Transcript File

Chapter 17 - Urinary System
• Cells produce waste that can become
toxic if they accumulate
• Functions
• -the urinary system removes salts and
nitrogenous wastes
-maintains normal concentration of water
and electrolytes
-maintains pH, controls red blood cell
production and blood pressure
• Composition
• -consists of a pair of kidneys which
remove substances from the blood
-ureters which transport urine from the
kidneys to the bladder
-urinary bladder stores urine
-urethra conveys urine to the outside of
the body
• 17.2 Kidneys
• -lie on either side of the verebral column
deep in the abdominal cavity
-positioned behind the parietal peritoneum
-lateral side is convex, medial is concave,
kidneys sit in a depression called the renal
sinus
• superior end of the kidney forms a funnel
shaped sac - renal pelvis
-renal medulla = center of the kidney
-renal cortex = outer shell around the
medulla; the cortex appears granulated
due to the presence of nephrons
-renal arteries and veins supply blood to
the kidneys
• Nephrons
• -each kidney contains about 1 million
nephrons
-renal corpuscle: composed of a tangled
cluster called a glomerulus which filters
fluid
• glomerular filtration - urine formation
begins, plasma is filtered
tubular reabsorption - returns most of the
fluid to the body
tubular secretion - removes what is not
needed; produces urine
• After urine forms in the nephrons,the
ureters (starting with the renal pelvis) carry
the urine away to the bladder
Bladder is an expandable structure that
stores urine before it is eliminated from the
body. Transitional epithelial cells change
shape to allow for expansion and
contraction.
• Micturation = urination; as the bladder fills
this reflex occurs though it is also under
voluntary control
• Urethra = tube carries urine to the outside
of the body
• Kidney Stones
• Extracorporeal shock wave lithotripsy (ESWL) is
a procedure used to shatter simple stones in the
kidney or upper urinary tract. Ultrasonic waves
are passed through the body until they strike the
dense stones. Pulses of sonic waves pulverize
the stones, which are then more easily passed
through the ureter and out of the body in the
urine.
• Cystitis = bacteria enters the bladder or
kidneys (kidney infection); more common
in women because the urethra is shorter
• Overactive Bladder = sudden contractions
of the bladder produce sensation of
urgency, also more common in women
Excretion
• The removal of waste from the body.
• Urea is a chemical waste product that
comes from the break down of proteins.
Filtering Process
• First, both wastes and needed material,
such as glucose, removed from the blood.
• Then, much of the needed material is
returned to the blood.
Analyzing Urine
• Urine can be tested to detect number of
diseases.
• High levels of glucose may indicate
diabetes.
• High levels of protein (blood) is a sign that
the kidneys are not functioning properly.
• High levels of protein (blood) is a sign that
the kidneys are not functioning properly.
Water Balance
• If there is a lot of water in the body the
kidneys will reabsorb all of the water left.
This makes the urine very concentrated.
Excretory Organs
• The lungs, skin and liver all excrete waste
from the body.
• The lungs excrete carbon dioxide and
water.
• The liver turns hemoglobin into bile.
Chapter Fifteen
Digestive System
Digestive System Function
• The mechanical and
chemical breakdown
of foods and the
absorption of
nutrients by cells.
• Consist of the
alimentary canal and
accessory organs.
Structure
• 1.) Mucosa – protects tissue, carries out
absorption.
• 2.) Submucosa – contains glands, blood
vessels, lymphatic vessels, nerves
• 3. Muscular layer – smooth muscle tissue
with circular and longitudinal fibers
• 4. Serosa – outer covering of the tube,
moistens and lubricates structures
Movements
• Mixing – rhythmic
contractions that mix
food with digestive
juices
• Propelling – ring of
muscles contract and
relax to push food
through a canal
Mouth
• Mouth begins the digestion by
mechanically breaking the food into
smaller pieces using the teeth. Then the
palate and tongue move the food.
Teeth
• Crown – projects from the gum.
• Root – extends below the gum and
anchors the tooth.
• Enamel – outer covering of the tooth,
made of calcium salts
• Dentin – surrounds the tooth’s central
cavity
• Blood vessels and nerves extend through
the tooth through the root canal.
Salivary Glands
• Serous cells produce amylase that splits
starch and glycogen into dissaccharides.
• The food material is then moved to the
pharynx and then the esophagus.
Stomach
• J-shaped organ, that contains four parts
and is located below the diaphragm.
• Produces chyme – a paste of food
molecules after it has been broken down
by digestive juices.
Pancreas
• Secretes juices that digest fat and break
down nucleic acids into nucleotides
Liver
• Hepatic portal vein – delivers blood to
the liver
Functions
• Functions: maintains normal
concentration of blood glucose,
breakdown of lipids and fats, protein
metabolism, stores iron and vitamins,
destroys damaged red blood cells,
removes toxic substances from the blood,
secretes bile
Bile
• Bile – yellowish-green liquid secreted from
hepatic cells. The cystic duct delivers bile
to the gall bladder.
• Bile is stored in the gallbladder and then
secreted into the duodenum via the
common bile duct
Cholesterol in bile may form crystals called
gallstones
• Bile aids in digestion, bile salts break
down fat globules into smaller droplets –
emulsification
Small Intestine
• *tubular organ that extends from the
pyloric sphincter, many loops and coils,
fills much of the abdominal cavity
*receives secretions from the pancreas
and liver, completes digestion of nutrients
and chyme, absorbs
• 1. Duodenum - first part of the small
intestine
2. Jejunum – second part, ~2.2 m
3. Ilium – third part, longest ~3.3 m
*jejunum and ilium are continuous
• *the main function of the small intestine is
to secrete chemicals to break down food
and carry away these nutrients in the
blood (absorption)
Large Intestines
• 1. Cecum – beginning of the large
intestine, pouchlike, closed end called the
vermiform appendix (ileocecal valve)
2. Colon – ascending / transverse /
descending / sigmoid
3. Rectum
4. Anal canal - ends in the anus
• Functions – secretes mucus to protect the wall
against abrasion; re-absorbs water and passes
along material that was not digested; contains
intestinal flora (bacteria to break down
cellulose, also produce intestinal gas)
• Mass movements – large portions of the colon
contract to move material through it, 2-3 times a
day usually after eating