What happens when you swallow?
�Nasopharynx closed off by the soft palate
�Epiglottis - A flap of tissue that covers the glottis (opening to the larynx) to prevent food from "going down the wrong pipe"
�Food passes into the esophagus ...no breathing occurs.
What is the functional unit of the respiratory system?
o300 million total
oEach sac made up of simple squamous epithelium + capillaries
oO2 ? From alveoli into bloodstream (diffusion)
oCO2 ? Out of bloodstream into alveoli (diffusion)
oSurfactant - A lipoprotein lining the alveoli
? Surface tension to help ke
glottis
the opening between the vocal cords in the larynx
epiglottis
the elastic cartilage at the back of the throat; covers the glottis during swallowing
tidal volume
amount of air inhaled or exhaled with a normal breath
external respiration
the actual exchange of gases between the alveoli and the blood capillaries (pulmonary gas exchange) occurs by diffusion
internal respiration
the exchange of gases between the capillaries and tissues occurs by diffusion
cellular respiration
metabolic processes in which ATP is produced in the mitochondria in the cells
vital capacity
the volume of air that can be expelled from the lungs by forcible expiration after the deepest inspiration; total exchangeable air
residual volume
even after the most strenuous expiration, air still remains in the lungs, and it cannot be voluntarily expelled, it is important because it allows gas exchange to go on continuously even between breaths and helps to keep the alveoli open
What happens to RV with a nasty disease like emphysema?
�Emphysema causes the residual volume to increase, over-inflation of the lungs leads to a permanently expanded barrel chest.
�Less air is available to supply the tissues with oxygen
What is normal RV?
1,000ml
Normal tidal volume?
500ml
What is asthma?
�Can be treated using epinephrine (remember that's a hormone of the thoraco-lumbar NS)
�ASTHMA - disease or allergic response characterized by bronchial spasms and difficult breathing
Constriction of the smooth muscle in bronchiole walls cause constrictio
What are the functions of the respiratory system?
�The major function of the respiratory system is.... to supply the body with oxygen and to dispose of carbon dioxide
�Other functions include...
oOlfaction & Speech
oRegulation of blood pH
How does the respiratory system help regulate blood pH?
�The most important factors that modify the rate and depth of breathing are chemical- the levels of carbon dioxide and oxygen in the blood.
�Co2 increases pH decreases - this is important stimuli leading to an increase in the rate and depth of breathing
�
What's HCO3-?
�HCO-3 - bicarbonate ion = plays a very important role in the blood buffer system
�CO2 is carried as
bicarbonate ion (HCO3-) dissolved in plasma
What affect does ? CO2 in the blood have on the respiratory system? How about ? CO2?
�As CO2 increases the blood pH decreases & breathing rate/depth will increase
�As CO2 decreases the blood pH increases& breathing rate/depth will decrease
What affect does ? O2 in the blood have on the respiratory system?
�Low O2 levels instead stimulate chemoreceptors in the aorta & carotid arteries
�When O2 levels ?, these tell the respiratory center to ?? rate & depth of breathing
What & where is carbonic anhydrase?
�An enzyme present in red blood cells that speeds up the whole gas exchange process. This happens in internal respiration AND in external respiration.�INTERNAL RESPIRATION .... H2O + CO2 ? H2CO3 (carbonic anhydrase helps here) ? HCO3- + H+�EXTERNAL RESPIR
What is the main way CO2 is carried in the blood?
�The main way CO2 is carried as = bicarbonate ion (HCO3-) dissolved in plasma
How is O2 carried in the blood?
�The main way O2 is carried in the = RBCs as oxyhemoglobin
What is inspiration?
(ACTIVE PHASE) - Respiratory center sends nerve impulses to intercostals muscles (between the ribs) & diaphragm ? contraction ? thoracic cavity size ?? ? lungs expand - Air enters due to negative pressure or partial vacuum
What is expiration?
(PASSIVE PHASE) - Respiratory center stops signaling ? Diaphragm (& intercostals) relax ? rib cage moves down ? air moves out
Why do we need O2? (What's it used for in the body?)
�Along with organic compounds, it's used to supply cells for aerobic cellular respiration
�Air moves into and out of the lungs so that the gases in the air sacs (alveoli) of the lungs are continuously refreshed. It is used for exchanges between blood and
Where does the CO2 come from?
�Along with water, CO2 is a byproduct of respiration.
�It diffuses from the pulmonary blood
Where is the breathing control center located? What chemical(s) (ions or molecules) $ it?
�MEDULLA OBLONGOTA
�Stimulated by CO2 & H+ IONS
Where are the peripheral chemoreceptors located? What chemical(s) (ions or molecules) $ them?
�AORTA & CAROTID ARTERIES
�Stimulated by VERY LOW O2 LEVELS
What type of cartilage is the epiglottis?
elastic cartilage
The C-shaped tracheal rings are what kind of cartilage?
hyaline cartilage
What is the relationship (in the body) between the esophagus & trachea? (Which is dorsal & which is ventral?)
�The trachea is fairly rigid because its walls are reinforced with C-shaped rings of hyaline cartilage. These rings serve a double purpose...... The open parts of the rings abut the esophagus and allow it to expand anteriorly/ventrally when we swallow a l
PROXIMAL
close to the origin of the body part (the elbow is proximal to the wrist)
DISTAL
farther from the origin of the body (the knee is distal to the thigh)
What is the cranial nerve for smell? Name & number!
I. OLFACTORY
What are the alimentary canal organs?
A long, winding tube open to the outside on both ends made up of the organs through which food passes
o Mouth
o Esophagus
o Stomach
o Small intestine
o Large intestine
What are the accessory organs?
Release digestive juices into the alimentary canal to aid in digestion Undigested food doesn't pass through these organs
o Salivary glands
o Pancreas
o Gallbladder
o Liver
MECHNAICAL DIGESTION
Process of physically chewing, mashing, & breaking down food
CHEMICAL DIGESTION
Changing food into simpler substances via enzymes (chemicals)
Where does mechanical digestion begin?
Mechanical digestion starts at the mouth - First food is physically broken down into smaller particles by chewing These reflexes, though initiated by different stimuli, are brought about by parasympathetic fibers in cranial nerves (V=Trigeminal) and (IX=G
Where does chemical digestion begin?
Chemical digestion starts in the mouth as well - When food is food is mixed with saliva, salivary amylase begins the chemical digestion of starch, breaking it down into maltose These reflexes, though initiated by different stimuli, are brought about by pa
What does amylase breakdown?
starch
What does lipase breakdown?
fats - fatty acids & glycerol
What does HCl breakdown?
proteins
What does pepsins breakdown?
starts protein digestion
Where is amylase secreted?
Amylase is secreted by the salivary glands into the mouth AND by the pancreas into the duodenum
Where is lipase secreted?
Lipase is secreted by the pancreas into the duodenum
Where is pepsin secreted?
Pepsin is secreted by the gastric glands to begin protein digestion in the stomach & by the pancreas to continue protein digestion in the duodenum
Where do enzymes like amylase, lipase, and pepsin come from?
They come from pancreatic secretions: Endocrine gland (ductless) - Secretes insulin & glucagon
Exocrine gland - Digestive secretions (enzymes & NaHCO3)
ENZYME
functional proteins that act as biological catalysts (a substance that increases the rate of chemical reaction w/o becoming part of the product or being changed itself)
What does NaHCO3 do?
NaHCO3 - (sodium bicarbonate) to increase pH & neutralize chyme (Thick, soupy liquid
What does bile do?
Bile's does not contain enzymes, but its bile salts emulsify fats by physically breaking large fat globules into smaller ones, thus providing more surface area for the fat-digesting enzymes to work on.
Where does bile come from?
The liver's digestive function is to produce bile.
Where is bile secreted?
Bile leaves the liver through the common hepatic duct and enters the duodenum through the bile duct.
What is bile?
a yellow-to-green, watery solution containing bile salts, bile pigments, cholesterol, phospholipids, and a variety of electrolytes.
Where does most digestion occur?
�Most digestion occurs in the DUODENUM
Where does most absorption occur?
Most absorption occurs in the JEJUNUM of the SMALL INTESTINE
What does the gallbladder do?
The muscular sac attached to the liver which stores & concentrates bile
o Enters duodenum through the common bile duct
o Excess cholesterol can crystallize here to form gallstones, which can obstruct the bile duct
What does the liver do?
Receives nutrient-rich blood from the (HEPATIC PORTAL VEIN)
o Produces bile (stored in gallbaldder)
o Bile = Bilirubin & biliverdin (pigments from hemoglobin breakdown ... These pigments give feces its color) + Bile Salts - Emulsify fat in the duodenum
What are the major functions of the large intestine?
�Major functions are to dry out the indigestible food residue by absorbing water and to eliminate these residues from the body as feces.
PERISTALSIS
the rhythmic contraction of the smooth muscle layer that pushes food through the digestive tract (& other hollow organs)
GOBLET CELL
individual cells (simple glands) that produce mucus (mucus-protects stomach lining from HCl)
What is the approximate pH of the stomach (low or high ... acidic or basic)? Why?
�2.0 = very acidic & this is because of the HCl which has to breakdown food
o The only enzyme that REALLY enjoys low pH like this is pepsin, which is activated by HCl & begins protein digestion in the stomach
What is the pH of the duodenum(low or high ... acidic or basic)? Why?
�6-7.5 = basic & this is because bicarbonate is secreted from the pancreas to help buffer the chime so enzymes can work properly
What is the function of the epiglottis?
As swallowing the larynx rises so that its opening (into the respiratory passageways) is covered by the flap-like epiglottis)
What is the function of the esophagus?
Has no digestive function,
Simply provides a passageway to carry food to the next processing site, the stomach
SPHINCTER
a circular muscle surrounding an opening which constricts to act like a valve by closing off a lumen
What's the difference between a sphincter & a valve?
Sphincters are circular muscle that constricts to ACT like a valve by closing off a lumen, BUT a VALVE - is an actual flap of tissue
POSITIVE FEEDBACK
feedback that tends to cause a variable to change in the same direction as the initial change; enhances the stimulus
Positive feedback mechanisms are rare in the body because they tend to increase the original disturbance (stimulus) and to push the variab
NEGATIVE FEEDBACK
feedback that causes the stimulus to decline or end
Most homeostatic control mechanisms are negative feedback mechanisms. In such systems, the net effect of the response to the stimulus is to shut off the original stimulus or reduce its intensity. (EX. OF
PARASYMPATHETIC
cranio sacral = "Rest & Digest" The parasympathetic division of the autonomic nervous system (primarily the vagus nerves) promotes the mobility of the digestive organs.
It also makes it so we do NOT have to continuously think to control the digestion & re
SYMPATHETIC
The sympathetic nervous division when activated will slow down the digestive process BUT speed up the respiration process. Sympathetic system (thoracolumbar) decreases digestion, but increases respiration & heart rate & dilates bronchiole smooth muscle.
CELLULAR RESPIRATION
The actual use of oxygen and production of carbon dioxide by tissue cells, that is, CELLULAR RESPIRATION, is the cornerstone of all energy-producing chemical reactions in the body.
What are the final products of aerobic cell respiration?
o Water
o Carbon dioxide &
o LARGE amounts of ATP
Products of aerobic cellular respiration are...
o Glucose & Oxygen
Bi-products of aerobic cellular respiration are...
o Carbon Dioxide & Water
How many ATPs are made from one molecule of glucose during aerobic cellular respiration?
36
How many ATPs are made from one molecule of glucose during fermentation (which requires NO energy)?
2
What happens when ATP breaks down?
it gives LOTS of ENERGY which is usually in the form of HEAT
PASSIVE TRANSPORT
Requires NO energy
o DIFFUSION = The movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached
o OSMOSIS = Diffusion of H2O across the plasma membrane
What serous membranes cover the organs?
VISCERAL
What serous membranes line the walls?
PARIETAL
What serous membranes the thoracic cavity?
PLEURA
What serous membranes are in the abdominal cavity?
PARITONEUM
Parietal pleura
lines the walls of the thoracic body cavity
Visceral pleura
covers the organs of the thoracic body cavity
Parietal peritoneum
lines the walls of the abdominal body cavity
Visceral peritoneum
covers the organs of the abdominal body cavity