Unit 12: Cardiovascular System Flashcards
What cavity is the heart located in?
The mediastinum (space between lungs)
What is the endocardium and what is it composed of?
The endocardium lines the inner surface of the heart and is composed of simple squamous epithelium (endothelium) and connective tissue
What are the 3 major veins that connect to the right atrium and carry deoxygenated blood into the chamber?
Inferior vena cava (below heart)
Superior vena cava (above heart)
Coronary sinus (from the myocardium)
What veins carry oxygenated blood into the left atrium?
There are 4:
Left pulmonary veins
Right pulmonary veins
How many blood vessels leave the left ventricle?
Just 1 artery, the aorta
What blood vessels connect to the right ventricle?
The pulmonary trunk exits the right ventricle and then divides to form the left and right pulmonary arteries
What separates the chambers within the heart?
The septa: the interatrial septum and the interventricar septum
What is the cardiac (fibrous) skeleton?
It separates the atria and ventricles and provides solid attachment points, forms rings around valves, and electrical insulation for SA node. It is composed of fibrous connective tissue.
What are chordae tendineae?
Strings of CT that attach AV valve cusps to papillary muscles that project from the ventricular myocardium. They prevent leakage or backflow through cusps by sealing them shut
What are the 2 types of cardiac muscle cells?
Contractile cells and conduction system cells
Describe contractile cells. How do they differ from skeletal muscle?
Contractile cells form the majority of the myocardium and are striated with sarcoplasmic reticulum and T-tubules. Unlike skeletal muscles, they are branched, uninucleated (1 nucleus), connected by intercalated discs, and contain anchoring and gap junctions
Describe conduction system cells
Forms the remainder of the myocardium. The cells are modified to produce and conduct electrical impulses (they don’t contract). They have many gap junctions to help electrical impulses spread quickly
What are the parts of the conduction system of the heart?
Sinoatrial (SA) node
Atrioventricular (AV) node
AV bundle (bundle of his)
AV bundle branches
Purkinje fibres
What makes up the general structure of blood vessels?
Tunica extrna (CT)
Tunica media (smooth muscle and elastic fibres (CT))
Tunica intima/interna (endothelium)
Lumen (contains blood)
Describe the 2 types of artery
Elastic arteries: largest arteries close to the heart, elastic CT in all 3 layers
Muscular arteries: makes up most arteries, smooth muscle, smaller
E.g. aorta (EA) vs coronary (MA)
Which type of blood vessel is only composed of tunica intima (endothelium + basement membrane)?
Capillaries
Give some examples of subdivisions of systemic circulation (the names or routes to individual organs)
Routes to individual organs:
Cerebral = brain
Hepatic = liver
Coronary = heart
Bronchial = respiratory system
What are some characteristics of blood?
CT
Higher viscosity that H2O
pH = 7.35 - 7.45
4-6 L in an adult
90% of plasma is made up of water. 8% is proteins. What are the major proteins?
Albumins: most plentiful, carries hormones, enzymes, and meds through the body, helps tissue water balance
Fibrinogen: clot formation
Globulin: antibodies
Protein-based hormones and enzymes
What are the types of leukocytes (WBC)?
Granulocytes, contain visible protein
Agranulocytes, do not contain visible protein granules
What are the types of lymphocytes?
T Lymphocytes: activate immune system, can kill virus or tumour cells directly
B Lymphocytes: become plasma cells that release antibodies that circulate in the plasma
What are monocytes?
A type of agranulocyte that enters a tissue and enlarge to become macrophages (“big eaters”) phagocytic
The pericardium is the protective sac surrounding the heart. What layers does it have?
Fibrous pericardium: DI-CT, anchors to surrounding structures
Parietal pericardium: epithelial and connective tissue, pericardial sac
Visceral pericardium (epicardium): epithelial and connective, fused to heart surface—part of heart wall
What is the name for the formation of blood cells?
Hemopoiesis/hematopoiesis. All blood cells arise indirectly from hemocytoblast cells (type of stem cell)
What is atrial septal defect?
A hole in the interatrial septum, which commonly occurs due to incomplete formation of the foramen ovale
Granulocytes are a type of WBC. What makes up the visible granules within?
Neutrophils (majority)
Eosinophils
Basophils
Platelets are fragments of cells called _______.
megakaryocytes
What are the 3 fetal shunts that allow most blood to bypass the lungs and liver?
Ductus venosus
Foramen ovale
Ductus arteriosus
In fetal circulation, which shunt permits the oxygenated blood coming from the placenta via the umbilical vein to bypass the liver capillaries to go straight to the inferior vena cava?
Ductus venosus
In fetal circulation, which shunt connects the pulmonary trunk and aorta to allow blood to bypass the lungs?
Ductus arteriosus
