Organs pt. 2: Digestive, urine

Question 1

Mechanical Digestion

Answer 1

Process of breaking large pieces of food into smaller ones. Increase surface area, for enzymes. Ex. Teeth/stomach muscles

Question 2

Chemical digestion

Answer 2

Process of breaking down food by cleaving bonds using specialized enzymes. Ex. stomach/small intestine

Question 3

Digestion

Answer 3

1. Oral cavity (carbs - Amylase) (tongue - bolus)
2. Pharynx (epiglottis)
3. Esophagus (peristalsis)
4. Stomach (proteins - Pepsin)
5. Small intestine (lipids - Bile salts, lipase) (proteins - chymotrypsin/trypsin) (nucleic acid - nuclease) (enterocytes)
6. Large intestine (water/mineral absorption) (bacteria - vitamins) (enterocytes)
7. Rectum/anus
8. Appendix (holds bacteria) (vestigial)

Question 4

Small Intestine

Answer 4

Breaks down and absorbs. Duodenum (first part), jejunum (middle part), ileum (last part). Villi and microvilli

Question 5

Large intestine

Answer 5

Colon: Ascending, transverse descending

Question 6

Stomach

Answer 6

Stores 2L, Parietal cells secrete gastric acid (hydrochloric acid) (pH 2) to activate pepsin, denature proteins, No absorption (except alcohol and aspirin), mucus

Question 7

Accessory organs

Answer 7

Liver, gall bladder, pancreas

Question 8

Liver/gall bladder

Answer 8

Liver creates bile salts, gall bladder stores until needed. Liver stores glucose and detoxifies (ammonia to urea)

Question 9

Pancreas

Answer 9

Creates enzymes: Amylase, lipase, nuclease, pepsin, trypsin, chymotrypsin (proteolytic enzymes)

Question 10

Macromolecules

Answer 10

Carbs (sugars: glucose, fructose, galactose), Proteins (amino acids), Lipids (hydrocarbon chains, non-polar, monomer), Nucleic acid (nucleotides)

Question 11

Glycogen

Answer 11

Way glucose is stored, has deviations. Body can break alpha-glyosidic linkages (but not beta, cellulose).

Question 12

Protein

Answer 12

Quaternary: polypeptides bonded through covalent/disulfide bridges. Body can create 11 types of amino acids but all 20 are needed. 9 must be through food (essential amino acids).

Question 13

Lipids

Answer 13

Store as fatty acid/triglyceride in Adipocyte cells. Absorb as triglyceride, 3 types of fatty acid and glycerol. Albumin (protein) carries

Question 14

Types of feeder

Answer 14

Fluid: flesh fly, Suspension: blue whale, Substrate: Caterpillar, Bulk: humans

Question 15

Kidneys

Answer 15

Filter blood, remove waste, regulate water concentration/pH, influence rbc creation and blood pressure. Weigh about 150g, retroperitoneal (between dorsal wall and peritoneum).
3 layers: Renal Cortex, Renal medulla (cone shaped tissue that secrete urine into sac-like tubules), Renal Pelvis (collects the urine, peristalsis).
Can hold over 20% of blood volume. Gets oxygenated blood through renal artery
Filter 120-140L

Question 16

Nephron stages

Answer 16

Glomerular filtration: Squirts out anything small enough to fit through (not rbc/proteins, stay in peritubular capillaries/vasa recta), Glomerular Capsule
Tubular reabsorption: Water and other molecules are moved back into the capillaries, Proximal Convoluted Tubule, Loop of Henle
Tubular secretion: Molecules are moved into the filtrate such as hydrogen and potassium ions, Collecting Tubule

Question 17

Parts of the nephron

Answer 17

1. Glomerulus/Glomerular Capsule (most things moved to filtrate) (high blood pressure, self regulation)
2. Proximal Convoluted Tubule (useful molecules reabsorbed through active transport, microvilli)
3. Loop of Henle (reabsorb water using sodium concentration) (cortex, medulla, cortex) (ascending=sodium/descending=water) (interstitial space, water absorbed through aquaporin (apical - filtrate, basal - capillary)
4. Distal Convoluted Tubule (reabsorb more molecules
5. Collecting Tubule (H/K ions moved into filtrate) (more water, some urea move out) (aquaporin on basal, ADH triggers more on apical side)

Question 18

Path of urine

Answer 18

1. Nephrons
2. Ureters
3. Bladder
4. Urethra
5. Internal urethral sphincter (involuntary)
6. Urogenital diaphragm
7. External urethral sphincter (voluntary)
8. Out of the body

Question 19

Bladder

Answer 19

Retroperitoneal
500mL, 1L maz
Inner Mucosa, detrusor (muscle), outer membrane (fibrous, protective)
Transitional epithelium to stretch
Collapses when empty to triangle shape (rugae = folds)
When full, stretch receptors send signal to sacral region of spine, to Pons (pontine storage centre, stop) (pontine micturition center, allow, override), excite parasympathetic (inhibit sympathetic), detrusor muscle, sphincter opens
As baby, have to reroute neural pathway

Question 20

Glycolosis

Answer 20

Using glucose to make ATP and pyruvate to make more ATP in kreb cycle

Question 21

Alpha amino acid

Answer 21

An amino acid in which the R group is located on the carbon atom at the position α to the carboxy group

Question 22

Urine composition

Answer 22

95% water, slightly acidic (pH 6), 3000 chemicals (urea, potassium ions, hydrogen ions, sodium ions, calcium)

Question 23

Urine composition abnormalities

Answer 23

Leukocytes/pyuria: UTI
Glucose: glycosuria, diabetes
Erythrocytes: hematuria, bleeding in urinary tract
Proteins: proteinuria, albuminuria, working out too much, pregnancy, high BP, severe hypertension, heart failure