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arteries
carry blood away from the heart closest to heart large amounts of elastic and fibrous connective tissue; large amounts of smooth muscle can withstand high blood pressure volume varies with contraction and relaxation
veins
carry blood to the heart large lumens with thin walls less connective tissue and smooth muscle than arteries comparatively lower blood pressure than in arteries vessels are furthest from the heart
Pericardium
3 layer membrane around heart that protects, connects, and secretes lubricant
vena cava
2 (superior and inferior) bring blood from the body to the heart
pulmonary arteries
exception to naming rule (carrying deoxygenated blood away from the heart) carry blood from the heart (right ventricle) to the lung
pulomonary veins
exception to naming rule (carrying oxygenated blood to the heart) carry blood from the lungs to the heart (left atrium)
aorta
main artery transport blood from the heart (left ventricle) to the body
AtrioVentricular valves
separate the atria from the ventricles
Semilunar valves
separate the ventricles from the aorta and pulmonary artery
path of blood flow
vena cava right atrium and right AV valve right ventricle and pulmonary semilunar valve pulmonary arteries to lungs pulmonary veins from lungs left atrium to left AV valve left ventricle to aortic semilunar valve exit through aorta
pulmonary circulation
begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs
systemic circulation
oxygenated blood through pulmonary veins to left atrium to left ventricle and out through aorta to the body
diastole
relaxation of the muscle to allow the chambers of the heart to fill with blood
systole
contraction of the muscle that pushes about 60% of the blood from the chamber
What are key differences in tissue composition and blood pressure gradient between arterial and venous side of circulation?
blood pressure in arteries is much higher than in veins due to receiving blood from the heart after contraction arteries are thicker; veins have less smooth muscle and connective tissue
myocardial
cardiac muscle cells striated, only have 1 nucleus per cell, branched, connected by intercalated disk (desmosomes and gap junctions)
desmosomes
provide structure and adhesion
gap junctions
provide rapid cell-cell communication
Autorhythmic cells
pacemakers generate action potentials, signal for contraction smaller and fewer contractile fibers compared to contractile cells do not have organized sarcomeres
Cardionyocytes
contractile cells striated fibers organized into sarcomeres
How does the anatomy of the cardiac conduction system contribute to the pathway of electrical signaling and resulting coordination of blood pumping?
action potential waits for ventricles to fill before going on to the atrioventricular node atria contracts a second before the ventricles so their blood empties into the ventricles before the ventricles contract
What is the main cellular feature that makes pacemaker signals automatically fire action potentials?
depolarization-repolarization cycle is continuous; no stable resting period ion funny channels that let both Na+ and K+ through
cellular mechanism causing the charge plateau
Ca2+ channels and fast K+ channels close creates plateau where the cell cannot depolarize again
contractile cardiac muscle cells
more "normal" mechanism of action potentials lower resting potential, longer peak because of Ca2+ entry
electrocardiogram (ECG)
summed electrical activity of all heart cells SA nose sets pace of heart beat at 70 bpm
P-wave
depolarization of atria
QRS complex
wave of ventricular depolarization and atrial repolarization
T-wave
repolarization of ventricle
cardiac muscle cells
striated; sarcomeres; heart muscle; uninucleate, shorter branching fibers; gap junctions and intercalated disks; pacemaker potential
skeletal muscle cells
striated; sarcomeres; attached to bone; multinucleate, large cylindrical fibers; gap junctions
smooth muscle cells
smooth; no sarcomeres; forms the walls of hollow organs and tubes; uninucleate, small spindle-shaped fibers; longer myofibrils; pacemaker potential
What type of muscles help control blood flow thru blood vessels?
vascular smooth muscle
“blood pressure reservoir”
arteries -> thick walled, help in regulating blood flow and the blood pressure
"variable resistance”
arterioles the resistance in the circulatory system that is used to create blood pressure, the flow of blood and is also a component of cardiac function
blood volume reservoir
veins, nearly 60% of total volume in human volume is in the veins can be mobilized to boost cardiac output
arterioles
smaller than arteries; move blood from arteries to capillaries contain little connective tissue; large amount of circular smooth muscle constricts to close, relaxes to open contributes to body temperature homeostasis and oxygen regulationc
capillaries
location of exchange smallest and most numerous blood vessels no muscle or connective tissue consist of lumen formed by epithelial tissue; single cell layer thick simple structure allows exchange of materials (nutrients and wastes) between cells and blood lowest density in cartilage and subcutaneous tissues highest density in muscles and glands
continuous capillaries
endothelial cells joined with leaky junctions junctions allow water and small dissolved solutes to pass through found in muscle, connective tissue, and neural tissue
fenestrated capillaries
large pores found in kidneys and intestines
Transcytosis
brings proteins and macromolecules across endothelium some vesicles may fuse to create temporary channels
venules
transport blood from capillaries to veins smaller than veins; no visible to the naked eye contain little connective tissue and little smooth muscle some exchange with cells here
Do capillaries vasodialate?
No, capillaries can not dilate or constrict
What is the role of the lymphatic system with respect to capillary exchange?
lymphatic system get fluid lost by the capillaries back to the circulatory system
What is the most important function of capillaries and what are some cellular features that can aid this function?
allow the exchange of nutrients and wastes between the blood and the tissue cells, together with the interstitial fluid hydrostatic pressure from heart forces things out on arterial side osmotic pressure dominates on venus side allowing for reabsorption
What is a skeletal muscle pump and what function does it serve?
help maintain venous return and consequently cardiac output by compressing underlying veins in order to increase blood flow back to the heart
plasma
55% of blood and 92% of that is water made up of water, ions, organic molecules, trace elements and vitamins, gases
Cells in blood
45% of blood is cellular elements red blood cells, white blood cells, platelets, and cell fragments
Erthrocytes
most abundant cell in body (about 5 billion per ml) in humans, lack nuclei, mitochondia, and ribosomes primary function in to transport oxygen and CO2 accomplished with the iron-based protein hemoglobinhe
hemoglobin
heme groups form a ring with iron to carry O2 each hemoglobin molecule can carry 4 O2 molecules iron is necessary to make heme group
Leukocytes
only fully functional cells in our circulation involved in immune response jobs are to recognize and destroy pathogens, make antibodies, cause inflammation
Platelets
fragments of bone marrow cells (megakaryocytes) that have broken off smaller than erythrocytes (no nucleus, have mitochondria and protein vesicles) less numerous important in blood clotting
hemostasis
process to prevent and stop bleeding
What is special about platelets?
platelets are important as they form clots to stop bleeding
How are platelets formed?
produced from very large bone marrow cells called megakaryocytes
Vasocontraction
first step of hemostasis vessel constricts due to paracrine release damaged cells release chemicals telling neighboring cells to contract less blood flow = less blood loss
Platelet plug formation
step 2a of hemostasis inactive platelets become active platelets to clog vessel wall platelets will not adhere to intact endothelium; exposed collagen triggers platelet plug formation
Coagulation
step 2b of hemostasis clot formation fibriogen to make a ne to trap RBC need anticoagulations to prevent infarcation
infarction
tissue deprived of blood by a clot
Vessel repair
third step of hemostasis clot dissolves via plasmin
ventilation
movement of air in/out of lungs (breathing)
respiration
exchange of gases (oxygen and CO2)
internal respiration
exchange of gases between systemic circulation and tissue provides O2 to cell/mitochondria and removes CO2
external respiration
exchange of gases between blood and air occurs between alveoi (lungs) and pulmonary capillaries main function of our respiratory system
why do we breathe?
to make it easier for internal tissues to exchange gases
bronchi
carry air to and from your lungs screen out foreign particles
bronchioles
carry air to the alveoli
alveoli
where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out
pleural sacs
membrane that wraps around the lungs and connects the lungs to the thoracic wall between the layers, there is fluid that creates a suction that keeps the sac connected to the chest if sac is punctured, causes a collapsed lung
How many sources of blood do the lungs have?
2 sources of blood for lungs pulmonary circulation: delivers unoxygenated blood to lungs Bronchial circulation: supplies oxygenated blood to supporting tissues of lungs (connetive tissues, bronchi, and bronchioles); part of systemic circulation
4 steps of gas exchange
pulmonary ventilation: moving air into and out of the lungs
external respiration: diffusion of gases between the alveoli and the blood of the pulmonary capillaries
Transport: transport of oxygen and carbon dioxide between the lungs and tissues
Internal respiration: diffusion of gases between the blood of the systemic capillaries and cells
Additional functions of respiratory system
vocalization
defense against pathogens (cilia, mucus, macrophages)
maintaining body pH (selective loss or retention of CO2)
dissipating water and heat (unavoidable loss through breathing)
What is mucociliary clearance?
self-clearing mechanism of the airways in the respiratory system removing inhaled particles or pathogens before they can reach the delicate tissue
What is the main site of gas exchange?
the millions of alveoli in the lungs and the capillaries that envelop them.
Type 1 alveolar cells
thin, primary site of gas exchange
Type 2 alveolar cells
cuboidal, produce surfactant
surfactant
phospholipids reduce surface tension, prevent collapse
How does ventilation work?
The air moves through the passages because of pressure gradients that are produced by contraction of the diaphragm and thoracic muscles.
What is the main muscle of inspiration and what does its contraction do to the lungs?
diaphragm when the diaphragm contracts, the lungs expand to increase lung volume and bring air in when the diaphragm relaxes it pushes up, lungs volume decreases and pushes air out
What are some factors affecting pulmonary ventilation?
air pressure gradient between atmosphere and alveoli (increase pressure gradient = increase ventilation)
airway resistance (decrease resistance = increase ventilation)
What is the main function of the urinary system?
to filter blood and create urine as a waste by-product
other functions of urinary system
removal of wastes water and ion homeostasis gluoneogensis
functional anatomy of urinary system
kidney (produce urine) Uter (transport urine to bladder) Urinary bladder (stores urine) Urethra (conduct urine to outside environment)
nephron
functional unit of kidneys (about 1 million per kidney)
Why do we form urine?
adjusts blood composition filter out water, metabolic wastes, and a few solutes reabsorb water, nutrients, and essential ions
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