Exam 3 Review Flashcards
conducting airways – they do not participate in gas exchange.
Trachea to the terminal bronchioles
participate in gas exchange
Alveoli
• Alveoli participate in gas exchange
Connected to respiratory bronchioles (___) and alveolar ducts (____)
simple cuboidal epithelium. Simple squamous
alveoli, alveolar sacs, respiratory
bronchioles, alveolar ducts and a terminal bronchiole
• the functional unit of the lung
• wrapped in elastic C.T.
Pulmonary lobule
Alveoli are composed chiefly of _____ allowing for exchange of gases with pulmonary capillaries.
type I alveolar cells,
secrete surfactant that prevents collapse of the alveoli during exhalation.
Type II alveolar cells:
carry deoxygenated blood from
the right heart to the lungs for oxygenation
Pulmonary arteries
branch from the aorta and deliver
oxygenated blood to the lungs (primarily the muscular
walls of the bronchi and bronchioles)
Bronchial arteries
Ventilation-perfusion coupling: matches perfusion
(____) of areas in the lungs to ventilation
(___) in that area
blood flow. airflow
surface tension moves two
pleaural layers together.
Mechanical coupling:
Function of what:
Filter, warm, moisten incoming air Smell incoming air Resonating chamber
Nose
Function of what:
duct that drains secretions of the sinuses and tears into the nose. Increases turbulence
mixing air for moisture
and warmth
The Three nasal conchae (or turbinates):
It functions as:
a passageway for air and food
a resonating chamber
a housing for the tonsil
Pharynx
composed of 9 pieces of cartilage: connects the
laryngopharynx with the trachea (the “windpipe”). • prevents food and water from entering
the lower respiratory system • Resonating chamber
Larynx
The trachea is composed of 4 layers:
• a mucous secreting epithelium: mucosa
• three layers of CT (submucosa, hyaline cartilage, and adventitia).
Earth’s atmosphere is composed of
Nitrogen (N2) 78%
Oxygen (O2) 21%
Carbon Dioxide (CO2) 0.04%
Water Vapor variable, but on average around 1%
The gases of the atmosphere
have a____ and a_____
(5 x____)
mass. weight. 1018 kg
The atmosphere exerts a significant____ on every object on the planet through _____(force applied per unit area, P = F/A.) Measured by a barometer
force. air pressure
At sea level, the air pressure is:
760 mmHg = 1 atmosphere
At high altitudes, the atmospheric pressure is____;
descending to sea level, atmospheric pressure is____.
less. greater
apply equally to the gases of the atmosphere,
the gases in our lungs, the gases dissolved in the blood,
and the gases diffusing into and out of the cells of our
body.
Gas laws
applies to containers with flexible walls – like
our thoracic cage.
Volume and pressure are inversely related.
o If there is a decrease in volume – there will be an increase in pressure.
o V ∝∝ 1/P
Boyles laws
applies to a mixture of gases.
The pressure of each gas is directly proportional to the percentage of that gas in the total mixture: PTotal = P1 + P2 + P3 …
O2 = 21% of atmosphere, the partial pressure exerted by the contribution of just O2 (written pO2 or PAO2) = 0.21 x 760 mmHg = 159.6 mmHg at sea level.
Dalton’s law
Gas molecules diffuse from regions of
High pressure (concentration) to lower p (c)
deals with gases and solutions.
Increasing the partial pressure of a gas “over” (in contact with) a solution will result in more of the gas dissolving into the solution.
The patient in this picture is getting more O2 in contact with his blood - consequently, more oxygen goes into his blood.
Henry’s law
Reducing the vol in a container will ____ the pressure. Increasing the vol in a container will ____ the pressure.
Increase. Decrease
movement of air between the atmosphere and
the alveoli: inhalation and exhalation.
Ventilation
___ is the exchange of gases.
Respiration
(pulmonary) gas exchange between the alveoli and the blood.
External respiration
(tissue) gas exchange between the systemic capillaries and the tissues of the body.
Internal respiration
Changing the volume of the thoracic cavity (and the lungs – remember the mechanical coupling of the chest wall, pleura, and lungs), changes the____
pressure in the lungs.
primary muscle of respiration – all the others are accessory.
Diaphragm
The 3 other factors also affect the ease with which we ventilate:
Surface tension of alveolar fluid, Lung compliance, and Larger diameter of an airway
accounts for 2/3 of lung elastic recoil. Surfactant prevents the complete collapse of alveoli at exhalation, facilitating reasonable levels of work.
Surface tension of alveolar fluid:
means the lungs and chest wall expand easily.
Lung compliance
-> less airway resistance->greater flow of air
Resistance proportional 1/d4 same as blood vessels Regulated by smooth muscle
Larger diameter of an airway
About 70% of the tidal volume reaches the xxx
zone – the other 30% remains in the xxx zone
(called the xxx ).
respiratory. conducting. anatomic dead space
Dalton’s Law : The pressure of a specific gas is the
Partial pressure Pp
Gas xxx (like the AC
membrane) from greater partial pressure to lower partial
pressure.
Greater the difference=faster diffusion.
diffuses across a permeable membrane
moves from the alveoli into the blood
O2
moves into the lungs.
CO2
In the blood, a tiny amount of O2 is dissolved in the plasma. Most O2 (about 98.5%) is carried
Attached to Hb
CO2 is transported in the blood in three different forms:
~ 7% is dissolved in the plasma, as a (gas.)
~ 70% is converted into (carbonic acid/bicarbonate) catalyzed by the enzyme carbonic anhydrase.
~ 23% is attached to (Hb) (but not at the same binding sites as oxygen).
The amount of Hb saturated with O2 is called the
SaO2
Although ___ is the most important determinant of SaO2,
several other factors influence the affinity with which Hb
binds O2 .
PO2
_____),____ and_____ shift the entire O2 –Hb saturation curve to the right (lower affinity for O2).
Acidity (pH), PCO2, blood temperature
Fever (^ temp.) , ^ CO2, and acidosis (^ H+ ) shift ______, making it easier to unload O2 at the tissues
* Hypothermia ( ↓temp.), ↓CO2, and alkalosis,
(↓H+ ) shift _____, binding 02 more strongly
the curve to the right. the curve to the left
Fetal hemoglobin (Hb-F) has a___ affinity for oxygen (it
is shifted to the___) than adult hemoglobin A, so it binds
O2 more strongly.
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The fetus is thus able to attract oxygen across the placenta and support life, without lungs.
higher. left
located in the brainstem, has
centers that control basic respiratory patterns for both
inspiration and expiration.
• Other sites in the pons help the
medullary centers manage the transition between inhalation and exhalation.
Medulla rhythmicity area:
voluntary control of breathing.
Cortex
Stretch receptors sensing over-inflation arrests breathing temporarily
(Herring Breuer reflex).
(limbic system) affect respiration.
Emotions
The hypothalamus, sensing a xxx, increases breathing, as does moderate xxx
fever. pain
Blood Chemistry (xxx) increases breathing *primary signal
pH*, O2 too low, CO2 too high
mouth, pharynx, esophagus, anus)
Stratified squamous
stomach and intestines)
Simple columnar
Mucosa
Areolar connective tissue
Lamina propria
Mucosa
Smooth muscle
Muscularis mucosae
Lamina propria contains “”, mucosa-associated
lymphatic tissue that protect against disease.
MALT
creates folds in the lining of the
stomach and small intestines
(Gastric pits and vili/micro)
Muscularis mucosae
• Muscularis: mouth, pharynx, superior and middle parts of
the esophagus, and anal sphincter contain
Skeletal muscle
Muscularis In Rest of the tract:
Smooth muscle
Inner circular sheet
• Outer longitudinal sheets,
• myenteric nerve plexus
between them.
Muscularis
attaches the liver to the anterior
abdominal wall
and diaphragm.
Falciform ligament
suspends the stomach and duodenum from
the inferior edge of the liver.
pathway for blood vessels to enter the liver
contains the common bile duct.
Lesser omentum
organs are covered by visceral peritoneum
only on their anterior surfaces
Retroperitoneal
retroperitoneal space include
The kidneys and ureters
Most of the pancreas
The adrenal glands
The aorta and inferior vena cava
smell, sight, thought, or initial taste of
food
neural centers in the CNS to prepare for digestion.
stimulate secretion of saliva and gastric juice
Cephalic phase:
food enters the stomach.
Nervous and endocrine systems, gastrin is a key hormone Promotes secretion of gastric juice and gastric motility.
Gastric phase
acidic food enters the small intestine.
Neural response decreases gastric motility Hormones (secretin, CCK) increases intestinal secretions and decreases gastric secretions and motility
Intestinal phase:
- a dense fibrous connective tissue that anchors the teeth.
Periodontal ligament
Degulation
Swallowing
a progression of coordinated contractions and relaxations of the circular and longitudinal layers of the muscularis, push the bolus onward.
Peristalsis
Upper and lower esophageal sphincters (xxx) at
each end of the tube.
The xxx regulates the movement of food from the esophagus into the stomach.
UES and LES. LES
• Finish mechanical digestion
• Start chemical digestion of proteins
• minimal chemical digestion of fats
Stomach
gland cells secrete:
◦ ◦ ◦ ◦
Mucus Gastric juice
HCl
pepsinogen
gastric lipase
intrinsic factor
Exocrine
Secretes gastrin
Enteroendocrine
kills many microbes,
partially denatures proteins in food
converts pepsinogen into pepsi
HCI
digests proteins.
Pepsin
digest triglycerides.
Gastric lipase
needed for absorption of vitamin B12
in the terminal ileum.
Intrinsic factor
• 1–3 mm layer of xxx mucus protects the stomach from
Xxx gastric juice
alkaline. acidic
Xxx reduce food and gastric juice to chyme.
Mixing waves
• NaHCO3 : neutralize acid • Digestive enzymes • Carbohydrates • Proteins • Lipids
Pancreatic juice
Small Intestine
• Plicae circulares • Villi • Microvilli
Absorption Structures:
Small Intestine
• Pancreatic juice • Bile • Intestinal juice • Brush border enzymes
Chemical Digestion
Villi finger-like projections that are covered with a xxx epithelium.
simple
columnar
passage of digested nutrients into the blood or
lymph: 90% occurs in the small intestine.
Absorbtion
Absorption goes through xxx into blood
capillaries
Active transport/facilitated diffusion
Lipids (Triglycerides /fats) aggregated globules coated with proteins called
Chylomicrons
enzymes on the villi Finish chemical
digestion. Small intestine
Brush borders
• Minimal mechanical digestion xxx
• Plicae circulares are circular folds/ridges that encourage
turbulent flow of chyme.
segmentations
Food is absorbed into the blood in the small intestine • That blood all goes to the
Liver
Liver is covered by
visceral peritoneum.
Outer margin: the triad • hepatic portal vein (venous blood) from small intestine • hepatic artery (arterial blood) • Bile duct (bile) • Blood goes through
sinusoids (a specialized capillary) towards the central vein.
Just read
liver macrophages) destroy red cells, white
cells, and bacteria in blood draining
from the GI tract.
Kupffer cells
Remove/transform toxins,
And
transform/store excess nutrients from the materials absorbed
in the small intestine
Hepatocytes
The mucosa of what organ is mostly an absorptive epithelium (mainly for
water),
Large intestine
The Large Intestine
• attached to the posterior abdominal wall by xxx
peritoneal membrane.
mesocolon
Ascending & descending colon
are retroperitoneal. Tor F?
T
Transverse & sigmoid colon
are retroperitoneal. T or F?
F
Segment the colon into small
pouches called
Haustra
~9 liters/day of fluid enter the
small intestine
(ingestion+secretion). • ~8 liters/day absorbed by Small
intestine; the remainder passes
into the large intestine, where
most of the rest of it is also
absorbed. • Only ~100 mL/d of water is
excreted in the feces.
Read
As these bacteria digest/ferment left-over food, they secrete
beneficial chemicals such as vitamin K, biotin (a B
vitamin), and some amino acids (they are our main source
of some of these nutrients.)
Read
haustral churning and peristalsis
Mechanical events
Both reflexes occur with distension of the stomach. food moved from small intestine to large intestine and from large intestine to rectum
gastroileal and gastrocolic
reflexes
