Flashcards in Lecture 10: Heart Deck (20)
Development of the heart.
When does development begin?
When does it begin to contract?
Look at slide 8 and learn it
Day 21blood is circulating
Day 22: heart starts pumping
Day 35 bending complete
Embryonic heart tube
When is it complete by?
What does it separate?
You have blood come in the venous end then gets pumped out the arterial end. Refer to slide 9
Separation- septa develop to separate atrium and ventricle. Complete by end of 5th week. Septum doesn't close communicating between L & R atria = foramen ovale. Important for embryos because blood goes through there.
Aortic arches. How do we end up with the varies arteries.
What are the derivatives?
1st pair: become part of maxillary artery in head
2nd pair: largely disappears
3rd: common and internal carotid arteries
4th: right subclavian artery and aortic arch
5th pair: degenerates
6th pair: ductus arteriosus and part of pulmonary arteries
What is the course of recurrent laryngeal nerves?
It is a branch of CN 10 vagus nerve.
Right recurrent laryngeal nerve hooks around the right subclavian artery (from 4th aortic arch)
Left recurrent laryngeal nerve remains hooked around 6th aortic arch which becomes the ductus arteriosus. In adult, nerve hooks around ligamentum arteriosum and the arch of the aorta.
They supply the laryngeal muscles
They are current because there like an electric fence carrying current ready to zap the laryngeal muscles
Fetal circulation differences
Fetus receives oxygenated blood from mother via?
How does the blood bypass the liver?
Blood from IVC enters RA and some flows to LA directly through?
Most of blood in pulmonary trunk is shunted via?
-Foetus receives oxygenated blood from mother via umbilical vein
-blood mostly bypasses the liver via ductus venous.
-ductus arteriosus takes blood from pulmonary trunk and dumps it straight into the aorta, coz babies don't breath capish. When born, this ductus shut the hell up
Describe the blood flow through the heart
SVC + IVC - right atrium - right ventricle -pulmonary trunk- pulmonary arteries -lungs-pulmonary veins-left atrium- left ventricle - aorta - body
Surface projections of the heart.
Describe we're you can locate the aortic valve auscultation point, pulmonary valve auscultation point, also mitral and tricuspid valve auscultation points. Slide 18
Aortic- right side in 2nd intercostal space. Right ➡Ate Rat shit
Pulmonary valve left side 2nd intercostal space
Tricuspid -right side 5th intercostal space-sternal margin ➡tri 3 +2 =5 fifth space, good maths. Everyone Tries to be R handed coz its cooler
Mitral- 5 intercostal space further down near end of cartilage -in line with middle of clavicle
Label the diagram on slide 20, 21, 22, 23, 24, 25, 26
Phrenic nerve. It also carries sensory fibres from wear?
Primary source of sensory fibres from pericardium.
Pain sensation carried by phrenic nerve is refer to C3-C5 dermatomes
Coronary arteries supply what?
Label diagram on slide 27 and 28
Supply myocardium and epicardium
Originate at base if ascending aorta
Cardiac veins and coronary sinuses.
Label diagram slide 30 and 31
What is the Name of the remnant of the foramen ovale?
Slide 32, know how to label
What is the function of the moderator band
Keeps the ventricles from over stretching
Label slide 34, and 35
Describe how conduction is spread through the heart
-sinoatrial node fires 70 x/min
-cardiac muscle of right atrium conducts and contracts
-impulses reach AV node
-impulses travel from AV node down the IV septum via AV bundles
-AV bundles branch to purkinje fibres that supply papillary muscles and walls of ventricles
What is the sympathetic innervation of the heart?
-Pre-sympathetic fibres from IML of T1-T5
-post-synaptic sympathetic fibres from cervical and superior thoracic sympathetic ganglia and end in SA and AV nodes
-sympathetic stimulation: ⬆HR, ⬆force of contractions, indirectly dilates coronary arteries by inhibiting their constriction ➡supplies more oxygen and nutrients to myocardium during increased activity
What is the parasympathetic innervation of the heart?
-pre-synaptic fibres from vagus nerve
-post-synaptic fibres from intrinsic ganglia located near SA and AV nodes and along coronary arteries
-parasympathetic stimulation ⬇Hr, ⬇force of contractions, constricts coronary arteries
-saves energy between period of increased demand
Label and understand diagram on slide 41 :)
Can refer to text book pg 139