what does the respiratory system contain?
- upper respiratory tract
- lower respiratory tract
upper respiratory tract contains
- the nose
- the nasal cavities
- pharynx
- larynx
- upper trachea
lower respiratory tract
- lower trachea
- bronchi
- bronchioles
- alveoli
nasal cavities
separated into right and left halves by a nasal septum
the pharynx includes three parts
- nasopharynx
- oropharynx
- laryngopharynx
thyroid cartliage
largest of the cartilaginous structures
epiglottis
located at the top of the larynx, acts as a flap, covers the opening of the trachea during eating so that the food doesn't enter the lungs
the space between the vocal cords
glottis
false vocal cords
do not produce sounds
true vocal cords
produce sound, air slowing, air flowing from the lungs through the glottis during exhalation
windpipe
tube 4 to 5 inches in length and 1 inch in diameter
carina
point where the trachea splits at the manubriosternal junction ( where the manubrium of the sternum meets the sternal body)
tracheostomy
tube that bypasses the obstruction and allows air to flow through the tube into the lungs
bronchial tree consists of
- bronchi
- bronchioles
- alveoli
- resembles an upside down tree
primary bronchi
enters the lungs at a region called the hilus
left bronchus
narrower because the heart lies to the left side of chest
right bronchus
shorter and wider and extends downward in a vertical direction
bronchioles
regulate the flow of air to the alveoli
alveoli
small grape like structures, tiny air sacs that form at the end of the respiratory passages
alveoli function
to exchange oxygen and carbon dioxide across the alveolar- pulmonary capillary membrane
pleura
lining of the inner chest wall, continuous serous membrane
tendency of the lungs to collapse is due to two factors:
- elastic recoil
- alveolar surface tension
surfactant
decreases surface tension
negative intrapleural pressure
remains negative when no holes exist in the chest wall
respiration includes
- ventilation or breathing
- exchange of oxygen and carbon dioxide
- transport of oxygen and carbon dioxide by the blood
respiratory cycle
one inhalation and one exhalation
anatomical dead space
some air that you inhale never reaches the alveoli, it is not available for gas exchange
normal breathing
rhythmic and involuntary
medullary respiratory control center
main control center for breathing, located in the medulla, sets the basic breathing rhythm
phrenic nerve
nerve for the diaphragm
the exchange of gases occurs at two sites
the lungs and the cells
three conditions make alveoli suited for exchange
- large surface area
- thin alveolar and capillary walls
- closeness of the alveoli to the pulmonary capillaries
functions of digestive system
- ingestion of food
- digestion
- absorption of end-products
- elimination of waste
accessory organs of digestive system include
- salivary organs include
- teeth
- liver
- gallbladder
- pancreas
digestion
process by which food is broken down into smaller particles suitable for absorption
two types of digestion
- mechanical- breakdown of large food particles into smaller pieces by physical means
- chemical- the chemical alteration of food by chemical substances such as digestive enzymes, acid and bile
the walls of the digestive tract has 4 layers
- mucosa
- submucosa
- muscle layer
- serosa
mouth AKA oral cavity
beginning of digestive tract
contains: teeth- tongue- salivary glands
teeth names
- incisors
- cuspids
- premolars
- molars
the tongue has two structures
- mucous membrane called frenulum which anchors the tongue to the floor of the mouth
- capillary network that provides sublingual area with rich blood supply
parotid glands
largest; lies below and anterior to the ears
submandibular glands
located in the floor of mouth
sublingual glands
located under the tongue and are the smallest
uvula
a v-shaped piece of soft tissue that hangs down from the upper back region of the mouth and aids in swallowing
pharynx
AKA throat
involved in swallowing by reflex action called delgtuiotn
esophagus
tube-like structure that carries the food from the pharynx to the stomach
two sphincters in esophagus
- phayngoesophageal sphincter-located at the top of the esophagus
- gastrosophageal or lower esophageal sphincter- located at the base of the esophagus
stomach performs 5 functions
- digestion of food
- secretion of gastric juices, digestive enzymes and hydrochloric acid
- secretion of gastric hormones and intrinsic factor
- regulation of the rate and delivery of partially digested food to small intestine
peristalsis
moves the propels the food toward the pylorus
small intestine
- 20 feet long
- held in place by the mesentery
small intestine has three parts
- duodenum
- jejunum
- ileum
most digestion and absorption occurs in where?
duodenum
large intestine has 4 parts
- cecum
- colon
- rectum
- anal canal
accessory digestive organs
liver
gallbladder
pancreas
phagocytsis
the kupffer cells can phagocytose bacteria and other substances within the liver
hepatic portal system
- receives 1.5 liters of blood/minute from the portal vein and hepatic artery
bile
green-yellow secretion produced by the liver and stored in the gallbladder
biliary tree
the ducts that connect the liver, gallbladder, pancreas and duodenum
gallbladder
- bile produced in the liver, flows through the hepatic ducts, cystic ducts and gallbladder
alkaline substances
rich in bicarbonate, neutralize the highly acidic chyme coming out of the stomach and entering the duodenum
primary role of the digestive system
the breaking down of food into particles suitable for absorption
mechanical digestion occurs
chewing in the mouth and mixing and churning activities of muscles in the digestive organs
chemical digestion
refers to a change in the chemical composition of the food molecule