Cardiovascular System Study Overview

Questions and Answers

At what stage of development does the heart start beating?

4 weeks (correct)

1 week

3 weeks

2 weeks

What is the structure that forms cardiac progenitor cells during embryonic development?

Neural folds

Pericardial cavity

Oropharyngeal membrane

Primitive streak (correct)

Which of the following best describes the cardiogenic field?

The area responsible for blood diffusion

A type of muscle tissue in the heart

A horseshoe-shaped endothelial-lined tube (correct)

A region where the heart and lungs develop

What occurs at about the 22nd day of development?

The heart tube fuses into a single structure Signup and view all the answers

Where is the apex of the heart located?

Above the diaphragm to the left of midline Signup and view all the answers

What is the main function of the cardiac progenitor cells?

To form blood vessels and blood cells Signup and view all the answers

Which embryonic process assists in the positioning of the heart in the thoracic cavity?

Cephalocaudal folding Signup and view all the answers

What do the inner and outer layers of the heart tube consist of?

Myocardial and endocardial layers Signup and view all the answers

How is the septum formed when it does not involve endocardial cushions?

A narrow strip of tissue remains static as surrounding areas grow. Signup and view all the answers

What is the structure referred to as the ostium primum?

The opening between the lower rim of the septum primum and endocardial cushions. Signup and view all the answers

What is a key characteristic of the septum secundum?

It does not create a complete partition in the atrial cavity. Signup and view all the answers

What does the foramen ovale refer to?

The opening left by the septum secundum. Signup and view all the answers

What happens to the upper part of the septum primum over time?

It completely disappears. Signup and view all the answers

What occurs as the right atrium incorporates the sinus horn?

A new crescent-shaped fold, the septum secundum, appears. Signup and view all the answers

How do extensions from the endocardial cushions contribute to septum formation?

They merge with the septum primum to close the ostium primum. Signup and view all the answers

What role does the surrounding proliferating tissue play in septum formation?

It contributes tissue to close a canal left by a septum. Signup and view all the answers

What structure connects both sides of the pericardial cavity after the dorsal mesocardium disappears?

Transverse pericardial sinus Signup and view all the answers

During the formation of the cardiac loop, which portion of the heart tube bends ventrally?

Cephalic portion Signup and view all the answers

What is the trabeculated proximal third of the bulbus cordis referred to as?

Primitive right ventricle Signup and view all the answers

What process contributes to the division of the heart's lumen into two canals?

Fusion of two separate masses of tissue Signup and view all the answers

Which of the following structures forms the outflow tracts of both ventricles?

Conus cordis Signup and view all the answers

The major septa of the heart are formed between which days of development?

27th and 37th Signup and view all the answers

What role do endocardial cushions play in heart development?

They assist in forming the septa and valves Signup and view all the answers

What happens to the atrial portion of the heart tube during its development?

It forms a common atrium Signup and view all the answers

What occurs after birth as lung circulation begins?

The oval foramen is obliterated. Signup and view all the answers

What is the term for the condition resulting from incomplete fusion of the septum primum and septum secundum?

Probe patency of the oval foramen Signup and view all the answers

What happens by the end of the fifth week of fetal development regarding the atrioventricular canal?

It is divided into right and left atrioventricular orifices. Signup and view all the answers

What can occur if there is a complete absence of the atrial septum?

Atrial septal defect. Signup and view all the answers

From where do the aortic arches arise?

From the aortic sac. Signup and view all the answers

What happens to the first aortic arch by day 27 of development?

It becomes the maxillary artery. Signup and view all the answers

Which arteries are remnants of the second aortic arch?

Hyoid and stapedial arteries. Signup and view all the answers

At 29 days of development, which aortic arches are noted to be large?

Third, fourth, and sixth. Signup and view all the answers

Study Notes

Objectives of Cardiovascular System Study

Understand the gross anatomy of the heart.
Explore the development of the cardiogenic field.
Describe the folding process of the embryo.
Discuss the formation and position of the heart tube.
Analyze the development of the cardiac loop.
Examine the formation of cardiac septa.
Describe the development of the atrial system.

Heart Basics

Starts beating by the end of the 4th week of embryonic development.
Beats approximately 100,000 times daily.
Functions primarily as a pump for blood circulation.

Location of the Heart

Positioned in the thoracic cavity, specifically within the mediastinum.
The base of the heart is located behind the sternum.
The apex is above the diaphragm and slightly left of the midline.

Establishment of the Cardiogenic Field

Vascular system begins developing in the middle of the third week.
Cardiac progenitor cells migrate through the primitive streak to form cardiac myoblasts.
Blood islands in mesoderm contribute to the formation of blood cells and vessels through vasculogenesis.

Formation and Position of the Heart Tube

By the 22nd day, two heart tubes fuse into one, lined by endocardium and surrounded by myocardium.
The heart tube remains attached to the dorsal side of the pericardial cavity via the dorsal mesocardium; this later disappears.

Formation of the Cardiac Loop

Occurs around day 23, with the heart tube bending to create a loop.
The atrial portion shifts dorsocranially and to the left, forming a common atrium.
At the end of this phase, the primitive left and right ventricles have distinctive regions.

Formation of the Cardiac Septa

Major septa develop between the 27th and 37th days.
Endocardial cushions assist in forming atrial and ventricular septa and atrioventricular canals.
Septum formation can occur via fusing tissue masses or growth of narrow tissue strips.

Atrial Septum Development

A septum primum grows from the atrial roof towards the endocardial cushions.
The ostium primum allows blood flow between right and left primitive atria.
The ostium secundum forms via perforations ensuring right to left atrial blood flow.

Functionality of the Oval Foramen

After birth, the oval foramen closes due to increased left atrial pressure, separating the right and left atria.

Atrioventricular Canal Septum Formation

Atrioventricular endocardial cushions develop and fuse, creating distinct orifices by the end of the fifth week.

Atrial Septal Defect (ASD)

ASD occurs due to the complete lack of atrial septum or inadequate septum secundum development.

Vascular Development Overview

The aortic arches arise from the aortic sac and are associated with pharyngeal arches.
Five pairs of aortic arches are numbered I, II, III, IV, and VI, some of which regress during development.
By day 27, remnants of the first and second arches form specific arteries, with the third, fourth, and sixth arches continuing to develop.
By day 29, the trunk-aortic sac has divided, linking sixth arches to the pulmonary trunk.

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Description

This quiz explores the objectives of studying the cardiovascular system, including the anatomy of the heart and its development throughout embryonic stages. Gain insights into the heart's formation, location, and significance as a circulatory pump. Perfect for students keen on understanding the intricate workings of human anatomy.