Exam 4 Flashcards
Renal pyramid
Drains urine from the nephrons through its apex
Renal Cortex
outer region; light colored
Location of most nephrons - functional units of the kidneys that filter blood and synthesize urine
Renal lobe
is formed of a renal pyramid plus its cap of cortical tissue
About 8 lobes/kidney
(ranges from 6-10 lobes)
Renal pelvis
: funnel-like expansion at the upper end of ureter
Pelvis is the point where 2-3 major calyces converge (calyx = “cup”)
Each major calyx divides into several minor calyces
Renal hilum
on medial margin where blood vessels, ureters, and nerves enter/exit
Myogenic mechanism
Nephron controls GFR (Glomerular Filtration Rate)
= negative feedback
Vascular smooth muscle in afferent arterioles responds to moderate changes in systemic blood pressure due to changes in posture, exercise, etc.
Muscle contracts (vasoconstricts) when stretched
Muscle relaxes (vasodilates) when not stretched
Renal Autoregulation: Myogenic Mechanism
Stimulus: Increased systemic BP
Causes immediate increase in stretch on afferent arteriole
HPgc, NFP and GFR increase
Response: Afferent arteriole vasoconstricts (contracts) (myogenic mechanism)
HPgc, NFP and GFR decrease back to normal
Renal Autoregulation: Myogenic Mechanism
EXAMPLE: Decreased blood pressure
Stimulus: Decreased systemic BP causes HPgc to decrease to 50 mm Hg
Calculate the new NFP
What is the immediate effect on GFR? GFR decrease back to normal
What is the immediate effect on stretch in the afferent arteriole? Vasodilation (relaxes)
What is the response according to the myogenic mechanism?
How does the response affect GFR? HPgc, NFP and GFR increase back to normal
Nephrons 3 renal processes and overall goals
Glomerular Filtration
Tubular Reabsorption
Tubular Secretion
Functional unit of the kidney
Filter blood and form urine
Where urinary and cardiovascular systems intersect
~1 million nephrons per kidney
Hepatic (portal) triad
Bile Ductules
Proper Hepatic Artery
Hepatic Portal Vein
Lymphatic Vessels
Branch of the Vagus Nerve
Agentaffin cells
are located in the mucosa of the small intestine and secrete serotonin
into the lamina propria to stimulate intestinal peristalsis.
Brunner’s Glands
Located in the duodenum submuscosa
Secrete an alkaline mucin that coats the intestinal walls to protect them from acid chyme
What should NOT be found in Urine?
Kidneys are located
retroperitoneal; located within the abdominopelvic cavity but outside the peritoneal cavity between parietal peritoneum and dorsal body wall
Somewhat protected by lowest ribs and cushioned by perirenal fat
Pathway of Urine
Nephrons
Pyramid
Papillae
Minor calyx
Major calyx
Renal pelvis
Ureter
Bladder
Urethra
HIGH GFR (glomerular filtration rate)
Too little time for reabsorption
Water and valuable solutes such as glucose, sodium are lost in the urine
LOW GFR Glomerular filtration rate
Too much time for reabsorption
Unwanted wastes are returned to blood
Differences in Glomerular and Systemic Capillarie
Glomerular
Have arterioles at each end
Can vasoconstrict or vasodilate
Give precise control of blood flow through the capillaries
Are extremely permeable fenestrated capillaries
Function is to filter water and solutes from the blood into the glomerular capsule
Systemic Arteriole at one end; venule (lacking smooth muscle) at the other end
Continuous capillaries; only slightly permeable to water and solutes
Function is to deliver O2 and nutrients from blood to tissue cells; pick up CO2 and wastes
Regulation of Glomerular Filtration Rate
Kidneys have INTRINSIC controls to directly regulate GFR
EXTRINSIC mechanisms from outside the kidneys INDIRECTLY control GFR by regulating systemic blood pressure
Purpose of kidneys is to maintain constant GFR despite fluctuations.
Podocytes contribution to glomerulus
“Foot cells” wrap around glomerular capillaries
Put down foot processes to form filtration slits
Contribute to filtration
Diabetes Mellitus
Carriers reach a transport maximum and cannot reabsorb all glucose GLUCOSURIA (glucose lost in urine)
POLYURIA (water lost in urine) because it follows glucose
Dehydration and extreme thirst
Reabsorption in the PCT
Glucose and amino acids are cotransported with sodium
Proximal Tubule-Na+ & glucose and amino acid
Na+ via transport protein &nGlucose and Amino acid cotransported with Na+ reabsorption
Na+ K+ pump
Results: low Na+ inside tubule cell
Gradient for Na+ to enter from filtrate into tubule cell
Proximal tubule reabsorption of HCO3 and secretion of H+
Reabsorption of HCO3 (base) dependent on Na+ coupled with H+ (acid) secretion
**if blood too acidic then HCO3 reabsorption increases (adds base to blood)
**H+ secretion INCREASES (removes acid from blood)
Proximal Tubule Reabsorption of H2O, Urea and other ions
Water absorbed through aquaporins by osmosis, water follows Na+and other solutes
Urea=lipid soluble waste product follows water by SOLVENT DRAG
Cl- K+ and other ions are passively reabsorbed down their electromagnetic gradient
Nephron Loop Reabsorption
Descending limb reabsorbs H2O, NO ions
Ascending limb reabsorbs ions but NOT H2O (very few aquaporins present)
Sets up mechanism for nephron to conserve water and produce concentrated urine
Function of the teeth-molars (premolars)(up to 3 on each side)
Grinding
Function of the teeth-Incisors (2)
Square shaped with beveled edge; used for slicing
Function of the teeth-Canine (1)
Triangular; used for piercing and puncturing
Numbering of the teeth
4 basic layer of digestive tract
Mucosa (either stratified squamous or simple columnar)
Submucosa
Muscularis Externa(circular and longitudinal muscle)
Serosa-OUTER(connective tissue and epithelium)
Thin layer of smooth muscle wrinkles the mucosa to increase surface area in
Muscularis Mucosae
Mucosa and its layers
Lamina propria- layer of loose areolar CT has capillaries to nourish epithelium needs direct access to circulatory system
Epithelium
Muscularis Musocea
Submucosa
Intrinsic nerve plexuses & Submucosa Nerve plexuses-controls secretion and contraction of mucosa
Burners glands
Layer of areolar CT has major blood vessels, lymphatic nodules to defend against pathogens
Muscularis Externa
Thick layer of smooth muscle
2 layers-circular layer encircles tract
Outer longitudinal layer runs parallel to tract
Carries out peristalsis and segmentation
Myenteric nerve plexus controls contractions
Splanchnic Circulation
Blood supply is rerouted away from the digestive tract organs during sympathetic stimulation due to vasoconstriction of blood vessels
Digestive organs receive 1/4 or more of cardiac output during digestion 1200 ml/min
Involves starting celiac trunk, superior and inferior mesenteric arteries
Blood vessels branch off the abdominal aorta
Slow down peristalsis and decrease salivation
Parasympathic Division (craniosacral)
Promote digestion
Increase perstalsis
Increases salivation
Promote deification
Parasympathetic Facial and Glossopharygeal Nerves (VII) & (IX)
Innervate the salivary glands
Frenulum’s
Labial Frenula anchor the lips to the gingivae
Lingual Frenulum median fold that anchors the tongue to the floor of the oral cavity
Uvula
Most posterior aspect of the palate, which helps to retain food in the mouth until you are ready to swallow
Palatine Ragae
Aid the tongue in holding and manipulating food
Gomphosis
Joint between tooth and bone
4 layers of the esophagus
Mucosa
Submucosa
Muscularis Externa
ADVENTITIA
5 items order of deglutition Step 1
1 upper esophageal sphincter is contracted; tongue forces food bolus into the oropharynx
5 items order of deglutition Step 2
Uvula ascents and epiglottis bends down to keep food out of the airways, upper esophageal sphincter relaxes to allow food enter the esophagus
5 items order of deglutition Step 3
Pharyngeal constrictor muscles contract, forcing food into the esophagus interiorly upper esophageal sphincter closes
5 items order of deglutition Step 4
Food bolus is propelled down the esophagus by peristalsis
5 items order of deglutition Step 5
The gastgroesophageal (cardiac sphincter) opens; food enters the stomach and becomes chyme
Gross Anatomy of the stomach 4 Regions
1 Cardia
2 Fundus
3 Corpus (body)
4 Pylorus
Gross anatomy of the stomach-sphincters
Parietal Cells
Secrete hydrochloric acid, intrinsic factor and appetite regulating hormone-ghrelin
G cells
Secrete gastric to stimulate secretion of gastric acid HCL
Enteroendocrine cells
Secrete hormones that regulate digestion
Foveolar Mucous neck cells
Secrete mucus to protect the stomach lining (similar to goblet cells)
Chief cells
Secrete the enzymes gastric lipase, leptin and pesinogen
Stomach cell types photo
Carbohydrates
Exit the basolateral membrane by facilitated diffusion and enter the capillary via intracellular clefts
Small enough to absorb from digestive tract into the blood unless larger than monosaccharides
Salivary amylase
Pancreatic amylase
Brush border enzymes lactase Maltese and sucrose
Lactose intolerance
Lactase enzyme missing or defective
Inactivate chyme
Pancreas secretes inactive proteases become activated HCO3 neautralizes chyme
Bile breaks down
Dietary lipids
Vasa Recta in Juxtamedullary Nephron
Efferent arteriole supplies vasa recta that run parallel to long nephron loops
Necessary to produce concentrated urine
ADH targets what in nephron
ADH targets collecting ducts
Makes them more permeable to water
Diff in PCT and DCT
DCT is hormone dependent by aldosterone and ADH but PCT is not
Loop of Henli
Ascending limb is thicker than descending limb
Net filtration Pressure
Outward pressure - inward pressure
Ie (55) - (15+30)=
55-45= 10 mmHg
Teniae Coli
In Muscularis layer in large intestine
3 bands of longitudinal smooth muscle in the Muscularis layer
Muscle tone of teniae coli draws colon up into the haustra
Contracts slowly to mix contents and propel them to next haustrum
Crypts of Lieberkuhn
Contain paneth cells that secrete lysozyme to regulate intestinal bacteria
Small pits on the intestine
