Exam 3: Respiratory System, Digestive System, Metabolism Flashcards
What is the primary function of the respiratory system
Respiration
what are the 4 components of respiration
-ventilation
-external respiration
-gas transport
-internal respiration
define ventilation
Breathing
Describe external respiration
Gas Exchange
-O2 enters & CO2 leaves through lungs
Describe internal respiration
Gas exchange in tissues
what are additional functions of the respiratory system
-regulation of blood pH
(by changing CO2 levels)
-Production of chemical mediators
(angiotensin-converting enzyme ACE: BP regulation)
-Voice production
-olfaction
-barrier to pathogens
What are the structural divisions of the respiratory system
-upper-respiratory tract
-lower-respiratory tract
What are the components of the upper-respiratory tract
Neck up to face
-external nose
-nasal cavity
-pharynx
-larynx
(sound production “voice box”)
what are the components of the lower-respiratory tract
Neck down into chest
-Trachea (splits into 2 tubes that then split again)
-Bronchi & Bronchioles
-Lungs
-Alveoli
Describe the symptoms of upper-respiratory tract infections
Usually symptoms occur above the neck
(not as serious as lower-resp. tract infections)
-cough
-sneezing
-sore throat
Describe the symptoms of lower-respiratory tract infections
usually last longer than upper infections and are more serious
-Bronchitis
-pneumonia
-etc.
what are the functional divisions of the respiratory system
-Conducting zone
-Respiratory zone
what is the conducting zone of respiratory system
functional division where air movement occurs
-includes everything from nose to bronchioles
what is the respiratory zone of respiratory system
functional division where gas exchange occurs
-includes alveoli
What are the components of the nasal cavity
-nasal turbinates
-pseudostratified ciliated epithelium
Describe the nasal turbinates of nasal cavity and what they do
3 pairs of thin bones covered by expandable tissue
-swell during allergies or other infections
(makes it hard to breathe)
Describe the pseudostratified ciliated epithelium of nasal cavity
-Lines nasal cavity
-Contains interspersed goblet cells
(Mucus production)
What are the functions of the nasal cavity
-air movement
-cleans air
-humidifies and warms air
-olfactory epithelium
-resonating chamber for speech
how does air movement occur in nasal cavity
nasal turbinates force air into slow steady pattern to contact surface area with epithelium
how does the nasal cavity clean air
turbulence facilitates contact with epithelium and mucus
when is it important for air to be humidified and warmed in nasal cavity
The winter
-but this occurs all the time
what do the olfactory epithelium do within the nasal cavity
scent detection
what does the resonating chamber for speech in nasal cavity do
amplifies sound we produce
what is the pharynx
Common opening for digestive & respiratory systems
what are the 3 regions of the pharynx (superior to inferior)
Nasopharynx
Oropharynx
Laryngopharynx
what is the function of the nasopharynx
connects to nasal cavity
what is the function of the oropharynx
connects to oral cavity
what is the function of the laryngopharynx
route food/drink to esophagus and air to lungs
Describe the larynx
Rigid and strong structure composed of 9 cartilages connected by muscles and ligaments
what are the parts of the larynx
-vestibular folds
-vocal folds
-epiglottis
-glottis
-cartilages
what are the vestibular folds of larynx
2 pairs of ligaments running anterior to posterior
what are the vocal folds of the larynx
“vocal cords”
-2 pairs of ligaments inferior to vestibular folds
-ligaments covered by mucus membrane
what is the epiglottis of the larynx
flap of elastic cartilage
-keeps food from entering lungs
what is the primary function of the vocal folds
sound production
-air vibrates ligaments
-sound is modified by lips, tongue, location of vibration on vocal folds
what is the largest cartilage of larynx
thyroid cartilage
REVIEW GRAPHIC OF VOCAL FOLDS
what happens when arytenoid cartilage attached to vocal folds in larynx is medially rotated
vocal folds are closed for sound production
what happens when arytenoid cartilage attached to vocal folds in larynx is laterally rotated
vocal folds are opened for breathing
what is the glottis
vocal folds and opening between them
what is the trachea
tube that moves air to the lungs
describe the structure of the trachea
C-shaped hyaline cartilage
-supports anterior and later sides of trachea
Trachealis (smooth muscle on posterior wall)
-contraction narrows diameter (coughing)
REVIEW TRACHEA FIGURE
what are the parts of the trachea
Hyaline cartilage
Right bronchus
Left bronchus (sits a bit higher than right)
Carina
what is the carina
A ridge of cartilage in the trachea at level of T4 vertebrae
what happens if foreign objects reach this area
Triggers very strong cough reflex
Describe the Tracheobronchial tree
Trachea branches into:
-primary bronchi
-secondary bronchi
-tertiary bronchi
-bronchioles
-terminal bronchioles
how big are the bronchioles
1mm in diameter
What are the terminal bronchioles made of
only smooth muscle
what is bronchodilation
smooth muscle relaxes
-increases airflow during exercise or stress
what is bronchoconstriction
smooth muscle contracts
-this happens during an asthma attack
(albuterol-inhaler promotes smooth muscle relaxation)
Which lung is larger
Right lung
what are the lobes of the right lung
superior, middle, inferior
what are the lobes of the left lung
superior, inferior
what notch is unique to the left lung
cardiac notch
what is each lobe of each lung supplied by
a secondary bronchus
what are lobes of lungs subdivided into
bronchopulmonary segments
what are bronchopulmonary segments supplied by
tertiary bronchi
how many bronchopulmonary segments are in right lung
10
how many bronchopulmonary segments are in left lung
9
what are alveoli
found within lungs at ends of terminal bronchioles
-alveolar ducts ending in alveolar sacs
what is the primary function of alveoli
site of gas exchange
what are the cell types of the alveolar wall
Type I pneumocytes
-simple squamous epithelium for gas exchange
Type II pneumocytes
-simple cuboidal epithelium that produce surfactant for alveolar expansion
what is required for airflow into lungs
-pressure gradient
-air moves from areas of higher pressure to areas of lower pressure
(atmospheric pressure vs. pressure in alveoli)
What happens during inspiration (inhalation)
air pressure outside body is greater than air pressure in alveoli
what happens during expiration (exhalation)
opposite of inhalation
-air pressure in alveoli is greater than air pressure outside of body
Describe how air flows into body
Through trachea, bronchi, to alveoli
What is Boyle’s Law
increase in volume=decrease in pressure (& vice versa)
-P=K/V
Describe how muscles and thoracic volume change during inspiration of quiet breathing
-contraction of external intercostals and diaphragm
-Expansion of ribcage/lungs
-Increase thoracic cavity volume
-decrease pressure
Describe how muscles and thoracic volume change during expiration of quiet breathing
-relaxation of external intercostals and diaphragm
-Recoil of ribcage/lungs
-Decrease thoracic cavity volume
-increase pressure
what is the pleural cavity
serous membrane around lungs
-allows lungs to “stick” to thoracic cavity
what is PB
Barometric pressure
-the approximate air pressure in the atmosphere
what is Palv
pressure within the alveoli
what is the relationship between PB and Palv at end of expiration
PB=Palv
-no air moves in or out of the lungs
what is the relationship between PB and Palv at end of inspiration
PB=Palv
-thorax and alveoli stop expanding
-no air moves in or out of lungs
how does pressure change during inspiration
-muscle contraction
-thoracic volume increases
-lungs expand
-air flows into lungs
PB>Palv
how does pressure change during expiration
-muscles relax
-thoracic volume decreases
-lungs recoil
-air flows out of lungs
PB<Palv
what is lung recoil
decrease after stretch, compression of alveoli
what is surfactant
lipoprotein produced by type II pneumocytes
-reduces tendency of lungs to collapse
where does gas exchange occur
alveoli
how does gas exchange occur
gasses cross alveolar respiratory membrane
what is partial pressure
% of total air made up of an individual gas
-can also think of this as being the “concentration” of a certain gas within the atmosphere
how do gasses move in relation to partial pressure
gasses move from higher partial pressure to lower partial pressure
what is gas exchange affected by
-diffusability of gasses
-thickness of alveolar respiratory membrane
-surface area of membrane
Describe the fate of gasses
O2 bound to hemoglobin
-Reversible binding
-delivered to tissues and used in ATP production
CO2 produced from ATP production
-transport: bicarbonate that is dissolved in plasma or on hemoglobin
REVIEW GAS EXCHANGE GRAPHIC
What are the major components of the digestive system
-alimentary canal (GI Tract)
-Accessory Organs
what is the alimentary canal
AKA Gastrointestinal (GI) Tract
-the entire “tube” through which food passes (mouth to anus)
what do the accessory organs of the digestive system do
aid in food breakdown outside of the GI tract
what are the four major layers of the tissues of GI tract
(superficial-deep)
Serosa
Muscularis
Submucosa
Mucosa
what is the serosa composed of and what is its function
-areolar connective tissue & epithelium
-holds GI tract in place ventral (in front) to spinal column
what is the muscularis composed of and what is its function
-smooth muscle for mechanical digestion
-inner circular layer, outer longitudinal layer
-stomach: additional oblique layer
what is the submucosa composed of and what is its function
-dense irregular connective tissue that supports mucosa
-connects mucosa to underlying smooth muscle
-has blood vessels and nerves
what is the mucosa composed of and what is its function
-epithelium, connective tissue, smooth muscle
-has direct contact with digested food
Describe the process of digestion
Ingestion:
-taking in food
Propulsion:
-swallowing, peristalsis (moving food)
Digestion:
-mechanical-physically breaking down food (chewing, stomach churning)
-chemical-breaking down food using chemicals (saliva, stomach, intestines)
Absorption:
-nutrients and water absorbed via intestines
Elimination/defecation:
-removal of wastes
what hormones control digestion
gastrin
secretin
cholecystokinin
gastric inhibitory peptide
what does the hormone gastrin do
stimulates gastric acid secretion in stomach mucosa
what does the hormone secretin do
from duodenum of small intestine, stimulates bicarbonate secretion by pancreas
-reduces acidity
what does the hormone cholecystokinin do
from duodenum, stimulates secretion of pancreatic enzymes
what does the hormone gastric inhibitory peptide do
inhibits gastric secretions & motility
how do neural mechanoreceptors, chemoreceptors, and osmoreceptors in walls of GI tract control digestion
stimulate gastric acid secretion in stomach mucosa
How does the enteric nervous system affect digestion
branch of autonomic nervous system that regulates motility and secretion via plexuses
what type of digestion do the teeth perform
mechanical digestion
what are the different salivary glands
parotid gland
-(slightly inferior to ears)
submandibular gland
-inferior to lower jaw
sublingual gland
-inferior to tongue
What is the function of saliva
-moistens food
-medium for tasted detection
-amylase aids in chemical digestion
(enzyme that breaks down starch)
How does parasympathetic NS stimulation affect salivary glands
-keeps saliva flowing enough to maintain “comfort”
-smell of food can increase stimulation
how does sympathetic NS stimulation affect salivary glands
-stressful situations reduce salivation = dry mouth
what is a bolus
“ball” of food that gets created as we chew and then swallow
where does a bolus of food go
through esophagus
where is the esophagus located
posterior to trachea
define peristalsis
wave-like contractions that move bolus of food through esophagus
what is the lower esophageal sphincter
allows food into stomach
-heartburn if sphincter allows digested food back into esophagus
what is the lower esophageal sphincter
allows food into stomach
-heartburn if sphincter allows digested food back into esophagus
Describe how peristalsis occurs
-muscularis activity produces “waves” of contraction
-circular and longitudinal layers contract simultaneously
-constriction of wall to push bolus
-expansion of wall to receive bolus
Describe the process of mechanical digestion in the stomach
Perstaltic churning from fundus (round superior area) to pylorus (narrow inferior area)
-helps move food around stomach, break into smaller pieces
what does the stomach secrete for chemical digestion
-gastric acid
-pepsinogen
-intrinsic factor
Describe the function of Gastric Acid
-pH is 1
-protein breakdown
-kills bacteria
-stomach protected by alkaline (basic pH) mucus
describe the function of pepsinogen
converted to pepsin
-breaks down proteins
Describe the function of intrinsic factor
-allows vitamin absorption
what is food mixed with stomach secretions called
chyme
what are the regions of the small intestine
-duodenum
-jejunum
-ileum
what is the primary function of the small intestine
nutrient absorption
what is the intestinal lining composed of
Circular folds
-spiralling movement of chyme
Villi
Microvillii
-brush border
what is the function of the intestinal lining
increases surface area
-when you increase surface area, increases absorption
what are the divisions of the large intestine
cecum
-joins with small intestine
colon
-reabsorbs water and salts
rectum
-stores solid waste until elimination
anal canal
-leads to anus for elimination
what are the four parts of the colon
Ascending colon
-superior from cecum, ends at R. colic flexure
Transverse colon
-extends from right to left colic flexure
Descending colon
-inferior from left colic flexure
Sigmoid colon
-s-shaped tube that ends at rectum
where is the site of many healthy/”friendly” bacteria
colon
what is fecal microbiota transplantation
Transplant of healthy feces :
-typically used to treat colostridium difficile (C. diff)
-C. diff is usually controlled by normal microbiota in colon
-antibiotics can kill normal flora & C. diff infects/reinfects
*can be life threatening
what is the endocrine role of the pancreas
insulin & glucagon secretion
what is the digestive role of the pancreas
Secretion of enzymes into duodenum
-enzymes breakdown carbohydrates, proteins, lipids
what are the lobes of the liver
-left
-right
-caudate (posterior)
-quadrate (posterior)
what does the liver house
glycogen (glucose storage)
what is the function of the liver
-detoxification of harmful substances
-production of bile
what is the function of the gallbladder
-storage of bile
-secretes bile into duodenum via common bile duct
what is the primary function of bile
lipid absorption
are lipids hydrophobic or hydrophilic
hydrophobic (fear water)
why are lipids difficult to absorb by intestinal lining
they are hydrophobic
what does bile contain
bile salts
how do bile salts work
-salts surround lipids, creating micelles
*micelles=hydrophilic (like water)
-Micelles allow absorption of fats
what is metabolism
the sum of all catabolic & anabolic reactions in the body
what does metabolic rate measure
amount of energy used to maintain life
how do we maintain our metabolic rate
ingesting sufficient food
what are catabolic reactions
breakdown larger molecules obtained from food via glycolysis, lipolysis, hydrolysis, etc.
what is hydrolysis
breakdown of ATP releasing energy stored in bonds
REVIEW HYDROLYSIS GRAPHIC
what are anabolic reactions
-synthesize (build) larger molecules from smaller parts via things like phosphorylation
what is phosphorylation
synthesis of ATP (reverse of hydrolysis)
what do errors in catabolic and anabolic reactions cause
disease
what is oxidation
losing an electron
what is reduction
gaining an electron
*energy release for synthesis
what are the four major groups of macromolecules
carbohydrates
lipids
proteins
nucleic acids (DNA/RNA)
how are carbohydrates metabolized
glycolysis
cellular (aerobic) respiration
anaerobic respiration
what is glycolysis
glyco=glucose lysis=breakdown
-breakdown of glucose
-some ATP produced
what are the steps of cellular respiration
- glycolysis
2.citric acid cycle
3.oxidative phosphorylation
about how much ATP is produced per glucose molecule in cellular respiration
36-38
what are the steps of anaerobic respiration
- glycolysis
- lactic acid fermentation
about how much ATP is produced per glucose molecule in anaerobic respiration
not as much ATP bc not as efficient as cellular respiration
-only 2-3 molecules
How are lipids metabolized
-lipids mostly absorbed from diet by small intestine
-fatty acids are oxidized (lose electron)
-then enter citric acid cycle where ATP is produced
-fats are fuel source when glucose is not available
how are proteins metabolized
-proteins broken down by gastric acid and pepsin
-secretin & cholecystokinin aid in digesting proteins
-liberation of individual amino acids
*used to create new proteins
*in excess, amino acids processed and stored as glucose or ketone
*can be used to ATP production if starvation occuring
what are the different metabolic states
fed state (absorptive)
fasted state (post-absorptive)
starvation
Describe the fed-state
-glucose and other molecules absorbed
-blood glucose increases—>insulin secretion
describe the fasted state
-glucose levels drop
-glucagon secretion (due to reduced blood glucose)
describe the starvation state
-initially glucose produced via gluconeogenesis
-after a few days, fats broke down–>ketone bodies
*used as fuel source by most organs
*this allows brain to still use glucose
-after glucose depletion, proteins broken down from organs first, then muscles later
—–THIS CAN BE FATAL
what is a common metabolic disorder
diabetes mellitus
what is diabetes mellitus characterized by
hyperglycemia (chronic high blood glucose)
what is one of the oldest diseases discovered
*earliest record from 1500 BCE Egypt “too great emptying of urine”
diabetes mellitus
in India diabetes originally called
madhumeha
-means honey urine - it attracted ants
when was diabetes mellitus dubbed this
230 BCE
when were 2 separate types of diabetes distinguished
400-500CE
how is diabetes tested for
fasting blood glucose: blood glucose usually first thing in the morning
A1C test: % of glycated hemoglobin
*glycated hemoglobin=monosaccharide bound to hemoglobin
Oral glucose tolerance test: how well body is able to lower blood glucose
what is prediabetes
high risk for developing diabetes
what is diabetes
chronic high blood glucose
what are the early physiological signs of diabetes
hyperglycemia (consistent high blood glucose)
glycosuria-glucose in urine
polyuria-excess urination
polydipsia-excess thirst
what are symptoms of diabetes
-fatigue from inability to take in/use glucose
-weight gain-due to carb/sugar craving from inability to take in glucose
why do we care about glucose
-glucose is important major source of energy
-brain requires regular supply of glucose
-we have several hormones that increase blood glucose (only one that lowers it!)
how does chronic high blood glucose affect cellular mechanisms
-high levels of glycated hemoglobin increases free radicals and alters blood cell membranes—>leads to cell aggregation and reduced blood flow
-inflammation and artherosclerotic plaque formation
-reduced blood flow to neurons—>neuropathy (nerve damage)
what are the effects of untreated diabetes
-neuropathy
*weakness, slow reflexes, tingling, loss of sensation
*amputation if severe
-Capillary damage
*kidney damage
*diabetic retinopathy-lack of blood supply to retina, causes spotty vision
How does insulin lower blood glucose
-only hormone that does this!
-striated muscle, adipose—>insertion of GLUT4s
*allows for facilitated diffusion of glucose into cells
-liver, pancreas, intestines, kidneys—>alteration of intracellular glucose levels creates concentration gradient
*allows for facilitated diffusion of glucose into cell
What is type 1 diabetes
no insulin produced —-> high blood glucose
*autoimmune destruction of pancreas
*get insulin injections
what is type 2 diabetes
insulin unable to bind to receptors —> high blood glucose
Prevalence of diabetes
fastest increase in asia and africa
-in U.S. 10% of population diagnosed with diabetes
how to prevent diabetes
healthy lifestyle habits including exercise, healthy diet, minimize stress, minimize stigma, minimize misinformation
