CHAPTER 18
1. List three arterial blood parameters that influence ventilation.
To avoid hypoxia and hypercapnia the body responds to 3 regulated variables:
- Oxygen
- Carbon dioxide
- pH
2. Diagram the normal partial pressures of O2 and CO2 in the atmosphere, alveoli, arterial
blood, resting cells, and venous blood.
3. Describe all the factors that influence gas exchange between the atmosphere and arterial
blood.
- Composition of air
- Low alveolar ventilation (hypoventilation)
- Increase in the thickness of the alveolar capillary exchange barrier
- Increase in the diffusion distance between the alveolar air space and blood
4. Explain the difference between the concentration of a gas in solution and the partial
pressure of that gas in solution, using O2 and CO2 as examples
The concentration of O2 dissolved in water at any given PO2 is the partial pressure of the
gas in the solution. The concentration of dissolved O2 also depends on the solubility of
O2 in water. The low solubility of O2 was a driving force for the evolution of O2 carrying
molecules in the blood.
O2 is not very soluble
CO2 has much higher solubility than O2
CO2 gradient is small, but very soluble. O2 has high gradient, not very soluble.
Partial pressure refers to the pressure exerted by a specific gas in a mixture, and
concentration refers to the amount of that gas dissolved in a given volume of liquid
5. Explain the role of hemoglobin in oxygen transport from the molecular level to the
systemic level.
Hemoglobin is able to bind 4 oxygens to transport throughout the blood. It has four iron
containing heme groups, each one of these binds to one O2. Hemoglobin + O2 is known
as oxyhemoglobin. The hemoglobin acts like a sponge and soaks up the O2 from the
plasma until the rxn reaches equilibrium.
6. Describe the relationship between plasma Po2 and oxygen transport.
Plasma PO2 is the primary factor determining what percentage of the available
hemoglobin binding sites are occupied by oxygen.
Increase in PO2, reaction shifts to right
Decrease in PO2 reaction shifts to the left
7. Draw the oxyhemoglobin saturation curve, explain the physiological
significance of the shape of this curve, and draw the shifts in the curve that result from
changes in pH, temperature, and 2,3-BPG.
The physiological significance of this curve is that it visually represents how readily
hemoglobin in the blood binds and releases O2 depending on the partial pressure of O2.
A shift to the right indicates that hemoglobin has a decreased affinity for O2 (such as low
pH, higher temperatures, higher PCO2, and added 2,3 BPG). A shift to the left indicates
that hemoglobin has an increased affinity for O2 (such as with high pH, lower
temperatures, lower PCO2, and no 2,3 BPG)
8. Write the chemical reaction for the conversion of CO2 to HCO3–, including the enzyme
that catalyzes the reaction.
CO2 + H2O carbonic anhydrase H+ + HCO3-
9. Map the transport of carbon dioxide in arterial and venous blood,
including the exchanges of CO2 between the blood and the alveoli or cells.
CO2 diffuses out of the cells into systemic capillaries, only 7% of the CO2 remains
dissolved in plasma, nearly ¼ of the CO2 load is converted to bicarbonate and H+.
Hemoglobin buffers H+. HCO3- enters plasma in exchange for Cl-. At the lungs, dissolved
CO2 diffuses out of the plasma. By the law of mass action, CO2 unbinds from
hemoglobin and diffuses out of the RBC. The carbonic acid rxn reverses, pulling HCO3-
back into the RBC and converting it back to CO2.
10. Map the reflex control of ventilation including appropriate
neurotransmitters and
their receptors.
11. Diagram the current model for the brain stem neural networks
that control breathing.
12. Explain the mechanisms by which central and peripheral chemoreceptors
monitor CO2 and O2 levels.
Central chemoreceptors: monitor CO2 by detecting changes in the pH of the
cerebrospinal fluid
Peripheral chemoreceptors: sense changes in blood O2 levels, send signals to brainstem
to adjust breathing rate accordingly to maintain proper gas exchange
CHAPTER 19
1. List and describe the six functions of the kidneys
Regulation of extracellular fluid volume + blood pressure
Regulation of osmolarity
Production of hormones
Excretion of wastes
Homeostatic regulation of pH
Maintenance of ion balance f
2. Trace the anatomic path of a drop of water from Bowman’s capsule to urine leaving the
body.
Bowman’s capsule proximal convoluted tubule descending loop of Henle ascending
loop of Henle distal convoluted tubule collecting duct renal pelvis ureter urinary
bladder urethra external environment
Know blood vessels on slide 7
3. Know the anatomic relationship between the vascular and tubular elements of the
nephron
Vascular: glomerulus, arterioles, peritubular capillaries
Tubular: bowman’s capsule, proximal tubule, loop of Henle, distal tube
4. Describe the three processes of the nephron Filtration
- Fluid from blood into the lumen of nephron
- Occurs at renal corpuscle
- Filtered plasma is called filtrate, excreted unless reabsorbed
Reabsorption
- Materials in filtrate passed back to blood
- Occurs w/ peritubular capillaries
Secretion
- Materials from blood into lumen of tubule
- Occurs w/ peritubular capillaries
5. Describe the filtration barriers between the blood and the lumen of the nephron and
explain how they can be modified to control filtration.
Substances leaving the plasma must pass through three filtration barriers before
entering the tubule lumen:
1. Glomerular capillary endothelium
2. Basement membrane
3. Epithelium of bowman’s capsule
6. Describe the pressures that promote and oppose glomerular filtrationThree pressures
influence glomerular filtration:
1. Capillary BP (hydrostatic pressure which favors filtration)
2. Capillary colloid osmotic pressure (due to proteins in plasma, opposes filtration, in
other words promotes absorption, pulls fluid back to plasma)
3. Capsule fluid pressure (hydrostatic pressure inside Bowman’s capsule, opposes
filtration)
7. Define glomerular filtration rate and give average values for GFR.
The rate of water moving across the glomerular capillaries from plasma into bowman’s
space/ Normal human GFR = 25 ml/minute
Volume of fluid filtered per unit time, influenced by net filtration pressure and filtration
coefficient
8. Explain how GFR can be influenced by local and reflex control mechanisms
Glomerular filtration rate can be changed or altered by changing afferent arteriole
resistance, efferent arteriole pressure, or the size of filtration surface
GFR is subject to autoregulation
- Myogenic response
- Tubuloglomerular feedback
- Hormones and autonomic neurons also influence GFR
9. Distinguish between transcellular transport and paracellular pathways.
Transepithelial transport (transcellular transport)
- Substances cross apical and basolateral membranes of the tubule epithelial cells
Paracellular pathway
- Substances pass through the cell-cell junction between two adjacent cells
10. Describe and give examples of active and passive reabsorption in the proximal tubule.
Active transport of Na
- Creates electrical gradient
- Anions follow Na which creates an osmotic gradient
- H2O follows and leaves behind higher conc. Of cations
- Cations follow down conc. Of gradients
- Exchangers and pumps
Passive reabsorption
- Urea
11. Using glucose as an example, create graphs to show filtration, transport
maximum, and renal threshold of a substance reabsorbed by proteinmediated transport
12. Explain and give examples of the importance of tubular secretion in renal function.
Active movement of molecules from extracellular fluid into nephron lumen, and K and
H+ are important in homeostatic regulation Increasing secretion increases nephron
excretion
13. Explain mathematically and in words the relationship between the excretion of a solute
and its renal clearance. Excretion = filtration – absorption + secretion
14. Explain how clearance can be used as an indirect indicator of renal handling of a solute.
Clearance acts as a direct indicator of renal handling of a solute because it represents
the theoretical volume of plasma that is completely cleared of a substance per unit time
by the kidneys. Basically, it shows how efficiently the kidneys are filtering and excreting
that specific solute from the blood.
15. Diagram the involuntary micturition reflex and include the
voluntary control pathway exerted by higher brain centers.
CHAPTER 20:
1. Explain how the countercurrent multiplier in the loop of Henle is the key to
the regulation of urine concentration
The renal countercurrent exchange system consists of closely associated tubules and
capillaries of the vas recta. Countercurrent multiplier transfers solutes by AT into the
medulla. Vasa recta removes water and prevents dilation of the medulla interstitial fluid.
Loop of Henle:
Transfers solutes by AT into the medulla, results in greater ECF osmolarities Vasa
Recta:
Removes water
2. Map in detail the reflex pathway through which vasopressin controls
water reabsorption in the kidney.
High osmolarity more vasopressin released
3. Diagram the cellular mechanism of action of vasopressin on principal cells
Vasopressin binds to membrane receptor receptor activates cAMP second messenger
system cells insert from AQP2 water pores into apical membrane water is absorbed
via osmosis into the blood bc
4. Map the homeostatic responses to salt ingestion.
5. Diagram the cellular mechanism of aldosterone action at principal cells
Released in response to low BP or high K conc.
6. Map the renin-angiotensin-aldosterone system (RAAS), including all
the
responses initiated by ANG II and aldosterone
Said you don’t have to map?*
Low BP results in renin production baroreceptor reflex
Renin is an enzyme, which converts angiotensinogen into angiotensin I, another enzyme
(ACE), converts ANG I ANG II, and it works in the body to increase BP. Binds and causes
vasoconstriction
7. Describe the release of natriuretic peptides and their effects on sodium and water
reabsorption.
ANP (atrial natriuretic peptide) and BNP (brain natriuretic peptide) BOTH made in the
heart
Stretch stimulates release, ANP does almost the opposite of ANG II
End for quiz
Won’t ask ab homeostatic compositions
8. Diagram the appropriate homeostatic compensations for different combinations of
volume and osmolarity disturbances.
9. Compare and contrast the three mechanisms by which the body copes with minute-to-
minute changes in pH.
The body primarily uses the
1. respiratory system
- corrects 75% of disturbances, but can also cause them (gets rid of CO2)
2. bicarbonate buffer system in the blood (includes proteins, phosphate ions, and
HCO3-)
- moderate changes in pH by combining with or releasing H+
3. renal system
- use buffers to buffer urine
- proximal tubule secretes H+ and reabsorbs HCO3-
- distal nephron can secrete or reabsorb H+ and HCO3- to regulate pH of extracellular
fluid
10. Diagram the reflex pathways and cellular mechanisms involved in respiratory
compensation of pH changes.
11. Diagram the mechanisms by which the kidneys compensate for pH changes.
Renal control of pH in collecting duct (slide 47)
Type B vs type A cells (same cells, signals just cause transporters to be switched)
12. Map the causes and compensations involved in each of the four classes of acid- base
disturbances (respiratory acidosis, metabolic acidosis, respiratory alkalosis, metabolic
alkalosis).
Respiratory acidosis: hypoventilation PCO2 increases pH decreases (too much CO2 in
blood)
Metabolic acidosis: dietary and metabolic output of H+ exceeds secretion pH
decreases (too much H+)
Respiratory alkalosis: hypoventilation PCO2 decreases pH increases (not enough CO2
in blood)
Metabolic alkalosis: loss of H+ thru excessive vomiting or excessive ingestion of
bicarbonate containing antacids pH increases (Too little H+)
CHAPTER 21
1. Trace a piece of undigested food from mouth to anus.
Oral cavity pharynx and esophagus
2. Describe the four layers of the GI tract wall
1. Mucosa (epithelial layer w/ connective tissue, very thick mucosal muscle layer)
2. Submucosa (connective tissue, a lot of blood vessels and nerves which control
secretion of the glands, contains submucosal plexus)
3. Muscularis externa (consists of two layers of smooth muscle, longitudinal and
circular layers. Contains myenteric plexus, stimulation of these nerves causes
contraction of muscles)
4. Serosa (connective tissue, continuation of the peritoneal membrane, forms
sheet of mesentery)
5. Describe the primary function of the digestive system.
To move nutrients, water, and electrolytes from external environment internal environment
(basically, absorbing nutrients)
Four basic processes and three challenges
6. Explain the challenges of autodigestion, mass balance, and defense
Preventing autodigestion, we must secrete digestive enzymes but NOT digest ourselves
Another challenge is maintaining fluid balance by matching output with input, secreted fluid
must be reabsorbed
Defense relates to pathogens and keeping our bodies safe, letting nutrients in but keeping
pathogens out can be a challenge
7. Describe and compare secretion, digestion, absorption, and motility
Secretion: movement of material from cells GI lumen/ECF
Absorption: movement of material from GI lumen ECF
Digestion: chemical and mechanical breakdown of food into absorbable units
Motility: movement of material thru the GI tract as a result of muscle contractions
8. Describe single-unit smooth muscle, slow wave potentials, tonic and phasic
contractions
Slow wave potentials are spontaneous depolarizations
Tonic contractions: take minutes/hours (Tonic Takes Time) Phasic contractions:
happens in seconds
9. 7. Describe and compare peristalsis, segmentation, and the migrating motor
complex.
Peristalsis is moving food through the tract (P for PROPEL)
Segmentation is mechanically mixing food to break it into uniformly small particles
Migrating motor complex basically “clears out” your digestive system. Strong peristalsis
contractions which start in stomach and go all the way down to large intestine, “housekeeping
contractions”
10. Compare the enteric nervous system to the central nervous system.
The enteric nervous system can act independently, controls motility, secretion, and growth of
the digestive system. Intrinsic neurons are neurons in the ENS, while extrinsic are from CNS to
digestive system. Shares features with CNS like neurotransmitters and integrating center. Short
reflexes integrate in ENS, while long reflexes integrate in CNS.
11. Contrast long reflexes, short reflexes, and control involving GI peptides.
Long reflexes are integrated in the CNS, some originate outside the GI tract, but others originate
in the enteric nervous system.
Short reflexes originate in the enteric nervous system and are carried out entirely within the
wall of the gut
12. Know the hormones in the table
They excite/inhibit GI motility and secretion
Gastrin (only one released in stomach)
Everything else released in small intestine
CCK (cholecystokinin) is released when we have fatty acids, especially amino acids, in the small
intestine. Secreted into blood, targets are gallbladder (stores bile, helps you digest), pancreas
(secretes enzymes to help you break down lipids and proteins), and stomach (secretions and
motility inhibited by CCK).
- Responds to fatty acids
- Pancreas secretes enzymes
- Stomach motility inhibited
- Gallbladder releases bile
Secretin is produced when the small intestine senses low pH (acidic), pancreas releases
bicarbonate in response to secretin, which neutralizes the acid. Goes to the stomach and
inhibits motility.
- Responds to low pH
- Pancreas released bicarbonate
- Inhibits motility in stomach
GIP (gastric inhibitory polypeptide) tells stomach to stop emptying, stopping acid secretion.
Produced in response to pretty much anything we eat. Stimulates pancreas to release insulin,
this is feedforward control. Knows blood sugar is about to get high.
- Responds to any food
- Tells stomach to stop emptying + stops acid secretion
- Stimulates pancreas to release insulin (feedforward control)
GLP (glucagon like peptide) released in response to meals that are high in carbs/fats, inhibits
stomach and glucagon, stimulates pancreas to release insulin.
- Responds to meals high in carbs/fats
- Inhibits stomach + glucagon
- Stimulates pancreas to release insulin
Motilin causes motility. Released in response to fasting, causes migrating motor complex which
basically “clears out” your digestive system. Strong peristalsis contractions which start in
stomach and go all the way down to large intestine, “housekeeping contractions”
- Released in response to fasting
- Causes migrating motor complex
13. Explain the functions of saliva
Soften and lubricate food, digestion of starch
14. Explain feedforward control in digestion
When you smell, see, or think about food, a reflex begins in your brain, the anticipation of or
presence of food in the oral cavity activates neurons in the medulla and initiate the cephalic
phase
15. Map the processes and control pathways of the cephalic phase The cephalic
phase is the initial stage of digestion.
Salivary secretions: exocrine, under autonomic control, has 4 functions (soften/lubricate food
and digestion of starch)
Mechanical digestion begins w chewing (mastication)
Swallowing moves food from mouth stomach (deglutition)
16. Map the processes and control pathways of the gastric phase
The gastric phase is the stage of digestion that begins when food enters the stomach and
stimulates the release of gastric juices, which break food down further.
You think ab food medulla oblongata preganglionic parasympathetic neuron in vagus nerve
AND sensory input in lumen of stomach enteric plexus postganglionic parasympathetic and
intrinsic enteric neurons target cells secretion and motility
Gastric secretions protect and digest
The three functions of the stomach are storage, digestion (lipids and proteins though acid,
enzymes, paracrine signal molecules, and hormones), defense
Digestion begins in stomach w/ long vagal reflex of cephalic phase, then food in stomach
initiates short reflex of gastric phase
17. Describe the gastric secretions and their major actions
Intestinal secretions promote digestion
Mucus: physical barrier between lumen and epithelium
Gastric acid (HCl): activates pepsin, kills bacteria
Intrinsic factor: complexes w/ vitamin B12 to permit absorption
Pesin(ogen): digests proteins
Gastric lipase: digests fats
Bicarbonate: buffers gastric acid
Somatostatin: inhibits gastric acid secretion
Gastrin: stimulates gastric acid secretion
Histamine: stimulates gastric acid secretion
18. Compare and contrast digestion and motility in the large and small intestines.
Most digestion and absorption happen at the small intestine
19. Describe the anatomy and function of the hepatic portal system.
A network of veins that carries blood from the digestive organs, spleen, and pancreas to the
liver which allows the liver to process nutrients absorbed from food and filter out toxins before
blood returns to original circulation via the hepatic veins.
Absorbed nutrients go to hepatic portal system for distribution
20. Describe the major secretions of the pancreas and liver.
Pancreas: enzyme and bicarbonate. Pancreatic and brush border enzymes complete digestion
(carbs, lipids, proteins). Trypsin (released when there is distension of the small intestine), CCK
(hormones that break down fats and proteins), bicarbonates (neutralizes stomach acid),
carbonic anhydrase (needed to produce bicarbonate)
Liver: secretes bile, can go directly to small intestine but most of it goes to the gallbladder which
stores bile (made of smooth muscle). Bile helps us digest lipids.
21. Diagram the cellular mechanisms for secretion or absorption of water and ions.
22. Diagram the digestion and absorption of carbohydrates, proteins, and fats.
23. Explain the neural and hormonal control of the intestinal phase of digestion
- Chyme enters intestine activates ENS which decreases gastric mobility + secretion
and slows gastric emptying
- Secretin, CCK, and GIP = hormones that reinforce the decrease in motility
- Secretin is released by the presence of acidic chyme in duodenum and inhibits acid
production and decreases motility. It also stimulates production of pancreatic
bicarbonate to neutralize acidic chyme
- CCK is secreted when fats are present, decreases mobility and acid secretion
- GIP is released when carbs are present, it feeds forward to promote insulin release
by pancreas so that it is well prepared for glucose so that it will be absorbed. It also
slows the entry of food into intestine by decreasing motility and acid secretion
- The mix of acid, enzymes, and food in chyme forms a hyperosmotic solution
- Sensors in the intestine wall are sensitive to osmolarity and are stimulated by high
osmolarity, inhibiting gastric emptying
CHAPTER 22
1. Identify factors that affect metabolic rate
Age and biological sex
Amount of lean muscle mass
Activity level
Diet and diet-induced thermogenesis
Hormones
Genetics
2. Distinguish between anabolic and catabolic pathways
Anabolic pathways: synthesize larger molecules from smaller ones, fed/absorptive state
Catabolic pathways: break large molecules into smaller ones, fasted/postabsorptive state
3. Distinguish between the fed (absorptive) state and the fasted (postabsorptive) state
The fed state refers to the period after a meal when the body is actively digesting and absorbing
nutrients.
The fasted state refers to the period after digestion is complete, when the body is relying on
stored energy reserved to meet its energy needs.
4. Describe the possible fates of ingested nutrients
1. Energy to do mechanical work
2. Synthesis for growth and maintenance
3. Storage as glycogen or fat
5. Create a map that summarizes the balance of nutrient pool and nutrient storage for
carbohydrates, proteins, and lipids
6. Summarize anabolic metabolism of carbohydrates, proteins, and lipids in the fed state
Carbohydrates: used immediately for energy thru anaerobic pathways, used for lipoprotein
synthesis in liver, stored as glycogen in liver and muscle, excess converted to fat and stored in
adipose tissue
Proteins: most amino acids go to tissues for protein synthesis, in liver to intermediates for
aerobic respiration, excess converted to fat and stored in adipose tissue
Fats: stores as triglycerides primarily in liver and adipose tissue, cholesterol used for steroid
synthesis or as a membrane component, fatty acids used for lipoprotein and eicosanoid
synthesis.
7. Summarize catabolic metabolism of carbohydrates, proteins, and lipids in the fasted state
Carbohydrates: glycogen polymers broken down to glucose in liver and kidney or to glucose 6-
phosphate for use in glycolysis
Proteins: broken down into amino acids, which are deaminated in liver for ATP production or
used to make glucose
Fats: triglycerides broken down into fatty acids and glycerol, fatty acids used for ATP production
through aerobic pathways.
8. Explain the roles of insulin and glucagon in the control of metabolism
In the Fed state, insulin dominates (trying to bring blood sugar down). Things that are up
include glucose oxidation, glycogen synthesis, fat synthesis, protein synthesis
In the fasted state, Glucagon dominates (glucagon promotes the breakdown of glycogen into
glucose in the liver). Things that are up include glycogenolysis, gluconeogenesis, and
ketogenesis
9. Create a reflex map for insulin, including mechanisms of action where
possible.
where possible
11. Explain the normal routes of heat gain and loss for the human body
Radiation – energy that is given off and can be absorbed by other objects and constitutes
radiant heat gain for those objects. Example: sitting in front of a fire/sitting in the sun. Your body
can also give off heat this way.
Convection – you can lose heat this way because warm air rising from the body’s surface carries
heat away.
Conduction – the transfer of heat between two objects that are close to each other, or the loss
of heat due to a cooler object touching the body.
Evaporation – heat loss in this way takes place as water evaporates at the skin’s surfaces and in
the respiratory tract. The conversion of water from the liquid to the gas state requires inputs of
energy, and when water on the body evaporates it removes heat from the body.
12. Map the homeostatic control of body temperature.
10. Draw a reflex map for glucagon, including mechanisms of action
CHAPTER 23
1. Diagram the HPA pathway in detail, including feedback signals and cellular
mechanisms of action.
Hypothalamic corticotrophin releasing hormone anterior pituitary stimulates release of
ACTH acts on adrenal cortex to promote release of cortisol negative signal to inhibit CRH and
ACTH. Cortisol enters the nucleus and binds to DNA, altering gene expression.
2. Identify the hallmarks of hypercortisolism and hypocortisolism and explain the
possible causes.
Hypercortisolism:
Causes:
- Adrenal tumor that autonomously secretes cortisol (primary hypercortisolism)
- Pituitary tumor that autonomously secretes ACTH (secondary hypercortisolism,
Cushing’s disease)
- Iatrogenic (physician caused) hypercortisolism (Cushing’s syndrome)
Symptoms:
- Hyperglycemia
- Tissue wasting (but with fast deposits in trunk and waist)
Hypocortisolism:
Cause:
- Addisons disease: hyposecretion of all adrenal steroid hormones
(auto-immune, genetic, infection, cancer) Symptoms:
- Hypoglycemia
- Fatigue
- Lack of appetite
3. Identify additional physiological functions of CRH and ACTH
Regulation of appetite, cardiovascular function, immune response, reproductive behavior,
energy metabolism
4. Diagram the synthesis and secretion of thyroid hormones.
Normally derived from amino acids and contain iodine. Synthesis takes place in the thyroid
follicles and binds to plasma proteins to be transported due to limited solubility.
5. Diagram the thyroid hormone control pathway, including feedback signals and
cellular mechanisms of action.
Thyroid hormone control is controlled by TRH and normally act as a negative feedback signal to
prevent over secretion.
6. Identify the hallmarks of hyperthyroidism and hypothyroidism and distinguish
between primary and secondary thyroid pathologies. Hyperthyroidism: thyroid
gland secretes TOO MUCH hormone Causes:
- Graves disease (body produces TSI’s that mimic TSH), often accompanied by
exophthalmos (bulging eyeballs) and can cause goiter
- Thyroid gland tumors/adenomas (can cause goiter) Symptoms:
- Increased O2 consumption and metabolic heat production
- Increase protein catabolism and may cause muscle weakness
- Hyperexcitable reflexes and psychological disturbances
- Influence beta adrenergic receptors in heart (increased HR and contractility)
Hypothyroidism:
Causes:
- Lack of iodine (can cause goiter)
- Autoimmune e
- Treatment of other disorders Symptoms:
- Slows metabolic rate + O2 consumption
- Decreases protein synthesis (brittle hair/nails)
- Nervous system changes in adults: slower reflexes, slow speech and thought
processes, fatigue)
- Primary cardiovascular change = bradycardia (slow HR)
7. List the factors that influence normal growth.
Growth hormone and other hormones
Adequate diet
Absence of chronic stress
Genetics
8. Diagram the control pathway for growth hormone release, including feedback
signals and cellular mechanisms of action.
Stimuli for secretion is sleep (within the first two hours), secreted by the anterior pituitary,
bound to plasma, targeting endocrine and nonendocrine cells.
Feedback: GH feeds back to inhibit GHRH, but HG also promotes release of somatostatin to shut
off GH secretion.
9. Identify the hallmarks of hypersecretion and hyposecretion of growth hormone in
children and adults Hypersecretion:
- In children: giantism
- In adults: acromegaly Hyposecretion:
- In children: dwarfism
10. Distinguish between hypertrophy and hyperplasia.
Increased cell size vs. increased cell number
11. Describe the structure of bone and explain how bone is a dynamic tissue.
Outer layer of compact bone, and inner layer of spongy trabecular bone
Osteoblasts produce calcified matrix of bone and become osteocytes
Osteoclasts are bone dissolving cells
Bone is composed largely of calcified extracellular matrix.
It is a dynamic tissue because it is constantly being remodeled throughout life.
12. Diagram the mechanisms by which bone adds diameter and length
13. Explain the physiological functions of calcium.
Important signal molecule
Part of intracellular cement that holds cells together at tight junctions
Cofactor in the coagulation cascade
Plasma Ca++ concentrations affect the excitability of neurons and all types of muscles
14. Diagram the distribution of calcium in the body and explain the factors that
influence its movement between compartments.
15. Diagram the endocrine control of plasma calcium concentration by parathyroid
hormone and calcitriol, and calcitonin including the cellular mechanisms of action
of each hormone.
16. Explain the role of osteoclasts and osteoblasts in bone remodeling,
Osteoblasts produce calcified matrix of bone and become osteocytes
Osteoclasts are bone dissolving cells
CHAPTER 24
1. Describe the body’s barriers and the four steps of the internal defense.
Barriers:
Physical, chemical, mechanical
Four steps of internal defense:
- Detection and identification
- Communication with other immune cells
- Recruitment of assistance and coordination of response
- Destruction/suppression of the pathogen
2. Distinguish between innate immunity and adaptive immunity.
Innate immunity: immediate immune response, nonspecific, rapid,
inflammation is characteristic, antigen-preserving cells, not remembered by immune system
- Surface barriers: skin and mucous membranes
- Internal defenses: phagocytes, NK cells, inflammation, antimicrobial proteins, fever
Adaptive immunity: specific immunity response, slow, remembered by immune system, cell
mediated immunity (contact dependent signaling), antibody mediated (humoral) immunity,
antibodies
- Humoral immunity (B cells)
- Cellular immunity (T cells)
3. Describe and differentiate between cell-mediated immunity and humoral
immunity.
Cell mediated:
- Involves T lymphocytes
- Destroys abnormal cells Humoral immunity:
- Involves B lymphocytes
- Uses antibodies
4. List the three major functions of the immune system
- Tries to recognize and remove abnormal “self’ cells
- Removes dead/damaged cells
- Protects body from disease causing pathogens
5. Diagram the humoral immune responses of B lymphocytes.
6. Describe how antibodies make antigens more visible to the immune system and
how they activate other immune cells.
7. Diagram the cell-mediated immune responses of T lymphocytes
8. Map and compare the immune responses in bacterial and viral infections, allergic
reactions, and following the transfusion of incompatible blood.
9. Describe how the breakdown of self-tolerance can lead to autoimmune diseases.
Self-tolerance is the lack of immune response by lymphocytes to cells of the body
Body’s attack on its own cells autoimmune diseases
- When self-tolerance fails
- Specific against a particular antigen and
- Usually restricted to a particular organ/tissue type
10. Explain how stress affects immunity.
Stress is nonspecific stimuli that disturbs homeostasis
Stressors: events/items that create stress
Acute stress fight/flight reaction
Chronic repetitive stress increased cortisol suppress immunity
CHAPTER 26
1. Describe the role of sex chromosomes in sex determination.
XX = female
XY = male
Sex chromosomes determine genetic sex, Y is essential for the development of male
reproductive organs.
22 pairs of homologous autosomes, one pair of sex chromosomes
Y is essential for development of male reproductive organs, sperm determines sex of zygote
2. Describe the bipotential reproductive structures of the early embryo.
Before differentiation, the embryonic tissues are considered bipotential because they cannot be
morphologically identified as male/female. The bipotential gonad has an outer cortex and an
inner medulla, and under the influence of the appropriate developmental signal, the medulla
will develop into a testis. In the absence of the signal, the cortex will differentiate into ovarian
tissue. The bipotential internal genitalia consist of two pairs of accessory ducts:
Wolffian ducts – derived from embryonic kidney
Mullerian ducts
As development proceeds (either male/female) one pair of ducts develops and the other
degenerates.
SRY protein present then it causes development of male reproductive organs (determines male
development)
3. Diagram the processes of sexual differentiation in male and female embryonic
development. FEMALE
- Gonadal cortex becomes ovary in the absence of SRY protein under the influence of
female-specific genes
- Absence of testosterone causes Wolffian duct to degenerate
- Absence of anti-mullerian duct to become the fallopian tube, uterus, and the upper
part of the vagina
MALE
- SRY protein in a male embryo directs the medulla of the bipotential gland to develop
into testis
- Anti-mullerian hormone from testis causes mullerian ducts to disappear
- Testosterone from testis converts Wolffian duct into seminal vesicle, vas deferens,
and epididymis. DHT controls prostate development.
4. Describe and compare male and female patterns of gametogenesis
MALE
- At birth, testes of a newborn boy have not progressed beyond mitosis and contain
only immature germ cells
- After birth gonads = quiescent until puberty - At puberty, germ cell mitosis
resumes
- Each primary spermatocyte creates 4 sperm.
- In the first meiotic division, a primary spermatocyte divides into two secondary
spermatocytes. In the second meiotic division each secondary spermatocyte divides
into two spermatids.
FEMALE
- In the embryonic ovary germ cells are called oogonia, which complete mitosis and
the DNA duplication stage of meiosis by the fifth month of fetal development,
resulting in primary oocytes
- At birth each ovary contains about half a million primary oocytes
- In the ovary, meiosis does not resume until puberty, and if a primary oocyte develops
it divides into two cells: a large egg and a tiny first polar body.
- If the secondary oocyte is selected for ovulation, the second meiotic division takes
place just before the egg is released from the ovary
- The sister chromatids separate but now meiosis pauses again. The final step of
meiosis does not take place unless the egg is fertilized
-If the egg is not fertilized, then meiosis never goes to completion and the egg
disintegrates. If fertilization by sperm does occur, the final step of meiosis takes
place.
5. Diagram the common hormonal control and feedback pathways for reproductive
function.
Slide 20
6. Explain the significance of pulsatile GnRH secretion.
GnRH = gonadotropin-releasing hormones from hypothalamus controls secretion of 2 anterior
pituitary hormones
FSH (regulates gametogenesis in gonads) and LH (controls production of sex hormones)
It is regulated by several hypothalamic peptides including kisspeptin, it inhibits FSH secretion
activins stimulate FSH secretion and promote spermatogenesis, oocyte maturation, and
development of the embryonic nervous system
7. Describe some environmental factors that influence reproductive physiology.
In women: stress, nutrition, daylight and environmental estrogens
In men: environmental estrogens
8. The internal and external anatomy of the adult male reproductive and accessory
structures and give the function(s) of each.
External: Penis
- Urethra
- Erectile tissue (corpus spongiosum, corpora cavernosa)
- Glans
- Prepuce (foreskin) Scrotum
- Testes: produce sperm and hormones
- At lower temperature Accessory glands:
- Prostate
- Seminal vesicles
- Bulbourethral (Cowper’s) glands
9. Diagram the process of spermatogenesis.
- As spermatocytes differentiate into sperm, they move toward the tubule lumen
continuously surrounded by Sertoli cells. The tight junctions of the blood testis
barrier break and reform around the migrating cells, ensuring that the barrier
remains intact.
- By the time the spermatocytes reach the luminal ends of Sertoli cells, they have
divided twice and become spermatids, which remain embedded in the apical
membrane of Sertoli cells while they complete the transformation into sperm, losing
most of their cytoplasm and developing a flagellated tail.
- The chromatin of nucleus condenses into a structure that fills most of the head,
while a Golgi-derived vesicle called an acrosome flattens out to form a cap over the
tip of the nucleus
- The acrosome contains enzyme essential for fertilization
- Mitochondria produces energy for sperm movement concentrated in the midpiece of
the sperm body, along with microtubules that extend into the tail.
10. Explain the hormonal control of spermatogenesis.
- Hypothalamic GnRH promotes release of LH and FSH from anterior pituitary, which in
turn stimulates the testes.
- FSH stimulates Sertoli synthesis of paracrine molecules needed for spermatogonia
mitosis and spermatogenesis.
- FSH also stimulates production of androgen binding protein and inhibin
- The primary target of LH is the interstitial cells
- Testosterone feeds back to inhibit LH and GnRH release, and is essential for
spermatogenesis
11. Describe the primary and secondary sex characteristics of the male and the
hormones that influence their development.
Primary sex characteristics are the internal sexual organs and the external genitalia that
distinguish males/females.
Androgens are responsible for the differential of male genitalia during embryonic development
and for their growth during puberty.
The secondary sex characteristic are other traits that distinguish males/females. The male body
= inverted triangle shape while female body = more pear shaped. Androgens are responsible for
other typical male traits like beard, body hair, muscular development, and thickening of vocal
cords/lowering of voice, and behavioral effects like sex drive.
12. the internal and external anatomy of the adult female reproductive and accessory
structures and give the function(s) of each.
Internal:
- uterus
- ovaries: produce eggs and hormones
- fallopian tubes
- cervix
- vagina external:
- labia minora and majora
- clitoris
- vagina
- urethral opening
13. Diagram and give the timeline for follicular development from primordial follicle
to corpus albicans.
Corpus luteum has lifespan of about 12 days
No pregnancy undergoes apoptosis. As it degenerates, progesterone and estrogen production
decrease and this fall removes the negative feedback signal to pituitary hypothalamus, so
secretion of FSH and LH increases. The remnants of the corpus luteum become an inactive
structure called a corpus albicans.
14. Explain the role of atresia in ovarian function.
Primordial follicles that never develop die over a period of years in an apoptosis known as
atresia
15. Diagram the ovarian and uterine stages of the menstrual cycle.
Follicular phase: period of follicular growth in ovary, most variable and lasts 10-21 days.
Ovulation: Once one or more follicles have ripened, the ovary releases the oocyte during
ovulation.
Postovulatory/luteal phase: the ruptured follicle is transformed into a corpus luteum, which
secretes hormones that prepare for pregnancy. If there is no pregnancy, the corpus luteum
ceases to function after about two weeks.
The beginning of the follicular phase in the ovary corresponds to menstrual bleeding from the
uterus. The latter of the ovary’s follicular phase corresponds to the proliferative phase in the
uterus, during which the endometrium adds a new layer of cells in anticipation of pregnancy
After ovulation, hormones form the corpus luteum convert the thickened endometrium into a
secretory structure. If there is no pregnancy, the superficial layers of the secretory
endometrium are lost during menstruation. And the cycle begins again!
16. Relate the hormonal control and feedback patterns of the menstrual cycle to different
stages of the ovarian and uterine cycles.
Early - mid follicular phase:
- Low levels of estrogen exert negative feedback on GnRH, LSH, and FH. Estrogen
promotes more estrogen secretion by follicle.
- AMH prevents more follicles from developing Late follicular phase – ovulation:
- Rising levels of estrogen plus increasing progesterone causes LH surge. FSH is
suppressed by inhibin.
Early – mid luteal phase:
- Combined estrogen shut off FSH and LH Late luteal phase:
- Estrogen and progesterone fall when corpus luteum dies.
- Gonadotropins start follicular development for a new cycle.
17. Describe the secondary sex characteristics of the female and the hormones that
influence their development
Estrogens control the development of primary sex characteristics in females (like androgens
control them in males)
Estrogens also control the most prominent female secondary sex traits: breast development and
the female pattern of fat distribution.
Other female secondary sex characteristics are governed by androgens and produced in the
adrenal cortex. Public and axillary hair growth and libido are under the control of adrenal
androgens.
and describe the four phases of the
human sexual response.
1. Excitement
- Vascular congestion, erection, and lubrication
2. Plateau
- Continuation of changes in excitement phase
3. Orgasm/climax
- Muscular constriction of vagina and uterus/ejaculation
- Increased HR and RR
4. Resolution
- Return to normal
19. Explain the anatomy or physiology of currently available contraceptive methods.
Abstinence: total avoidance of sexual intercourse Sterilization:
- Female: tubal ligation, consists of tying off and cutting the fallopian tubes. You still
ovulate, but egg remains in abdomen
- Male: vasectomy, vas deferens is tied and clipped. Sperm still made, but cannot leave
reproductive tract sot hey are reabsorbed Interventional methods of contraception:
- Barrier methods which prevent union of eggs and sperm (diaphragm, contraceptive
sponge, condom)
- Methods that prevent implantation of fertilized egg (IUD)
- Hormonal treatments that decrease/stop gamete production (oral contraceptives,
injections, vaginal ring)
20. Describe the common causes of male and female infertility.
MALE
- Low sperm count/high number of defective sperm
- Heat FEMALE
- Can be mechanical or hormonal, leading to decreased/absent ovulation
18. Diagram the erection reflex
One problem involving both is that the female can produce antibodies to her partners sperm.
Also, abnormal anatomy, or abnormal hormones.
Also: obesity, toxins in environment (BPA, pesticides, smoking, possibly soy)
21. Diagram the process of sperm capacitation and fertilization of an ovum.
Capacitation is the final maturation step, enabling sperm to fertilize an egg. It occurs in the
female reproductive tract.
Sperm and egg plasma membranes fuse, triggering cortical reaction (first polar body expelled)
sperm nucleus moves into cytoplasm of egg oocyte nucleus completes meiotic division
sperm and egg nuclei fuse to form zygote nucleus (second polar body is expelled)
22. Diagram the process of embryo development from fertilization
through implantation in the endometrium.
23. Describe the role of placental hormones during pregnancy.
Human chorionic gonadotropin (hCG):
- Maintains corpus luteum
Human chorionic somatomammotropin (hCS):
- Necessary for breast development and lactation Estrogen and progesterone:
- Estrogen helps develop milk secreting ducts in the breasts
- Progesterone maintains endometrium
(placenta takes over progesterone production corpus luteum degenerates)
24. Describe what we currently understand about the processes of labor and
parturition.
- Parturition begins w/ labor, signals that initiate these contractions could begin with
either the mother or the fetus, or a combination of signals from both
- Another potential trigger could be oxytocin, the peptide hormone that causes
uterine muscle contraction
- As pregnancy nears full term, the number of uterine oxytocin receptors increases
(studies show that oxytocin secretion does not increase until after labor begins).
- Another possibly is that the fetus somehow signals that it has completed
development
- One theory supported by clinical evidence is that CRH secreted by the placenta is the
signal to begin labor. In the weeks prior to labor, maternal CRH levels increase
rapidly, in addition, women w/ elevated CRH levels as early as 15 weeks are more
likely to go into premature labor.
25. Diagram a mammary gland and the control of milk and
colostrum production.
26. Diagram the let-down (milk ejection) reflex.
- The ejection of milk from the glands is known as the letdown reflex, and it requires
the presence of oxytocin from the posterior pituitary, which initiates smooth muscle
contraction in the uterus and breasts.
- In the lactating breast, oxytocin causes contraction of myoepithelial cells surrounding
the alveoli and in the walls of the ducts
- Contraction creates high pressure in the ducts that sends milk squirting into the
baby’s mouth
- Prolactin release requires the mechanical stimulus of suckling, oxytocin release can
be stimulated by various cerebral stimuli including the thought of the child
27. Describe how the reproductive systems of males and females change at puberty
and with menopause and andropause.
In girls:
- Onset of puberty marked by budding breasts and first menstrual period (menarche),
the average age being 12 In boys:
- Onset of puberty marked by growth and maturation of external genitalia
- Development of secondary sex characteristics such as pubic + facial hair
- Lowering of voice pitch
- Changes in body shape
- Changes in height
Puberty requires maturation of the hypothalamic pituitary control pathway
Before puberty the child has low levels of both steroid sex hormones and gonadotropins,
because low sex hormone levels normally enhance gonadotropin release, the combination of
low steroids and low gonadotropins indicates that the hypothalamus and pituitary are not yet
sensitive to steroid levels in the blood.
Menopause:
- Women’s reproductive cycles stop completely at the time known as menopause
- After about 40 years of periods, they become irregular and then stop completely
- Due to the ovaries which can no longer respond to gonadotropins, and in the
absence of negative feedback, gonadotropin levels increase dramatically in an effort
to stimulate the ovaries into maturing more follicles Andropause:
- The counterpart to menopause
- Testosterone production decreases with age
