Anatomy and Physiology Notes: Conduction System of the Heart

   Key Concepts

1. The electrical activity of cardiac cells is caused by the selective opening and closing of plasma membrane channels for sodium, potassium, and calcium ions.

2. Depolarization is achieved by the opening of sodium and calcium channels and the closing of potassium channels.

3. Repolarization is achieved by the opening of potassium channels and the closing of sodium and calcium

channels.

4. Pacemaker potentials are achieved by the opening of channels for sodium and calcium ions and the closing of channels for potassium ions.

5. Electrical activity is normally initiated in the sinoatrial (SA) node where pacemaker cells reach threshold first.

6. Electrical activity spreads across the atria, through the atrioventricular (AV) node, through the Purkinje system, and to ventricular muscle.

7. Norepinephrine increases pacemaker activity and the speed of action potential conduction.

8. Acetylcholine decreases pacemaker activity and the speed of action potential conduction.

9. Voltage differences between repolarized and depolarized regions of the heart are recorded by an electrocardiogram (ECG).

10. The ECG provides clinically useful information about rate, rhythm, pattern of depolarization, and mass of electrically active cardiac muscle.

Pathway

SA Node

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Walls of the Atrium (Atrial Contraction)

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AV Node

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Delay in transmission

(To provide ample time for ventricular filling)

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Bundle of His

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Left and Right Bundle Branch

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Purkinje Fibers

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Ventricular Contraction

Notes on Fluid and Electrolytes 4 FLUID VOLUME DEFICIT

FLUID VOLUME DEFICIT

A. Description
1. Dehydration occurs when the fluid intake of the body is not sufficient to meet the fluid needs of the body.
2. The goal of treatment is to restore fluid volume, replace electrolytes as needed, and eliminate the cause of the fluid volume deficit.

B. Types of fluid volume deficits
1. Isotonic dehydration
a. Water and dissolved electrolytes are lost in equal proportions.
b. Known as hypovolemia, isotonic dehydration is the most common type of dehydration.
c. Isotonic dehydration results in decreased circulating blood volume and inadequate tissue perfusion.

2. Hypertonic dehydration
a. Water loss exceeds electrolyte loss.
b. The clinical problems that occur result from alterations in the concentrations of specific plasma electrolytes.
c. Fluid moves from the intracellular compartment into the plasma and interstitial fluid spaces, causing cellular dehydration and shrinkage.

3. Hypotonic dehydration
a. Electrolyte loss exceeds water loss.
b. The clinical problems that occur result from fluid shifts between compartments, causing a decrease in
plasma volume.
c. Fluid moves from the plasma and interstitial fluid spaces into the cells, causing a plasma volume deficit and causing the cells to swell.

C. Causes of fluid volume deficits
1. Isotonic dehydration
a. Inadequate intake of fluids and solutes
b. Fluid shifts between compartments
c. Excessive losses of isotonic body fluids

2. Hypertonic dehydration—conditions that increase fluid
loss, such as excessive perspiration, hyperventilation,
ketoacidosis, prolonged fevers, diarrhea, early-stage
renal failure, and diabetes insipidus

3. Hypotonic dehydration
a. Chronic illness
b. Excessive fluid replacement (hypotonic)
c. Renal failure
d. Chronic malnutrition

D. Assessment
1. Cardiovascular
a. Thready, increased pulse rate
b. Decreased blood pressure and orthostatic (postural) hypotension
c. Flat neck and hand veins in dependent positions
d. Diminished peripheral pulses

2. Respiratory: Increased rate and depth of respirations

3. Neuromuscular
a. Decreased central nervous system activity, from lethargy to coma
b. Fever

4. Renal
a. Decreased urinary output
b. Increased urinary specific gravity

5. Integumentary
a. Dry skin
b. Poor turgor, tenting present
c. Dry mouth

6. Gastrointestinal
a. Decreased motility and diminished bowel sounds
b. Constipation
c. Thirst
d. Decreased body weight

7. Hypotonic dehydration: skeletal muscle weakness

8. Hypertonic dehydration
a. Hyperactive deep tendon reflexes
b. Pitting edema

9. Laboratory findings
a. Increased serum osmolality
b. Increased hematocrit
c. Increased blood urea nitrogen (BUN) level
d. Increased serum sodium level

E. Interventions
1. Monitor cardiovascular, respiratory, neuromuscular, renal, integumentary, and gastrointestinal status.
2. Prevent further fluid losses and increase fluid compartment volumes to normal ranges.
3. Provide oral rehydration therapy if possible and intravenous (IV) fluid replacement if the dehydration is
severe; monitor intake and output.
4. Generally, isotonic dehydration is treated with isotonic fluid solutions, hypertonic dehydration with hypotonic fluid solutions, and hypotonic dehydration with hypertonic fluid solutions.
5. Administer medications as prescribed such as antidiarrheal, antimicrobial, antiemetic, and antipyretic
medications, to correct the cause and treat any symptoms.
6. Administer oxygen as prescribed.
7. Monitor electrolyte values and prepare to administer medication to treat an imbalance, if present.

Pre-Board Exam Drill

SITUATION 1: A patient just arrived in the Oncology unit from the Post Anesthesia Care Unit (PACU) following a Left Modified Radical Mastectomy because of Inflammatory Breast Cancer (IBC). She has a pressure dressing over the surgical site and two drains. Assessment shows her vital signs are stable, fully awake and claims that pain is under control. Fortune is the nurse assigned to the patient.
1. From the following data obtained from the chart by Fortune, which is NOT a risk factor which could have predisposed the patient to breast cancer:
a. Age – 55
b. Height 5’2”, weight 160 lbs.
c. Menarche at age 13
d. Mother died of colon cancer
2. Fortune read a literature which says that by the time Inflammatory Breast Cancer (IBC) is diagnosed, 50% - 75% have palpable auxiliary nodes; as many as 30% have gross distant metastasis; and as few as 30% of patients have an underlying breast mass. Which of the following is the APPROPRIATE interpretation of this research findings.
a. Auxiliary nodes were palpated on 20 out of 30 women positive for IBC3
b. Out of the 20 women who were positive for IBC, only 5 have metastasis
c. If there were 10 women diagnosed with IBC, 3 have positive lymph nodes
d. Breast mass was identified on 8 out of 30 women positive for IBC
3. Fortune recognizes that adjuvant chemotherapy for breast cancer may include any of the following EXCEPT:
a. Monoclonal antibody
b. Antibiotics
c. Proton inhibitors – this is a drug for ulcer
d. Antiestrogen – tamoxifen

4. Fortune understands that when the antineoplastic  agent leaks through the peripheral vascular access during chemotherapy procedure, which of the following is expected to be done FIRST?
a. Refer to the physician
b. Stop the chemotherapy infusion
c. Cleanse site with saline solution
d. Call another nurse to check the intravenous site

5. A clinical trial is currently being undertaken to test treatments for Inflammatory Breast Cancer (IBC). The research team leader wishes to include the patient as a participant in the study. As a patient advocate, which of the following will Fortune do FIRST?
a. Obtain informed consent from the patient
b. Explain to the patient the scope of the clinical trial
c. Inquire from the team leader benefits for the patient
d. Read more related literatures
SITUATION 2: During a staff meeting in the Intensive Care Unit, the nurse manager reported a list of procedures that need to be reviewed and updated. One of these procedures is the precautionary measures related to ventilator associated pneumonia.- on mechanical ventilation through an endotracheal or tracheostomy tube for at least 48 hours
6. While brainstorming, the group mentioned the use of evidence-based techniques. Which of the following statements given by the members of the group reflect evidence-based methods?
a. “Let us ask opinions of experts”
b. “The experiences of the nurses must be obtained”
c. “Review of related literature will be very helpful”
d. “We must agree on a common procedure”
7. The nurse manager assigned a group to develop a project intended to improve the existing procedure related to the prevention of ventilator associated pneumonia among ICU patients. A first team leader was selected by the group. Which of the following will the team leader do FIRST?
a. Tell the group to state their objectives
b. Formulate a list of desired outcomes
c. Set a target
d. State actions to be done by each member of the group
8. Which of the following definitions best describes pneumonia?
 A. Inflammation of the large airways
B. Severe infection of the bronchioles
C. Inflammation of the pulmonary parenchyma
D. accumulation of fluids in the lungs
9. The nurse is preparing her plan of care for her patient diagnosed with pneumonia. Which is the most appropriate nursing diagnosis for this patient?
        A. Fluid volume deficit
        B. Decreased tissue perfusion.
        C. Impaired gas exchange.
        D. Risk for infection

10. What action should the nurse take in assisting Mr. Ramos in doing deep breathing and coughing exercise?
A. Recognize that the patient is too sick to cough at this time
B. Splint the patient’s chest while he coughs
C. Turn Mr. Ramos to the unaffected side and ask him to cough
D. Encourage her to cough and then give her pain medication as ordered
11. Ms. Sy undergoes surgery and the abdominal aortic aneurysm is resected and  replaced with a graft. When she arrives in the RR she is still in shock. The nurse's priority should be
         A. placing her in a trendeleburg position
         B. putting several warm blankets on her
         C. monitoring her hourly urine output
         D. assessing her VS especially her RR

12. Ana's postoperative vital signs are a blood pressure of 80/50 mm Hg, a pulse of 140, and respirations of 32. Suspecting shock, which of the following orders would the nurse question?
         A. Put the client in modified Trendelenberg's position.
         B. Administer oxygen at 100
         C. Monitor urine output every hour.
         D. Administer Demerol 50mg IM q4h

13. When assessing Luther for hypovolemic shock, which of the following data indicates that he is in IRREVERSIBLE stage of shock?
a. Restless, anxious and confused
b. Anuria
c. Skin, cool, pale and moist- compensatory stage
d. Pulse rapid and weak – reversible stage
14. The physician ordered colloid solution such as Dextran 40. During the infusion, Luther complained of dyspnea. Upon auscultation, you noted wheezes. Which of the following will you do FIRST?
a. Discontinue the infusion
b. Place Luther on a Fowler’s position..
c. Decrease infusion rate
d. Call the attending physician

15. Luther’s central venous pressure is monitored every hour. When you measure the CVP using a water manometer, you are expected to observe which of the following to ensure accuracy of CVP measurement?
a. Maintain the client on a Fowler’s position
b. Use a one way stopcock to regulate flow of IV fluids to the water manometer
c. Immobilize client’s right arm
d. Keep the zero point of the manometer in level with the client’s right atrium
SITUATION 4: You are caring for Warren, 58 years old, who is diagnosed with Laryngeal cancer
16. Warren, who is scheduled for a total laryngectomy and radical neck dissection for cancer of the larynx, asks you, “How will I talk after the surgery?” as his nurse your BEST response will be:
a. “You will breathe through a permanent opening in your neck, but you will not be able to communicate orally”
b. “You won’t be able to talk right after surgery, but you will be able to speak again once the tracheostomy tube is removed”
c. “You will have a permanent opening in your neck, and you will need to have rehabilitation for some type of voice restoration”
d. “You won’t be able to speak as you used to but there are artificial voice devices that will give you the ability to speak normally”
17. Warren returns from surgery with a tracheostomy tube after a total laryngectomy and radical neck dissection. In caring for Warren during the first 24 hours after surgery, your PRIORITY nursing action is to:
a. Avoid changing tracheostomy ties
b. Monitor for bleeding around stoma
c. Assess the airway patency and breath sounds
d. Clean the inner cannula every 8 hours
18. After doing assessment, one of the nursing diagnosis you identified is “Body image disturbance related to loss of control of personal care.” To evaluate effectiveness of your interventions, the expected outcome for the problem that Warren should demonstrate is that he:
a. Lets his wife provide hygiene and stoma care
b. Wears clothing that minimizes the disfigurement caused by surgery
c. Asks that only family members be allowed to visit
d. Learns to remove and clean the laryngectomy tube independently
19. Warren is scheduled to start radiation therapy. You have just taught Warren all about radiation therapy. Which of the following statements by Warren would indicate that your teaching has been EFFECTIVE?
a. “I can use lotions to moisturize the skin on my throat”
b. “I will need to buy a water bottle to carry with me”
c. “I need to use alcohol-based mouthwashes to help clean oral ulcers”
d. “I may experience diarrhea, I may have diarrhea until radiation is complete”
20. After completing the discharge instructions for Warren, you  determine that ADDITIONAL instruction is needed when he says:
a. “I can participate in most of my prior fitness activities except swimming”
b. “I should wear a Medic Alert Bracelet that identifies me as a neck breather”
c. “I must keep the stoma covered with a loose sterile dressing at all times”
d. “I need to eat nutritious meals even though I can’t smell or taste very well”

Anatomy and Physiology Notes: Gastrointestinal-Hepatobillary System

This is an outlined lecture note on the Anatomy and Physiology of theGastrointestinal-Hepatobillary System. Some information are so compressed that some concepts are not explained in detail. If it is your first time to meet such information please refer to your textbook for further explanation of the concept. This review material requires a student to have a prior knowledge and good foundation of the subject matter for this only emphasizes important/ key information deemed important in understanding advanced concept in Pathophysiology and Medical Surgical Nursing.

Functions of the gastrointestinal system
- Process food substances.
- Absorb the products of digestion into the blood.
- Excrete unabsorbed materials.
- Provide an environment for microorganisms to synthesize nutrients, such as vitamin K.

 Mouth
- Contains the lips, cheeks, palate, tongue, teeth, salivary glands, muscles, and maxillary bones
- Saliva contains the amylase enzyme (ptyalin) that aids in digestion.

Esophagus
- Collapsible muscular tube about 10 inches long
- Carries food from the pharynx to the stomach


The stomach
- Contains the cardia, fundus, the body, and the pylorus
- Mucous glands are located in the mucosa and prevent autodigestion by providing an alkaline protective covering.
- The lower esophageal (cardiac) sphincter prevents reflux of gastric contents into the esophagus.
- The pyloric sphincter regulates the rate of stomach emptying into the small intestine.
- Hydrochloric acid kills microorganisms, breaks food into small particles, and provides a chemical environment that facilitates gastric enzyme activation.
- Pepsin is the chief coenzyme of gastric juice, which converts proteins into proteases and peptones.
- Intrinsic factor is necessary for the absorption of vitamin B12.
- Gastrin controls gastric acidity.

Small intestine
- The duodenum contains the openings of the bile and pancreatic ducts.
- The jejunum is about 8 feet long.
- The ileum is about 12 feet long.
- The small intestine terminates in the cecum.

Pancreatic intestinal juice enzymes
- Amylase digests starch to maltose.
- Maltase reduces maltose to monosaccharide glucose.
-  Lactase splits lactose into galactose and glucose.
- Sucrase reduces sucrose to fructose and glucose.
- Nucleases split nucleic acids to nucleotides.
-. Enterokinase activates trypsinogen to trypsin.


Large intestine
- About 5 feet long
- Absorbs water and eliminates wastes
- Intestinal bacteria play a vital role in the synthesis of some B vitamins and vitamin K.
- Colon: Includes the ascending, transverse, descending, and sigmoid colons and rectum
- The ileocecal valve prevents contents of the large intestine from entering the ileum.
- The anal sphincters control the anal canal.

Peritoneum: Lines the abdominal cavity and forms the mesentery that supports
the intestines and blood supply

Liver
-The largest gland in the body, weighing 3 to 4 lb.
-Contains Kupffer's cells, which remove bacteria in the portal venous blood
- Removes excess glucose and amino acids from the portal blood
- Synthesizes glucose, amino acids, and fats
- Aids in the digestion of fats, carbohydrates, and proteins
- Stores and filters blood (200 to 400 mL of blood stored)
- Stores vitamins A, D, and B and iron
- The liver secretes bile to emulsify fats (500 to 1000 mL of bile/day).
 Hepatic ducts
a. Deliver bile to the gallbladder via the cystic duct and to the
duodenum via the common bile duct.
b. The common bile duct opens into the duodenum, with the pancreatic duct at the ampulla of Vater.
c. The sphincter prevents the reflux of intestinal contents into the
common bile duct and pancreatic duct.

Gallbladder
-Stores and concentrates bile and contracts to force bile into the duodenum during the digestion of fats
- The cystic duct joins the hepatic duct to form the common bile duct.
- The sphincter of Oddi is located at the entrance to the duodenum.
- The presence of fatty materials in the duodenum stimulates the liberation of cholecystokinin, which causes contraction of the gallbladder and relaxation of the sphincter of Oddi.

Pancreas
Exocrine gland
- Secretes sodium bicarbonate to neutralize the acidity of the stomach contents that enter the duodenum
-. Pancreatic juices contain enzymes for digesting carbohydrates, fats, and proteins.
Endocrine gland
- Secretes glucagon to raise blood glucose levels and secretes somatostatin to exert a hypoglycemic effect
- The islets of Langerhans secrete insulin.
- Insulin is secreted into the bloodstream and is important for carbohydrate metabolism.

“If at first you don't succeed, try, try again. Then quit. No use being a damn fool about it.”  -WC Fields

Anatomy and Physiology Notes: Endocrine System

This is an outlined lecture note on the Anatomy and Physiology of the Endocrine System. Some information are so compressed that some concepts are not explained in detail. If it is your first time to meet such information please refer to your textbook for further explanation of the concept. This review material requires a student to have a prior knowledge and good foundation of the subject matter for this only emphasizes important/ key information deemed important in understanding advanced concept in Pathophysiology and Medical Surgical Nursing.


Functions of Endocrine Glands
- Maintenance and regulation of vital functions
- Response to stress and injury
- Growth and development
- Energy metabolism
- Reproduction
- Fluid, electrolyte, and acid-base balance

Hypothalamus 
- Portion of the diencephalon of the brain, forming the floor and part of the lateral wall of the third ventricle
- Activates, controls, and integrates the peripheral autonomic nervous system, endocrine processes, and many somatic functions, such as body temperature, sleep, and appetite

Pituitary gland 
- The master gland; located at the base of the brain 2. Influenced by the hypothalamus; directly affects the function of the other endocrine glands
- Promotes growth of body tissue, influences water absorption by the kidney, and controls sexual development and function

Adrenal gland
- One adrenal gland is on top of each kidney.
- Regulates sodium and electrolyte balance; affects carbohydrate, fat, and protein metabolism; influences the development of sexual characteristics; and sustains the fight-or-flight response
 Adrenal cortex
- The cortex is the outer shell of the adrenal gland.
-. The cortex synthesizes glucocorticoids and mineralocorticoids and secretes small amounts of sex hormones
Adrenal medulla
- The medulla is the inner core of the adrenal gland.
- The medulla works as part of the sympathetic nervous system and produces epinephrine and norepinephrine.

Thyroid gland
- Located in the anterior part of the neck
- Controls the rate of body metabolism and growth and produces thyroxine (T4), triiodothyronine (T3), and thyrocalcitonin

Parathyroid glands
- Located on the thyroid gland
- Control calcium and phosphorus metabolism; produce parathyroid hormone

Pancreas
- Located posteriorly to the stomach
- Influences carbohydrate metabolism, indirectly influences fat and protein metabolism, and produces insulin and glucagon

Ovaries and testes
-The ovaries are located in the pelvic cavity and produce estrogen and progesterone.
-The testes are located in the scrotum, control the development of the secondary sex characteristics, and produce testosterone.

Negative feedback loop
-Regulates hormone secretion by the hypothalamus and pituitary gland
-Increased amounts of target gland hormones in the bloodstream decrease secretion of the same hormone and other hormones that stimulate its release.

“Success is getting what you want, happiness is wanting what you get” -Kinsela