinates GI tract mobility, secretions, and accessory digestive organs
PNS and SNS GI activity regulation
PNS promotes GI tract activity, and SNS opposes GI tract activity
Hormone control of digestive system
several hormones participate in regulation of digestion
Parotid - salivary glands
largest, 25-30% of the saliva
Submandibular - salivary glands
floor of the oral cavity and medial to mandible, produces about 60-70% of the saliva (most saliva)
Sublingual - salivary glands
Inferior to the tongue, 3%-5% of saliva
What does saliva contain?
water, electrolytes, salivary amylase (carbohydrate breakdown, pH sensitive- high), mucin, and lingual lipase (lipid breakdown, pH sensetive- low)
Esophagus function (pathway of food)
- Bolus enters through the esophageal sphincter (skeletal muscle)
- Waves of muscle contractions move the food bolus towards the stomach (peristalsis)
- Bolus enters the stomach after passing through the lower/inferior esophageal sphincter
Lower esophageal sphincter
regulates the passageway of food bolus into the stomach
Pyloric sphincter
regulates the passage of chyme from the stomach into the duodenum (small intestine)
Gastric mixing
- contractions of smooth muscle in the stomach wall mix bolus with gastric secretions to form chyme
- peristaltic waves result in pressure gradients that move stomach contents toward the polyoric region
Gastric emptying
- pressure gradient increases the force in pylorus against the pyloric sphincter
- pyloric sphincter opens, and a small amount of chyme enters the duodenum
- pyloric sphincter closes and retropulsion occurs
Vomiting
- Rapid expulsion of gastric contents through the oral cavity
- controlled by the vomiting center in the medulla oblongata
- responds to head injury, motion sickness, infection, toxicity, food irritation
- closure of nasal passages and the glottis
- danger of aspiration
Lower GI tract
- large intestine
- small intestine (duodenum, jejunum, ileum)
- accessory = liver, gallbladder, pancreas
Small intestine tunics
- hollow organ with circular folds (slow movement of chyme 3-5 hrs)
- large surface area
- multiple layers of smooth muscle that mix and propel the chyme through the small intestine
Villi increase _____ in the small intestine
surface area
Which lobe of the liver is larger
Right lobe
What is the second largest organ in the body?
liver
Right and left lobes of the liver are separated by what?
a large ligament
The liver produces what?
bile - aids in digestion
Where is bile stored
gallbadder
galbladder is ___ to the liver
posterior
What is stored in the liver
glycogen
Bile aids in what
digestion of lipids
Which organ has a head and tail
pancreas
_____ wraps around the head and and the tail points laterally
duodenum
Liver detoxifies the ___
blood
Endocrine glands secrete directly into the blood where exocrine glands secrete into ____
ducts
How does the pancreas (& gallbladder) get pancreatic juices (& bile) into the small intestine
ducts
Pancreatic juices breakdown ____
carbohydrates, fats, proteins (>90% exocrine cells)
Large intestine
- wide and shorter
- cecum, colon, and rectum
- absorbs water and electrolytes
- watery chyme compacted into feces
- stores feces until eliminated through defecation
speed of peristalsis
slow and sluggish
Large intestine produces ___
CO2
Mass movements of large intestine
- powerful contractions
- propel fecal matter towards rectum (2-3 times a day often after a meal)
Anal canal
last few centimeters of the large intestine
internal sphincter of anal canal
Involuntary smooth muscle to the base
External sphincter of anal canal
voluntary skeletal muscle
Carbohydrate digestion in the small intestine
- starts in the oral cavity: salivary amylase
- pancreatic amylase: produced by the pancreas and secreted into the small intestine
- pancreatic amylase continues digestion of starch that began in the oral cavity
- brush border enzymes break down starch into individual glucose molecules
Digestion of other disaccharides in small intestine
Specific enzymes needed, ex: lactase for lactose, sucrase breakdown of sucrose, both located in the brush border
Protein breakdown in the stomach
- begins within stomach lumen with pepsin (formed pepsinogen, inactive precursor)
Stomach’s low pH factors
- due to HCl released from parietal cells
- activates pepsinogen to activate pepsin
- denatures protiens to facilitate chemical breakdown
- trypsinogen is activated to trypsin
single amino acids absorbed across epithelial cells, released into bloodstream - stomach pH is about 2
Lipid digestion and absorption in the small intestine
- bile salts emulsify lipid droplets (pulls apart, higher surface area)
- pancreatic lipase breaks triglycerides in monoglycerides and free fatty acids
- triglycerides are reassembled and wrapped in a protien (chylomicrons) and absorbed into lacteals
Water absorption
- small intestine absorbs almost all ingested water
- absorbed across epithelia and into blood vessels via osmosis
Electrolyte and vitamin absorption
- small intestine absorbs almost all electrolytes and vitamins that enter
- most unregulated, depend on diet, except IRON