Week 1 Flashcards
What are the basic functions of the cardiovascular system?
- transport essential substances to tissues
- remove by-products of metabolism
- regulation of body temperature
- humoral communication throughout body
- adjustments of oxygen and nutrient supply in different physiologic states
Basic components of the circulatory system
- pump: has an electrical system for regular running
- series of distributing and collecting tubes
- extensive system of this vessels that permit rapid exchange between the tissues an the vascular channels
Basic description of heart
- 2 pumps
- RV: pulmonary circulation
- LV: systemic circulation
-valves cause unidirectional flow in the heart
ant parts of the heard cause unidirectional flow in the cardiovascular system?
-valves
what part of the circulation distributes blood to the tissues?
Arteries and arterioles are responsible for distribution
What part of the circulation contains the majority of total blood volume?
The venous system (venules, veins, and vena cava contain 70% of the blood volume
The greatest resistance in blood flow occurs in what part of the circulation?
Vascular resistance is greatest in the arterioles
What is the function of the capillaries?
This is where exchange takes place of diffusion substances
Is blood flow is pulsatile or non-pulsatile in the capillaries?
Non-pulsatile
As the cross-sectional area of a vascular bed increases, the velocity of blood flow increases or decreases?
Decreases
Velocity of blood flow in inversely related to the cross-sectional area of the vascular system
What contributes to optimal conditions of capillary function?
- blood velocity is slow in capillaries
- vessels are thin to permit rapid exchange between the tissue and the vascular channels
What is the control of blood flow related to in the majority of the tissue beds of the body?
It is almost always controlled in relation to the tissue needs.
Describe the boundaries of the mediastinum
-it contains the heart and its vessels, portion of the esophagus, trachea,
- anteriorly: sternum to vertebral column
- laterally: mediastinal pleura
- superiors: thoracic inlet
- inferiorly: diaphragm
In what part of the mediastinum is the heart located?
Middle portion of inferior mediastinum
Name the different layers of the pericardium
- Fibrous
- Serous
- parietal layer: outer layer
- visceral layer: inner wall, in contact with heart
What nerve travels across the pericardium to the diaphragm?
From which nerve roots do these nerves originate?
The phrenic nerve
Phrenic nerve originates in C3-C5
What is the sympathetic innervation of the heart?
- T1-T4
- stellate ganglia and middle cervical ganglia
- innervation of SA and AV nodes and ventricles
If sympathetic output is increased, both HR and contractility will increase
What is the parasympathetic innervation to the heart?
- originates in medulla oblong at a
- Vagus nerves
- much innervation to SA and AV nodes (and atrial tissue)
- little innervation to ventricles
Stimulation will slow HR and decrease contractility; at maximum only decrease by about 30%
What are the different parts of the condition system?
- sinoatrial node (SA)
- interatrial conduction pathways (SA to LA)
- internode conduction pathways (SA to AV)
- atrioventricular node
- bundle of HIS
- Bundle branches
- left bundle branch
- left anterior division
- left posterior division - right bundle branch
- left bundle branch
What structures are part of the right atrium?
- Vena cavae
- superior
- inferior
- eustachian valve: part of fetal circulation
- Crista terminalis: divides right atrium
- right atrial appendage (right auricle)
- Coronary sinus (venous drainage of heart)
- Fossa ovalis
- Tricuspid valve
What is the coronary sinus?
What does it drain into?
- collection of veins joined together to form a large vessel that collects blood from the heart (myocardium)
- drains into the right atrium
Describe the tricuspid valve apparatus.
How many leaflets does the valve have?
-separates the right atrium from right ventricle
- 3 leaflets
- anterior leaflet
- posterior leaflet
- septal leaflet
Describe the thickness of the walls of the RV in comparison to those of the LV
The walls of the LV are thicker than the RV
Describe the shape of the right ventricle in cross-section
Crescent- shaped
