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