Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biol 233 > Exam 3: Urinary & Digestive > Flashcards

Exam 3: Urinary & Digestive Flashcards

1
Q

Functions of the Kidneys

A

Filters blood, excreting toxic metabolic wastes
Regulates blood volume, pressure, and osmolarity
Regulates electrolytes
Regulates pH balance
Secretes erythropoietin
Regulates Ca2+ levels
Clears hormones from the blood via urination
Detoxifies free radicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Peristaltic Contraction

A

A wave contraction from one end of the ureter to the other, ensuring constant outflow. This same contraction occurs in the intestines.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What Nitrogenous Wastes are removed through urination?

A

Urea, Uric Acid, & Ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Urea Formation Steps

A

Proteins -> Amino Acids -> NH2 removed -> Ammonia

Ammonia is converted to Urea by the liver

Urea can be converted to Uric Acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Major Nitrogenous Wastes

A

Ammonia - Most toxic when abundant in the body

Urea - Formed from converted Ammonia, less toxic

Uric Acid - Product of Nucleic Acid Catabolism

Creatinine - Product of creatine phosphate catabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does filtration occur in the kidneys?

A

Filtration starts in the cortex and then moves into the medulla via nephrons. Most of the work occurs in the medulla.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are calyxes

A

Dumping stations where anything that enters becomes urine. There is no more filtration, secretion, or absorption from the calyx to the urethra.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why is the kidney highly vascularized?

A

There is constant filtration occurring, which is highly metabolic and requires more blood flow. They receive about 21% of all cardiac output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the route of Renal Circulation?

A

Renal Artery, Segmental Artery, Interlobar Artery, Arcuate Artery, Cortical Radiate Artery, Afferent Artery, Glomerulus, Efferent Arteriole, Peritubular Capillaries or Vasa Recta, Cortical Radiate Vein, Arcuate Vein, Interlobar Vein, Renal Vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does O2 transport occur in the Kidneys?

A

Peritubular Capillaries, after blood passes through them it is deoxygenated and begins venous return

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is the Glomerulus Capillary Bed different from others?

A

The Glomerulus is for filtration, only moving sugars and not O2/CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two principal parts of a nephron and what are their functions?

A

Renal Corpuscle (Glomerulus) - Filters the blood plasma

Renal Tubule (PCT, Loop, DCT) - A long, coiled tube that converts the filtrate into urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Glomerular Capsule Layers and Tissue Types?

A

Parietal Layer - Simple Squamous Epithelium

Visceral Layer - Podocyte cells provide structure and support to keep the capillaries from tearing under high-pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Types of Nephrons and their Abundance

A

Juxtamedullary Nephrons - 15% of all nephrons

Cortical Nephrons - 85% of all nephrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Juxtamedullary Nephrons

A

Better at conserving water

Efferent Arterioles branch into the vasa recta

The loop branches down farther into the medulla

Longer of the two types

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cortical Nephrons

A

Shorter of the two types

Efferent arterioles branch into peritubular capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Stages of Urine Formation

A

1) Glomerular Filtration: Ultra-filtration Filtration is driven by BP where small molecules (Ca2+, Na+, K+, glucose, Mg+, H2O) are pushed out to the proximal tubule and large proteins and cells remain in the blood.

2) Tubular Reabsorption: Useful molecules are transported from the tubule to the blood

3) Tubular Secretion: Waste from the blood is moved to the tubule

4) Water Conservation: Water is removed from the urine and returned to the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Hydration and Water Conservation

A

Dehydration causes an increase in water conservation

Overhydration causes a decrease in water conservation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Glomerular Filtration Membranes

A

Fenestrated Endothelium: Highly permeable with large filtration pores, doesn’t let blood cells through

Basement Membrane: Proteoglycan gel with a negative charge that repels albumin and has very small filtration pores

Filtration slits: Openings through podocytes that are medium in size and negatively charged. Increases the rate of flow out of the capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Molecule Size and Glomerular Filtration

A

Any molecule smaller than 3 nm can pass freely through the membrane. This includes water, electrolytes, glucose, fatty acids, amino acids, nitrogenous wastes, and vitamins

Some substances of low molecular weight are bound to the plasma proteins and cannot get through the membrane. This includes calcium, iron, and thyroid hormone. If these molecules are unbound, they pass through.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Forces involved in Glomerular Filtration

A

Blood Hydrostatic Pressure (BP) is the only force driving substances out of the capillary

Colloid Osmotic Pressure is a concentration pressure from the surrounding fluids (H2O) pushing back into the capillary

Capsular Pressure is the hydrostatic pressure that pushes back into the capillary.

If BP falls too low, the kidneys will not work due to the lack of pressure driving fluid through the glomerulus.

Adding all three forces gives us Net Filtration Pressure, which must be positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Glomerular Filtration Rate

A

The amount of filtrate formed per minute by both kidneys. The total amount of filtrate produced per day is about 50-60 times the amount of blood in the body, though nearly all of it is reabsorbed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why is it important to regulate the Glomerular Filtration Rate?

A

If GFR is too high, fluid cannot reabsorb. Urine output will also rise, potentially leading to dehydration and electrolyte depletion.

If GFR is too low, wastes are reabsorbed rather than expelled to the bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Methods of GFR Control

A

Renal Autoregulation

Sympathetic Control

Hormonal Control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Renal Autoregulation

A

The ability of the nephrons to adjust their blood flow and GFR through the myogenic mechanism and tubuloglomerular feedback

The myogenic mechanism is the ability of the smooth muscle to contract when stretched. When BP rises, arterioles stretch and then constrict. When BP falls, arterioles relax and dilate.

Tubuloglomerular feedback is received based on the concentration of molecules in the tubular fluid. It is the communication between macula densa cells and granular cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Tubuloglomerular Feedback

A

Macula Densa cells detect NaCl concentrations in the filtrate. When GFR is high, NaCl cannot be reabsorbed, thus concentration is high. This leads to macula densa cells absorbing the NaCl and in turn, they secrete ATP.

This ATP is metabolized and turned into Adenosine which stimulates granular cells.

Granular (Juxtaglomerular) cells wrap around the afferent arteriole and respond to Adenosine. When Adenosine is detected, the cells constrict the afferent arteriole, reducing blood flow and correcting GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Sympathetic Controlof GFR

A

Sympathetic Nerve Fibers innervate the renal blood vessels and constrict the afferent arterioles during strenuous exercise or in conditions like circulatory shock. This constriction reduces GFR and urine output and redirects blood to the heart, brain, and skeletal muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Renin-Angiotensin-Aldosterone Mechanism

A

The Kidneys release renin from granular cells when pressure or GFR drop

Angiotensin from the liver interacts with the Renin to produce Angiotensin I, which is then converted to Angiotensin II via Angiotensin-Converting Enzyme (ACE) found in the lungs and kidneys

Angiotensin II acts on the body to raise BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Angiotensin II Effects on BP

A

Acts on the hypothalamus to induce thirst. Higher H2O intake will raise BP

Acts on the cardiovascular system, causing vasoconstriction and raising BP

Acts on the Adrenal Cortex of the Kidneys, stimulating the release of Aldosterone, promoting Na+ and H2O retention, and increasing BP

Acts on the posterior pituitary to secrete ADH, which promotes water reabsorption by the collecting duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Proximal Convoluted Tubule

A

The PCT reabsorbs (sends out of the tubule) roughly 65% of the glomerular filtrate, removes substances from the blood, and secretes them into the tubular fluid.

The PCT saves glucose, H2O, and sugar

Sodium is reabsorbed into the bloodstream, meaning H2O is as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Peritubular Capillaries

A

Solutes and water that leave the basal surface of the tubular epithelium are reabsorbed by these capillaries via osmosis and solvent drag

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Angiotensin II Effects on Tubular Reabsorption

A

Efferent arterioles are constricted, maintaining or increasing GFR and Glomerular BP

This constriction reduces BP in the peritubular capillary and reduces resistance to tubular reabsorption

Increased tubular reabsorption removes H2O from the tubules, decreasing urine volume but increasing concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Transport Maximum

A

When all of the transport proteins in the tubule cells are occupied, any remaining solutes will pass by and appear in the urine

In cases of hyperglycemia, all sugar transporters are saturated, resulting in a high sugar concentration in the urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Tubular Secretion

A

The renal tubule extracts chemicals from peritubular capillary blood and secretes them into the tubular fluid

The purposes of secretion are acid-base balance, waste removal, and the clearance of drugs and contaminants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

The Nephron Loop Functions

A

The primary function of the loop is to generate a salinity gradient that enables the collecting duct to concentrate the urine and conserve water. Water is saved by manipulating Na+.

The loop also plays a role in electrolyte reabsorption. The thick segment reabsorbs 25% of Na+, K+, and Cl- from the filtrate via active transport.

At the end of the loop, tubular fluid is very dilute because solutes were reabsorbed without water due to the impermeability of the thick segment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Distal Convoluted Tubule & Collecting Duct functions

A

The DCT and Collecting Duct reabsorb water and salt through hormonal pathways.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Aldosterone in the DCT

A

Aldosterone is secreted by the Adrenal Cortex when Na+ concentration falls or K+ concentration rises.

When released, it acts on the thick segment of the nephron loop, the DCT, and the cortical portion of the collecting duct, stimulating reabsorption of Na+ and secretion of K+.

Water follows the Na+, reducing urine volume and increasing K+ concentration in the urine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Atrial Natriuretic Peptides in the DCT

A

Made by the atrial myocardium in response to high blood pressure, Natriuretic Peptides help to dilate the afferent arteriole and constrict the efferent arteriole, increasing GFR.

It also inhibits the secretion of renin, aldosterone, and ADH along with inhibiting NaCl reabsorption by the collecting duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

ADH in the DCT

A

ADH is secreted by the posterior pituitary in response to dehydration, loss of blood volume, and increased blood osmolarity.

ADH makes the collecting duct more permeable to H2O, leading to increased water reabsorption, and decreasing urine output.

40
Q

Alcohol’s effects on ADH

A

Alcohol inhibits ADH, resulting in an increase in urine output and leading to dehydration.

41
Q

Parathyroid Hormone in the DCT

A

PTH is secreted from the parathyroid gland in response to Ca2+ deficiency in the blood.

PTH acts on the thick segment of the loop and the DCT to increase Ca2+ reabsorption.

PTH also acts on the PCT to increase phosphate secretion, resulting in more phosphate content in the urine.

42
Q

H2O Reabsorption by the Collecting Duct

A

As tubular fluid flows through the collecting duct, it passes through increasingly concentrated medullary tissue fluid. This increasing osmolarity causes more H2O to flow out the farther down the fluid flows.

The CD is ALWAYS impermeable to H2O unless Aquaporins are opened by ADH

43
Q

Water Diuresis effects on Urine

A

Drinking large volumes of water will produce a lot of hypotonic urine (high H2O, less Na+)

The Cortical portion of the CD reabsorbs NaCl, but it is impermeable to water, thus the H2O stays in the CD

44
Q

Dehydration effects on Urine

A

Dehydration leads to hypertonic urine that is dark in color due to its high concentration.

High blood osmolarity from dehydration also stimulates the posterior pituitary to release ADH, which opens Aquaporins on the CD, resulting in more H2O reabsorption and a higher concentration of Na+ in the urine

45
Q

Countercurrent Multiplier of the Nephron Loop

A

H2O flows out of the descending limb through passive diffusion (osmosis)

Na+ is removed from the ascending limb through active transport (NEEDS ATP)

The Na+ that is removed from the ascending limb increases the concentration of the surrounding tissues/fluids, resulting in more H2O flowing out of the descending limb.

Removed H2O and Na+ are reclaimed by the body

46
Q

Muscles of the Urinary Bladder

A

Internal Sphincter: Smooth Muscle that is autonomously controlled by the brain

External Sphincter: Skeletal Muscle that can be controlled manually

47
Q

The Process of Voiding Urine (Micturition)

A

As the bladder fills, the detrusor muscle in the bladder wall relaxes while the internal sphincter contracts. Both are caused by sympathetic activity in the lumbar spinal cord.

Somatic nerve fibers give the external sphincter voluntary control

The Micturition reflex is an involuntary spinal reflex that partly controls urination

48
Q

Renal Insufficiency

A

A state in which the kidneys cannot maintain homeostasis due to the destruction of their nephrons.

Nephron destruction occurs due to hypertension, chronic kidney infections, trauma, prolonged ischemia and hypoxia, poisoning, blockage of renal tubules, atherosclerosis, or glomerulonephritis

49
Q

Hemodialysis

A

The process of artificially clearing wastes from the blood through transplantation, though the risk of rejection is high.

50
Q

Types of Homeostatic Balance (3)

A

Fluid Balance: Urination & Defecation results in H2O loss

Electrolyte Balance: Sweating causes loss of electrolytes

Acid-Base Balance: Respiration causes changes in blood pH

51
Q

Fluid Compartments

A

65% of body fluid is in the intracellular fluid (inside cells)

35% of body fluid is in the extracellular fluid
- 25% in the interstitial fluid (between the outside of cells)
- 8% in the blood plasma and lymphatic fluid
- 2% in the transcellular fluid (CSF, synovial, pleural, pericardial, humors of the eye, etc.)

52
Q

Osmotic Fluid Balance in the Body

A

Osmotic Balance is present between the intercellular and extracellular areas of the body. There is, however, ionic imbalance which is the driving force behind ion transport in the body.

53
Q

Water Intake and Output

A

H2O intake is typically the same as water loss each day.

54
Q

Effects of Dehydration

A

Dehydration increases blood concentration while reducing blood pressure

Highly concentrated blood stimulates hypothalamic osmoreceptors, reducing salivation and causing a sense of thirst.

Reduced BP stimulates Renin production, which leads to Angiotensin II formation, which stimulates the hypothalamic osmoreceptors, reducing salivation and causing thirst.

55
Q

Effects of ADH on the blood

A

When blood osmolarity (Na+ concentration) increases, osmoreceptors in the hypothalamus stimulate the posterior pituitary to release ADH

Similarly, a decrease in plasma volume inhibits baroreceptors in the atrium and blood vessels which also stimulates the post. pituitary to release ADH

ADH targets the collecting ducts of the kidneys, increasing H2O absorption and resulting in an increase in osmolarity and plasma volume as well as scant urine

56
Q

Effects of Aldosterone on the blood

A

When K+ concentration rises or Na+ concentration decreases, the Adrenal cortex is stimulated, releasing Aldosterone which targets the distal tubules of the kidneys

The distal convoluted tubules are affected, increasing Na+ reabsorption and K+ secretion

These effects restore homeostatic plasma levels of Na+ and K+

57
Q

Effects of Atrial Natriuretic Peptide (ANP) on the blood

A

ANP is an “OPPOSITE MOLECULE” because it gets rid of H2O rather than reabsorbing it

High BP causes a stretch in the atria, which stimulates ANP release

ANP targets the JG Apparatus of the Kidney, reducing Renin release and resulting in less Angiotensin II, causing vasodilation and lowering BP

ANP targets the hypothalamus and posterior pituitary, decreasing ADH release, inhibiting the collecting duct, and decreasing Na+ and H2O reabsorption. This decrease in reabsorption also reduces blood volume, which lowers BP

ANP targets the Adrenal Cortex, which causes a decrease in the release of Aldosterone, inhibiting the collecting ducts and decreasing Na+ and H2O reabsorption which also reduces blood volume and BP

58
Q

Renin-Angiotensin System and BP

A

Decreased stretch in the afferent arterioles and decreased NaCl concentration cause the granular cells of the kidney to release Renin.

Renin and Angiotensinogen (from the liver) interact to form Angiotensin II

Angiotensin II causes vasoconstriction in the systemic arterioles, increasing peripheral resistance

Angiotensin II also stimulates the Adrenal Cortex to secrete Aldosterone. This Aldosterone targets the DCT, causing increased Na+ & H2O reabsorption

Increased peripheral resistance raises BP. Increased Na+ and H2O reabsorption increases blood volume, which in turn raises BP

59
Q

Neural Regulation (SNS) of BP

A

Decreased systemic BP inhibits the baroreceptors in blood vessels

This causes the sympathetic nervous system to stimulate the granular cells, starting the Renin-Angiotensin System

The SNS also stimulates the systemic arterioles, causing vasoconstriction and increasing peripheral resistance, raising BP

60
Q

ADH release and its effects on BP

A

Systemic BP along with Angiotensin II stimulates the posterior pituitary to release ADH

ADH stimulates the collecting ducts of the kidneys, opening Aquaporins and increasing H2O reabsorption

More H2O reabsorption increases blood volume which increases BP

61
Q

PTH effects on blood Ca2+ levels

A

The parathyroid gland produces PTH, which goes from the blood to the bones, causing Ca2+ release into the blood

PTH causes the kidneys to reabsorb Ca2+

PTH promotes the activation of Vitamin D in the kidneys, increasing Ca2+ absorption from food

62
Q

Sweating and H2O Volume

A

Water loss occurs through sweating

Sweat glands obtain water from capillary filtration

As filtration occurs, blood volume and pressure drop, and concentration rises

Tissue fluids are reabsorbed into the blood to replace the lost sweat

Intracellular fluid diffuses out of the cells to replace the lost tissue fluid

63
Q

Fluid Intake & Kidney Function

A

1-3L of H2O are needed for kidneys to properly function

Drinking less than 1L/day will lower blood volume

Drinking more than 3L/day will cause frequent urination and larger amounts of Na+ to be lost, leading to osmotic shock

64
Q

What is the normal pH range of blood and tissue fluid?

A

7.35-7.45

Metabolism constantly produces acid (Lactic acid, Phosphoric acid, Nucleic acid, Fatty acid, and Carbonic acid)

65
Q

Physiological Buffer

A

A body system that controls the output of acids, bases, or CO2

The Urinary System buffers the greatest quantity of acid or base

The Respiratory System buffers quicker than the urinary system but has less of an effect

66
Q

Chemical Buffer

A

A substance that binds to H+ and removes it from a solution as its concentration begins to rise or that releases H+ into a solution as its concentration falls

Bicarbonate Buffer System

Phosphate Buffer System

Protein Buffer System

67
Q

Bicarbonate Buffer System

A

A solution of Carbonic Acid and Bicarbonate ions

The ions in this solution participate in a reversible reaction where HCO3- binds to H+ to raise pH or it releases H+ to lower pH

68
Q

Phosphate Buffer System

A

A solution of Hydrogen Phosphate and Dihydrogen Phosphate

This solution plays an important role in buffering the ICF and Renal Tubules

69
Q

Protein Buffer System

A

The protein buffer system accounts for 75% of all chemical buffering in the body fluids

The side groups of proteins allow them to effectively pick up and release H+

70
Q

Respiratory Control of pH

A

The Bicarbonate Buffer system is the basis for respiratory control over pH

Respiratory Control can neutralize 2-3x as much acid as the chemical buffers can

71
Q

What happens if pH changes too drastically?

A

Altering pH too far one way or the other will drastically alter the shape and function of proteins

Damaged proteins cannot regrow or recover

72
Q

Stages of Digestion (5)

A

Ingestion: Selective intake of food
Digestion: Mechanical & Chemical breakdown of food into usable form
Absorption: Uptake of nutrient molecules into the epithelial cells of the digestive tract and then into the blood and lymph
Compaction: Absorbing H2O and consolidating the ingestible residues into feces
Defecation: Elimination of feces

73
Q

Mechanical vs. Chemical Digestion

A

Mechanical Digestion: The physical breakdown of food via mastication and the churning action of the stomach and intestines. This churning exposes more surface area of the food to digestive enzymes

Chemical Digestion: Hydrolysis reactions that break dietary macromolecules into monomers.

74
Q

Parts of the Digestive Tract in order

A

Mouth

Pharynx

Esophagus

Stomach

Small Intestine: Duodenum, Jejunum, Ileum

Large Intestine: Cecum, Ascending, Transverse, Descending Colon, Sigmoid Colon, Rectum, Anal Canal, Anus

75
Q

Accessory Organs of the Digestive Tract

A

Teeth, tongue, salivary glands, liver, gallbladder, and pancreas

76
Q

Types of Tongue Muscles

A

Intrinsic: Help with subtle tongue movements for speech

Extrinsic: Produce stronger movements for food manipulation

77
Q

Types of Teeth

A

Incisors: Used for chopping/clipping foods like carrots

Canines: Used for tearing tougher foods like meat

Molars: Used for crushing and grinding foods

78
Q

Enamel

A

The hardest substance in the human body coats the crown portion of each tooth. It cannot regrow

79
Q

Dentin

A

The yellowish living tissue underneath the enamel. It can restore itself

80
Q

Gingival Sulcus

A

The groove between gums and teeth where they connect

81
Q

Cementum

A

“Glue” that holds the tooth roots in place

82
Q

Root Canal

A

Houses nerves and blood vessels in the roots

83
Q

Pulp Cavity

A

Houses nerves and pulp. Tooth pain comes from this region

84
Q

Periodontal Ligament

A

Connects the mandible to the bones of the teeth

85
Q

Plaque

A

Sticky residue on the teeth that is made of bacteria and sugars

Once calcified, it becomes calculus

The bacteria metabolizes the sugars and produces acid, which causes cavities

86
Q

Solutes found in Saliva

A

Amylase: digests starch and begins working in the mouth
Lingual Lipase: digests fat and begins working in the stomach
Mucus: binds and lubricates food, aids in swallowing
Lysozyme: an enzyme that kills bacteria
Immunoglobulin A: an antibody that slows bacterial growth
Electrolytes: Na+, K+, Cl-, phosphate, and bicarbonate

The pH of saliva is between 6.8-7.0

87
Q

Intrinsic Salivary Glands

A

Small glands that secrete saliva at all times

88
Q

Extrinsic Salivary Glands

A

Large glands that produce saliva in response to food

Parotid, Submandibular, and Sublingual glands

89
Q

Swallowing (Deglutition) Phases

A

Oral Phase: Under voluntary control, the tongue presses against the palate, forming a bolus and pushing it back to the pharynx. The epiglottis tips posteriorly and the bolus slides around it into the laryngopharynx

Pharyngeal Phase: Under involuntary control, the palate, tongue, vocal cords, and epiglottis block the oral and nasal cavities while the bolus passes into the esophagus

Esophageal Phase: Peristalsis contractions occur, pushing the bolus through the esophagus into the stomach where the bolus becomes chyme

90
Q

Digestion in the Stomach

A

The stomach churns to mechanically break up food. As the food liquefies, proteins and fats begin to be digested

91
Q

Pyloric Sphincter

A

A ring of smooth muscle around the bottom of the stomach that controls the release of contents into the small intestine

92
Q

Mucosa of the Stomach Wall

A

Mucous Cells: Secrete Mucus
Regenerative Cells: Sit at the base of each gastric pit and divide rapidly to replace dead cells
Parietal Cells: Secrete hydrochloric acid and intrinsic factor. Their shape allows for more secretion
Chief Cells: Secrete gastric lipase and pepsinogen for the breakdown of proteins and fats
Enteroendocrine Cells: Secrete hormones and paracrine messengers that regulate digestion

93
Q

Functions of Hydrochloric Acid and Pepsin in the stomach

A

HCl kills bacteria and helps to break down proteins

When mixed with pepsinogen, HCl cleaves a peptide from it, leaving Pepsin

Pepsin can digest proteins and aid in further peptide removal

94
Q

What Causes HCl Production

A

Stomach stretching can stimulate HCl production. The more full the stomach is, the more HCl is secreted

95
Q

Phases of Gastric Function Regulation (3)

A

Cephalic Phase: The brain is involved, causing the stomach to respond to sight, smell, taste, or the thought of food, leading to stomach secretions

Gastric Phase: Ingested food stretches the stomach and increases the pH of the stomach contents, causing secretion

Intestinal Phase: The duodenum responds to arriving chyme and moderates gastric activity via hormones and nervous reflexes

96
Q

Liver and Gallbladder (Bile) function

A

The Liver produces bile, which is then stored in the gallbladder where it becomes more concentrated

Bile is a salt that breaks down fats through emulsification

Biol 233 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions