Exam 2: Ch.4 Circulatory System Flashcards
What two systems does the circulatory system consist of?
cardiovascular system –> to carry blood
lymphatic system –> to collect and transport lymph
What are the three parts of the circulatory system that this unit is broken down into?
- heart
- blood vessels
- lymphatic vessels
What are the 3 main layers of the heart wall?
- Endocardium
- Myocardium
- Pericardium
What are the three layers of the Endocardium?
- Endothelium
- Sub-endothelium
- Sub-endocardium
What type of cells is the endothelium of the endocardium made out of?
simple squamous cells
Describe the Sub-endothelium layer of the heart. What “two” layers does it have and what are they made up of?
= CT layer (of endocardium)
- looser CT layer–> fibro-elastic CT
- Dense irregular CT layer–> more collagen I and elastic fibers and some smooth muscle
What does the Sub-endocardial layer of the heart contain?
looser CT with blood vessels and PURKINJE FIBERS
What layer of the heart are the Purkinge fibers located in?
the Sub-endocardial layer of the endocardium
What are Purkinje Fibers?
modified cardiac myocytes
What do Purkinje Fibers contain fewer of? What do they store? How are they attached? What is their function*?
- fewer myofibrils and peripherally placed
- contain stored glycogen
- attached by gap junctions and macula adherens
- *Fxn–> to conduct contraction impulse rapidly
What layer of the heart are the atria and ventricle located in?
Myocardium
Compare and contrast the atria verses ventricle.
atria– less muscle and more elastic fibers
ventricle– well-developed muscle layer
What heart layer contains intercalated discs?
Myocardium
What are the two parts of intercalated discs? And what do they contain?
- Transverse portion–> macula adherens and fascia adherens
2. Longitudinal portion–> gap junctions
What are the three functions of the intercalated discs?
- attach cardiac myocytes in a row using –> macula adherens
- attach and stabilize myofibrils using using–> fascia adherens
- cell to cell communication using –> large gap junctions
How does the ANS impact the heart heart?
SNS–> increase HR and increase contraction force
PSNS–> slow HR and decrease contraction force
What are the specialized cardiac muscle cells that are associated with hormone secretion in atria and interventricular septum?
myoendocrine cells
in myocardium layer
Where do myoendocrine cells release hormones into and where will they target?
(located in myocardium layer)
Hormones released into surrounding capillaries–> will target kidneys and renal arteries*
(will influence BP in renal arteries and fluid and electrolyte balance)
What can the Pericardium layers of the heart also be called?
Serous pericardium
What are the two sub-parts of the Pericardium (also called serous pericardium)?
- Epicardium (= visceral pericardium)
2. Parietal Pericardium
Within the Epicardium (aka visceral pericardium) what are the two layers?
- Sub-epicardial layer
2. Mesothelium
What is the sub-epicardial layers of the heart made up of? what three things does it contain?
(layer in Epicardium of pericardium) layer of fibro-elastic CT Contains: - coronary vessels - nerves - sometimes-- much adipose
What layer of the heart are the coronary vessels located?
in sub-epicardial layer of the Epicardium (aka visceral pericardium), or the major Pericardium layer(aka serous pericardium)
What does the mesothelium layer of the Pericardium (aka serous pericardium) do?
(technically located in Epicardium(visceral pericardium) layers and Parietal Pericardium layer of the serous pericardium)
secretes a serous lubricating fluid
What layer of the heart secretes a serous lubricating fluid?
mesothelium
What does the Parietal Pericardium layer of the Serous pericardium contain?
- mesothelium–> secretes serous fluid
- layer of fibroelastic CT
What does the Pericardial Sac consists of?
- Parietal pericardium
2. Fibrous pericardium (much collagen I)
How much fluid can the pericardial cavity hold and what two sub-layers of the heart is it between?
~ 15-50 ml of fluid
B/w:
1. parietal pericardium
2. visceral pericardium
What does the general histology of a heart valve entail? What type of CT does it have?
endothelium with dense irregular CT below
What does the dense irregular CT of a valve contain?
- collagen type I
- elastic fibers
- almost avascular
T/F. Heart valves have a lot of vascularity.
False- they are almost avascular
What type of CT is the Cardiac Skeleton made up of?
dense irregular CT
What are the three main components of the Cardiac Skeleton?
- Annuli fibrosi
- trigonum fibrosum
- septum membranaceum
Besides the three main components, what else does the Cardiac skeleton contain?
Chordae tendinae
What part of the cardiac skeleton is around the base of the aorta, pulmonary artery, and the openings to the chambers?
annuli fibrosi
What part of the cardiac skeleton is by the cusps of the aortic valve?
trigonum fibrosum
What part of the cardiac skeleton is the upper portion of the interventricular septum?
septum membranaceum
What is the function of the Septum Membranaceum?
to provide an origin and insertion for cardiac monocytes
What type of CT are chordae tendinae made up of?
they are tendon-like–> therefore made up of Dense regular CT
T/F. In general, the dense irregular CT of the cardiac skeleton isolates artrial and ventricular myocardia to ensure individual chamber contractions.
True
What is chest pain that is usually brought on by exertion? What is the cause?
Angina
Cause–> slow progressive narrowing of coronary vessels, therefore less oxygen
What is an abnormal heart rhythm called? How can this results?
dysrhythmia
Can result when–> damage or death occurs to purkinje fibers and other conducting tissues
What is often due to an infection in the pericardial cavity? Where does this cause inflammation?
pericarditis
causes inflammation of serous pericardium (aka its two sub-parts–> visceral and parietal pericardia)
What three layers do all blood vessels, except the smallest and thinnest have?
tunica intima
tunica media
tunica adventitia
What are the three layers in blood vessels continuation of from the heart layers?
Tunica intima–> endocardium
Tunica media–> myocardium
Tunica adventitia–> epicardium
What type of epithelium does the endothelium of blood vessels consists of?
simple squamous epithelium
What are the 6 basic functions of the vascular endothelium?
- Maintain selective permeability
- prevent and promote clotting along its surface
- influence blood flow
- regulate cell growth in surrounding tissues
- influence local immune responses
- maintain extracellular matrix
Our vascular endothelium has selective permeability. What can pass by diffusion? What molecules are blocked?
pass by diffusion–> small lipid-soluble molecules (O2, CO2)
are blocked–> water and water-soluble molecules (glucose, electrolytes, AAs)
What can vascular endothelium secrete to prevent and promote clotting?
anticoagulants, antithrombogenic, and prothombogenic molecules
(i.e. heparin – an anticoagulant)
How does vascular endothelium regulate cell growth in surrounding tissues?
produces growth-stimulating and growth-inhibiting factors
i.e. platelet-derived growth factors
How does vascular endothelium influence local immune responses?
- encourages WBC movement out of vessel wall
- produces interleukins
How does vascular endothelium influence exracellular matrix?
maintains it by producing basal lamina and glycocalyx when present
What are the three types of Arteries? Do they all contain all 3 layers of a vessel wall?
- Elastic Arteries
- Muscular Arteries
- Arterioles
~yes–just varies what composed of
What are examples of elastic arteries?
- aorta
- common iliacs
- common carotids
- brachiocephalics
- subclavians
What are the other names for:
- Elastic Arteries
- Muscular Arteries
- Conducting arteries
2. Distributing arteries or medium arteries
What type of artery has a thicker CT with elastic fibers in its tunica intima?
Elastic arteries (unique to this layer)
Describe the structure of the Tunica intima of Elastic arteries.
- attenuated endothelium (thin)
- thin/incomplete internal elastic lamina
- Thicker CT with ELASTIC fibers, collagen I, fibroblasts, smooth ms
What are the two primary components of the tunica media of an elastic artery?*
thin layers of SMOOTH MUSCLE alternating with fenestrating sheets of ELASTIC laminae
Does the Tunica Media of elastic arteries have an external elastic lamina or fibroblasts?
possible, but thin
no
What does the outer portion of the tunica media of elastic arteries typically contain?
vasa vasorum (vessels that supply the vessels)
What is the make up of the tunica adventitia of elastic arteries?
- loose fibroelastic CT
- numerous vasa vasorum
What is the function of vasa vasorum?
to supply needed materials to near-by cells in the vessel wall
What are examples of Muscular arteries?
- brachial
- radial
- renal
- femoral
- ulnar
- anterior tibial artery
What type of artery for sure has an internal elastic lamina in its tunica intima layer?
Muscular arteries
elastic arteries–may have a thing/incomplete one
(arterioles–unlikely, but can)
Describe the structure of the tunica intimia of a muscular artery.
Very thin
- endothelium
- some CT–> few smooth ms cells
- internal elastic lamina*
What layer is the thickest and most dominant of a muscular artery?
tunica media
Describe what the tunica media of a muscular artery is made up of.
Primarily made up of?
Fibers contains?
Elastic Lamina?
thickest/most dominant
- primarily smooth muscle*
- gap junctions b/w smooth muscle cells
- elastic and reticular fibers, chondroitin sulfate
- external elastic lamina possible*
Describe the structure off the tunica adventitia for muscular arteries.
- fibroelastic CT with sulfated GAGs
- fibroblasts
- vasa vasorum
- richly innervated by ANS fibers–> strong contraction over a small area
What type of artery is richly innervated by ANS fibers in its tunica adventitia? Why?
muscular arteries (richly innervated by ANS fibers–> so can have a strong contraction over a small area)
What type of artery has a tunica media that is 1-2 layers of smooth muscle and has NO extneral elastic lamina?
arterioles
What type of artery has a lumen size about the width of the vessel wall? What other type is it similar to?
arterioles
very similar to muscular arteries
What should we remember for the structure of the lumen wall layers for an Arteriole?
- tunica intima–> possible/unlikely internal elastic lamina
- tunica media–> 1-2 layers smooth ms and NO ext. elastic lamina
- tunica adventitia–> thin CT layer
What type of artery has a thin CT layer for its tunica adventitia?
arterioles
What type of artery lead to metarterioles and capillaries?
arterioles
Which vessel are typically partially closed (due to smooth ms in tunica media partially contracted) and is therefore important in contributing to an inds. BP?
arterioles