Lecture 4 - Cardiovascular I Flashcards
The cardiovascular system delivers ___ to all body cells and removes ___ from the cells
Oxygen and nutrients / carbon dioxide and waste
Homeostasis
The maintenance of the interstitial fluid environment surrounding the cells of an animal’s body
How does the digestive system interact with the cardiovascular system
Food and water intake is processed in the digestive system. the nutrients, salt, and water from food are then transported to cells through the circulatory system
How does the respiratory system interact with the cardiovascular system
The respiratory system is responsible for oxygen intake. there is gas exchange between the lungs and blood and the circulatory system will acquire the oxygen, then the CO2 from the blood will be released through the respiratory system
How does the urinary system interact with the cardiovascular system
There is an exchange of water and solutes between these two systems to maintain homeostasis. the urinary system will eliminate excess water, salts, and waste from the body
Location of the heart compared to the lungs, sternum, vertebral column, and diaphragm
- Medial to the lungs
- Dorsal to the sternum
- Ventral to the vertebral column
- Anterior to the diaphragm
Pericardium
Double-walled membranous sac enclosing the heart (outermost layer), the pericardial cavity is fluid-filled
Myocardium
Layer of cardiac muscle which forms the bulk of the heart
Fibrous skeleton of the heart
Crisscrossing, interlacing layer of connective tissue
Endocardium
Endothelial layer of the inner myocardial surface
Function of the pericardium
- Protects and anchors the heart
- Prevents overfilling of the heart with blood
- Allows for the heart to work in a relatively friction-free environment
Functions of fibrous skeleton of the heart
- Provides structural support by creating a firm base for heart valves/great vessels and anchors the cardiac muscle
- Provides electrical insulation through separation of the atria from the ventricles and by directing action potentials to specific pathways
Atrium function
Receives blood from veins and delivers blood to the ventricle
Ventricle function
Pumps blood out of the heart
Septum
Wall of cardiac muscle that divides the heart chambers
Vessels that return blood to the heart
Inferior vena cava, superior vena cava, pulmonary veins (left and right)
Vessels that direct blood out of the heart
Aorta, pulmonary trunk (becomes left and right pulmonary arteries)
Myocardial thickness
Varies according to the function of the chamber, atria are thin walled, ventricle walls are thicker and stronger
Diastole
Heart is relaxed and fills with blood, AV valves are open
Systole
Heart is contracting, semilunar valves are open
Atrioventricular valves
Between atria and ventricles, tricuspid on right, bicuspid (mitral) on left
Semilunar valves
Pulmonary and aortic valves located between the right ventricle and the pulmonary artery and between the left ventricle and the aorta
Lub heart sound
When AV valves close, blood recoiling against the closed AV valves
Dup heart sound
When semilunar valves close, the recoil of blood against closed valves
Cardiac muscle cells
Branched cells, single nucleus, striated, lots of mitochondria, connected by intercalated disks
Intercalated disks
Desmosomes transmit tension by connecting the cytoskeletons of adjacent cells, gap junctions transmit action potentials
Sarcomere
Basic contractile unit of muscle
Thin filament
Actin
Thick filament
Myosin
A band
Region occupied by thin and thick filaments
I band
Thin filaments only
Which band shortens during contraction?
i band
