Exam 3 Flashcards
The smallest vessels that are sites of O2, CO2, nutrient, and waste product exchange
Capillaries
Process of blood bringing nutrients and oxygen to and removing wastes from tissues
Systematic circulation
These return proteins and fluids from tissue spaces all over body to the blood
Lymphatic capillaries
Atrioventricular valves are anchored in the hearts
Dense irregular connective tissue
Ventricular papillary muscles are attached to the atrioventricular valves by
Chords tendinae
Myocardium is thicker in the
Ventricles
This structure holds AV valves shut during contractions of ventricles and prevent evertion
Chords tendinae
These structures do not have chorda tendinae and prevent back flow from arteries into ventricles
Semilunar valves
Which node is the pacemaker of the heart and initiates conduction
Sinoatrial node
After impulses travel to the AV node they continue to
Bundle of His (AV bundle)
The bundle of his branches into
Left and right branches along intraventricular septum, towards apex
Bundle branches subdivide into
Purkinje fibers
Purkinje fibers extend into
Myocardium of ventricles
This structure rapidly spreads impulses to ventricular muscles
Purkinje fibers
What type of tissue surrounds large Purkinje fibers
Subendocardial layer of connective
Modified cardiac muscle fibers specialized for impulse conduction rather than contraction
Large Purkinje fibers
Which ventricle is three times thicker, producing sufficient force to propel blood through the larger systemic circulation
Left ventricle
Visceral layer of pericardium, covered by simple mesothelium
Epicardium
Site of coronary vessels and adipose tissue
Epicardium
coronary vessels supply myocardium with
Oxygen and nutrients
Semipermeable barrier between blood and the interstitial fluid
Endothelial cells
Site where blood will not clot and secretes agents that control clot formation and smooth muscle contraction/relaxation
Nonthrombogenic surface
Smooth muscle cells are connected with gap junctions and permit vasoconstriction/vasodilation that is key for
Regulating overall blood pressure
Collagen fibers are found in
The subendothelial layer
Provide resiliency required for vascular wall to expand under pressure, forming parallel lamellae
Elastic fibers
3 concentric layers
Intima, media, and adventitia (externa)
Has a thicker media and narrow lumen
Artery
Has a large lumen and thickest layer is the adventitia
Vein
Intima of veins is folded to form
Valves
Only has an endothelium and no other tunics
Capillaries
Bring oxygen and nutrients to local cells in adventitia that are too far away from lumen
Vasa vasorum (vessels that supply vessels)
The aorta, pulmonary artery, and their largest branches are examples of
Elastic arteries
The major role of elastic arteries is to
Carry blood to smaller arteries
Have a thick tunica media, elastic lamellae alternate with layers of smooth muscle fibers
Elastic arteries
Two types of sensory receptors in walls of arteries
Baroreceptors and chemoreceptors
Monitor blood pressure changes, found in carotid sinuses and aortic arch
Baroreceptors
Carotid sinuses and aortic arches send information to the brain through
The vagus nerve
Monitor blood CO2 and O2 levels, as well as pH
Chemoreceptors
Chemoreceptors contain what type of cells
Glomus
As arteries get more distant from heart they contain less
Elastin, more smooth muscles
Distribute blood to organs and help regulate blood pressure by stimulating smooth muscle
Muscular arteries
Smallest artery branches that have 1 or 3 smooth muscle layers with no elastic laminate
Arterioles
Where the exchange of substances between blood and tissue fluid occur
Arterioles
Capillaries lack
Media and adventitia tunics
Capillaries have the smallest/slowest
Diameters, blood flow
Capillaries are made of a simple layer of
Endothelial cells, surrounded by basement membrane
Tissues with high metabolic rates like the kidneys and liver are abundant in
Capillaries
Have tight junctions sealing clefts and requiring diffusion, found in muscle, connective tissue, and nervous tissue
Continuous capillaries (most common)
Have perforations and allow for greater exchange, found in kidneys, endocrine organs, and intestinal walls
Fenestrated capillaries
Have a wider diameters and discontinuities in endothelial cells/basement membrane, found in bone marrow, liver, and spleen
Sinusoid (discontinuous) capillaries
Primary site for white blood cells to adhere to epithelium and leave the circulation at sites of infection/tissue damage
Endothelial cells form valves from folds in the intima to prevent
Backflow of lymph
Lymphatic vessels converge as two large trunks:
Thoracic duct and right lymphatic duct
Lymph is rich in and usually does not contain
Proteins, red blood cells
Has lower mineral content and higher proportion of osteocytes
Woven bone
Complex of concentric lamellae surrounding a central canal that contains small blood vessels, nerves, and endosteum
Osteons
Osteons make up most of the
Compact bone
Osteocytes get nutrients and oxygen from
Blood vessels in the central canal though canaliculi
Old bone is removed by
Osteoclasts
new bone is formed by
Osteoblasts (in periosteum/endosteum)
Forms fluorescent complexes with calcium at ossification sites
Tetracycline
Ossification where osteoblasts differentiate directly from mesenchyme and secrete osteoid, most flat bones
Intramembraneous
Ossification where pre-existing matrix of hyaline cartilage is eroded and invaded by osteoblasts, most bones especially long bones
Endochondral
Longitudinal growth of a bone occurs by cell proliferation in the
Epiphyseal plate cartilage
Joint with dense connective tissue and osteogenic cells
Synostoses
Joint with only dense connective tissue (posterior region of SI/inferior tibiofibular)
Syndesmoses
Joint with thick pad of fibrocartilage between thin articular cartilage
Symphyses
