A&P Module 2 - All Review Questions

Question 1

Endocrine System

What is an endocrine cell? What is a hormone?

Answer 1

An endocrine cell is a glandular secretory cell that releases hormones or factors into the ECF to travel in bloodstream either bound or free to its target cell where it binds and affects the target cell.

A hormone is a chemical messenger that is necessary for many body functions such as digestion and metabolism.

Question 2

Endocrine System

What are the three classes of hormones? What factor separates them into these classes?

Answer 2

The three classes of hormones are:

• Amino Acid Derivatives
• Peptide Hormones
• Lipid Derivatives.

They are either lipid or water soluble.

Question 3

Endocrine System

How are the nervous and endocrine systems similar?

Answer 3

The nervous system and endocrine systems are stimulated by the same types of chemical messengers, when used in the Nervous system they are known as neurotransmitters, when used by Endocrine system they are known as Hormones.

They also use negative feedback as a control method to regulate other cells, tissues, and organs that belong to other systems to maintain homeostasis .

Question 4

Endocrine System

Why is lipid or water solubility an important hormone characteristic?

Answer 4

Being lipid or water soluble is important because it determines both how the hormone travels to and how it interacts with the target cell.

Water soluble hormones can travel easily in the blood stream where lipid soluble hormones must bind to a transport protein to reach target cell.

Once at the target cell a water soluble hormone must bind to receptor site on cell membrane and through a series of reactions cause intended effect via second messenger.

A lipid soluble hormone can easily pass through membrane and bind to intracellular receptor site in cytoplasm on an organelle or the nucleus.

Question 5

Endocrine System

What is a second messenger?

Answer 5

Second messengers are used by water soluble hormones that bind to receptor site that is typically linked to G-proteins which trigger a cascade of reactions activating a second messenger (inside of cell) that carries out hormones intended effect.

Typical second messengers are: cGMP, cAMP, and Ca2+.

Question 6

Endocrine System

In what two ways can hormones travel to their target organs?

Answer 6

Water soluble hormones can travel easily in the blood stream where lipid soluble hormones must bind to a transport protein to reach target cell.

Question 7

Endocrine System

What are the three possible fates of free hormones?

Answer 7

Free hormones are typically deactivated within an hour due to:

• Diffusion out of blood stream binding to target tissue or cell
• Absorption by liver or kidneys where it is broken down
• Broken down by plasma or interstitial enzymes

Question 8

Endocrine System

What are the three mechanisms that exert control over endocrine activity?

Answer 8

Endocrine activity is controlled by:

• Humoral (Local) Control – changes in local ECF composition
• Hormonal Control – changes in circulating levels of hormones
• Neural Control – Arrival of neurotransmitter at neural-glandular junction; ie the hypothalamus is the link between neural and endocrine systems

Question 9

Endocrine System

What is the role of the hypothalamus in the endocrine system?

Answer 9

The hypothalamus is the link between the neural and endocrine systems.

It secretes regulatory hormones (inhibitory/releasing) into anterior pituitary and synthesizes ADH and OT which is secreted into posterior pituitary.

Question 10

Endocrine System

What is the Hypophyseal Portal System?

Answer 10

The Hypophyseal portal system is a system of blood vessels that **link the hypothalamus and the anterior pituitary in the brain. **

It is comprised of two capillary systems separated by a portal vessel.

It transports hormones secreted by hypothalamus to the anterior pituitary where 7 hormones are secreted that regulate various body functions.

Question 11

Endocrine System

What are the nine hormones secreted by the pituitary gland? How is their secretion controlled?

Answer 11

The posterior pituitary’s secretions are controlled by neural signals received from the hypothalamus. It releases:

ADH - Anti-diuretic Hormone and OT – Oxytocin.

The anterior pituitary’s secretions are controlled by hormonal control initiated by the hypothalamus via the hypopyseal portal system.

The hormones it secretes are:

• ACTH - Adrenocorticotropic Hormone
• TSH - Thyroid Stimulating Hormone
• FSH - Folicle Stimulating Hormone
• LH - Luteinizing Hormone
• PRL – Prolactin
• GH - Growth Hormone
• MSH - Melancyte Stimulating Hormone

All of the hormones are water soluble.

Question 12

Endocrine System

What is the primary responsibility of T3 and T4? How do these hormones exert their effects?

Answer 12

T3 and T4’s primary responsibility is the regulation of metabolism.

Because T3 and T4 are lipid soluble they pass through the cell membrane and act on the mitochondria to increase the rate of ATP production.

Increased body heat is a byproduct of the increase in ATP production.

Question 13

Endocrine System

What two hormones regulate plasma calcium? How do they do it?

Answer 13

Calcitonin is secreted by the C-cells (parafollicular cells) of the thyroid gland if blood calcium levels are elevated to inhibit the release of stored Ca2+ in bone., and increase Ca2+ excretion from kidneys.

The chief cells of the parathyroid produce PTH (parathyroid hormone) in response to low levels of blood Ca2+, causing an increase in Ca2+ released from bone, and decreasing Ca2+ excretion from kidneys.

PTH also stimulates the production of calcitrol which increases Ca2+ absorption in the digestive tract.

Question 14

Endocrine System

Which hormones are produced by the adrenal cortex? By the adrenal medulla?

Answer 14

The adrenal cortex produces corticosteroids (steroid hormones).

The three types of these hormones are:

• Mineral corticoids – which regulate electrolyte composition
• Glucocorticoid steroids – glucose metabolism and anti-inflammatory response
• Androgen – Sex cell and reproductive impact

The adrenal medulla produces Epinephrine, and **Norepinephrine ** which are:

• continually produced and released
• water soluble and travel easily in blood stream
• rapidly produced with sympathetic stimulation.

Question 15

Endocrine System

What are the roles of alpha, beta, and delta cells in the pancreas?

Answer 15

• Alpha cells are responsible for the production of glucagon
• Beta cells are responsible for the production of insulin
• Delta cells slow food absorption by suppressing insulin and glucagon production and producing a peptide hormone similar to GHIH

Question 16

Endocrine System

How does the body compensate for an elevated blood glucose level? For a decreased level?

Answer 16

The body compensates for an elevated BGL by secreting insulin which allows for:

• glucose to be transported into target cell
• utilization of glucose and generation of ATP
• helps convert glucose to glycogen
• participates in fat synthesis
• amino acid absorption and protein synthesis

The body compensates for an low BGL by secreting glucagon which:

• promotes breakdown of glycogen into glucose
• breakdown of fats into fatty acids
• synthesis of glucose – process called gluconeogenesis

Question 17

Digestive System

What are the six functions of the digestive system?

Answer 17

The six functions of the digestive system are:

• Ingestion – Food enters the mouth and digestive tract
• Mechanical – Physical manipulation of food into smaller organic fragments
• Digestion – Chemical breakdown of food into smaller organic compounds
• Secretion – release of water/enzymes/acid
• Absorption – movement of small molecules (nutrients), vitamins, water across digestive lining
• Excretion – Removal of waste products from the body

Question 18

Digestive System

Can you briefly describe each layer of the digestive tract?

Answer 18

There are four major layers of the digestive tract:

• Mucosa – Consists of Lamina Propria (connective tissue), Muscularis Mucosa (thin muscle layer), villa and plica
• Sub-mucosa – Consists of nerves and bloodvessels
• Muscularis externa – consists of two layers of smooth muscle (inner- circular, outer-longitudinal), separated by a layer of nerves
• Serosa – Visceral Peritoneum consists of visceral lining (next to organ), peritoneal fluid (sits between visceral and parietal lining), parietal lining

Question 19

Digestive System

What is peristalsis? What is segmentation?

Answer 19

Peristalsis is rhythmic contractions of smooth muscle that propel food through digestive tract

Segmentation is the mechanical mixing of materials in the digestive tract

Question 20

Digestive System

What is acites?

Answer 20

Acites is excess peritoneal fluid, commonly the result of liver disease or heart failure.

Question 21

Digestive System

What is the primary function of the parotid gland?

Answer 21

The Parotid gland is a salivary gland located anterior to the ear.

It produces salivary amylase enzyme which is a digestive enzyme which is necessary for the breakdown of starches.

It is the only part of digestion that begins in the mouth.

Question 22

Digestive System

At what point does the process of swallowing become involuntary?

Answer 22

Swallowing begins voluntarily with the tongue compacting the food bolus, followed by compression of the food bolus against the hard palate during the oral phase.

During the pharyngeal phase the bolus contact sensory receptors in the pharynx which initiates involuntary swallowing.

Question 23

Digestive System

What is the esophageal hiatus? What is hiatal hernia?

Answer 23

The esophageal hiatus is the hole through which the esophagus passes through the diaphragm and into the stomach.

A hiatal hernia forms when there is a tear or injury between the diaphragm and the esophagus which allows the high pressure contents of the abdomen to force their way out of cavity through injured tissue.

Question 24

Digestive System

Which chemicals are secreted in the stomach to form chyme?

Answer 24

Chyme consists of:

HCl, mucous, and pepsinogen which along with partially digested food are passed along into the small intestine through pyloric sphincter.

Question 25

Digestive System

What is the role of the parasympathetic nervous system in digestion?

Answer 25

The parasympathetic nervous system stimulates digestion by providing promoting gastric motility and increased gastric juices due to positive feedback of the peptide hormone – gastrin’s affect on the stomach.

The sympathetic nervous system provides negative feedback to the digestive system, in form of stress which dries secretions and halts digestion in preparation for fight or flight.

People who have high anxiety or stress levels are prone to ulcers due to the negative feedback of the sympathetic nervous system which dries the mucosa of the stomach and exposes it to HCl, and injury.

Question 26

Digestive System

What are the functions of the structures found in the liver lobules, including hepatocytes, Kupffer cells, sinusoids, and the central vein?

Answer 26

Hepatocytes – the primary cell in the liver, what performs the bulk of liver function

Kupffer Cells – immune cells of the liver, job is to destroy damaged RBC’s and Pathogens that enter the liver

Sinusoids – capillaries that belong to the liver; sinusoids feed central vein

Central vein – where blood is routed once it has completed liver function and is routed back via the central vein to the Inferior Vena Cava.

Question 27

Digestive System

What is the hepatic portal system? Why is it important?

Answer 27

The hepatic portal system is the portal system which routes blood that interacts with the GI tract (Lg/Sm Interstine, Stomach, spleen) then to the liver.

The system is designed to remove chemicals and nutrients that are dissolved in blood before returning it to circulation.

Question 28

Digestive System

Why is portal hypertension problematic for patients?

Answer 28

Portal hypertension causes the formation of collateral circulation, enables unfiltered blood to bypass the liver, potentially causing toxins to move systematically through body. ie Ammonia = AMS

Question 29

Digestive System

What is the function of bile? How does it work?

Answer 29

Bile is a substance produced by the liver to help with the digestion of lipids.

Initially bile salts form a micelle around the lipid droplet. Once micelle is formed it has the ability to diffuse across the cell membrane into the intestines where it can be broken down further into a protein coated complex called a chylomicron.

Question 30

Digestive System

Name one example of positive feedback in the digestive system.

Answer 30

The digestive system uses positive feedback of Gastrin during the Gastric phase of digestion. Continuing the digestion process by stimulating the production of muscous, Pepsinogen, and HCl.

Question 31

Digestive System

Name one example of negative feedback in the digestive system.

Answer 31

The digestive system uses negative feedback of GIP, Secretin, and CCK during the intestinal phase of digestion. Discontinuing the digestion process by inhibiting muscous, Pepsinogen, and HCl.

Question 32

Nutrition & Metabolism

What is nutrition? What is metabolism?

Answer 32

Nutrition is the absorption of essential nutrients from food.

Metabolism is the chemical conversion of nutrients that happen in the body, occurring at the cellular level (anabolism & catabolism).

Question 33

Nutrition & Metabolism

What is the difference between aerobic and anaerobic metabolism?

Answer 33

Aerobic metabolism requires Oxygen to be present. Anaerobic metabolism is always taking place, and is able to continue in the absence of Oxygen. Anaerobic metabolism does not require Oxygen to function.

Question 34

Nutrition & Metabolism

What is glycolysis? What are the products of glycolysis?

Answer 34

Glycolysis is the breakdown of glucose into pyruvic acid occurring in the cytosol of the cell. It is an anaerobic process that is not efficient enough to keep up with the demand for ATP. Glycolysis produces 4 ATP molecules and NADH and the product pyruvic acid.

Question 35

Nutrition & Metabolism

Why does lactic acid build up in tissues?

Answer 35

Lactic acid builds up in tissues when the body cannot remove it fast enough. During high levels of exertion when oxygen demand and aerobic production for ATP is surpassed the body continues to produce ATP anaerobically. The byproduct of anaerobic metabolism is lactic acid.

Question 36

Nutrition & Metabolism

What is the goal of the TCA cycle?

Answer 36

The goal of the TCA is to transfer electrons captured in Krebs cycle, and pump them via chemiosmosis through the protein structures located in the mitochondrial membrane, creating the H+ gradient necessary for the synthesis of ATP.

Question 37

Nutrition & Metabolism

What is the role of oxygen in the electron transport chain? What happens when it is absent?

Answer 37

2 Oxygen molecules interact with 8 electron molecules forming 2- water molecules and pumping 4 hydrogen molecules across the membrane, creating the chemical gradient necessary for ATP synthesis. If Oxygen is absent, anaerobic production of ATP remains as the source of ATP production.

Question 38

Nutrition & Metabolism

In the absence of glucose, what other organic molecules are available to form one of the precursors to the citric acid cycle?

Answer 38

In the absence of glucose, triglycerides and proteins can be modified to form one of the precursors to the citric acid cycle.

Question 39

Nutrition & Metabolism

What is the difference in energy gain between one molecule of glucose and one fatty acid molecule?

Answer 39

One fatty acid molecule can produce 144 units of ATP versus one molecule of glucose which can produce 36 units of ATP.

Question 40

Nutrition & Metabolism

What are lipoproteins? Why are some classified as good or bad?

Answer 40

Lipo-proteins are lipids like cholesterol and triglycerides that bind with proteins, enabling them to be transported in the blood. Some are classified as good or bad due to the direction of travel within the body. Higher density Lipo-proteins (HDL) travel from peripherial tissues toward the core and are thought to be better. Low density Lipo-proteins travel from core to peripheral tissues enabling them to clog or cause circulatory problems.

Question 41

Nutrition & Metabolism

What are ketone bodies? What are their sources?

Answer 41

Ketones are acids which release their H+ into the bloodstream causing a shift in pH, leading to increased CO2 and respiratory effort to discard excess CO2. Ketones are a byproduct of lipid and protein metabolism which occurs in Type I diabetes when insulin is not present in bloodstream to provide access to cell for glucose.

Question 42

Nutrition & Metabolism

Why is acidosis seen with DKA and not with HHNK?

Answer 42

Acidosis is seen in DKA and not HHNK because Type II diabetics typically have sufficient insulin in bloodstream to prevent cells from resorting to lipid or protein metabolism for energy production where Type I diabetics do not, resulting in the production of Ketones.

Question 43

Nutrition & Metabolism

What is the role of vitamins in the body? The role of minerals?

Answer 43

Vitamins are essential organic nutrients in the diet, and are organically similar to lipids and carbohydrates. They can be fat soluble (ADEK) and be stored for long periods of time in body tissues, or water soluble. They have many functions in the body from the synthesis of fatty acids (vitamin H, aka biotin) to metabolism (B5, aka Aceytl CoA). Minerals are inorganic ions, electrolytes and salts. Ie. Potassium, Calcium, Chloride, Sodium. Many function as Cofactors for enzymatic reactions.

Question 44

Nutrition & Metabolism

What is basal metabolic rate? How does it relate to weight loss or gain?

Answer 44

Basal metabolic rate is the amount of energy expended at rest, and is calculated by height and weight. Weight gain is seen when caloric intake exceeds metabolic output, and vice versa when metabolic output exceeds caloric consumption.

Question 45

Nutrition & Metabolism

What is the role of the hypothalamus in thermoregulation?

Answer 45

The hypothalamus houses the heat loss and heat gain centers for the body. The heat loss center activates the parasympathetic nervous system when we want to lose heat on purpose ie vasodilation, sweating and increased respiration. The Heat gain center is linked to the sympathetic nervous system when we want to gain body temperature ie. vasoconstriction, shunting, shivering and non shivering.

Question 46

Nutrition & Metabolism

What is non-shivering thermogenesis?

Answer 46

Non-shivering thermogenesis is hormonal stimulation of metabolic rate ie. epi and thyroxnine.

Question 47

Nutrition & Metabolism

What is the relationship between body temperature and homeostasis?

Answer 47

In order for the body to maintain homeostasis, it must operate within a fixed range of temperatures. Variation of temperature, either higher or lower, affects the metabolic and physiological responses of the body. It is critical that body temperature in maintained in order to ensure normal body function.

Question 48

Renal System

What are the three basic functions of the renal system?

Answer 48

The basic functions of the renal system are:

Excretion – eliminating the “stuff” that we don’t want
Elimination – physical process of getting it out of the body
Homeostatic Regulation – regulating BP/blood volume/Acid-Base Balance, and water balance

Question 49

Renal System

Where are the kidneys located in the body? Why are they at risk for injury?

Answer 49

The top of the kidneys are located at the 11th and 12th ribs, the remainder of the kidneys are exposed below this point. They sit retroperitoneal between T12 and L3, and are about the size of the owner’s fist. They are at risk for injury from blunt trauma because they are not protected by the ribcage, and they receive 25% of the blood pumped from the heart.

Question 50

Renal System

What are the renal medulla, cortex, and pelvis?

Answer 50

The renal cortex is the superficial internal structure of the kidneys. The medulla aka the pyramid is the deeper internal structure. The nephron straddles the cortex and the medulla. The renal pelvis is the dumping basin before the urine gets moved to the ureter.

Question 51

Renal System

What is a nephron? What are the components?

Answer 51

The nephron is the functional unit of the kidneys, there are over 2 million of them in the human body. They are composed of: the afferent and efferent arteriole, the glomerulus, Proximal/Distal Convoluted Tubules, the loop of Henele, the peritubular capillaries, the vasa recta, and the collecting duct.

Question 52

Renal System

What is the difference between filtrate, tubular fluid, and urine?

Answer 52

Filtrate is the initial fluid once it has been filtered through the fenestrations of the glomerulus. Filtrate consists of water, salt, glucose, amino acids, and waste products (urea, uric acid, creatitnine). 95% of the nutrients are reabsorbed in the PCT such as water, Na, Ca2+, Cl-, AA’s, glucose, and salts. This leaves waste products, Na, water, and K as the main components of Tubular fluid. Urine consists of waste products, water, Na, and K depending on what the body needs for homeostasis.

Question 53

Renal System

What type of capillary is present in the glomerulus? Why are these necessary for kidney function?

Answer 53

The glomerulus has a fenestrated capillary which has podocyte cells that wrap around the capillaries and hold back large particles like plasma proteins. They are necessary because they allow filtration to occur, removing smaller particulate while retaining larger structures that the body needs to retain.

Question 54

Renal System

What happens to the capillaries of the glomerulus with long-term diabetes?

Answer 54

The capillaries of patients with long-term diabetes are damaged due to the caustic nature of glucose on the vasculature. Chronically high bgl’s (>180 mg/dL) destroys the filtration mechanism, allowing everything to pass and remain circulating in the blood stream, hence the reason many diabetics will need dialysis to filter blood of the circulating toxins.

Question 55

Renal System

What is the primary function of the PCT? Of the descending loop of Henle? Of the ascending limb?

Answer 55

95% of the nutrients are reabsorbed in the PCT such as water, Na, Ca2+, Cl-, AA’s, glucose, and salts. The descending loop of Henle’s main function is the reabsorbtion of water which is complimented by the Na reabsorption that occurs in the ascending limb. This Na follows H2O follows Na follows H2O is known as the countercurrent multiplier and is important to the 80% of water that is reabsorbed in the loop of Henle.

Question 56

Renal System

What is the primary role of the DCT? Of the collecting duct?

Answer 56

The primary role of the DCT is secretion and the regulation of acid-base balance by secretion of H+ or Bicarb. The Collecting duct collects urine to be taken to the renal presence. In the presence of ADH, aquaporins form to collect water and prevent dieresis.

Question 57

Renal System

What are the three types of waste products eliminated via the kidneys?

Answer 57

Three types of waste products found in urine are urea, uric acid, creatitnine.

Question 58

Renal System

What is the difference between filtration, reabsorption, and secretion?

Answer 58

Filtration takes place in the renal corpuscle and is the separation of waste products and nutrients (to be reabsorbed later) from the blood. Reabsorption is the process in which nutrients lost in filtration are reclaimed by the body. Reabsorption take place primarily in the PCT and the loop of Henle. Secretion is the excretion of ions and water depending on need out of the body into the nephron. Secretion primarily takes place in the DCT and the Collecting duct.

Question 59

Renal System

How do hydrostatic (filtration) pressure and osmotic pressure interact in Bowman’s Capsule?

Answer 59

In order for filtration to work hydrostatic pressure must be greater than osmotic pressure. The body controls this via mechanical receptors, chemoreceptors and hormones (stimulated by hormones) housed in the Juxtaglomerular Apparatus.

Question 60

Renal System

How does local regulation of the afferent and efferent arteriole allow for maintenance of homeostasis?

Answer 60

Local regulation reacts to minor changes in BP. A minor drop in BP causes vasodilation of the afferent arteriole (increasing the amount of blood flow arriving) and vasoconstriction of the efferent arteriole (increasing hydrostatic pressure and maintaining filtration). A minor increase in BP causes stretch receptors to cause vasoconstriction of Afferent arteriole limiting the amount of blood arrival into the glomerulus for filtration.

Question 61

Renal System

What is the effect of sudden hypotension on the filtration process?

Answer 61

Sudden hypotension (

Question 62

Renal System

What is the role of the peritubular capillaries?

Answer 62

The Peritubular capillaries travel along outside of the nephron and allow the reabsorption and secretion of nutrients to occur.

Question 63

Renal System

In which part of the nephron do aldosterone and ADH exert their effects?

Answer 63

Aldosterone exerts it most of effect in the DCT and ADH exerts most of its effect in the collecting duct.

Aldosterone causes increased Na reabsorption.

ADH causes production of aquaporins to form to collect water.

Question 64

Renal System

What type of neural control is exerted over the kidneys?

Answer 64

Sympathetic neural control activates systemic vasoconstriction which aims at increasing BP enough perfuse the vital organs (Heart, Lungs, Brain, Kidneys).

Prolonged absence of BP (approximately 2 hrs) will result in kidney failure.

Question 65

Renal System

What hormones are involved in maintenance of homeostasis in the kidneys? Why is angiotensin II so important?

Answer 65

ADH and Aldosterone are involved help to retain water.

ATP is secreted by cardiac muscle cells in response to high levels of water and blood volume, works by reducing water uptake by inhibiting aldosterone and ADH

PTH helps to maintain Calcium balance by promoting reabsorption in the PCT.

Renin an enzyme released by cells in the Juxtaglomular Apparatus converts Angiotensinogen into Angiotensin I which via Angiotensin Releasing Enzyme (ACE) is converted into Angiotensin II which causes: Peripherial Vasoconstriction, Constriction of efferent arteriole, release of ADH, and the release of E and NE

Question 66

Renal System

What are the functions of the bladder? How does its structure correspond with its functions?

Answer 66

The bladder collects urine secreted by kidneys and moved via ureters into the pelvic cavity collection and storage of urine.

The bladder has slits on posterior surface where the urine enters the bladder that prevents backflow.

It has three layers, the transitional epithelium which can expand and contract like the rugae in the stomach to accommodate increases in volume.

The muscular layers are known as detrusor muscles, which contract to expel urine when given the signal.

Question 67

Renal System

What is the effect of an enlarged prostate on urine excretion?

Answer 67

The top of the urethra is guarded by the prostate. An enlargement in the prostate puts pressure on the urethra making expulsion of urine difficult.

Question 68

Renal System

How does the brain become aware of the body’s need to urinate?

Answer 68

The brain receives a signal via the parasympathetic nervous system once the bladder has 200ml of urine, providing conscious awareness of the body’s need to urinate.

Contraction of the detrusor muscle via parasympathetic stimulation occurs.

Relaxation of the external uretheal sphincter is followed by relaxation of the internal urethral sphincter and urination follows.

If the external urethreal sphincter is not relaxed, detrusor muscles relax and process repeats in one hour.

Question 69

Renal System

How do the kidneys contribute to compensation for acid/base imbalance?

Answer 69

Where the lungs are responsible for fast maintenance of acid/base via respiration, the kidneys secrete either H+ or Bicarb to regulate blood pH through expulsion of urine.

If the blood is acidic, as in DKA, excess hydrogen ion will be secreted into the urine to eliminate it.

Question 70

Lymphatic System

What are the three functions of the lymphatic system?

Answer 70

The three functions of the lymphatic system are:

• the production, maintenance, and distribution of lymphocytes;
• to return body fluids and solutes from ECF and peripheral tissues to the vascular system;
• Distribution of nutrients, hormones, and waste products to circulation (ie the chrylomicron being absorbed by the lacteal and distributed by lymphatic system.)

Question 71

Lymphatic System

What are the three types of lymphocytes?

Answer 71

The three types of lymphocytes are:

T-Cells (Thymus dependent cells) – aka Cytotoxic T’s – responsible for cell mediated immunity and account for 80% of all Lymphocytes

B-Cells – responsible for Anti-body mediated Immunity – account for 10-15% of all lymphocytes.

NK-Cells – Natural Killer cells – responsible for immunologic surveillance – account for 5-10% of all lymphocytes.

Question 72

Lymphatic System

Why is removal of a lymphoid organ problematic for patients?

Answer 72

Removal of a lymphoid organ can have serious immunologic implications due to the role each organ plays in fighting infection. The lymphnodes filter 99% of all pathogens and activate B & T cells, which is a reason why they are often examined for places where cancer may present itself. A common side effect of removal of part or all of lympnodes in a region may result in lymphedema swelling of the arm. The spleen initiates B & T cell response, and stores iron from recycled RBC’s. Due to the large amount of blood that flows to the spleen a laceration can cause severe bleeding. Hepatic portal hypertension can also cause spleenomegy (an enlarged spleen) and be indicated for removal. Because if its role in the lymphatic system a concerted effort is made to leave the spleen intact rather than remove it if there is any hope for it to recover from the damage. Patient who have their spleen removed are at a much higher risk of infection for remainder of their life.

Question 73

Lymphatic System

How do natural killer cells manage an encountered pathogen?

Answer 73

Natural killer cells manage an encountered pathogen by attacking: foreign cells, body cells infected with a virus, and normal body cells infected with cancer. They are responsible for immunologic surveillance. Once a NK cell locate the pathogen it moves close to it and secretes Perforin which creates holes in the surface of the pathogen which causes ions to move freely in both directions across the cell membrane, causing the cell to lyse.

Question 74

Lymphatic System

What is the role of interferons?

Answer 74

Interferons are small proteins that are released by activated lymphocytes and macrophages due to the presence of a virus in cells. Interferons work by second messenger to prevent replication of the virus. Interferons don’t destroy the virus or reverse other damages; they slow the rate of spread by the virus. Interferons belong to a class of chemical messengers that coordinate local activities.

Question 75

Lymphatic System

What is the difference between specific and non-specific defenses?

Answer 75

Specific and non-specific defenses are immunological responses by your body to fend off pathogens. Non-specific responses react the same way to every kind of invader or pathogen to deny entry and limit the spread of pathogens in the body. Examples of non-specific defenses are: physical barriers such as skin, oil, hair, and mucous membranes, digestion, and the body’s excretion systems (urine & fecal); Phagocytes; NK cells; Interferons; Compliment proteins; Fever; and Inflammation. Specific defenses and immunity are specific resistance or immunity developed in response to the presence of a pathogen.

Question 76

Lymphatic System

What are the four types of acquired immunity?

Answer 76

The four types of acquired immunity are:

• Naturally Acquired Active Immunity – response to an antigen in environment, exposure leads to the development of the anti-body
• Induced Active Immunity – immunity in reponse to the administration of a vaccine ie chicken pox
• Natural Passive Immunity – immunity gained by the fetus transferred maternally
• Induced Passive Immunity – immunity gained by medication administered to fight an infection.

Question 77

Lymphatic System

What is antigen recognition?

Answer 77

Antigen recognition is used to generate a specific defense when activated by a specific antigen.

Antigen receptors sitting on surface of the B cell are activated only by antigen that matches that receptor.

Question 78

Lymphatic System

Where does cell-mediated immunity take place? Where does antibody-mediated immunity take place?

Answer 78

T cells protect against abnormal cells and pathogens in living cells, ie cell mediated immunity.

B cells protect against antigens and pathogens in body fluids (humoral), antibody mediated immunity.

Question 79

Lymphatic System

What is the difference between Class I MHC proteins and Class II MHC proteins?

Answer 79

Class I MHC is found on all nucleated cells. They work by presenting fragments of proteins from within the cell (cytosol) to the T cells outside of the cell, healthy cells will be left alone, while foreign proteins will be attacked and killed. Cytotoxic T cells are activated only by Class I MHC proteins.

Class II MHC’s are only found on Antigen presenting cells and lymphocytes. Helper T cells are activated by Class II MHC proteins to coordinate specific and non-specific defenses, and to stimulate cell and antibody mediated immunity.

Question 80

Lymphatic System

Once cytotoxic T cells encounter an antigen bound to MHC, what subsequent steps must occur before it will attack the cell?

Answer 80

The cytotoxic T cell will recognize an antigen bound to a class I MHC protein then it will divide and differentiate into: active cytotoxic T cells which help to manage current presentation of antigen; and memory T cells which lie dormant until a second presentation of antigen.

Question 81

Lymphatic System

What three ways can cytotoxic T cells destroy the target cell?

Answer 81

The three ways can cytotoxic T cells destroy the target cell are:

• Secretion of lymphotoxins which disrupt the metabolism of the cell
• Secretion of cytokines (interfere with genes), affects genes and stimulates Apoptosis (programmed cell death)
• Release of Perforin which causes lysis of the target membrane by causing holes in cell membrane which allow for the free movement of ions in/out of the cell.

Question 82

Lymphatic System

Memory T cells can differentiate into what two types of cells following secondary exposure?

Answer 82

Memory T’s can only be activated by second exposure or later and differentiate into cytotoxic T’s and Helper T cells.

Memory T’s help to create a rapid response in event of second exposure, increasing the effectiveness of the immune response.

Question 83

Lymphatic System

What actions follow sensitization of B cells? What is the role of helper T cells in this process?

Answer 83

B cells launch a chemical attack by producing antibodies. Once the B cell is sensitized, meaning that an antigen has been engulfed by the B cell and a fragment has been presented to the surface. Circulating Helper T’s come along and recognize the presence of the antigen and secretes cytokines which allows for B cell activation and differentiation. B’s differentiate into Active B cells for circulation against current pathogen, and memory B’s for use against future invasions by same antigen. Active B’s turn into plasma cells which are responsible for the production of antibodies.

Question 84

Lymphatic System

Which class of immunoglobulins is responsible for allergic reactions?

Answer 84

IgE is bound to the surface of MAST cells and basophils. It stimulates the release of histamine and other chemicals, and promotes inflammation.

Question 85

Lymphatic System

What is agglutination and precipitation?

Answer 85

Agglutination is the clumping together of Antigens by antibodies when in close proximity. Typically seen when blood types are incompatible.

Precipitation is when the larger clumps form particulate and fall out of the solution, as when a clot forms and is no longer solulable in the blood.

Question 86

Lymphatic System

What is the difference between a first exposure and a second exposure to an antigen?

Answer 86

The peak response to a first exposure to an antigen is about 2 weeks, where IgM is secreted in response to the presence of the antibody. This response is delayed due to the body needing time to become sensitized to antigen, causing activation of B cells and the formation of plasma cells to make the antibodies, meanwhile we are making memory B cells. The first exposure takes about 4 weeks to complete. The second exposure can take place anytime after the first exposure, this time IgG is primarily released, causing a earlier peak response with a stronger effect.

Question 87

Lymphatic System

How does a Type I allergy respond to the presence of an antigen?

Answer 87

A Type I allergy response is the anaphylactic response to the presence of an antigen. It is an immediate hypersensitivity or inappropriate/extreme response to an allergen which still follows the first exposure, second exposure rule. On first exposure the B cell is sensitized causing the production of IgE (caused by B cell activation which causes Activated B cells to produce plasma cells which produce IgE). This portion of the reaction is too slow to create the hives or swelling etc. However, Memory B cells are made once the B cells are activated which make antibodies and attach to MAST and Basophil cells which then release: Histamine, prostaglandin, heparin, and cytokines which stimulate inflammation.

Question 88

Integumentary System

What are the functions of the integumentary system?

Answer 88

The 5 main functions of the integumentary system are:

• Protection – loss of body fluid, impact, chemicals, and infection
• Temperature maintenance – regulate heat loss to environment
• Synthesis and storage of nutrients (ie Vit D)
• Sensory Reception – Touch, pressure, pain
• Excretion/Sucretion – Salts, water, organic waste loss to the environment

Question 89

Integumentary System

What are the five strata of the epidermis? Which layer is only noted on palms and soles?

Answer 89

• Stratum Corneum – cornified/keratinized, most of the barrier functions are associated with this layer, 15 to 30 layers of dried/dead epithelial cells
• Stratum Lucidum – Only noted in palms and soles; clear/glassy layer
• Stratum Granulosum – receives one daughter cell from below; synthesis of keratin
• Stratum Spinosa – receives one daughter cell from below
• Stratum Germinativum – Attached to basement layer by hemidesmosomes

Question 90

Integumentary System

What is the process by which skin cells move from the germinal layer to the exterior?

Answer 90

Cells divide via mitosis (regular cell division), which make more daughter cells, some of which move up into next layer.

This process continues until the cells reach the surface.

For every cell that divides, two daughter cells are created, one daughter cell stays in original layer and one moves up into the next layer.

Question 91

Integumentary System

What is the function of epidermal ridges?

Answer 91

The function of the epidermal ridges is similar to the vili in the intestines, it is to increase the surface area between the epidermis and the dermis.

This is helpful because the Epidermis is avascular and it gets its nutrients through this structure.

These ridges also result in the formation of finger prints on hands which allows for grip security and friction.

Question 92

Integumentary System

What two components affect skin color?

Answer 92

Melanocytes, located in the stratum germantivum produce melanin which is partially responsible for skin color, along with Carotene.

Melanin makes your skin darker with increased exposure to sun.

Freckles are concentrated areas of melanin.

The change is color is intended to protect the sun from UV radiation.

Carotene also protects the skin from ultraviolet rays, and converts to Vit A, which is also good for your eyes. (UV exposure promotes Vit D resynthesis; Vit D3 converts to calcitrol by kidneys which acts as a hormone for the absorption of calcium and phosphorus in small intestines).

Question 93

Integumentary System

What is the function of the subcutaneous layer?

Answer 93

The subcutaneous layer or hypodermis stabilizes the position of skin relative to the underlying organs. It permits movement of underlying organs as the body moves.

Question 94

Integumentary System

Why does skin shed in sheets?

Answer 94

The stratum corneum is comprised of 15-30 layers of flattened and dead epithelial cells.

The cells of this layer are still connected by desmosomes which hold cells tight to one another, and cause the skin to flake off as a unit when damaged.

Question 95

Integumentary System

What is the arrector pilli muscle?

Answer 95

• The arrector pilli muscle is found spanning from the bottom of the hair follicle to the sebaceous gland.
• It is enervated by the sympathetic nervous system which, which with contraction will make the hair stand on end, ie. goosebumps.
• Contraction of this muscle also secretes a small amount of sebum (oily substance) which helps to protect from growth of bacteria.

Question 96

Integumentary System

What do hair and skin have in common?

Answer 96

• Hair and skin both get their pigment from melanin.
• The lack of production of melanin in old age will result in gray hair.

Question 97

Integumentary System

What is the function of sebum?

Answer 97

Sebum is an oily substance secreted by the sebaceous gland, designed to prevent the growth of bacteria and is responsible for oily hair.

Question 98

Integumentary System

What is the function of a fingernail or toenail?

Answer 98

The finger and toe nails are located on the dorsal surfaces of fingers and toes.

They provide protection by limiting distortion secondary to mechanical stress.

Question 99

Reproductive System

What is ovarian torsion?

Answer 99

Similar to testicular torsion, ovarian torsion is the result of the twisting of the ovary around surrounding vasculature. As with testicular torsion if severe enough the blood flow to the ovary may be occluded and necrosis may occur. Patients often present with sudden onset, acute lower abdominal pain. Delay in treatment can cause loss of ovary.

Question 100

Reproductive System

What is the difference between mitosis and meiosis?

Answer 100

Mitosis is the division of somatic cells, creating identical duplicates of the 23 diploid pairs of chromosomes (46 chromosomes in all). Meiosis is two cycles of cell division in which the goal is to yield 4 haploid cells with a total of 23 chromosomes each; these are then carried by the gamete cells (sperm & ova) in hope of fertilization. During meiosis crossing over of genes or traits creates 4 unique gametes versus mitosis which always yields genetically identical cells.

Question 101

Reproductive System

Why is the scrotum located outside of the body?

Answer 101

The scrotum is located outside the body in order to regulate the temperature of the testes. The cremaster muscle raises and lowers the scrotum in order to maintain optimal temperature of 2 degrees Fahrenheit/1 degree Celsius cooler than the body.

Question 102

Reproductive System

What is testicular torsion?

Answer 102

Testicular torsion is the twisting of the testes around the spermatacord. The twisting, if not remedied, can impede blood supply and cause necrosis of the testes. Testicular torsion is viewed as an acute injury and patients are fast-tracked into surgery for repair.

Question 103

Reproductive System

What type of autonomic innervation is involved with the penis? What neurotransmitter is released? And what is the result?

Answer 103

Parasympathetic innervation is responsible for the processes of the penis. The penile arteries have neurons that release Nitric Oxide, which causes vasodilation, which causes erection.

Question 104

Reproductive System

Can you describe the anatomy of a spermatozoan?

Answer 104

The spermatozoa has 3 sections: The head, middlepiece, and Tail.
The head consists of: the Acrosomal cap which contains enzymes which help to break down exterior of ovum in case of fertilization, and the Nucleus which contains the haploid product of meiosis. The middle piece joins at the neck and contains the mitochondrial spiral which is used to produce energy(ATP) for the sperm, necessary for locomotion. The Tail or flagellum is a whip like structure that once capacitation has taken place, is used for locomotion.

Question 105

Reproductive System

What is capacitation?

Answer 105

Capacitation is what is necessary for the sperm to become mobile. Two things must take place for the sperm to become viable: It must mix with the secretions from the seminal vesicles, and it must be exposed to the conditions of the female reproductive tract.

Question 106

Lymphatic System

What is agglutination and precipitation?

Answer 106

Agglutination is the clumping together of Antigens by antibodies when in close proximity. Typically seen when blood types are incompatible.

Precipitation is when the larger clumps form particulate and fall out of the solution, as when a clot forms and is no longer solulable in the blood.

Question 107

Reproductive System

What is different about the generation of sperm in males and the generation of ova in females?

Answer 107

The goal of meiosis is to produce 4 haploid gametes. Sperm use all of the gametes to form 4 individual spermatozoa. In female reproduction, the primary oocyte (produced from mitosis) splits into one secondary oocyte and one polar body during meiosis I, and the formation of one mature ovum and 3 polar bodies during meiosis II. The one mature ovum is the only viable gamete yielded from this process, the other 3 polar bodies will be broken down by the body.

Question 108

Reproductive System

What is the path of travel of a secondary oocyte after it leaves the ovary?

Answer 108

When ovulation occurs and the secondary oocyte ruptures from the ovary, it is released into the interstitial space between the ovary and the uterine/fallopian tube. Once inside the uterine tube, it travels via cilia and peristalsis approximately 13 cm to uterus. If ovum meets a dashing sperm within 12-24 hours fertilization has the opportunity to take place, if successful the union will yield a zygote.

Question 109

Development and Inheritance

What physiologic changes occur in a neonate to help him or her transition to life outside of mom?

Answer 109

The neonate undergoes several physiological changes at birth to enable him/her to transition to life in outside world.

• Passing through the birth canal squeezes fluid out of lungs and enabling them to be filled with oxygen for first time.
• A powerful inhalation is required to fill the lungs with air, because lungs are somewhat flat before birth.
• The powerful inhalation also initiates the separation of pulmonary and systemic circulation; the foramen ovale closes due to greater left atrial pressure and ductus arteriosus begins to close (may take 24-48 hours to completely close).
• The digestive system releases stored waste products (meconium = mucous, bile, epithelial cells).
• The neonate is unable to retain heat or concentrate urine which causes him/her to lose heat to environment easily.

Question 110

Reproductive System

Benign Prostate Hyperplasia (BPH) is an enlargement of the prostate. What is the significance of this problem?

Answer 110

BPH is an enlargement of the prostate due to an increase in the number of cells. This becomes a problem when the enlargement of the prostate causes a partial or total obstruction of the urethra. It can cause frequent or painful urination, along with an increased risk of UTI.

Question 111

Reproductive System

Can you briefly describe the phases of the uterine cycle?

Answer 111

The uterine cycle lasts an average of 28 days and consists of three phases. Menses (days 1-7), due to a low level of hormones in the body the functional zone of the endometrium degrades and sloughs off, releasing 35-50ml of blood each time. These hemorrahages are known as menstruation. The proliferative phase (days 7-14), surviving epithelial cells in uterus spread across endometrium yielding a couple mm of tissue (caused by release of estrogen by developing follicle). The Secrectory Phase (days 15-28), increased production of progesterone by the corpus luteum causes the endometrium to double in thickness in preparation of the arrival of an embryo and the uterine glands to mature. If fertilization does not take place, the corpus luteum degenerates and the low level of the hormones in the body causes the cycle to repeat.

Question 112

Reproductive System

Can you briefly describe the phases of the ovarian cycle?

Answer 112

In the follicular phase (day 1-14), the development of a follicle under the influence of FSH, causes the development of the follicle (which secretes estrogen) and of the secondary oocyte. On approximately day 14, ovulation occurs and follicle ruptures, releasing secondary oocyte into the pelvic cavity. Once in the uterine tube it is swept along via cilia and peristalsis. The second half, or luteal phase (days 14-28), the cells that surrounded the ovum are transformed into a mass of yellow cells to form the corpus luteum, which secretes progesterone. If fertilization does not take place within 12 days, this mass of cells degenerates, menstruation occurs, and a new cycle begins.

Question 113

Reproductive System

Which hormones are involved with the uterine cycle?

Answer 113

The uterine cycle utilizes the hormones estrogen and progesterone, which are released by the developing follicle and the corpus luteum respectively, in response to FSH and LH released by the anterior pituitary.

Question 114

Development and Inheritance

What are the three stages of prenatal development? What time frame marks each boundary?

Answer 114

The stages of prenatal development are divided into 3 stages: Fertilization, Embryonic development, and Fetal development. Fertilization starts at conception (union of egg and sperm) until the blasyocyst (developing zygote) implants itself in the uterine wall, approximately 6-7 days. During weeks 1-8, Embryonic development takes place as germ layers differentiate into different tissues and structures. At week 9, until delivery, the embryo becomes a fetus, and the structures differentiated during the fetal stage continue to develop and grow.

Question 115

Development and Inheritance

What things have to happen in order for fertilization to occur?

Answer 115

For fertilization to occur a viable sperm (which has met the conditions of capacitation) must reach the upper third of the uterine tube and penetrate a secondary oocyte within 12 to 24 hours after ovulation. The enzymes within the acrosomal cap are released which help break down the bonds of the corona radiata, a protective shell that surrounds the secondary oocyte. If a sperm is successful in penetrating the oocyte, a fusion of membranes takes place which triggers oocyte activation and engulfs the sperm into the cytoplasm. Each nucleus will then reorganize to form a pronucleus which then fuses and completes fertilization.

Question 116

Development and Inheritance

How many days pass by after fertilization before implantation occurs?

Answer 116

Approximately 6 days pass between fertilization in the uterine tube to when the blastocyst implants itself into the uterine wall.

Question 117

Development and Inheritance

What blood vessels are contained in the umbilical cord?

Answer 117

The umbilical cord contains 2 umbilical arteries carrying deoxygenated blood from the embryo, and 1 umbilical vein carrying oxygenated blood.

Question 118

Development and Inheritance

Can you list the maternal changes during pregnancy?

Answer 118

The changes that the pregnant mother will experience during pregnancy are:

• Increased tidal volume and respiratory rate
• Increased blood volume; 50% more by the end of gestation
• Increased GFR by 50%
• Increased requirement of vitamins and nutrients by 10-30%
• Slowed GI motility for increased nutrient absorbtion
• Increase in size of mammary glands and uterus

Question 119

Reproductive System

What are the three major functions of the vagina?

Answer 119

The vagina is elastic muscular tube that: acts as a passageway for menstrual fluids; receives the penis during intercourse and temporarily holds sperm; forms lower portion of the lower portion of the birth canal through which a baby (fetus) passes during delivery.

Question 120

Development and Inheritance

How is fetal circulation different from adult circulation?

Answer 120

The oxygenated blood is delivered from the mother via the placenta and umbilical vein which passes through the fetus’ liver (located just a few cm’s inside of umbilicus) and joins the inferior vena cava and flows into the right atrium. Once the blood reaches the right atrium it either is pumped out of the pulmonary artery or continues on via the formen ovale into the left atrium. The blood that falls into the right ventricle which due to minor flow of blood to non-functioning (still developing) lungs, is pumped through the ductus arteriosum which joins the pulmonary artery to the aortic arch where it joins systemic circulation bypassing pulmonary circulation. If the blood from the umbilical vein passes through formen ovale it will be pumped into left ventricle and out the aorta for systemic circulation. The umbilical arteries collect the deoxygenated blood and return it to the mother via the placenta.

Question 121

Development and Inheritance

What hormone is responsible for maintaining the corpus luteum? Why is this important?

Answer 121

The corpus luteum is maintained by the production of progesterone. The production of progesterone is important because it promotes the development of the endometrium and uterine glands in anticipation of implantation of embryo. If fertilization does not take place within 12 days the corpus luteum degenerates and stopping the production of progesterone, causing the endometrium to break down and menstruation to occur.

Question 122

Development and Inheritance

Can you list and briefly describe the three stages of labor?

Answer 122

The three stages of labor are: Dilation, Expulsion, and Placental.

Dilation stage (from onset of labor for approximately 8 hours): the cervix dilates and the fetus slides down the cervical canal; contractions begin, one every 10-30 minutes with or without amniotic sac rupture.

Expulsion stage (

Placental stage (within one hour of delivery of fetus): muscle tension builds in the uterus; the uterus decreases in size; contractions cause placenta to tear away from endometrium.

Question 123

Development and Inheritance

What is Hemolytic Disease of the Newborn? How is it treated?

Answer 123

Hemolytic disease of the newborn is a condition where the mother is Rh- and her fetus is Rh+. It presents when during childbirth, the mother who does not poses Rh antibodies, is exposed to the Rh+ blood of her child. This primary exposure is going to cause production of maternal antibodies against the Rh antigen, creating anti-Rh antibodies in case of a second exposure. On second pregnancy with same blood types involved, this time the mother has anti-Rh antibodies; if the mother is exposed to the baby’s blood it will cause sensitization. Sensitization activates B cells, which make active B cells, memory cells and plasma cells and the initiates the circulation of antibodies. Maternal antibodies now can cross the placental barrier and cause precipitation and agglutination, or clotting that would kill the fetus. To treat this disease the mother is injected with an intramuscular injection of Rhogan (IgG) at 6 months of pregnancy through delivery. Administration of Rhogan prevents the circulation of antibodies which would kill the fetus.