Heart Flashcards
Between which ribs is the heart?
Between 3rd and 6th ribs
What are the 3 layers of the heart?
Endocardium: inner wall
Myocardium: thick muscular wall
Epicardium: visceral serous pericardium
What is also known as atria proper for the right heart?
Sinus vinarum
What are the 2 notable parts in the sinus venarum?
Intervenous tubercle
Fossa ovalis
What are the 2 notable things in the right auricle?
Pectinate muscle
Crista terminalis
What are the 5 places that the right atrium receive blood from?
Cranial vena cava
Caudal vena cava
Azygos vein
Coronary sinus
Small cardiac veins
How many papillary muscles are in the right ventricle
3
How many pulmonary veins does the left atrium receive blood from?
5-6
What structure of the foramen ovale is left in the left atrium?
The valve of the foramen ovale
Where is the cranial scapular angle?
Spinous process of T1
Where is the caudal scapular angle?
Spine bodies of T4-T5
Where is the shoulder joint?
Ventral end of 1st rib
Where is the olecranon?
Below ventral end of 5th intercostal space
What are the 2 parts of the vertebral arch?
Lamina and Pedicles
What are all 13 of the vertebral foramen put together called? A few?
Spinal cord. Vertebral canal
What are the foramen between the vertebrae called?
Intervertebral foramen
What special name does T11 have?
Anticlinal vertebra
What are the 2 layers of the vertebral disc called?
Anulus fibrosis and nucleus pulposus
What ribs are part of the costal arch and which is the floating rib?
10-12.
13
What nerves and arteries supply the thoracic wall muscles?
Intercostal arteries and intercostal nerves
Where do arteries and nerves run in the intercostal space?
Caudal medial
Which direction does muscles of expiration run?
Cranioventral
What direction do muscles of inspiration run?
Caudoventralis
What are the muscles of inspiration?
Scalenus
serrates dorsalis cranialis
external intercostal
rectus thoracis
What are the muscles of expiration?
Serrates dorsalis caudalis
Transfersus thoracis
Internal intercostal
What are the aortic cusps
Left semilunar cusp
Right semilunar cusp
Septal semilunar cusp
What are the cusps of the pulmonary valve
Right semilunar cusp
Left semilunar cusp
Intermediate semilunar cusp
What is the cardiac skeleton also known as?
Fibrous base
What are the borders to the thoracic inlet?
Bilateral: First rib
Ventrally: manubrian
Dorsally: first thoracic vertebrae
What 3 structures pass through the aortic hiatus?
Azygos vein
Aorta
Thoracic duct
What passes through the esophageal hiatus?
Esophagus
Vagal nerve trunks
What are the two components to the cardiovascular system?
Blood and lymph
What are the 3 layers of arteries and veins?
Tunica intima
Tunica media
Tunica adventitia
What is the main noteable function of the tunica intima?
It’s coagulation properties
What is the tunica media made of?
Smooth muscle
Extracellular matrix (elastin and ground substance)
What are the characteristics of elastic arteries?
Aorta
High pressure, high volume
Thick tunica media
Lots of layers of elastin fibers
What’s the major difference between muscular and elastic arteries
Elastic arteries are closer to the heart and contain a lot more elastin fibers
Muscular arteries contain mostly smooth muscle and a lot of it
What’s a continuous endothelium?
Continuous endothelium and basal lamina
What’s fenestrated endothelium?
Fenestrated endothelium but continuous basal lamina
What’s sinusoidal endothelium?
Fenestrated endothelium AND basal lamina
What are 2 major differences between veins and arteries?
Arteries have a much larger tunica media and veins have valves
What is lymph fluid plus fat droplets called?
Chyle
What layer of the heart are the valves a part of?
The endocardium
What are the differences between cardiac cells and skeletal muscle cells?
Branching
Prominent connective tissue
Central nuclei
Intercalated discs
Purkinje fibers
What are the 2 layers of the parietal pericardium
Serous: mesothelium
Fibrous: collagenous stroma
What are the 3 types of cardiac conduction cells?
Cardiomyocytes
Purkinje cells
Pacemaker cells (nodes)
What are the 2 types of action potentials?
Cardiomyocytes and Purkinje use Na for depolarization
Pacemaker cells use Ca for depolarization
What are the 5 phases of action potentials?
In Cardiomyocytes and Purkinje cells
0: depolarization Na enters
1: brief repolarization K exits
2: plateau Ca enters and balances K leaving
3: repolarization more K channels open
4: resting membrane potential
What makes pacemaker cells automatic?
Spontaneous phase 4 depolarization
What phases do pacemakers lack?
1 and 2 (brief depolarization and plateau)
What is the funny current of pacemaker cells?
What is phase 0 for pacemaker cells?
Na and K in
Slow Ca in
What is the funny current?
Occurs in pacemaker cells and it’s a slow drift of Na and K into the cell until Ca channels open at -50
What determines cell to cell conduction velocity?
How fast sodium enters the cell during depolarization (phase 0)
What are the types of calcium channels?
Voltage-gated: T-type (transient) and L-type (long-lasting)
Ligand Gated: epinephrine and norepinephrine
What channel determines the speed of repolarization?
Potassium (K) leaving
What does ERP mean?
Effective refractory period
Time before cell can be re stimulated
What slope is increased in sympathetic activity?
Slope of the funny current (the slow Na and K into the cell)
Explain excitation-contraction coupling
Stimulus causes a rush of Na to enter which allows L type Ca channel to let in a little Ca which binds Ryanodine receptor and causes a large rush of Ca from SR which binds tropomyosin and expresses actin, allowing myosin heads to swing and cause tension pulling Z band. Muscle relaxes and ATP drives Ca back into the SR through SERCa
What does hyperkalemia cause?
Sodium channels to become inactivated
What is the areolar tissue that attaches the muscles, ligaments, and bones to the underlying costal and diaphragmatic plurae?
Endothoracic fascia
What are the 2 pleural recesses?
Costodiaphragmatic recess
Costomediastinal recess
What is the cupula pleura?
Cranial part of parietal plura that extends outside of the thoracic inlet (left is larger)
What divides the dorsal and ventral mediastinum?
Divided by the roots of the lungs
What are the 3 layers of the pericardium?
Fibrous (outer layer)
Parietal serous (outer inner layer)
Visceral serous (inner inner layer also epicardium)
Mediastinal pleura on outside of this
What are the 2 ligaments that anchor apex of the heart?
Phrenicopericardial ligament
Sternopericardial ligament
Describe the relationship of the esophagus and trachea
Esophagus is left of trachea at thoracic inlet and dorsal after thoracic inlet
How many incomplete rings on the trachea are there?
35
What connects consecutive tracheal rings?
Annular ligaments of the trachea
Where is the tracheal bifurcation?
T4-T5
What is the crest inside of the trachea called?
Tracheal carina
What are the 4 surfaces of the lungs?
Costal
Diaphragmatic
Interlobar
Mediastinal
Where is the cardiac north located?
At 4th and 5th intercostal spaces (between cranial and middle lobes of right heart)
What are the borders of the triangular area of lung auscultation?
Cranial: triceps and Teres major mm @ 5th rib
Dorsal: back muscles, ribs 5-11
Basal border: caudoventral 6th rib at the costochondral junction to mid 8th rib, to dorsal 11th rib