Quiz 4/4/14 Flashcards
The diameter of the lumen of an ___ is narrower than that of a ___.
Artery
Vein
The SA node is located where?
Posterior wall of the R atria
The AV node is located where?
Floor of R atrium nr coronary sinus
What is the AV bundle?
Connection pt between the AV node and the L and R bundle branches
What are purkinje fibers?
Sm myelinated axons around the apex of the heart
The P wave represents atrial ___.
Depolarization
The QRS complex represents what?
Ventricular depolarization
A T wave represents what?
Ventricular repolarization
Each big box on an EKG strip represents what period of time?
0.2 sec
The lumen of a vessel is what?
The inside diameter
Tunica intima is located where and compromised of what?
Inner layer of a blood vessel
Simple squamus epithelium
Tunica media is located where?
Middle layer of a blood vessel
How does the thickness of the tunica media of an artery compare to that of a vein?
Arteries are thicker than veins
___ ___ is the outer layer of a blood vessel.
Tunica Externa
How does the thickness of the tunica externa of an artery compare to that of a vein?
It is thicker in veins than in arteries
A backflow preventer in a vein is called a ___ and is located in the tunica ___.
Valve
Intima
The lumen of a vein often appears how when cut in cross section?
Collapsed
What is the thickest tunic in an artery?
Tunica media
What is the thickest tunic in a vein?
Tunica externa
Blood pressure is ___ in arteries than in veins.
Higher
The ___ ___ ___ is a network of veins that drain blood fr the gastrointestinal organs & shunt the blood to the liver.
Hepatic Portal system
The hepatic portal vein does what?
Delivers nutrient rich blood to the liver
What 3 veins make up the hepatic portal vein?
Inferior mesenteric
Splenic
Superior mesenteric
___ veins collect blood fr liver & return it to the inferior vena cava
Hepatic
The hepatic portal system begins in the ___ of the digestive sys & ends in the liver ___.
Capillaries
Sinusoids
Why is blood in the hepatic portal system different fr that in other systemic veins?
B/c it contains substances absorbed fr stomach & intestines
The ___ ___ ___ collects blood fr capillaries along the inferior portion of the lg intestine.
Inferior Mesenteric Vein
The ___ vein is formed by the union of the inferior mesenteric vein & veins of the spleen, lateral border of the stomach & the pancreas
Splenic
The ___ ___ ___ collects blood fr veins draining the stomach, sm intestine & 2/3 of lg intestine
Superior Mesenteric Vein
Most of the venous blood of the cranium drains through the ___ ___ ___.
Dural Venous Sinuses
Where are the dural venous sinuses located?
Between 2 layers of dura mater
Blood in the dural venous system can flow in more than one direction. Why?
B/c there are no valves
___ arteries branch fr the subclavian arteries & travel through the transverse foramina of the cervical vertebrae.
Vertebral
Vertebral arteries enter the cranium through the ___ ___ where they merge to form the ___ artery.
Foramen Magnum
Basilar
The basilar artery & the internal carotid arteries give off several branches that creates an anastomosis of arteries just superior to the sella turcica called the ___ ___ ___.
Cerebral Arterial circle
The cerebral arterial circle is also known as what?
Circle of Willis
Internal carotid arteries enter the cranium through where?
Carotid canal
Internal carotid arteries divide into anterior & middle cerebral arteries which supply what 2 structures?
The brain
Opthalmic Arteries going to the eyes
L and R ___ ___ arteries supply most of the blood to the head and neck.
Common Carotid
What are the 3 control mechanisms for precapillary sphincters?
- NS
- Hormones
- Paracrine factors (local control) ie: Nitric
Oxide - Keeps sphincters open
What is the effect of Nitric Oxide on precapillary sphincters?
It keeps them open
Nitric oxide is a paracrine factor the keeps precapillary sphincters ____.
Open
The internal carotid artery sends blood to the ___ where as the external carotid feeds blood to the ___.
Face
Brain
The 2 vertebral arteries merge together to form the ___ ___.
Bassillar artery
What is a anastomosis?
The joining of vessels together to prevent any type of blockage that could cause tissue damage
What is an example of an anastomosis?
Circle of Willis
What are 3 types of anastomoses?
- Venous
- Arterial
- Venous-arterial
Why are arterial-venous anastomoses so bad?
B/c they may cause an aneurism due to high arterial pressure rupturing a vein
Dural sinuses are located between what 2 layers of the dura mater?
Endosteal and meningeal layers
The dural sinuses drain into where?
Internal jugular
What drains into the internal jugular from the brain?
Deoxygenated blood
Old CSF
What veins empty into the hepatic portal system?
- Gastric
- Splenic
- superior mesenteric
- Inferior mesenteric
- Cystic
The liver sends blood out through the L & R hepatic veins into where?
Inferior vena cava
How many umbilical arteries are there?
2
Blood in a fetus does what with the liver?
It bypasses it by going thru the ductus spinosis
In a fetus blood goes out of the R ventricle into the pulmonary trunk and directly into the aorta, bypassing the lungs, through a duct called the __ __.
Ductus arteriosus
In fetal circulation, blood can go directly fr the R atrium to the L atrium through what passageway?
Foramen ovale
When fetal blood passes thru the foramen ovale into the L atrium where does it go fr there?
L ventricle and into the Aorta
What are the 2 ways blood bypasses the lungs in fetal circulation?
- By passing thru the Ductus arteriosus
2. By passing thru the foramen ovale
What passageway does blood fetal blood go thru in order to bypass the liver?
Ductus Spinosus
Fr the aorta blood goes into the ___ ___ arteries which branch into the ___ ___ to return to the mother in fetal circulation.
Internal iliac arteries
Umbilical arteries
What is the resting membrane potential of cardiac cells?
-90mV
What is the plateau indicative of in a cardiac action potential?
K is going out and Ca is coming in at the same time
What happens during the rapid depolarization phase of an action potential?
Sodium rushes in thru fast sodium channels
During the plateau phase of an action potential what happens?
Voltage gated calcium channels open and Calcium ions move in
During the repolarization phase of an action potential what happens to potassium?
Slow potassium channels open and potassium rushes out of the cell
What makes the action potential of cardiac muscle cells different fr skeletal muscles?
The presence of the plateau period
A membrane will not respond normally to a 2nd stimulus for some time aft an action potential begins. This time period is known as what?
Refractory period
If the membrane of cardiac muscle cells in the SA node become permeable to K ions what will happen to HR?
It will decrease
If the connection between the SA node and the AV node becomes blocked what will happen to ventricular rate?
The ventricles will beat more slowly
What effect will a blockage between the AV node and the AV bundle have on an EKG?
There will be more P waves that QRS complexes
Compared to arteries, veins have a (thicker/thinner) tunica advantitia?
Thicker
T or F: Contraction relaxation pumping of smooth muscle in the walls of veins helps to move blood forward.
F - There is no smooth muscle in a vein
At the carotid sinus, what does the common carotid form?
An internal and external branch
The superior sagittal sinus collects blood from where?
The brain
Nutrients from the digestive tract enter where?
Hepatic portal vein
Blood is drained fr the liver into the inferior vena cava by the ___.
Hepatic Vein
The blood vessel that carries blood to the fetus fr the placenta is the ___ ___.
Umbilical vein
Abnormally slow conduction through the ventricles would change the shape of what on an EKG?
QRS complex
