- Can you explain how a piece of food gets digested from the point it enters the mouth to the point it reaches the stomach using terms like peristalsis, deglutition, absorption, mastication, buccal and pharyngeal phase. Which part is mechanical digestion occurring?
- Enters mouth → mastication (chewing) → buccal phase occurs where tongue pushes bolus into oropharynx(voluntary) → Deglutition (pharyngeal-esophageal phase prevents food from entering respiratory tract) → peristalsis moves food down pharynx and esophagus into stomach → segmentation mixes in enzymes to allow contact with food for absorption.
- Mechanical digestion = Chewing(mastication) of the food, and movement of bolus
- Chemical = enzymatic breakdown of food
2. What are the components of saliva?
- Electrolytes: Na+, K+, Cl-
- Digestive enzyme: salivary amylase – begins chemical breakdown of starch
- Proteins: mucin, lysozyme
- Metabolic wastes: urea, uric acid
- Saliva function: cleans mouth, moisten food, help form bolus.
3. What hormones/chemicals do the following cells of the stomach secrete/produce?
- Chief Cells: Pepsinogen → pepsin to break peptides into shorter peptides.
- Parietal Cells: secrete HCl and intrinsic factor (for vitamin B12 absorption)
- Activated by Histamine and gastrin
- Enteroendocrine cells: Gastrin, serotonin, Histamine, Somatostatin
4. Microvilli (increase/decrease) surface area to aid in absorption in small intestine.
5. How do the liver and gallbladder work together? Which makes bile, and which releases it?
- The liver makes bile and the gallbladder stores and releases it.
- Bile breaks up fats to increase surface area for fat and cholesterol digestion so they don’t clog openings.
6. What helps neutralize the acidic chyme entering the duodenum from the stomach?
- Pancreatic juice: CCK and secretin (bicarbonate rich - alkaline, helps neutralize acid)
7. What regulates secretion of enzymes from the pancreas?
- CCK induces secretion of enzyme-rich pancreatic juice (acinar cells)
- Secretin causes secretion of bicarbonate-rich pancreatic juice. (duct cells)
- Vagal (PNS) stimulation causes pancreas to release juice.
8. 3 phases of Gastric Regulation: The __cephalic____ phase occurs before food enters the stomach. Once food reaches the stomach, the ___gastric____ phase occurs. The __intestinal______phase occurs when the partially digested food enters the duodenum.
9.Nutrition is: Substance promoting normal growth, maintenance and repair
- What are the three major nutrients: Proteins, lipids, carbohydrates
- What are three other kinds of nutrients: Water, vitamins, minerals
10.What are some complex and simple carbohydrates? Provide some examples:
a.Starch: Found in pasta, cereal, bread, nuts, etc.
a.Sugars: Found in soft drinks, candy, fruit, ice cream
b. Glucose: Used in cellular respiration to make ATP
11. What happens to excess glucose?
Excess is converted into glycogen or fat and stored
12.What is the most abundant type of lipid? Triglycerides
13. What are the two types of essential fatty acids? What types of foods can be found with these fatty acids?List some of the functions of fats in your diet.
-Linoleic(omega-6) and linolenic(omega-3) fatty acids
- Vegetables and vegetable oil
- Helps body absorb fat-soluble vitamins, major source for energy for hepatocytes and skeletal muscle, component of myelin sheath and all cell membranes, protective cushion around organs, insulating layer under skin, energy store
14.List some of the functions of leukotrienes and prostaglandins.
a.Building blocks for long chain fatty acids
b.Smooth muscle contraction
c.Control blood pressure
15.Cholesterol is a precursor for which two molecules?List some of the functions of cholesterol in your diet.
-Bile salts and steroid hormones
- Used to synthesize bile salts, steroid hormones and Vitamin D and is a component of the plasma membrane, NOT used for energy
16.How are cholesterol and triglycerides transported? Lipoproteins
Match the correct lipoprotein with what it is composed of and fill in the blanks for their functions
- VLDL: Mostly composed of triglycerides
i. Main source is the liver
ii.Transports triglycerides to peripheral tissues
b. LDL: Mostly composed of cholesterol
i. Transports cholesterol to peripheral tissues
c. HDL: Mostly composed of protein
i. Made by liver and intestinal cells
ii. Transports excess cholesterol from peripheral tissues to liver and steroid-producing organs
17.What factors increase LDL levels? What factors increase HDL levels? LDL:Stress, coffee, smoking HDL:Aerobic exercise
18. How do complete proteins differ from incomplete proteins? Where can you find complete and incomplete proteins?
Complete proteins contain all essential amino acids, while incomplete do not contain all essential amino acids. Complete: meat, fish, eggs Incomplete: grains, beans, seeds
19. True or false: Only some amino acids need to be present for protein synthesis to occur-false all aa need to be present
20.Rate of protein synthesis = Rate of breakdown and loss, what happens when this equation is not equal?
Positive: Synthesis exceeds breakdown (normal in children and tissue repair)
Negative: Breakdown exceeds synthesis (stress, burns, injury)
21.What are the two main functions of enzymes? Where/how can you obtain enzymes?
Coenzymes, Vitamins A, C, E: Antioxidants
Diet, Vitamin D made in body, Vitamins B and K by normal flora
22.What are the two main types of vitamins?
a.Water-soluble vitamins: B and C
b.Fat-soluble vitamins: A, D, E, K
23. Define metabolism: All chemical reactions necessary for life
24. Anabolism is the synthesis of larger molecules from smaller ones, while catabolism is the breakdown or hydrolysis of complex molecules into simpler ones.
25. Describe the difference between the absorptive and the postabsorptive states.Which would be catabolic? Anabolic?
Absorptive is also known as the “Fed” state and is the time during and shortly after nutrient intake- is anabolic and builds molecules
Postabsorptive or “Fasting” is the time when the GI tract is mostly empty-catabolism occurs to break molecules down
26. Cellular respiration is the metabolic process where food is broken down to yield energy
27. What occurs in the absorptive state for each of these molecules
- Amino acids are converted into proteins
- Glycerol and fatty acids are converted into triglycerides
- Glucose is stored as glycogen
- Excess amino acids are deaminated and are either used for energy or stored in the liver
28. What hormone controls the absorptive state? What triggers this hormone to be secreted?
Insulin, triggered by Increased blood glucose, Elevated blood amino acid levels, Gastrin, CCK and secretin
29.What does this hormone enhance?
Active transport of amino acid into tissue cells, and facilitated diffusion of glucose into tissues
30.What is the disease where glucose becomes unavailable for most body cells? What are the two causes of this disease?
Diabetes mellitus Causes: Inadequate insulin production & Abnormal insulin receptors
31.What occurs in the postabsorptive state for each of these molecules
- Proteins are broken down into amino acids
- Triglycerides are converted into fatty acids and glycerol
- Glycogen is converted into glucose
- In the muscle, protein is broken down into amino acids, and glycogen is converted into ATP and pyruvic acid.
- In the liver, amino acids, pyruvic acid, glycogen and fat are all converted into glucose. Fat is also converted into keto acids to make ATP
32.What hormone controls the postabsorptive state? What does this hormone enhance? Glucagon by pancreatic alpha cells and it enhances Glycogenolysis and gluconeogenesis, Fat breakdown in adipose tissue and Glucose sparing
33. Identify the caloric yield for each of the macromolecules
a. Proteins: 4 kcal/g
b. Lipids: 9 kcal/g
c. Carbohydrates: 4 kcal/g
34. How does the basal metabolic rate differ from the total metabolic rate?
Basal Metabolic Rate (BMR) is the energy that the body needs to perform its functions at rest
Total Metabolic Rate (TMR) is the total rate of kilocalorie consumption fueling all ongoing activities
Male Accessory Glands
35.Which two organs contribute in the production of semen?
Prostrate gland (1/3) and seminal vesicles (2/3)
36.What glands produce mucus that neutralizes acidic urine in urethra? Bulbourethral glands
37. Fill in the table below:Components of Semen / Function
Fructose / Nutrients
Prostaglandins / a. Decrease viscosity of mucus in cervix
b. Suppress female’s immune response to semen
c. Facilitate sperm movement through female tract
d. stimulate reverse peristalsis in uterus
Relaxin / Hormone that enhances sperm motility
Alkalinity / Neutralizes acidic environment found in male urethra and female vagina
Clotting factors / Coagulates semen after ejaculation à fibrinolysin breaks it down
Seminalplasmin / Antibiotic that destroys certain bacteria
38.Which nervous system stimulates the erection during sexual arousal? Parasympathetic (PNS)
39.What hormone acts as a blood vasodilator? Nitric Oxide (NO)-review from unit 4: what does this do to your BP??? Decreases it
40.Corpus (spongiosum, cavernosa) keeps the urethra open during ejaculation, and corpus (spongiosum, cavernosa) fill with blood during an erection.
41.Which type of cells aid in spermatogenesis and form the blood-testis barrier? Where are these cells found? What types of cells produce testosterone?
Sustentacular cells found In the testes in the seminiferous tubules. Testosterone is produced Leydig cells
42. Fill out the chart about the Brain-Testicular Axis(hormonal regulation of spermatogenesis and testicular androgen production)Location / Hormone / Function
Hypothalamus / GnRH / Stimulates anterior pituitary to produce FSH and LH
Anterior Pituitary / Lutetinizing Hormone / Stimulates leydig cells to secrete testosterone
Follicle Stimulating Hormone / Stimulates sertoli cells to release Androgen Binding Protein (ABP) to enhance spermatogenesis
Leydig Cells / Testosterone / Sperm development
Sertoli Cells / Inhibin / Negative feedback mechanism for FSH
Female Reproductive System
43. What is the follicular phase? What is the beginning and ending follicle?
Follicular Phase: Period of follicle growth; occurs at days 1-14.
Primordial follicle → Primary→ Secondary→ Mature Graafian follicle
44.What process occurs mid-cycle? What two hormones “spike” and signify this process? What is the primary hormone that stops the two hormones from releasing? Ovulation, LH and FSH (LH triggers ovulation). Estrogen stops LH and FSH from releasing
45.What happens to an egg during ovulation? It is released from a follicle into oviduct and will be available for fertilization by sperm during the luteal phase
46. What is the luteal phase?
Luteal Phase: Period of corpus luteum activity; occurs at days 14-28.
47.Which cells enlarge to form the corpus luteum? What hormones are secreted by the corpus luteum and what are their function?Granulosa cells, progesterone and estrogen are secreted and their function is to maintain the uterine endometrium
48.If a pregnancy occurs estradiol and progesterone are secreted, why?
To maintain the endometrium(lining of the uterus) therefore ovulation cannot occur anymore