Chapter 20 Flashcards
Three categories of blood vessels
Arteries veins capillaries
Arteries
Vessels that carry blood away from the heart Efferent
Veins
Vessels that carry blood back to the heart afferent
Capillaries
Thin walled vessels that connect the smallest arteries to the smallest veins
Interna tunica
Deep endothelium simple Squamous selectively permeable barrier to materials entering or leaving direct contact endothelium
Tunica media
Middle smooth muscle collagen prevents blood pressure from rupturing strengthens vessels
Tunica externa
Superficial loose connective tissue provides passage for small nerves vasa vasorum
Endothelium
Simple Squamous epithelium in the Tunica interna
Vasa vasorum
Small vessels that nourish at least the outer half of the wall of the larger vessel
Vasoconstriction
Narrowing of a vessel
Vasodilation
Widening of a vessel
Vasoreflexes
What vasoconstriction and vasodilation are collectively called
Elastic conducting
Biggest artery aorta common carotid subclavian arteries three layers expand it during ventricular systole recoil diastole
Distributing muscular
Smaller branches that distribute blood to specific organs brachial femoral renal splenic up to 40 layers of smooth muscle
Resistance arteries
Too variable and number and location 25 layers of smooth muscle thicker Tunica media
Arterioles
Smallest of arteries 1-3 layers of smooth muscle very little tunica externa major point of control over how much blood an organ or tissue receives
Metarterioles
Short vessels provide shortcuts through blood can bypass the capillaries and flow directly to a venule
Carotid sinuses
Wall of the internal carotid artery he monitors blood pressure adjust blood pressure
Carotid bodies
Branch of common carotid adjusts changes in blood composition adjust breathing to stabilize the blood
Aortic bodies
Aortic arch monitors changes in blood composition adjust breathing to stabilize the blood
Continuous capillary
Found in skeletal muscle endothelial cells held together by tight junctions for small solutes pass-through cleft
Fenestrated capillaries
Found in the kidney endocrine gland small intestines. Passage of small molecules organs for absorption and Filtration
Sinusoid capillary
Irregular blood-filled spaces where proteins can pass through and blood cells found in the liver bone marrow and spleen
Basal lamina
Thin protein carbohydrate layer surrounds the endothelium and separates it from the adjacent connective tissue’s
Pericyte
Cells that lie external to the endothelium elongated tendrils that wrap around the capillary contact and regulate blood flow through the capillaries
Post capillary venules vein classification
Smallest receives blood from capillaries or channels tunica interna with a few fibroblasts no muscle surrounded by pericyte
Muscular venules vein classification
Receives blood from the post capillary venules Tunica media of one or two layers of smooth muscle
How do veins differ from arteries
Veins have valves and a greater capacity for blood containment then arteries do
Perfusion
Flow per given volume or mass of tissue
Peripheral resistance
The opposition to the flow that the blood encounters and vessels away from the heart
Relationship between flow pressure gradient and resistance
Greater the pressure difference the greater the flow
The greater the resistance the less the flow
Pressure depends on how much resistance blood encounters
Pressure affecting flow
Greater pressure the greater the flow
Resistance affect flow
Greater the resistance the less the flow
Blood radius verse peripheral resistance
When vessel dilates average flow may be faster
When vessel constricts more of the blood is close to the wall and average flow is slower
Vessel length affect peripheral resistance
Pressure and flow decline with distance
The farther a liquid travels the more cumulative friction it encounters
Blood pressure
The force that the blood exerts against a vessel wall
Systolic pressure
Peak arterial blood pressure attained during ventricular contraction
Diastolic pressure
Minimum arterial blood pressure occurring during the ventricular relaxation between heart beats
Pulse pressure
Difference between systolic and diastolic pressure
Syncope
Fainting
Arteriosclerosis
Hardening of the arteries
Atherosclerosis
The growth of lipid deposits in the arterial walls
Hypertension
Chronic resting blood pressure higher than 140/90
Hypotension
Chronic low resting blood pressure consequence of blood loss dehydration anemia
Autoregulation
Ability of tissues to regulate their own blood supply
Reactive hypermia
Blood increases above the normal level of low
Angiogenesis
The growth of new blood vessels
Baroreflex
Detects Changes in blood pressure
Chemoreflex
Detects Blood chemistry
Vasometer center
Medulla oblongata exert sympathetic control over blood vessels throughout the body
Angiotensin
Increases blood pressure block enzyme
Aldosterone
Increases blood pressure salt retaining hormone
Natriuretic peptide
Decreases blood pressure increased sodium excretion by kidneys
Adh
Increases blood pressure promotes water retention
Epinephrine
Increases blood pressure stimulates Vasoconstriction
Vasoreflexes
Raising or lowering blood pressure throughout the body modifying
Vasoconstriction
Raises overall blood pressure
Vasodilation
Lowers blood pressure throughout the system
Capillary exchange
To way movement of fluid
Chemicals given off by capillary
Oxygen glucose and other nutrients antibodies and hormones
Diffusion
Glucose and oxygen out of blood carbon and other waste into blood
Transcytosis
Pick up material on one side of the plasma membrane transport across cell and discharge material on other side by exocytosis
Filtration
Fluid filters out of arterial end of capillary delivers materials to cells and removes metabolic waste
Reabsorption
Osmotic pressure overrides filtration pressure
Hydrostatic pressure
Physical force by a liquid against a surface
Edema
Accumulation of excess fluid in a tissue
Swelling of face ankles fingers abdomen
Venous return
Pressure gradient
Gravity
Skeletal muscle pump
Thoracic pump
Cardiac suction
Venus pooling
When blood accumulates in the limbs because venous pressure is not high enough
Circulatory shock
State in which cardiac output is insufficient to meet the bodies metabolic needs
Cardiogenic shock
In adequate pumping by the heart
Low venous return
Cardiac output is low because too little blood is returning to heart
Venus pooling shock
When the body has a normal total blood volume but too much of it accumulates in the lower body
Obstructed venous return shock
When any object such as a growing tumor compresses a vein and impedes its blood flow
Anaphylactic
Results from exposure to something someone is allergic to release of histamine
Compensated shock
Homeostatic mechanisms bring out recovery
Uncompensated shock
Poor cardiac output results weaken heart reduce output
Transient ischemic attack
A moment to a few hours temporary dizziness loss of vision weakness paralysis and a headache
Cerebrovascular accident or stroke
Sudden death of brain tissue caused by ischemia Linus paralysis loss of sensation loss of speech
Skeletal muscles
Muscular contraction compresses the blood vessels and impedes blood flow
Brain
Bloodflow constant because oxygen deprivation can cause irreversible damage regulates own blood flow
Lungs
Pulmonary circuit is the only route in which arteries carry oxygen poor blood in the veins carry oxygen rich blood
Function of pulmonary circulation
Exchange CO2 for 02
Systemic circulation function
Supplies oxygen and nutrients to all organs and removes their metabolic wastes
