Histology
Diseases/Abnormalities
Conduction
Keeners trying to keen but failing
100
Where are the nuclei located in cardiac muscle cells, and how does this differ from skeletal muscle?
Cardiac muscle has nuclei located in the center of the cell, whereas skeletal muscle has nuclei located at the periphery
100
This disease occurs secondary to a streptococcal infection and damages heart valves.
What is Rheumatic Fever?
100
onic conductance through _______ _______ results in the rapid spread of the depolarizing impulse between cardiac muscle cells.
What is A. Gap Junctions.
100
Name one of the teams playing for the Super Bowl this Sunday.
A. The Denver Broncos OR The Seatlle Seahawks
200
What 2 types of junctions are intercalated disks composed of?
Intercalated disks are composed of adhesive junctions that attach the ends of the cells to one another, and gap junctions that allow electrical conductance to travel between the cells.
200
Name the hormones released by cardiac cells? What other hormones in the body antagonize the actions of this(these) hormone(s)?
- ANP - atria; BNP - ventricles. - Function: Both hormones lower blood pressure by relaxing arterioles/inhibiting the secretion of renin and aldosterone/inhibiting the reabsorption of sodium ions by the kidneys. - angiotensin, aldosterone, ADH.
200
What is the purpose of the heart’s Fibrous Skeleton, in regards to electrical conductance?
A. It isolates the atrial and ventrical myocardium so that they are only connected electrically at the bundle of His
200
Name any three movies and three actresses nominated for an Oscar.
Movies - American Hustle Captain Phillips Dallas Buyers Club Gravity Her Nebraska Philomena 12 Years a Slave Wolf of Wall Street Actresses - Amy Adams (American Hustle) Cate Blanchett (Blue Jasmine) Sandra Bullock (Gravity) Judi Dench (Philomena) Meryl Streep (August: Osage County)
300
why is the banding pattern of cardiac muscle cells less obvious than the banding pattern of skeletal muscle?
the myofibrils in cardiac muscle are not as highly aligned, and less uniform in size as they are in skeletal muscle. Myofibrils also form a 3D network within the cardiac muscle cells. The myofibrils separate to pass around the nucleus, leaving a perinuclear clear area (not always evident in standard preparations). This clear area is occupied by organelles, especially mitochondria. As in skeletal muscle, individual muscle fibres are surrounded by delicate connective tissue. Numerous capillaries are found in the connective tissue around cardiac muscle fibres. (retrieved from http://www.courseweb.uottawa.ca/medicinehistology/english/ss_basictissues/muscle_tissue.htm)
300
- Define and differentiate between fibrillation, asystole, tachycardia, and arrhythmia. Informal is okay. How would you differentiate?
- Asystole - no heart beat (aka flatline) - Fibrillation - quivering. - Tachycardia- rapid heart beat. - Arrhythmia - any disorder with altered electrical activity.
300
DAILY DOUBLE: what is Wolff-Parkinson-White Syndrome AND what is a possible treatment for it?
This occurs when there is an accessory pathway electrically connecting the atria to the ventricles. This can lead to electrical impulses being sent back to the atria from the ventricles, and tachycardia. An effective treatment is to burn the secondary connection, creating scar tissue through which electricity cannot pass.
300
What two transmembrane proteins are mainly responsible for regulating cytoplasmic calcium ion concentrations in muscle cells? Why does this need to happen?
Plasma Membrance Calcium ATPase (PMCA) and Sodium-Calcium Exchanger (NCX)
400
What makes Purkinje fibers histologically distinct from other types of cardiac muscle cells?
Purkinje fibres are of larger diameter than ordinary cardiac fibres, with fewer myofibrils and an extensive, well-defined clear area around the nucleus. They conduct impulses at a rate about four times faster than that of ordinary cardiac fibres and serve to coordinate the contraction of the atria and ventricles. (retrieved from http://www.courseweb.uottawa.ca/medicinehistology/english/ss_basictissues/muscle_tissue.htm)
400
Name any two types of cardiomyopathies. Briefly discuss.
- Discussion question. - Hypertrophic (HCM) - inflammation and fibrosis/myocardial fiber disarray. - Congestive/Dilative (DCM) - thin wavy myofibers/some fibrosis. - Restrictive (RCM) - hypertrophied myofibers. -Arrhythmogenic Right Ventricular Cardiomyopathy - myofibers replaced with adipose and fibroblasts. (http://people.upei.ca/lmiller/2009_CV_Myocardial_Diseases/shortened%20version%20-Diseases%20of%20the%20Myocardium2009.pdf)
400
Describe the pathway of a normal cardiac conduction cycle. Are there any delays?
- SA - Atria - AV - AV bundle - L/R bundle - Purkinje. - Atrioventricular Nodal Delay? Ensure that the atria contract before the ventricles OR allows ventricles time to fill completely before they contract
400
Draw and label an ECG reading for a normal person. Describe what happens at each location.
P - atrial depol. QRS- ventricular depol. T - ventricular repol. U- papillary/purkinje fibers repol.
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