-
What is the order an action potential travels through the heart?
- SA Node
- AV Node
- Atrioventricular bundle (bundle of hiss)
- Bundle branches (right and left)
- Purkinje Fibers
-
What are the characteristics of the SA Node?
- Depolorizes spontaneously
- Pacemaker of the heart
- 100% more permeable to NA ions than other cells
- Without modification runs at 100 BPM
-
What two systems modify pace?
- Nervious System: Sympathetic (fight or flight) speed up Parasympathetic (rest digest) slow down
- Hormones: Catecholamines like epi and nor epi
- cortisol increases sensitivity
-
What are the 4 properties of cardiac muscle fibers
- Contract like skeletal muscle
- short fat branches that are interconnected
- many mitochondria
- calls (branches) connect at interclated disks
-
What is cardiac output?
The amount of blood pumped by each ventricle in one minute
Heart rate x stroke volume = cardiac output
-
How much blood in the heart is pumped out?
60%
-
What is stroke volume
How much blood is pumped out by the ventricle in one beat
-
What are the three components of stroke volume regulation
Preload, contractility, afterload
-
What is preload?
Stretch of fibers prior to contraction. Increase stretch = increased stroke volume
-
What is contractility?
Increased contractility = increased stroke volume
-
What is afterload?
- Presure needed to push blood past semilunar valves
- Increase afterload = decrease in stroke volume
-
What is a tunic
Layer in blood vessel
-
What is the most internal tunic
Tunica interna (endothelium)
-
What is the middle layer of tunic
Tunica media: Smooth muscle and elastic connective tissue
-
What is the most external layer of tunic?
Tunica Externa: Collegen fibers and protein
-
What are the three types of arteries?
Elastic, Muscular, Arterioles
-
What are elastic arteries?
- Have large expansion properties
- close to the heart due to pressure from the heart
- thick walled
- large lumen
- withstand and smooth out BP fluctuations
-
What are muscular arteries
- Deliver blood to body organs
- more smooth muscle and control over lumen size and flow
- Controlled by nervous system
-
What are arterioles
- Smallest of arteries
- Control flow into capillaries
- Smooth muscle
-
What is a cappilary
- Smallest blood vessel, 1 cell thick (squamous)
- 1 RBC pass at a time
- Many have pores or capillary exchange (gasses / nutrients / waste diffuse along concentration gradients
-
What is a venule?
- Drain blood from capillaries
- thin walled
- begin the return of blood to the heart (deoxygenated)
-
What are the properties of Veins?
- More elastic tissue
- Contain 65% of blood
- Lower BP than arteries
-
What 4 aspects aid in the return of blood to the heart?
- Large diameter lumens (less resistance to flow)
- Muscle contraction (milks blood toward hearts)
- Valves (once blood passes it cannot go back)
- Pressure changes in the body (breathing etc)
-
What is blood pressure?
Force per unit exerted on the blood vessel by blood
-
What is the order of the pressure gradient in the heart
- highest in aorta
- lowest in vena cava
- zero in right atrium
-
What 3 factors influence blood pressure
- Cardiac output
- Blood volume
- Vascular resistance
-
What influences vascular resistance (3 items)?
- Blood viscocity (Increase thickness=increase resistance)
- Blood vessel length (increase length = increase resistance)
- Blood vessel diameter (lower diamter = increase in resistance)
-
What is the function of Atrial Natiuretic Peptide hormone (ANP)?
Released by cells of atria casues vasodilation, decrease in BP, and loss of salt / H20 in urine
-
What are the 5 components of the lymbic system?
- bone marrow
- thymus
- lymph
- spleen
- lymph nodes
-
What are the functions of the lyphatic system?
- Drain interstitial fluid
- Protect against invasion
- Transport dietary fats
-
What is lymph
Intersitial fluid that moves into lymphatic vessels through pressure gradient
-
Describe lymphatic vessels
- Have terminal ends
- Valves
- Allow tissue fluid in but not out
- capillaries join to form vessels
- lymph flows through lymph nodes toward heart
-
What is the destination of lymph
It is dumped into subclavain veins and becomes plasma
-
What are lymph nodes?
- reticular connective tissue
- located along lymphatic vessels
- network of fibers
- contain WBC's
-
What are lymphatic nodules
Located in small intestine, appendix, tonsils: Help with filtration
-
What happens in the thymus gland?
WBC become specialized into T Cells
-
What is the function of the spleen?
- Contains RBC / WBC / Platelets.
- Filters worn out cells
-
What is a pathogen?
A disease producing microbe
-
What are the 2 broad areas of disease resistance?
specific and nonspecific
-
What are the 6 mechanisms of nonspecific resistance to disease?
- Physical and chemical barriers of the skin
- antimicrobe substances
- natural killer cells
- phagocytes
- inflammation
- fever
-
What are the 2 main mechanisms in which the skin acts as a barrier of defense?
physical and chemical barriers
-
What are natural killer cells
Lack membrane molecules but have the ability to kill a wide variety of infected body cells
-
What is phagocytosis
Process by which phagocytes ingest and destroy microbes, cell debris, and other foreign matters
-
What are the 5 phases of mechanism of action of phagocytosis
- 1) Chemotaxis
- 2) Adherence
- 3) Ingestion
- 4) Digestion
- 5) Killing
-
What is inflammation?
Nonspecific defensive response to tissue damage
-
4 symptoms of inflammation?
Heat, Pain, Redness, Swelling
-
What are the 3 stages of inflammation?
- Acute: Swelling
- Subacute: Regenerative stage
- Chronic: Scar tissue rematuration and remodeling stage
-
Trace a drop of blood
Superior Vena Cava > Right atrium > Tricuspid Valve > right ventricle > Pulmonary Valve > Pulmonary artery > Lungs > pulmonary vein > Left atrium > mitral valve > Left ventricle > Aortic valve > aorta
-
What is pericardium?
Double walled sac that contains the heart and the roots of the great vessels
-
What is epicardium?
Outer layer of the pericardium made of connective tissue (protectve coating)
-
What is Myocardium:
Middle of the three layers forming the walls of the heart
-
What is endocardium:
Inner tissue that lines the chambers of the heart made of epithelium tissue
-
What is the function of the left atrium?
recieve oxygenated blood from the pulmonary veins and pump it to the left ventricle via teh artioventricular valve
-
What is the function of the right atria?
Receive deoxygenated blood from the superior and inferior vena cava and pump it to the right ventricle via the tricuspid valve
-
What is the function of the left ventricle?
Recieve oxygenated blood from the left atria (via mitral valve) and pump it to the aorta via aortic valve
-
What is the function of the right ventricle?
Recieves deoxygenated blood from the right atria via the tricuspid valve and pumps it to the pulmonary artyer via the pulmonary valve
|
|
