Wet Room 2 Flashcards
What are the autonomic motor fibres travelling?
Travelling in the vagus nerves (parasympathetic) and spinal cord segments T1-4 (sympathetic) are routed to the heart and coronary arteries via the cardiac/cardiopulmonary plexus situated at the bifurcation of the trachea
How do sensory and pain fibres travel?
Travel back from the heart to spinal cord levels T1-4 in the sympathetic nerves
What do the motor fibres do?
Innervate and influence nodes (SA and AV nodes) of modified cardiac muscle cells that spontaneously generate electrical impulses.
These modified cells are known as Purkinje cells and their branches as Purkinje fibres.
Where is the sinu-atrial node?
Lies near the opening of the SVC in the right atrium
(chamber)
Where does the atrioventricular node lie?
Lies in the inferior part of the intra-atrial septum
Where does the atrioventricular bundle (of His) lie?
Lies within each side of the intra-ventricular Septum
Where does the pain associated with cardiac ischemia carried back to?
Carried back to levels T1-4 of the spinal cord via afferent fibres within the sympathetic nerves supplying the heart.
This severe, ‘constricting’ pain is experienced on the anterior chest wall and also on the medial side of the left arm.
Such pain as emanating from an organ/viscus but experienced somatically is known clinically as “referred pain”.
What does the heart lies immediately in front of?
The oesophagus and vertebra T5-T8 in the recumbent (lying down) position
What is the base of the heart?
The base of the heart (left atrium) therefore lies immediately anterior to the oesophagus
What is the vertical position of the heart descend?
Heart descends by a small amount relative to the vertebral column.
Where is the apex?
5th left intercostal space, in the midclavicular line
What forms the right border of the heart
Right atrium
What forms the left border of the heart?
Left ventricle and left atrium
What forms the inferior border of the heart?
Right ventricle
The left ventricle contributes near the apex
What is the superior border of the heart?
Right and left atrium and the great vessels.
What forms the anterior border of the heart?
Right ventricle
What forms the base of the heart?
LA
What is the diaphragmatic surface form?
R and L ventricles
What does the dashed line represent?
Represent the sternomanubrial (T4) and xiphisternal T8/9) planes
Posterior to which bone is the heart situated?
Breastbone plate
Anterior to which four vertebrae is the heart situated?
Inferior 8 thoracic vertebrae
Upon what structure does the inferior surface of the heart lie?
Sternum near the costal cartilages
Where are the heart valves located
Where can the heart valves be auscultated?
Where can the pulmonary valve be auscultated?
2nd left space parasternally
Where can the aortic valve be auscultated?
2nd right space, parasternally
Where can the mitral valve be auscultated?
5th left space, mid clavicular line
Where can the tricuspid valve be auscultated?
Over lower sternum, or just to right of it
What do the heart and blood vessels all have?
Same basic histological plan: An innermost epithelium, a middle muscle layer, and an outer connective tissue layer.
These layers are also known, respectively, as the tunica intima, tunica media and tunica adventitia.
There are three main histological types of artery: elastic arteries, muscular arteries and arterioles.
What differences can you observe in the three layers making up the wall of each vessel above?
Different thickness and colour and cells
What is the muscular artery layers?
Tunica intima: Presence of internal elastic lamina
Tunica media: Smooth muscle cells, elastin and collagen. Different colour and transverse arrangement of fibres
Tunica adventitia: Presence of vasa vasorum, broad layer
What is the elastic artery?
Tunica intima: Layer of loose connective tissue below the endothelium
Tunica media: Presence of concentric fenestrated sheets of elastina nd only few smooth muscle fibres
Tunica adventitia: Circufrential arranged smooth muscles
What type of artery are the aorta and pulmonary trunk?
Conducting and elastic
What type of artery are the radial and femoral arteries?
Distributing and muscular
What tissue predominates in the tunica media of arterioles?
Smooth muscle cells
What are valves formed from?
The tunica intima of the vessels.
Conducting arteries are closer to the heart and elastic; distribution arteries are further from the heart and are muscular.
What do the arterioles stem from?
Muscular arteries
