Introduction Flashcards
What are the cranial, dorsal, lateral, ventral and caudal boundaries of the thorax?
Cranially = Thoracic inlet Dorsally = Thoracic vertebrae Laterally = Ribcage Ventraly = Sternum Caudally = Diaphragm
Describe the articulation of the ribs in a dog
Ribs 1-9 join the sternum ventrally
Ribs 10-12 form the costal arch
Rib 13 is floating
How many sternebrae does a dog have?
8
Name the palpable features on the sternebare
First sternebrae = manubrium
Last sternebrae = xiphoid process that has rings of xiphoid cartilage
Describe the divisions of the lungs
Left lung = 2 lobes, cranial and caudal
Right lung = 4 lobes, cranial, middle, caudal and accessory
How would you be able to tell apart pigs lungs?
- less obvious divisions between lobes
- surface appears marbled
What is the serous membrane lining the thorax?
Pleura
How is the pleura sub divided?
Into visceral and parietal
Visceral further divided into: mediastinal, diaphragmatic and costal
What is present between the visceral and parietal pleura? What is the purpose of this?
A potential space
- eliminates friction and maintains negative pressure within the pleural space
Where does the base of the heart sit compared to the apex?
Dorsally and cranially
Name the serous membrane that surrounds the heart
Pericardium
What are the 3 layers of the heart, from the inside -> out?
Inner = endocardium Middle = myocardium Outer = epicardium
What is the name of the additional outpouching on the atria?
Auricle / Atrial appendage
The left atrium receives oxygenated blood from the lungs via … ?
The pulmonary veins
The right atrium receives deoxygenated blood from the body via … ?
The cranial and caudal vena cavae
The left ventricle pumps blood out into … to go to … ?
The aorta, via the aortic valve, to the tissues of the body
The right ventricle pumps blood out into … to go to … ?
Into the pulmonary artery, via the pulmonic valve, to the lungs
What are the contraction and relaxation phases of the cardiac cycle called?
Contraction = systole Relaxation = diastole
What are the 4 broad phases of the cardiac cycle?
- isovolumetric relaxation
- filling
- isovolumetric contraction
- emptying
What do heart sounds S1 and S2 mark?
The start and end of systole
If S3 and S4 are audible during diastole, what is this heart rhythm referred to as?
A gallop rhythm
What is a murmur?
Any abnormal turbulence within the heart or great vessels that generates a sound
Where can you auscultate the heart?
Left side rib space: - 3 = pulmonic valve - 4 = aortic - 5 = mitral Right side rib space: - 5 = tricuspid valve
Where is the initial electrical impulse in the normal heart generated?
An area of specialised cardiac muscle cells situated in the wall of the right atrium, called the sinoatrial (SA) node.
Which node serves as electrical communication between the atria and ventricles?
Atrioventricular (AV) node in the distal interatrial septum
Where does the impulse go following the AV node?
Enters the Bundle of His, then divides into 2 branches supplying the ventricular muscle via the Purkinje fibres
