Module 1: Heart Flashcards
(174 cards)
What are the functions of the lymphatic system?
The lymphatic system has several functions including:
* Fluid recovery
* Immune response
* Lipid absorption
What organs or tissues are part of the lymphatic system?
The organs and tissues of the lymphatic system include:
* Lymph nodes
* Spleen
* Thymus
* Bone marrow
* Lymphatic vessels
Where is the lymphatic system located within the body?
The lymphatic system is distributed throughout the body, with lymphatic vessels running parallel to blood vessels and lymph nodes located at various points.
What are the characteristics and roles of lymphatic vessels?
Lymphatic vessels are:
* Thin-walled
* Valved
* Transport lymph fluid back to the bloodstream
* Help maintain fluid balance
What is the role of lymph nodes?
Lymph nodes filter lymph fluid, trapping pathogens and foreign substances, and are sites for immune cell activation.
Describe the role of the lymphatic system in microcirculation and fluid recovery.
The lymphatic system collects excess interstitial fluid, returns it to the bloodstream, and helps maintain tissue fluid balance.
Define edema.
Edema is the abnormal accumulation of fluid in the interstitial spaces of tissues.
What are the four main causes of edema?
The four main causes of edema are:
* Increased hydrostatic pressure
* Decreased oncotic pressure
* Increased capillary permeability
* Lymphatic obstruction
What is the structure and role of the pericardium?
The pericardium is a double-walled sac surrounding the heart, consisting of:
* Visceral pericardium
* Parietal pericardium
It protects the heart and allows it to contract with minimal friction.
Identify the layers of the heart.
The layers of the heart are:
* Epicardium
* Myocardium
* Endocardium
What chambers are found in the heart?
The heart contains:
* Left atrium
* Right atrium
* Left ventricle
* Right ventricle
What are the types of valves in the heart?
The heart has:
* Right atrioventricular (AV) valve (Tricuspid valve)
* Left atrioventricular (AV) valve (Bicuspid/Mitral valve)
* Semilunar valves (Pulmonary and Aortic valves)
Define cardiomyocytes.
Cardiomyocytes are specialized muscle cells of the heart that contract to pump blood.
What are the histological components of cardiac muscle?
Cardiac muscle is characterized by:
* Striated appearance
* Intercalated discs
* Single nucleus per cell
* Myofibrils
What is the function of intercalated discs?
Intercalated discs connect cardiomyocytes, enabling synchronized contraction and electrical signal transmission.
Describe the role of desmosomes and gap junctions in cardiac muscle.
Desmosomes provide mechanical strength, while gap junctions allow for electrical coupling and ion movement between cells.
What is the cardiac conduction system?
The cardiac conduction system is a network of specialized cells that initiate and propagate action potentials throughout the heart.
What is the significance of a positive inotropic stimulus?
A positive inotropic stimulus increases the end-diastolic volume (EDV), decreases the end-systolic volume (ESV), leading to increased stroke volume (SV) and cardiac output (CO).
What are the phases of the myocyte action potential?
The phases of the myocyte action potential include:
* Phase 0: Depolarization
* Phase 1: Initial repolarization
* Phase 2: Plateau
* Phase 3: Repolarization
* Phase 4: Resting potential
What ions are involved in the cardiac myocyte action potential?
The main ions involved are:
* Sodium (Na+)
* Calcium (Ca2+)
* Potassium (K+)
What distinguishes nodal (non-contractile) cells from contractile cells?
Nodal cells spontaneously generate action potentials and do not have a stable resting membrane potential, unlike contractile myocytes.
What is the role of the SA Node?
The SA Node is the primary pacemaker of the heart, initiating action potentials that regulate heart rate.
What happens during the plateau phase of the myocyte action potential?
During the plateau phase, calcium channels remain open, allowing calcium ions to enter the cell, prolonging depolarization.