BI-242: Test 2 Flashcards
Describe the process of exchanging gases
Gases in and out between lung and air
Gases exchange between capillaries and lungs
Gases transport in the bloodstream
Gases exchange between capillaries and tissues
Cellular respiration
What is pulmonary ventilation?
Gases in and out between lung and air; movement of air into and out of lungs
Aka breathing
What is external respiration?
Gases exchange between blood and lungs; O2 and CO2 exchange
What is internal respiration?
Gases exchange between capillaries and tissues; O2 and CO2 exchange between systemic blood vessels and tissues
What is cellular respiration?
Making ATP and metabolites
5 processes of respiration
Pulmonary ventilation External respiration Transport Internal respiration Cellular respiration
Organs of the upper respiratory tract
Nose, pharynx, larynx
Organs of the lower respiratory tract
Trachea, Bronchus, bronchiole, respiratory zone
Organs of the lung
Bronchus, bronchiole, alveoli
What is the pharynx?
Passage for both food and air One end: nose, mouth Another end: larynx, esophagus Made of muscle only Not moveable
What is the larynx?
Air only; voice production One end: pharynx Another end: trachea Made of mainly cartilages Is moveable Contains voice box
What is the epiglottis?
Prevents food from entering larynx
Made of elastic cartilage
What is the trachea?
One end: larynx
Another end: 2 bronchi
Made of 20 C shaped hyaline cartilage rings
Has 4 layers: (inside) mucosa, submucosa, hyaline cartilage, adventitia (outside)
What makes up the mucosa layer of the trachea?
Ciliated pseudostratified columnar epithelium with goblet cells on connective tissue
What is the adventitia of the trachea
Outermost layer (serosa)
Bronchus characteristics
One end: trachea
Another end: bronchiole
Right main bronchus is wider, shorter, and more vertical than left bronchus
3 branches: primary, secondary, tertiary
Tertiary bronchus leads to primary bronchiole
Bronchiole characteristics
One end: bronchus
Another end: alveoli
From cartilage to elastic fibers and smooth muscles
From pseudostratified columnar to simple cuboidal epithelium
Cilia decreases to non
What’s the smallest type of bronchioles?
Terminal bronchioles
3 parts of the respiratory zone
Respiratory bronchiole
Alveolar duct
Alveoli
Function of the respiratory zone
Only alveoli like are to exchange gases
Pulmonary arteriole is full of deoxygenated blood; pulmonary venule is full of oxygenated blood
3 layers of the respiratory membrane
Simple squamous epithelium
Fused basement membrane
Continuous capillary endothelium
Blood-air barrier or membrane
Alveolar- capillary barrier or membrane
3 types of cells in the respiratory zone
Type 1 alveolar cells
Type 2 alveolar cells
Macrophages
Describe type 1 alveolar cells
Simple squamous epithelium Most surface area Less number Organelles clustered around the nucleus Large areas of free cytoplasm Unable to replicate Susceptible to toxic insults
Describe type 2 alveolar cells
Secrete surfactant
Most number
Stem calls giving rise to more type 1 cells
Describe macrophages
Least number
Dust cells
List the different types of macrophages and their location
Lung: alveolar macrophage (dust cell) Skin: dendritic cell (Langerhans cells) CNS: microglia Liver: Kuffer cell Bone: osteoclasts
Describes the differences between the two lungs
Left lung smaller than right
Left lung have 2 lobes, while the right one has 3
Left lung has cardiac notch
What’s in the mediastinum surface of the lung
Pulmonary artery and vein; bronchus; nerves; lymphatic vessels
What is bronchopulmonary segments?
Portion of lung supplied by the tertiary bronchus (segmental bronchus)
Anatomical and functional units
Epithelium that makes up trachea, bronchus, bronchiole, and alveoli
Trachea, bronchus: ciliated pseudostratified
Bronchiole: simple cuboidal epithelium
Alveaoli: simple squamous epithelium
What makes up the trachea, bronchus, bronchiole, and alveoli
Trachea: cartilage
Bronchus: less cartilage
Bronchiole: no cartilage, but smooth muscle
Alveoli: no cartilage and no muscle
Pulmonary arteries supply…
Deoxygenated blood to respiratory zone (alveoli)
Pulmonary veins contain…
Oxygenated blood
Bronchial arteries supply…
oxygenated blood to non-respiratory zone (no alveoli)
-arise from thoracic aorta to azygos vein
Characteristics of pulmonary circulation
Low pressure, high volume
What does the parietal pleura line? Visceral pleura?
Parietal: thoracic cavity
Visceral: attaches to the lung
What is the pleural cavity filled with?
Intrapleural fluid
Mechanic of breathing where gases flow into lungs? Out of lungs?
Inspiration and expiration
Muscles involved in breathing
Diaphragm and intercostal muscles (no skeletal muscles within lungs)
What is the force that moves air into the lungs?
Atmospheric pressure
What is intrapulmonary pressure
Pressure inside respiratory tract; can be positive or negative; varies
What is Intrapleural pressure
Pressure inside pleural cavity; varies but is always negative
What is transpulmonary pressure?
Intrapulmonary pressure-intrapleural pressure=4mmHg constant and always positive
All the mechanics of breathing (intrapulmonary/intrapleural/transpulmonary pressure) do what?
Prevent the lung from collapse
What causes pneumothorax (collapsed lung)
If intrapleural pressure is 0 or positive
Instrument for measuring respiratory volumes and capacities
Spirometer
On a spirometer, what means inspire and what means expire?
Curve up-inspire
Curve down-expire
What is tidal volume?
Amount of air inhaled or exhaled with each breath under resting condition
What is inspiratory reserve volume (IRV)
Amount of air that can be forcefully inhaled after normal tidal volume inspiration
What is expiratory reserve volume?
Amount of air that can be forcefully exhaled after normal tidal volume expiration
What is residual volume
Amount of air remaining in the lungs after a forced expiration
What equals inspiratory capacity?
TV+IRV
What is vital capacity?
Max amount of air that can be expired SLOWLY after a max inspiratory effort
VC=TV+IRV+ERV
Difference between forced vital capacity (FVC) and vital capacity (VC)
FVC: has expelled forcefully and rapidly
VC: has expelled slowly
Function of spirometry
Contributes to diagnose pulmonary diseases
What does Total lung capacity equal?
TV+IRV+ERV+RV
What happens in the alveoli during gas exchange?
O2 goes down and CO2 goes up
How is oxygen transported in the blood?
Binding to hemoglobin, producing oxyhemoglobin
What is ventilation-perfusion coupling?
Perfusion-blood flow reaching alveoli
Ventilation-amount of gas reaching alveoli
Ventilation and perfusion matched (coupled) for efficient gas exchange
What happens when alveolar O2 is low/high in ventilation-perfusion coupling
High O2: pulmonary arterioles dilate
Low O2: pulmonary arterioles constrict
Organs of the digestive system (alimentary canal)
Mouth, esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, anus
Other digestive organs
Teeth, salivary glands, pancreas, liver and gallbladder
How many teeth do we have?
32
Differences between bone and teeth Composition Peripheral membrane Regenerative power Medulla cavity contents
Composition: bone=collagen; teeth=dentine Peripheral membrane: bone=periosteum; teeth=enamel Regenerative power: Bones=very strong; teeth=none Medulla cavity contents: Bone=bone marrow; teeth=dental pulp
What do salivary glands produce?
Salivary amylase
Amylase function?
Starting point of carbohydrate digestion-from carbohydrate to smaller sugar (partial digestion)
How does the nervous system effect your salivary glands?
Parasympathetic stimulation increases salivary glands secretion; sympathetic nervous system decreases its secretion
What is the esophagus and oral cavity made out of?
Stratified squamous epithelium
What is the stomach to large intestine made out of?
Simple columnar epithelium
Function of mouth and esophagus
Mastication and deglutition
Starting point of carbohydrate digestion
No absorption
Where is the human stomach
In abdominal cavity
4 parts of the stomach?
Cardia
Fundus
Body
Pylorus
2 sphincters of the stomach
Cardiac sphincter and pyloric sphincter
Where is the cardiac sphincter
Separates esophagus from stomach
Where is the pyloric sphincter
Separates stomach from duodenum
2 curvatures of stomach and where they are
Greater curvature- convex lateral surface
Lesser curvature- concave medial surface
What are two omentas made out of
Folded visceral peritoneum; fat deposition
What does mesentery part of the stomach do?
Attaches abdominal organs at the posterior abdominal wall; folded visceral peritoneum
What are the 4 layers of the stomach?
Mucosa, submucosa, muscle, and serosa
What kind of surface epithelium is the mucosa made of?
Simple columnar epithelium; folds to form gastric pits
What kind of cells are on the surface epithelium of the mucosa
Mucous cells, parietal cells, chief cells, and G cells
What do mucous cells do?
Secrete alkaline, viscous liquid protecting stomach, most top of pit
What do parietal cells do?
Make HCL and gastric acid is made within epithelium by CO2
What do chief cells do?
Make pepsinogen
What does G cells do
Enteroendocrine cells: gastrin
Regulate acid secretion
What is the first organ to digest protein and how?
Stomach; pepsinogen, activated by HCL, becomes active pepsin to digest protein
What is the function of pepsin in the stomach (physical and chemical)
Digest proteins into smaller polypeptides
Physical functions:
Mechanical breakdown; delivers chyme to small intestine
Chemical functions:
Enzymatic digestion of proteins; no absorption for food but alcohol
What parasympathetic nerve and hormone help in the regulation of gastric secretions
Vagus nerve and gastrin
What bacteria is the main reason for gastritis
Helicobacter pylori
Explain digestion in mouth
Salivary amylase for carbohydrate
Explain digestion in stomach
Pepsin and HCL for protein
What is the major duodenal papilla
Opening of pancreatic and hepatic duct into duodenum
Duodenum characteristics
Curves around head of pancreas
Bile acids and pancreatic juice enter duodenum through major duodenal papilla
Where is the liver located
Upper right quadrant of the abdominal cavity; largest internal organ; lesser omentum anchors liver to stomach
Functions of the liver
Protein, lipid, and carbohydrate metabolism; bile production
What enters the hepatic hilum
Portal vein Hepatic artery Bile duct Vagus nerve Lymphatic vessels
Where does the portal vein drain blood from?
The GI tract
Portal vein characteristics
Receives nutrients from superior mesenteric veins and sends them into liver; first processed by liver before systemic circulation
Does the mesenteric veins with nutrients drain into the heart directly?
No
What are the two capillary systems that are connected directly by the portal vein?
Intestinal and hepatic capillaries
Where does the hepatic artery branch from?
Celiac trunk of abdominal aorta; mixes with portal vein into liver capillaries; then back into inferior vena cava
What kind of capillaries are in the liver?
Sinusoid
What are liver lobules?
Hexagonal structural and functional units
Central vein
Center of hepatic lobule; receiving mixed blood from liver sinusoids peripherally
Connective tissue in liver?
At peripheral with hepatic arterioles and portal venules
Liver blood vessels
Portal vein and hepatic artery in, portal venules and hepatic arterioles in, capillary: liver sinusoids, central vein out and then fuse hepatic veins out, the inferior vena cava out
Portal vein and hepatic artery fuse.
Nutrients and oxygen used by liver cells in sinusoid
Function of gallbladder
Stores and squeezes out bile acids, NOT makes
Where is the common hepatic duct?
Leaves liver
Where is the cystic duct?
Connects with gallbladder
Where is the bile duct?
Formed by union of common hepatic and cystic ducts for bile acids excretion
Bile acids are amphipathic meaning…?
Both hydrophilic and hydrophobic heads present
What is emulsification by bile acids?
Break down of large fats (water insoluble) into smaller droplets (water soluble)
Aid in the absorption of fatty acids
Terminal digestion of fat
Needs bile acids
What is enterohepatic circulation
Recycles bile salts
Bile salts->duodenum->reabsorbed from ileum->hepatic portal blood
->liver->secreted into bile
Where is the pancreas?
Mostly retroperitoneal
Head encircled by duodenum
Endocrine function of the pancreas
Pancreatic islets (langerhans) secrete insulin and glucagon into blood
Exocrine function of the pancreas
Pancreatic acini secrete pancreatic juice into duct and then into duodenum
What is pancreatic juice?
Alkaline solution that neutralizes chyme
What is the exocrine function of pancreatic juice
Enzymes- only pancreas secretes three types of enzymes that can digest three major nutrients (carbs, fats, proteins)
What are the three types of enzymes (pancreatic juice)
Pancreatic amylase
Pancreatic lipase
Trypsinogen and chymotrypsinogen
What does pancreatic amylase do?
Digests carbohydrates From carbs to smaller sugar Partial digestion of carbs Stronger than salivary amylase Needs intestinal enzymes
What does pancreatic lipase do?
Digests fats
Terminal digestion of fat
Needs bile acids
What does trysinogen and chymotrypsinogen do?
Inactive form
Digests proteins after activation
Partial digestion of protein
Needs intestinal enzymes
What activates trypsinogen?
Enteropeptidase (enterokinase)
Process of activation of trypsinogen and chymotrypsinogen
Trypsin and chymotrypsin are secreted in inactive form (trypsinogen)
Trypsinogen is converted to trypsin by enteropeptidase upon reaching the small intestine
Chymotrypsinogen is converted to chymotrypsin by trypsin
Carbohydrate polysaccharide: food examples, enzymes, and end product
Food: sugar, fiber (veggies), starch (bread)
Enzymes: amylase, BB enzyme
End product: glucose
Protein polypeptide: food examples, enzymes, and end product
Food: egg white, fish, meat
Enzymes: pepsin (HCL), trypsin, chymotrypsin, BB enzymes
End product: Amino acids
Fat triglyceride: food examples, enzymes, and end product
Food: saturated fat (meat), unsaturated fat (vegetable oil)
Enzymes: lipase (bile acids)
End product: fatty acids, glycerol
Where does the small intestine start and finish
From pyloric sphincter to ileocecal valve
What are the 3 parts of the small intestine
Duodenum
Jejunum
Ileum
Function of jejunum
Digestion and absorption
Nutrients are absorbed into mesenteric veins and then fused into hepatic portal vein; transports the residues to ileum
Microanatomy of the stomach
Mesentery contains arteries and veins of intestine
Layers are the same as stomach
Explain the microanatomy of the mucosa epithelium of the jejunum
Simple columnar cells
Only monomers such as glucose, amino acids and fatty acids can be absorbed into blood
Explain the transportation of nutrients
Almost all monomers of nutrients are transported into mesenteric veins and then portal vein
Salivary amylase in what Pancreatic amylase in Pepsin in Pancreatic trypsin and chymotrypsin in Pancreatic lipases in
Mouth Pancreas Stomach Small intestine Small intestine
Function of ileum
Reabsorb bile acids
Almost no absorption of nutrients
No digestion
Name all the parts of the large intestine
From ileocecal valve to anus
Cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anus
Surrounds small intestine
Functions of large intestine
Continue digestion by bacteria
Nerves for digestive tract: enteric nervous system
What is it?
Major nerve supply GI tract wall: auto-
Sympathetic NS inhibits digestive activities
Parasympathetic NS stimulates digestive activities
