231 Physiology Term 2 Learning Objective 3 & 4 plus 3 diseases Flashcards
What are the functions of the respiratory system?
- Main function is gas exchange
- Also plays an important role in pH balance
- Sound production
What are the four processes of respiration?
- Pulmonary ventilation (breathing)
- External respiration
- Transport of respiratory gases
- Internal respiration
Describe the pulmonary ventilation process.
- Ventilation consists of inspiration and expiration
- Inspiration moves air into the lungs from the atmosphere
- Expiration moves air out of the lungs into the atmosphere.
Describe the external respiration process.
- oxygen diffuses from the lungs to the blood
- carbon dioxide diffuses from the blood into the lungs
Describe the transport of gases process.
- the cardiovascular system transports gases using blood as the transporting fluid
- oxygen is transported from the lungs to the tissue cells of the body
- carbon dioxide is transported from the tissue cells to the lungs
Describe the internal respiration process.
- oxygen diffuses from blood to tissue cells
- oxygen diffuses from the tissue cells to blood
When you contract your diaphragm and your external intercostal muscles you cause the intraplural cavity size to _________________.
increase.
When you contract your diaphragm and your external intercostal muscles you cause the intraplural pressure to ____________________.
decrease.
Define atmospheric pressure.
Pressure exerted by the air (gases) surrounding the body. At sea level, atmospheric pressure is 760 mm Hg (the pressure exerted by a column of mercury 760 mm high).
Does atmospheric pressure increase or decrease as elevation increases?
It decreases as you increase elevation.
What is the purpose of serous fluid in the lungs?
Prevents friction.
What are the steps involved in breathing in?
- Contract the diaphragm and the intercostal muscles. This will lift the rib cage up and out and increase the volume of the intrapleural space.
- The pressure will decrease to about 754 mmHg.
- Because there is less pressure pushing on them, the volume of the lung can increase. They expand and the pressure in the lungs decreases (from 760 to 759). Now air can come in. (had to alter the pressure gradient).
What is the typical intrapleural pressure?
756 mm Hg (minus 4 from atmospheric pressure)
What is the intrapulmonary cavity defined as?
pressure inside the lungs
What is intrapleural pressure defined as?
surrounding pressure in the pleural cavity
Define digestion.
System that processes food into absorbable units and eliminates undigestible wastes.
What are the functions of the digestive system?
- mechanical breakdown
- propulsion
- digestion
- absorption
- defecation
Which digestive system activity actually moves nutrients from the outside to the inside of the body?
The process of absorption moves nutrients into the body.
What are the four layers of the alimentary canal?
- mucosa
- submucosa
- muscularis externa
- serosa
What kind of tissue makes up the mucosa layer?
Nearly all is simple columnar, which is excellent for absorption and secreting.
What is the function of the layer of muscularis?
produce local movement
Describe how the muscularis layer works.
This layer is responsible for segmentation and peristalsis. It typically has an inner circular layer and an outer longitudinal layer of smooth muscle cells. In several places along the tract, the circular layer thickens, forming sphincters that act as valves to control food passage from one organ to the next and prevent backflow.
Define the enteric nervous system.
The enteric nervous system (enter = gut) is the in-house nerve supply of the alimentary canal. It is staffed by enteric neurons that communicate widely with one another to regulate digestive system activity.
What is primary hypertension?
Known as the silent killer. Blood pressure silently increases over time and is idiopathic in nature. No evident symptoms.
What are the short reflexes of the enteric nervous system?
Mediated entirely by enteric nervous system plexuses in response to stimuli within the GI tract. Control of the patterns of segmentation and peristalsis is largely automatic, involving pacemaker cells and reflex arcs between enteric neurons in the same or different organs.
What are the long reflexes of the enteric nervous system?
Long reflexes involve CNS integration centers and extrinsic autonomic nerves. The enteric nervous system sends information to the central nervous system via visceral sensory fibers. It receives sympathetic and parasympathetic motor fibers from the autonomic nervous system. These enter the intestinal wall to synapse with neurons in the intrinsic plexuses. Long reflexes can be initiated by stimuli arising inside or outside of the GI tract. In these reflexes, the enteric nervous system acts as a way station for the autonomic nervous system, allowing extrinsic controls to influence digestive activity (Figure 23.7). Generally speaking, parasympathetic inputs enhance digestive activity and sympathetic impulses inhibit them.
What is the major function of carbohydrates in the body?
The major function of carbohydrates in the body is to provide a ready, easily used source of cellular fuel
What are the three types of carbohydrates?
Monosaccharide
(simple sugars)
Disaccharides
(double sugar)
Polysaccharides
What makes up sucrose?
glucose + fructose
What makes up lactose?
glucose + galactose
What makes up maltose?
glucose + glucose
List the common monosaccharides.
glucose
fructose
galactose
List the common disaccharides.
sucrose
lactose
maltose
List the common polysaccharides.
starch
glycogen
What are proteins made up of and how can the body use them?
Protein is made up of amino acids and to be absorbed the body must break them down.
What are the three types of lipids?
triglycerides
phospholipids
steroids
To what level do you need to break down lipids for them to be usable in the body?
glycerol and fatty acids
Where would someone get nucleic acids within their diet?
The DNA/RNA found in the nucleus of cells within meat o plants.
What is the subunit of nucleic acids?
nucleotides
What are the components of a nucleotide?
- sugar
- phosphate
- base
What 3 main concepts govern the regulation of digestive activity?
- Digestive activity is provoked by a range of mechanical and chemical stimuli.
- Effectors of digestive activity are smooth muscle and glands.
- Neurons (intrinsic and extrinsic) and hormones control digestive activity.
What is the role of saliva in digestion?
- Cleanses the mouth
- Dissolves food chemicals so they can be tasted
- Moistens food and helps compact it into a bolus
- Contains the enzyme amylase that begins the digestion of starchy foods
- Contains the enzyme lipase that starts the minimal breakdown of lipids
How does amylase work in saliva to break down starch?
It attacks large carbohydrates and makes them a little bit shorter. They turn polysaccharides into oligosaccharides (bigger than a disaccharide).
What two enzymes in saliva play a role in the initial breakdown of food?
- Amylase starts to breakdown starchy foods
- Lipase starts the minimal breakdown of lipids
What are the three muscular layers of the stomach?
longitudinal, circular, and oblique
Where are the gastric folds located and what is their purpose?
They are on the internal surface of the stomach. They increase surface area and allow for greater stretch.
What layer does the surface mucosal cell belong to and what does it produce?
Mucosal layer. Produced alkaline mucous, which helps to protect the walls of the stomach from acid.
List the cells of the mucosal layer in the stomach wall.
surface mucous cells- mucous neck cells- parietal cells- chief cells- enteroendocrine cells
What are four different types of cells in the stomach mucosa and what are their functions?
surface mucous cells: produce alkaline mucous, which helps protect The wall of The Stomach from acid- parietal cells: produce HCl and intrinsic factor- chief cells: produces pepsinogen and lipase- enteroendocrine cells: produces gastrin hormone
What is the only thing in the stomach that you would die from if it didn’t happen?
not having intrinsic factor - need it for your blood cells to be produced
What 3 ways is the tissue of the small intestine modified to maximize surface area and absorption?
circular folds (force chyme to slowly spiral through lumen)- villi: fingerlike projections of mucosa- microvilli: cytoplasmic extensions (brush border) of mucosal cells on villi
Define partial pressure.
The pressure exerted by a single component of a mixture of gases.
What is the approximate percentage of nitrogen in atmospheric air?
78.6%
What is the approximate percentage of oxygen in atmospheric air?
20.9%
What is the approximate percentage of carbon dioxide in atmospheric air?
0.04%
What is the approximate percentage of water in atmospheric air?
0.46%
What is the partial pressure of nitrogen in atmospheric air?
597 mm Hg
What is the partial pressure of oxygen in atmospheric air?
159 mm Hg
What is the partial pressure of carbon dioxide in atmospheric air?
0.3 mm Hg
What is the partial pressure of water in atmospheric air?
3.7 mm Hg
What is the approximate percentage of nitrogen in the lungs?
74.9%
What is the approximate percentage of oxygen in the lungs?
13.7%
What is the approximate percentage of carbon dioxide in the lungs?
5.2%
What is the approximate percentage of water in the lungs?
6.2%
What is the partial pressure of nitrogen in the lungs?
569 mm Hg
What is the partial pressure of oxygen in the lungs?
104 mm Hg