Lecture 16: The Heart Flashcards
List and Describe the layers of the pericardial cavity and sac and the 3 layers of the heart wall
3 layers of the pericardial cavity/sac:
- parietal pericardium-outer
- pericardial cavity-intermediate
- visceral pericardium-inner
3 layers of the heart:
- epicardium
- myocardium
- Endocardium
List and describe in order the subdivisions of the typical fish heart and describe the characteristics of each component and trace the flow of blood through the heart of a fish and distinguish btw oxygenated and deoxygenated blood.
4 chambers:
- sinus venosus w/ SA valve: receives deoxy from cardinals
- Atrium w/ AV valve
- ventricle-thickest
- conus arteriosus w/ semilunar valve: ventral aorta
Single pass, unidirectional pump
List and describe, in order, the subdivisions of the typical amphibian heart and describe the characteristics of each component.
3 chambered heart.
Atrium is completely divided.
Single ventricle that receives both blood.. trabecular arrangement keeps 2 blood supplies separate.
-conus/truncus arteriosus:spiral valve partially separating
Trace the flow of blood through the heart of an amphibian and distinguish btw oxygenated and deoxygenated blood and compare the amphibian heart w/ the fish heart.
Amphibian: R atrium receives deoxygenated blood. L atrium= oxygenated. Ventricle receives both oxy and deoxy but trabecular arrangement in ventricular wall mostly keeps 2 separate. Conus/truncus arteriosus-main artery carrying blood away from heart preferentially sends blood from R ventricle to pulmonary arteries and vice versa.
Fish heart is single pass and one directional. It is not all connected like amphibian.
List and describe in order the subdivisions of the typical reptilian (turtle) heart and describe the characteristics of each component.
Atria: completely divided like amphibian.
Ventricles incompletely divided in most reptiles [except crocodillian]
-R atrium receives deoxy. L receives oxy.
L ventricle: cavum arteriosum.
R ventricle: cavum venosum and pulmonale. These are divided by a muscular septum. -one-way valve for interventricular canal.
Trace the flow of blood through the heart of a typical reptile such as the turtle and distinguish btw oxy and deoxy blood and compare w/ amphibian heart.
Sys deoxy from vena cava->R atrium->through R atrioventricular valve->cavum venosum ->cavum pulmonale-> semilunar valve->pulmonary artery->lungs->deoxy thru pulmonary veins->L atrium->L atrioventricular valve->cavum arteriosum->interventricular canal->cavum venosum->semilunar valves->L and R aortae
The difference w/ amphibian- undivided ventricle [just trabeculae] and reptile: partially divided ventricle and separated truncus arteriosus into separate vessels
Trace the flow of blood through the heart of a crocodillian and distinguish between oxy and deoxy blood and compare w/ turtle heart.
Crocodillians ventricles are completely divided- turtles and most other reptiles are incompletely divided.
Explain the specialization of the reptilian hearts w/ regard to diving adaptations.
While diving,
- blood is hunted from lungs-via vagus nerve, constriction of pulmonary arteries.
- slowing of HR
- Blood from the R atrium must bypass lungs-shunted to L ventricle in crocodillian [through foramen of panizzae]. Sent to aortae from R ventricle in other reptiles.
Describe the general development of the mammalian heart.
Cardiac tubes paired and double walled.
Linear arrangement: Conus arteriosus, ventricle, atrium,sinus venosus
Fusion of cardiac tubes- arteriosus pulsates first. Last is sinus venosus=SA node.
As heart grows it loops out inverting the atrium and ventricle
Describe the compartments and related structures of the typical mammalian heart and trace blood flow through the mammalian heart distinguish oxy and deoxy blood.
Completely divided atria and ventricles. Papillary muscles. Chordae tendinae. Coronary arteries and veins.
Vena canvas->Ratrium->R ventricle via AV valve (tri)->lungs via pulmonary artery thru pulmonary semilunar valve->L atrium via pulmonary veins->L ventricle (AV valve-bi)->aortic trunk thru semilunar valve-> aortic arch ->body
Describe the specific features of the developing mammalian heart that serve as adaptations for fetal development and describe the changes that occur in the heart after birth.
- foramen ovale: R to L atrium :bypassing lungs—-closes after first breath
- ductus arteriosus: pulmonary trunk to aortic arch and body. —becomes ligamentum arteriosum.
Fetal heart blood flow:
Oxy from placenta->R atrium->FORAMEN OVALE->L atrium->L AV valve->L ventricle->semilunar valve->aortic trunk->body
Entering R ventricle:
R atrium-> R AV valve-> R ventricle->R semilunar valve->pulmonary trunk->DUCTUS ARTERIOSUS->Aortic arch and body
Describe the coronary arteries asso. W/ adult heart and state their origin
RCA- R side of heart
LAD- L side of heart, major vessel in heart.
