DOC PREVIEW
UH KIN 3304 - The Heart

This preview shows page 1 out of 3 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

KIN 3304 1nd Edition Lecture 14Outline of Last Lecture I. Review of Exam 1Outline of Current Lecture I.Current Lecture*Heart image is on test (also on final)I. The Cardiac Cyclea. Period between the start of one heartbeat and the beginning of the nextb. Includes all periods of contractions (systole) and relaxation (diastole)c. Systole – blood ejected from chamber into another chamber or arterial trunki. Goes up with exercised. Diastole – chamber fills with blood, prepares for next cyclei. Increases, decreases with exercise but stays the same really!e. Normal BP is 120/80i. 120 being systoleii. 80 being diastole*Know the image that consists of:- atrial systole begins- atrial systole ends, atrial diastole begins- ventricular systole – 1st phase- ventricular systole – 2nd phase- ventricular diastole - early- ventricular diastole – lateII. Conduction of Contractionsa. Heart is a pumpi. Moves fluid (blood) in a specific direction/speedii. Heart muscle contracts on its own1. Rhythmic intricity (autorhythmicity)iii. Precise sequence of eventsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Steps of Contraction (image will be on exam)a. Step 1i. SA node activity atrial activity beginsb. Step 2i. Stimulation spreads across atrial surfaces reach AV nodec. Step 3i. There’s a 100 msec delay at AV node. Atrial contraction beginsd. Step 4i. Impulse travels along interventricular septum..e. Step 5i. Impulse distributed by purkinge fibersIV. Sequencea. Atrial contraction firstb. Ventricle Nextc. Coordinated by conducting cellsi. Cardiac muscle cells that are incapable of undergoing powerful contractionii. Two populations: nodal and dconducting fibersd. Nodal Cells – establishes rate of contraction e. Conducting Fibers – distributes contractile stimulates to myocardium*EKG cant prevent a heart attack*90% of who will have a heart attack will not make it, even with CPRV. Nodal Cellsa. Membranes spontaneously depolarize (like brawny paper towels)i. AP sweeps through all cardiac tissue, causes contractionii. These cells determine HRiii. Nodal cells depolarize at different ratesiv. 1st to reach threshold is called pacemaker cellv. Found in SA node (cardiac pacemaker)VI. Sinoatria (SA) Nodea. Embedded in right atrium (posterior wall) near superior vena cavab. Generates 80-100 action potentials/minutei. Why does your heart rate not 80-100 bpm?1. Because any changes in rest potential or spontaneous depolarization at SA does not alter HR2. ANS can slow spontaneous depolarizationa. Ach from parasympathetic neurons slows depolarization, decreasing HRb. Resting parasympathetic neurons decrease HR to 60 bpm3. Issues can of course arisea. Bradycardiac – low HRb. Tachycardia – righ HRc. Normal is 60-90 bpmVII. Conducting System (heart picture)a. SA node to AV nodei. Atrial depolarizationb. AV node down bundle of HISi. Ventricle depolarizationc. Down bundle of HISd. To Purkinge


View Full Document

UH KIN 3304 - The Heart

Documents in this Course
The Cell

The Cell

23 pages

Load more
Download The Heart
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view The Heart and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view The Heart 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?