what does the heart do
a pump that provides the force needed to move blood
vessels
the routes along which blood moves from one area of the body to another
capillaries
provide the surfaces across which exchange between plasma and Interstitial fluid occurs
heart is made of
cardiac muscle tissue, connective tissue, and epithelial tissue and it has nerves and vessels (blood and lymphatic)
muscle tissue has
striated cells and many of the cells branch
the heart is lined by a membrane composed of …
endothelium and connective tissue
the outside layer of the heart is the …
visceral pericardium
fibrous pericardium
sac like structure that surrounds the heart
-composed of dense connective tissue
serous pericardium
- two parts
- parietal and visceral
parietal pericardium
-lines the inside of the fibrous pericardium
visceral pericardium
covers the heart itself (on the viscera)
pericardial fluid
fills the pericardial cavity
- reduces friction
blood travels away from the chambers in ___.
arteries
blood traveled toward the chambers via ___
veins
the arteries of the pulmonary circuit take blood to the
lungs
blood is pumped by the left ventricle into the _____ circuit.
systemic circuit
the arteries of the systemic circuit take blood to _____
all parts of the body
as blood flows through pulmonary capillaries it picks up ____ and loses ____.
oxygen ; carbon dioxide
as blood flows through the systemic capillaries, substances are exchanged between it and the IF. what are the substances?
oxygen , carbon dioxide, nutrients, cellular waste products
the largest veins of the systemic circuit empty blood into the ______.
right atrium
the pericardial cavity is located between the
visceral pericardium and the parietal pericardium
fetal blood flows to and from the placenta via ___.
umbilical vessels
the placenta has both _____ and _____ blood vessels
fetal and maternal blood vessels
foramen ovale
an opening in the interatrial septum
ductus arteriosus
a vessel connecting the pulmonary trunk and aortic arch
what do the foramen ovale and ductus arteriousus do?
the allow most blood to bypass the pulmonary circulation
ductus venosus
allows some blood to bypass the hepatic (liver) vessels
specialized cardiac muscle cells in the atria secrete a hormone called ____. what is ists function
atrial natriuretic peptide
-vasodilation
aveolar and capillary walls are the surfaces across which _____ occurs.
gas exchange
the walls of the airways in the respiratory system have ____ or ___ to prevent them fro collapsing.
bone or cartilage
many of the airways are lined by _______.
ciliated epithelium
explain the significance of ciliated epithelium in the airways
small particles that are inhaled stick to the mucus secreted by this epithelium and ciliary action moves the mucus and entrapped particles out of the airwaysw
alveolar walls are composed of _______.
simple squamous epithelium
what is the significance of alveolar walls being composed of simple squamous epithelium?
the thin membrane makes it easy for gases to diffuse
visceral pleura
covers the lung directly
parietal pleura
lines the wall of the thoracic cavity
what type of fluid fills the pleural cavity?
pleural fluid
what does pleural fluid do
acts a lubricant that reduces friction during lung movements
-acts as an adhesive that helps in lung expansion and prevents collapse of the lungs
the only portion of the digestive tract found in the thoracic cavity is the ______.
esophagus
the esophagus extends from the _____ to the ____ where is passes through the foramen (hiatus) into the abdominal cavity
laryngopharynx to the diaphragm
the layers of the esophageal wall are the same as we studied before except which exception
- the muscularis externa
- in the first two thirds of the esophagus it is composed of skeletal muscle tissue, but in the last one third, it is composed of smooth muscle tissue.
thymus
located over the heart in fetus
- eventually replaced by connective tissue
- endocrine organ that secretes hormones
- organ of the lymphatic system involved in immunity
phrenic nerve
innervates the diaphragm
vagus nerve
innervates structures of the thorax
a series of ganglia called the ___________ run along either side of the vertebral column.
sympathetic chain ganglia
function of the heart
moves blood
-located in the mediastinum between ribs 2-5
base
posterior surface
-formed mostly by the L atrium
apex
pointed end
-located in the left 5th intercostal space (slightly below left nipple)
Right atrium
receives blood from the systemic veins
superior vena cava
drains the head, neck, thorax, and upper limbs
-feeds the right atrium
inferior vena cava
- drains the lower limbs and the abdominal and pelvic regions
- feeds the right atrium
right ventricle
pumps blood through the pulmonary circuit
pulmonary trunk
takes blood to the lungs
-exits right ventricle
pulmonary arteries
- paired
- take blood to the lungs
pulmonary veins
- paired
- drain blood from the lungs
left atrium
receives blood from the pulmonary veins
left ventricle
pumps blood through the systemic system
ascending aorta
its branches supply the entire body
aortic arch
supplies most of the body
ligamentum arteriosum
chord extending from the pulmonary trunk to the aortic arch
-remnant of the ductus arteriosus
fassa ovalis
thin region in the interatrial septum
-remnant of the foramen ovale
atrioventricular valves
prevent the backflow of blood into the atria
chordae tenineae
anchors cusps to the papillary muscles
-prevent eversion of the cusps
papillary muslces
anchor chordae tendineae to the ventricular walls’ prevent eversion of the cusps
semilunar valves
prevent backflow of blood into the ventricles
right coronary artery
- runs to the back of the heart
- supllies the heart
posterior interventricular artery
- branches from the right coronary arter
- runs to the apex
- supplies the posterior ventricular walls
left coronary artery
- branches from the left side of the ascending aorta
- supplies the heart
anterior interventricular artery
- branch of the left coronary artery
- runs to the apex
- supplies the interventricular septum and the anterior ventricular walls
coronary sinus
formed by the merging of cardiac veins
-drains the heart
true or false: papillary muscles cause atrioventricular valves to open
false
