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Digestive & Urinary System by Miabella Aguilar per. 5 - Coggle Diagram
Digestive & Urinary System by Miabella Aguilar per. 5
8. Nephron anatomy and physiology
Anatomy:
Nephrons are the structural and functional units that forms urine in the kidneys
1 million per kidney
Two main parts
-
Renal corpuscle
Renal tubule
1. Glomerulus:
Tuft of capillaries composed of fenestrated endothelium
highly porous capillaries
allows for efficient filtrate formation
-
Filtrate:
plasma derived fluid that renal tubules process to form urine
2. Glomerular capsule:
also called Bowmans capsule: cup shaped hollow structures surrounding glomerulus
consists of two layers
-Parietal layer: simple squamous epithelium
-Viseral layer: clings to glomerular capillaries; branching epithelial podoctytes
-Extensions terminate in foot processes that clean to basement membrane
-filtration slits between foot processes allowing filtrate to pass into capsular space
Renal tubules:
consists of single layer of epithelial cells, but each region has its own unique histology and function
three major parts:
1. Proximal convoluted tubule:
cuboidal cells with dense micro villi that form brush border
-increase surface area
-also have large mitrochondrial
-functions in reabsorption and secretion
-confined to cortex
2. nephron loop:
formerly called loop of tlenle
U shaped structure consisting of two limbs
-
Descending limb:
proximal part of descending limb is continuous with proximal tubule's & distal portion also called descending thin limb; simple squamous epithelium
Ascending limb:
thick ascending limb, been in some nephrons, and cuboidal or columnar cells
3. Distal convoluted tubule:
cuboidal cells with very few microvilli
function more in secretion than reabsorption
confined to cortex
Collecting ducts:
two cell types
-
Principal cells:
spars with short microvilli & maintain water and Na+ balance
-
Intercalated cells:
cuboidal cells with abundant microvilli
two types of intercalated cells
Physiology:
Step 2: Tubular Reabsorption
Tubular reabsorption
quickly reclaims most of tubular contents and returns them to blood
selective transepithelial process
-almost all organic nutrients are reabsorbed
-water and ions reabsorption in hormonally regulated and adjusted
includes active and passive tubular reabsorption
substances can follow two routes:
-1. transcellular
-2. paracellular
Step 3: Tubular Secretion
Tubular secretion
is reabsorption in reverse
occurs almost completely in PCT
selected substances are moved from peritubular capillaries through tubule cells out into filtrate
-substances synthesized in tubule cells also are secreted
tubular secretion is important for:
-disposing of substances such as drugs or metabolites is that are bound to plasma proteins
-eliminating undesirable substances that were passively reabsorbed
-Ridding body of excess K+
-trolling blood pH by altering amounts of H+ or HCO
Step 1: Glomerular
Glomerular filteration
is a passive process
-no metabolic energy required
hydrostatic pressure forces fluids and solutes through
Filtration membrane
into glomerular capsule
no reabsorption into capillaries of glomerulus occurs
3. Major organs of the digestive system
Stomach:
is a temporary storage tank that starts chemical breakdown of protein digestion
converts bolus of food to paste like chyme
empty stomach has 50 ml volume but can expand to 4L
when empty stomach mucosa forms many folds called rugae
major regions of the stomach:
-
Cardial part:
surrounds cardioorifice
-
Fundus:
dome shaped region beneath diaphragm
-
Body:
mid portion
-
Pyloric part:
wider and more superior portion of the pyloric region antrum narrows into pyloric canal that terminates in pylorus
Small intestine:
is the major organ of digestion and absorption
2-3 m long from pyloric sphincter to ileocecal valve point at which it joins large intestine
Subdivisons
-
Duodeum:
mostly retroperitoneal curves around head of pancreas
-
Jejunum:
~2.5m long; attached posteriorly by mesentery
-
ileum:
~3.6m long; attached posteriorly by mesentery; joins large intestine atileocecael valve
esophagus:
flat muscular tube that runs from laryngopharynx to stomach
-is collapse when not involved in food propulsion
Gastroesophageal (cardiac) sphincter:
surrounds cardio Orifice
-keeps Orifice clothes when food is not being swallowed
-mucus cells on both sides of sphincter help protect esophagus from acid reflex
Large intestine:
has 3 unique features not seen elsewhere:
Tenia coli:
three bands of longitudinal smooth muscles in the muscularis
Haustra:
pocket like sax caused by tone of Tenia coli
Epiploic appendages:
fat filled pouches of visceral peritoneum
Pharynx:
food passes from mouth into oropharynx and then into laryngopharynx
-allows passage of food, liquids, and air
-external muscle layers consist of two scout or muscle layers
Anus:
Internal anal sphincter: smooth muscle
External anal sphincter: skeletal muscle
Mouth:
Also called the oral (buccal) cavity
Oral orifice is the anterior opening
walls of mouth lined with stratified squamous epithelium
Lips and Cheeks:
-Lips(Labia): composed of fleshy orbicularis Orbis muscle
-Cheeks: composed of buccinator muscles
-Labial frenulum: median attachment of each lip to gum
Palate:
forms the roof of the mouth and has two distinct parts
Hard palate: formed by palitine bones and palitine process of Maxillae with a midline ridge called raphe
Soft palate: Gold formed mostly of skeletal muscle
-closes of nasal pharynx during swallowing
-
Uvula:
finger like projections that faces downwards from free edge of soft palate
Liver, Gallbladder, and Pancreas:
liver, gallbladder, and pancreas are accessory organs associated with small intestine
-
liver:
digestive function is production of bile
-
Gallbladder:
chief function is storage of bile
-
Pancreas:
supplies most of enzymes needed to digest chyme as well as bicarbonate to neutralize stomach acid
5. Digestive enzymes (including names and functions)
Brush border enzymes (amino peptidase, carboxypeptidase, and dipeptidase):
site of action: small intestine
path of absorption: amino acids leave epithelial cells by facilitated diffusion, enter the capillary blood in the villi and are transported to the liver via the hepatic portal vein
Lingual lipase:
site of action: Mouth
Path of absorption:
fatty acids and monoglycerides enter the intestinal cells via diffusion
fatty acids and monoglycerides and then combined with other lipids and proteins within the cells. The resulting chylomicrons and extruded by exocytosis
Pancreatic enzymes (trypsin, chymotrypsin, carboxypeptidase):
site of action: small intestine
path of absorption: infrequently, transcytosis of small peptides occurs
Gastric lipase:
site of action: stomach
path of absorption: the chylomicrons enter the lacteals of the villi and are transported to the systemic circulation via the lymph in the thoracic duct
Pepsin (Stomach glands) in presence of HCI:
Site of action: stomach
path of absorption:
amino acids are absorbed via cotransport with Na+
some dipeptides and tripeptides are absorpted via cotransport with H+ and hydrolyzed to amino acids within the cells
Emulsification by the detergent action of bile in from the liver:
site of action: small intestine
path of absorption: Some short chain fatty acids are absorbed move into the capillary blood in the liver via the hepatic portal vein
Brush border enzymes in small intestine (dextrine, glucoamylase, lactase, maltase, and sucrase):
Site of Action: Small intestine
Pancreatic lipase:
site of action: small intestine
path of absorption:
Pancreatic amylase:
Site of action: small intestine
path of absorption:
all monosaccharides leave the epithelial cell via facilitated diffusion enter the capillary blood in the villi and are transported to the liver via the hepatic portal vein
Pancreatic ribonuclease and deoxyribonuclease:
site of action: small intestine
path of absorption:
units enter intestinal cells by active transport via membrane carries
Salivary amylase:
Site of action: mouth
Path of absorption: glucose in Galactose are absorbed via cotransport with Na+
fructose passes via facilitated diffusion
Brush border enzymes (nucleosides and phosphates):
site of action: small intestine
path of absorption: units are absorbed into capillary blood in the Vive and transported to the liver via the hepatic portal vein
9. Disorders of the digestive and urinary systems
Colon disease; Polyps:
growths
Causes:
-age
-heredity
-diet
symptoms:
-asymptomatic
-bloody stool
-diarrhea
Treatment:
-none
-surgical removal
-diet
Colon disease; Spastic colon:
abnormal abdominal conditions
causes:
-diet
-stress
-lifestyle
symptoms:
-abdominal pain
-cramping
-diarrhea
treatment:
-medication
-diet
-lifestyle changes
Peptic Ulcers:
Sores that develop in the lining of the stomach or duodenum
causes:
-imbalance in gastric juices
-stress
-smoking
symptoms:
-heart burn
nausea
vomiting
Treatment:
-life style changes
-medication
-endomicroscopic surgery
Bladder cancer:
Cancer in the bladder
causes:
-smoking
-chemical
-radiation
Symptoms:
-back pain
-pain during urination
Treatment:
-surgery
-chemotherapy
-radiation therapy
Inflammatory Bowel Disease:
A chronic complex intestinal condition that causes inflammation in the digestive system
causes:
-unknown
-possibly genetics, environment, and immune
Symptoms:
-abdominal pain
-cramps
-fever
Treatment:
-medication
antibiotics
surgery
Urinary tract infection:
Abnormal growth of bacteria anywhere along the urinary tract
Causes:
-sexually active
-pregnant women
-menopausal
symptoms:
-burning when urination
-pain and blood in urine
Treatment:
-antibiotics
-medication
Gastroesophageal Reflux disease:
A chronic disease that occurs when the esophageal sphincter relaxs
Cause:
-frequent acid reflex
-obesity
-pregnancy
Symptoms:
-chest pains
-heart burn
-dry couch
Treatment:
-over the counter medication
-prescription
-surgery
Kidney Stones:
High levels of minerals and salts in urine
Causes:
-chronic UTI
-poor bladder emptying
Symptoms:
-sharp, cramping pain
-intense need to urinate
-burning
Treatment:
-medication
-surgery
-let in pass
Cholecystitis:
An inflammation of the gall bladder
Causes:
-Blockage of gall duct by gallstones
-Digestive tumor
-diet
Symptoms:
-tender abdomen
-sweating
-nausea
Treatment:
-medication
-fasting
-antibiotics
7. Layers of the GI tract (including stomach)
2. Submucosa:
consists of areolar connective tissue
contains blood and lymphatic vessels, lymphoid follicles, and submucosal nerve plexus that supply surrounding G.I. tract tissues
has abundant amounts of elastic tissues that help organs to regain shape after storing large meals
3. Musclaris externa:
muscle layer responsible for segmentation and peristalsis
contains inner circular muscle layers and outer longitudinal layers
-Circular layer thickens in some areas to form sphincters
1. Mucosa:
Tunic layer that lines lumen
functions: different layers perform one of all three
-secretes mucus, digestive enzymes, and hormones
-absorbs and products of digestion
-protects against infectious disease
4. Serosa:
outermost layer, which is made up of the visceral peritoneum
2. Major functions of the urinary system
Functions of the kidneys
kidneys a major expiratory organ, maintain the bodies internal environment by:
regulating total water volume and total solute concentration in water
regulating ion concentrations in extra cellular fluid
ensuring long-term acid base balance
excreting metabolic waste, toxins, drugs
producing erythropoietin ( regulates blood pressure and renin)(regulates RBC production)
activating vitamin D
carrying out glucogenesis if needed
kidneys are a part of the urinary system which includes:
-
Ureters
: transport urine from kidneys to urinary bladder
-
Urinary bladder
: temporary storage reservoir for urine
-
Urethra
: transports urine out of the body
6. Location of digestion and absorption of each macromolecule
3. Mechanical break down:
includes chewing, mixing food with saliva, churning food in stomach, and segmentation
Segmentation:
local constriction of intestine that mixes food with digestive juices
4. digestion:
series of catabolic steps that involves enzymes that break down complex food molecules into chemical building blocks
2. Propulsion:
meant of food through the alimentary canal, which includes:
swallowing
Peristalsis:
major means of propulsion of food that involves altering waves of contractions and relaxation
5. absorption:
passage of digested fragments from lumen of GI tract into blood or lymph
1. Ingestion:
eating and taking in food
6.Defecation:
elimination of indigestible substances via anus in form of feces
1. Major functions of the digestive system
Major functions of the digestive system:
take in food
Break it down into molecules
absorb molecules into the bloodstream
rid body of any indigestible remains
4. Major organs of the urinary systems
Urinary Bladder:
muscular sac for temporary storage of urine
retroperitoneal on pelvic floor posterior to pubic synthesis
-Males: prostate inferior to bladder neck
-Females: anterior to vagina and uterus
Urethra:
transports urine out of body
Ureters:
transport urine from kidneys to urinary bladder
Kidneys:
kidneys a major expiratory organ, maintain the bodies internal environment by:
regulating total water volume and total solute concentration in water
regulating ion concentrations in extra cellular fluid
ensuring long-term acid base balance
excreting metabolic waste, toxins, drugs
producing erythropoietin ( regulates blood pressure and renin)(regulates RBC production)
activating vitamin D
carrying out glucogenesis if needed
kidneys are a part of the urinary system which includes:
-
Ureters
: transport urine from kidneys to urinary bladder
-
Urinary bladder
: temporary storage reservoir for urine
-
Urethra
: transports urine out of the body