Exam 3 Flashcards
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What are the four tunics of the alimentary canal?
mucosa, submucosa, muscularis externa, visceral peritoneum
What is the structure and function of the mucosa?
the innermost layer that secretes mucus, digestive enzymes, hormones, and absorbs DIGESTED nutrients into the blood
What is the structure and function of the submucosa?
external to the mucosa and has elastic fibers, blood vessels, lymphatic vessels, glands, and nerves
What is the structure and function of the muscularis externa?
helps push the food along in the digestive tract
What is the structure and function of the serosa?
the outermost layer (protective visceral peritoneum)
Where is the upper esophageal sphincter?
top of the laryngopharynx
What are rugae?
squiggly lines that flatten in the stomach when it gets full
What is the pyloric region made of?
thick muscle tissue
What is the fundus made of?
thin muscle tissue
What does the mesentery do?
provides nutrients for organs (think of a heated weighted blanket with wires that provides everything for the organs)
What do the gastric glands do and where are they located?
located in the middle of the stomach and produce gastric juice, mucus, enzymes, and hormones
What do parietal cells do and where do they located?
on the walls of the gastric glands and secrete HCl
What do the chief cells do and where are they located?
on the bottom of the gastric glands and secrete pepsinogen, which is converted to pepsin by HCl.
What do enteroendocrine cells do?
releases histamine, serotonin, gastrin, secretin, and cholecystokinin (CCK)
What does CCK do?
inhibits the sensory activity, stimulates contraction of the gallbladder, stimulates release of pancreatic juice
What do the duodenal glands do?
releases bicarb and neutralizes stomach acid
What do intestinal glands do?
secretes intestinal juice and are located between the bases of the villi
What is the ileocecal valve?
where the ileum and cecum come together
Where are the parotid glands and what do they do?
located just in front of the ear and extend down and secrete saliva
What do hepatocytes do?
secrete bile, process nutrients, clear toxins
What are hepatic sinusoids and what do they do?
the pockets that things move through between hepatocytes and they moves everything nutrient rich before getting it to the central vein
What is the hepatic portal triad?
3 structures that are at each of the 6 corners of the liver lobule that includes the hepatic portal arteriole, the hepatic portal vein, and the bile duct
What does the hepatic portal arteriole do?
supplies O2 rich blood to the liver
What does the hepatic portal vein do?
supplies nutrient rich blood from GI to the liver
What does the bile duct do?
transports bile from liver to the duodenum
What are bile canaliculi and what do they do?
canals that secrete bile and sends it from the center to the corners of they do?
What do pancreatic acini do?
secrete enzyme-rich component of pancreatic juice
What does the visceral peritoneum do?
covers the external surfaces of most digestive organs
What does the parietal peritoneum do?
lines the body wall
What are haustral contractions?
slow segmenting movements
What are mass movements?
long, slow-moving, powerful contractile waves over large areas of colon that happen 3-4 times during or after digestion
What is elmulsification?
The process of breaking down fats in the liver
Where are vitamins absorbed?
in the SI
Where are minerals absorbed?
along the entire length of the SI
What are bile salts?
steroids made of cholesterol that help with fat digestion and
What is enterohepatic circulation?
process of conserving bile salts by having them reabsorbed in the ilium, returned to the liver through the hepatic portal vein, and put back into bile
What does the cephalic phase do?
anticipates food and is controlled by vagus nerve excitation
What does the gastric phase do?
activates stretch receptors and chemoreceptors after food has entered the stomach
What does the intestinal phase do?
inhibits gastric activity to make sure food doesn’t get into the duodenum too fast
What are the villus?
contains columnar (absorptive) & mucus-secreting goblet epithelial cels
What is the villus core?
contains an arteriole, a capillary network, a venule, a lymphatic capillary (called a lacteal)
What are the six main classes of nutrients?
carbs, proteins, lipids, minerals, water soluble vitamins, fat soluble vitamins,
Which vitamins are water soluble?
B-complez and C
What do vitamins do?
they act as coenzymes, which enable us to utilize macronutrients for fuel
What do minerals do?
help us regulate numerous body functions
What is nitrogen balance?
Protein intake = protein breakdown (nitrogen is a component of protein)
What is catabolism?
Breakdown of molecules
What is anabolism?
The synthesis of molecules
What is oxidation?
The loss of electrons
What is reduction?
The gain of electrons
What do the coenzymes NAD+ and FAD do?
They collect H+ ions during respiration so that the process can continue without the products becoming acidic
What does coenzyme A do?
helps create acetyl CoA, which is needed for the Kreb’s cycle
What are the products of the Krebs cycle going once (if it goes with both acetyl CoA molecules, double these values)?
3 NADH, 1 FADH2, 1 ATP, CO2
What are cytochromes?
the things in the ETC that pass the electrons down, releasing energy at specific locations
What is glycogenesis and what enzyme does it use?
synthesis of glycogen when ATP is not needed - glycogen synthase
What is glycogenolysis and what enzyme does it use?
the breakdown of glycogen releasing glucose when ATP is needed - glycogen phosphorylase
What is gluconeogenesis and why can it occur?
synthesis of glucose from non-carbohydrates during prolonged fasting - it can occur because all macronutrients are made with the same elements
What is the process of protein metabolism?
Deamination, which removes NH2 to make the AA a keto acid, the keto acid is converted to pyruvic acid and the rest of the cycle can occur
What happens to the NH2?
It becomes ammonia, which is very toxic, so the liver adds CO2 to make urea and excrete it through urine
How are lipids transported?
in the blood as lipoproteins (cholesterol, triglyceride core with a protein and a phospholipid coating)
What are chylomicrons (dietary lipids)?
a type of lipid that is formed in the cells of the SI, enters the lymphatic system then the blood and drops of FA and TG cells and skeletal muscle for storage
What is bad cholesterol?
Low density or LDL
What is good cholesterol?
HDL or high density and it helps eliminate fat molecules
What are the total plasma cholesterol recommendations?
<200 = desirable
200-239 = borderline high
>239 = considerably high
What is lipogenesis?
Triglyceride synthesis and sugar which happens when ATP and glucose levels are high
What is lipolysis?
the breaking down of fat for fuel
What stimulates lipolysis?
Epi, Noreip, thyroid, growth hormone
What is betaoxidation?
The breaking down of fatty acids by removing to C atoms to create acetyl CoA
What regulates the postabsorptive state?
the sympathetic nervous system and glucagon
What do hepatocytes do when blood sugar needs to be raised?
increase glycogenolysis and glucagongenesis
What does adipose tissue do in metabolism?
activates lipolysis
What part of the brain controls appetite?
the hypothalamus
What affects BMR?
age, gender, body temperature, stress, thyroxine (chemical from thyroid gland)
What are the functions of the kidneys?
filter blood plasma, eliminate waste, and regulate volume and composition of body fluids
What does the renal fascia do for the kidney and what is it made of?
binds the kidney to the abdominal wall - dense fibrous connective tissue
What does the fat capsule in the kidney do?
protects the kidney and holds it in place
What does the fibrous capsule do?
encloses the kidney and protects it from infection and trauma
What are the renal columns that are in the renal cortex?
extensions of cortex that divide the medulla into 6-10 renal pyramids
What part of the renal pyramids point internally?
the apex or the papilla
What is the hilum of the kidney?
The slit on the inside of the kidney where nerves, blood vessels, lymphatic vessels, and ureter enter
Where does filtration happen?
In the cortex
What is the flow of blood in the kidney, starting with the renal artery?
renal artery, segmental arteries, interlobar arteries, arcuate arteries, cortical radiate arteries, afferent arteries
What is the flow of blood from the efferent arteriole (out of the kidney)?
drains the glomerulus, peritubular capillaries, cortical radiate veins, arcuate veins, interlobar veins, renal veins, inferior vena cava
What is the renal corpuscle?
has a glomerulus and is where blood plasma is filtered
What is the glomerulus?
a group of blood capillaries
What does the glomerular capsule do?
collect fluid and bring it to the nephron
What is the renal tubule and what does it contain?
duct leading away from glomerular capsule that processes the filtrate into urine - contains proximal convoluted tubule, nephron loop, and distal convoluted tubule
What is the PCT?
high coiled region of the renal cortex that has a dense microvilli brush border which allows for high absorption and secretion
What is the nephron loop?
long U-shaped loop that passes from the cortex into the medulla and back again
What is the DCT?
coiled end of the nephron that lacks microvilli
Does the nephron include the collecting duct?
no, but the DCTs flow into it
What is the difference between cortical nephrons and juxtamedullary nephrons?
85% are cortical which means the entire nephron is in the cortex except for a small part of the NL, while juxtamedullary is closer to the cortex-medulla junction and has a long NL that dips into the medulla
What are peritubular capillaries?
they arise from efferent arterioles supplying a cortical nephron, cling to the renal tubules and empty into nearby vessels
What are the vasa recta?
they arise from the efferent arteriole and supply the juxtamedullary nephrons
What are the three types of cells in the JGC?
macula densa, granular, and extraglomerular mesangial
What do macula densa cells do?
monitor NaCl content of filtrate with chemoreceptors
What do the granular cells do?
monitor blood pressure and release the enzyme renin
What does the extraglomerular mesangial do?
pass signals between the macula densa and the granular
What are the three layers of the filtration membrane?
fenestrated wall of capillary, basement membrane, foot processes of podocytes of glomerular capsule
What is the net filtration pressure?
10 mmHg
What causes filtration pressure?
the blood hydrostatic pressure in the capillaries is greater than the pressure in the capsule
What is the glomerular filtration rate (value and definition)?
amount of filtrate formed per minute by the 2 kidneys combined (180 L/day or 120-125 mL/min)
What is renal autoregulation?
part of intrinsic control and is the ability of the nephrons to control their own blood flow without external control
What are the extrinsic controls of filtration?
Sympathetic control (when sympathetic nerve fibers constrict afferent arterioles when ECF is low)
Renin-Angiotensin-Aldosterone Mechanism (when BP drops, renin is released, which removes angiotensin from angiotensinogen, then gets converted to angiotensin II, which releases aldosterone, therefore increasing Na+ and H2O absorption and increase in BP)
Which part of the NL absorbs ions and lacks aquaporins?
ascending limb
What solutes are supposed to be present in urine?
urea, uric acid, creatinine, Na+, Cl-, K+)
Where is the majority of the water in the body?
Intracellular fluid (35 L or 40% body weight)
What is the normal pH range of blood?
7.35-7.45
