Download Small Intestines - Liberty Union High School District

Internal Organs Structure
& Function
Heart & Respiratory System
Heart:
-Located in the left center of the chest, below the ribcage & sternum,
between lungs.
-Size of a clenched fist
Heart:
 A muscular organ
 Consists of 4 chambers: right & left atria and right & left ventricle
 Each chamber is separated by a valve to prevent blood from flowing the wrong
way
 Primary Function:
 Circulates oxygenated blood throughout the body to the working tissues
 A single heartbeat consists of contraction of both atria followed by
contraction of both ventricles
 Path of blood flow:
 Right side pumps blood to lungs to become oxygenated blood
 Left side pumps blood to the rest of the body
 Back from body -- into Right Atrium- into Right Ventricle - To the Lungs--
Back to the Left Atrium- To the rest of the body!
Conduction System
 Specialized electrical conduction system controls the
contraction of the heart
 Called the Purkinje Fibers
Electrocardiogram
P wave : atrial depolarization (contraction)
QRS Complex : ventricle depolarization /
contraction
T wave : ventricle repolarization
Key Terms
 Bradycardia : fewer than 60 beats per minute
 Tachycardia : greater than 100 beats per minute
 Stroke Volume (SV): amount of blood ejected with each beat
 Cardiac Output : the volume of blood ejected per minute from the
heart
 Cardiac output = SV x HR
 Artherosclerosis : excessive build up of cholesterol in the heart
arteries, which blocks blood flow
 Maximal Heart Rate :
220 – (a person’s age in years)= max. heart rate
Lungs:
-Located within the ribcage; 2 sides (or lobes), made of elastic
tissue
Lungs:
 Deliver oxygenated blood to the tissues of the body through gas
exchange!
 Oxygen to Carbon Dioxide
 Oxygenation of blood
 2 lungs sitting in thoracic cavity
 Under rib cage, anterior to the heart
 Weigh approximately 1 kg
 Volume : 4-6 Liters of air
 Huge surface area
 If spread out, lung tissues would cover half of a tennis court
 Highly vascularized area
Respiratory Pathway
Mouth or Nose
Bronchioles
Alveoli
Trachea
Bronchi
Lungs
Alveoli
 Lungs contain more than 300 million alveoli.
 Thin-walled, membranous sacs
 Receive largest blood supply of all organs!
Alveoli
Alveoli
 Millions of thin-walled capillaries (blood) and alveoli (air) lie side by side
 Gas diffuses across the thin barrier
Exercise
 Exercise increases the total lung capacity
 Better shape = more efficient gas exchange
 Max VO2 = maximal oxygen consumption
The region where oxygen consumption plateaus
during exercise
Measures a person’s aerobic fitness
The Lymphatic / Immune System
How the Body Fights Against Disease
The Network of Channels
The System
 Network of channels with specialized tissues and organs
 Lymph organs : spleen, tonsils, & thymus
 Lymph nodes
The Channels
 The vessels are very low in pressure
 Connect lymph nodes and the organs
 About 3 Liters of lymph enter the blood stream every 24
hours
The Warriors
 Lymphocytes are created in red blood cells
 Protect the body against foreign substances
 Macrophages help the immune system by gobbling up
foreign substances and activate the lymphocytes
Lymph Nodes
 Clusters of the lymphatic channels
 Filters lymph as it heads to the bloodstream
 Activates the Immune system if needed!
Lymphoid Organs
 Thymus : early years, secretes hormones to fight against
certain diseases
 Tonsils : “invite” infections in to trap the bacteria
The Spleen:
-Largest Lymph organ in the body
-Located under the diaphragm on the left side
The Spleen:
 Resevoir for Red Blood Cells
 Regulates number of Red Blood Cells in Circulation
 Destroys ineffective Red Blood Cells
 Produces antibodies & Lymphocytes
 Cleans blood and is on immune system surveillance
Digestive Organs
Digestive Organs:
 Stomach
 Small Intestines
 Large Intestines
 Pancreas
 Liver
 Gallbladder
Stomach:
-Found
in left quadrant, between esophagus and small intestines
Stomach:
Storage and mixing chamber for ingested food
Some digestion & absorption occur here
Gastric secretions assist in the partial digestion of
proteins and alcohol & caffeine
Food is mixed with secretions from stomach
glands to form Chyme, which then passes into
the small intestines
Small Intestines:
-Found between the stomach and large intestines
-3 Portions: Duodenum, Jejunum, & Ileum
-20 feet in length
Small Intestines:
 Chyme mixes with secretions from the liver & pancreas
 Chyme moves through the small intestines over a period
of 3-5 hours, propelled by peristaltic contractions
 Most digestion and absorption occurs in the small
intestines
Large Intestines:
-Connected to the small intestines
-3 divisions: Cecum, Colon, & Rectum
-6 ½ feet long
Large Intestines:
 Chyme is converted into feces through the absorption of
water, secretion of mucus, & activity of microorganisms
Pancreas:
-Located between small intestines & the Spleen
Pancreas:
 Secretes Pancreatic juice, critical in digestion of protiens,
fats, & carbohydrates
 Produces insulin and glucagon, controls the amount of
sugar & amino acids in the blood
Liver:
-Largest internal organ in the body
-Found in upper right quadrant, underneath the diaphragm
-Weighs about 3 pounds
Liver:
 Consists of 2 lobes
 Performs digestive & excretory functions
 Absorbs & stores excessive glucose
 Processes nutrients
 Detoxifies harmful chemicals
 Secretes bile, essential in neutralizing & diluting stomach
acid and digesting fat
Gallbladder:
-Pear-shaped, saclike structure found underneath the liver
Gallbladder:
 Storage reservoir for bile secreted by the liver
 Secretes stored bile into the small intestines after a meal
The Urinary System
Kidneys:
-Situated on either side of the spine, in center of the back
Kidneys:
 Primary function is to filter metabolic wastes, ions, or
drugs from blood and expel them from the body via
urination
Bladder:
-Hollow organ, lies posteriorly to the Pubic Symphysis
Bladder:
 Stores Urine