CVPR Histology Notes

Question 1

The bulk of the heart tissue is

Answer 1

striated involuntary cardiac muscle

Question 2

Cardiac muscle can undergo what changes

Answer 2

hypertrophy

atrophy

necrosis

apoptosis

Question 3

3 layers of the heart

Answer 3

epicardium

myocardium

endocardium

Question 4

Answer 4

3 layers of the heart

Question 5

Epicardium

Answer 5

thin layer of flat to cuboidal mesothelial cells covering fibbrous and asipose connective tissue (also called visceral layer of the pericardium

contains nerves and blood vessels that supply the heart (coronary vessels found in this connective tissue layer)

Question 6

What type of cells is the epicardium made of

Answer 6

thin layer of flat to cuboidal mesothelial cells

Question 7

Answer 7

Epicardium

Question 8

Myocardium

Answer 8

thickest layer of the heart. Composed of bundles of cardiac muscle cells organized into spiraling fascicles that efficiently squeeze blood out of the heart chambers.

Cardiac muscle cells distinguished by striations, intercalated discs, branched fibers and centrally located nuclei

Strands of connective tissue and vascular elements course through the myocardium between the fascicles

Question 9

Thickest layer of the heart

Answer 9

myocardium

Question 10

Answer 10

myocardium

Question 11

Endocardium

Answer 11

simple quamous epithelium over a layer of variable thickness connective tissue called the subendocardium. Purkinje fibers associated with the conduction system are found in the subendocardium

Question 12

Purkinje fibers associated with the conduction system are found in the

Answer 12

subendocardium

Question 13

Answer 13

Endothelium and subendothelium

Question 14

Cardiac muscle cells are

Answer 14

striated muscle cells with a single centrally located nucleus and branching shape

contains contractile proteins, sarcoplasmic reticulum, and T tubules similar to skeletal muscle cells

Question 15

Cardiac muscle cells have a ____ density of mitochondria compared to skeletal muscle

Answer 15

HIGHER

40% compared to 2%

Question 16

Cardiac muscles rely on what to contract

Answer 16

large influx of calcium

Question 17

Answer 17

Cardiac muscle cells

Question 18

Cardiac muscle cells are joined together by

Answer 18

intercalated discs

Question 19

Intercalated discs

Answer 19

contain desmosomes and adherens junctions that hold the cells together under the forces of contraction

gap junctions to facilitate the movement of signals to contract from one cell to another

Question 20

Are ther NMJs in cardiac muslce

Answer 20

NO

Question 21

Answer 21

intercalated discs

Question 22

Answer 22

Cardiac conduction

Question 23

SA node

Answer 23

Pacemaker

Under normal conditions, electricle activity is spontaneously generated by the SA node. Propagated through the right atrium to the L atrium and AV node

Question 24

AV node

Answer 24

An area of speciaalized tissue between the atria and the ventricles of the heart, specifically in the posteroinferior region of the interatrial septum near the opening of the coronary sinus (Koch’s Triangle)

AV node conducts the normal electrical impulse from atria to ventricles

Question 25

Bundle of His

Answer 25

A collection of heart muslce cells specialized for electrical conduction that transmits the electical impulses from AV node through cardiac skeleton and membranous interventricular septum to a point at the apex of the muscular interventricular septum where it splits into the bundle brances

Question 26

Left and Right Bundle Branches

Answer 26

a group of purkinje fibers that run in the subendocardial space along the interventricular septum and give rise to purkinje fobers that are distributed to the cardiac muscle. cells of the ventrucular muscles

Question 27

Purkinje fobers and Purkinje cells

Answer 27

specialized cardiac muslce cells that are able to conduct cardiac action pitentials more quickly and efficiently than any other cells in the heart Appear as large light staining cells on H and E Have fermyofilaments, increased glycogen content, and increased number of gap junctions

Question 28

Answer 28

Purkinje cells

Question 29

Angiogenesis

Answer 29

Formation of new capillaries from existing capillaries

Question 30

Steps in Angiogenesis

Answer 30

1. Stimulation of endothelial cells by angiogenic factors such as VEGF 2. Degradation of the vessel membrane by activated endothelial cells and the formation of endothelial sprouts 3. Proliferation of endothelial cells and formation of new capillary tubes 4. New vessel stabilization/maturation (new basement membrane formation and association of pericytes)

Question 31

Respiratory System- Conducting Portion

Answer 31

* Conditions inspired air * consists of trachea, bronchi, bronchioles * overall structure contains mucosa, lamina propria, submucosa, adventitia

Question 32

Mucosa

Answer 32

* pseudostratified columnar epithelium with goblet cells = the respiratory epithelium. * Respiratory epithelium= cleanse, moisten, warm the inspired air before it enters lungs * Goblet cells produce mucous abundant in upper portions of the conducting tubes and decrease as conducting tubes proceed to respiratory epithelium * Ciliated pseudostratified columnar epithelium transitions to simple columnar and cuboidal epithelium.

Question 34

Oxygenated blood flows

Answer 34

within arteries of decreasing diameter into arterioles which lead to capillary beds

Question 35

Deoxygenated blood-

Answer 35

leaves capillaries and flows into venules that lead into veins of increasing diameter

Question 36

Answer 36

Vessels

Question 37

Answer 37

Layers of vessels

Question 38

Except for capillaries, blood vessels are organized into what 3 layers

Answer 38

Tunica intima tinuca media tunica adventitia

Question 39

Lamina Propria

Answer 39

Thick, loosely organized vasculararized connective tissue that supports the mucosa

Question 40

Waht type of cells make up the tunica intima

Answer 40

single layer of squamous endothelial cells

Question 41

Tunica intima

Answer 41

innermost layer sincle layer of squamous endothelium physiologic regulation of vascular tone (release of factors that affect contraction of relaxation of smooth muscle) nonthrombogenic surface

Question 42

Submucosa

Answer 42

* Forms the bulk of the thickness of the wall and contains three main components of varying amounts depending upon the level of the bronchial tree; smooth muscle, hyaline cartilage and seromucous glands * Smooth muscle organized into bundles of cells that increase in quantity as the diameter of the tube decreases. Smooth muscle contracts and regulates amount of airflow through conducting tubes. * Hyaline cartilage can form C shaped rings, irregular rings and small plates. Prevents collapse of the tubular walls. Decreases in quantity as the diameter of the tubes decreases.

Question 43

Tunica media

Answer 43

Concentric layers of smooth muslce cells with elastic fibers, type III collagen, and proteoglycans Smooth muscle of the tunica media is primarily responsible for the regulation of vascular tone, vessel diameter, and blood pressure Fibers of smooth muscle are elongated, tapering, nonstriated cells, each of which is enclosed in a thin basal lamina adjacent cells linked with gap junctions (to contract in unison)

Question 44

Changes in Structural Components of the Respiratory system (table)

Answer 44

Question 45

Structure of the Trachea

Answer 45

* Thin walled tube 10 cm long extending from larynx and divides into the two main bronchi * Lined with ciliated pseudostratified columnar epithelium with goblet cells * 16-20 C shaped rings of hyaline cartilage in the submucosa to help keep the tube from collapsing * fibroelastic cartilage and smooth muscle (trachealis muscle) support the portion where the rings end posteriorly

Question 46

Structure of the Bronchi (primary, secondary, tertiary)

Answer 46

* Trachea divides into two primary bronchi, one to each lung * Primary bronchi divide into secondary or lobar bronchi of smaller diameter that each supply a lobe of the lung (3 rt and 2 left) * Secondary bronchi divide into tertiary (segmental) bronchi that supply segments of the lung and give rise to the bronchioles *

Question 47

Tunica Adcentitia

Answer 47

Connective tissue layer: contains fibroblasts, type I collagen, and elastic fibers Autonomic nerve fibers (sympathetic) that control contraction of the smooth muscle of the tunica media are also located here

Question 48

Answer 48

Tunica adventitia

Question 49

Vasa vasorum

Answer 49

small vessels located in the adventitia of large vessels to provide blood supply to the outer layers of the vessel

Question 50

Answer 50

Arteries vs veins

Question 51

Artery vs vein

Answer 51

Artery More developed tunica media Holds its shape on histology Vein More developed tunica adventitia Contains valves to prevent backflow Usually colapsed on histology

Question 52

Structure of the Bronchioles

Answer 52

* airways with 5mm or less, no glands or cartilage * Epithelium decreases in height to become cuboidal epithelium * Submucosa contains mainly smooth muscle and elastic fibers

Question 53

Arterioles

Answer 53

small vessels with 1-3 layers of smooth muscle cells in the tunica media important in regulation of blood flow into tissue capillary beds

Question 54

Capillaries

Answer 54

smallest diameter blood vessels site of fluid, gas, and small molecule exchange single layer of endothelial cells and a basement membrane some tissues have pericytes associated with outer wall of capillary

Question 55

Answer 55

Pericyte support

Question 56

Answer 56

Continuous Capillary Found in muscle, nerve, and connective tissue Have tight intercellular junctions to restrict leakage and utilize pinocytotic vesicles in transport functions

Question 57

Answer 57

Fenestrated Capillary Found in GI and Endocrine systems Countain permenent channels or fenestrations across endothelial cells

Question 58

Structure of Respiratory Bronchioles

Answer 58

* each terminal bronchiole divides into two or more respiratory bronchioles. * mucosa of respiraotry bronchioles resembles the terminal bronchioles except walls are interrupted by numerous saccular alveoli where gas exchange can take place

Question 59

Sinusoidal capillary

Answer 59

found in bone marrow, liver, spleen and LNs Contin large discontinuities between the endothalial cells

Question 60

Structure of the Alveoli

Answer 60

* Sac like structures about 200uM in diameter that are organized into larger structures called acini * 300 million alveoli with a surface area of 140 m2 form the parenchymal structure of the lungs * Oxygen and carbon dioxide are exchanged between air and blood here * alveoli are covered by rich capillary network, fibroblasts, and elastic reticular fibers

Question 61

Alveolar wall cell types

Answer 61

1. Type 1 Pneumocytes- squamous cells that make up 97% of alveolar surface. All have desmosomes and tight occluding junctions and form a gas permeable barrier of minimal thickness 2. Type II Pneumocytes-Interspersed among the type I cells. Cuboidal. Resemble secretory cells with a foamy cytoplasm caused by presence of lamellar bodies that contain lipid, glycoaminoglycans and protein. Lamellar bodies are continuously synthesized and realeased from the apical surface providing a coating of pulmonary surfactant that lowers the alveolar surface tension. 3. Alveolar macrophage/dust cell- found within the alveolus or on outer surface. derived from monocytes. contain large amounts of carbon and dust which they phagocytose from the alveolar lumen

Question 62

Blood-air barrier

Answer 62

separates air in the alveoli and blood in the capillar

Question 63

Components of the blood-air barrier

Answer 63

1. Surface of the cytoplasm of the type I alveolar cells 2. fused basal laminae of the alveolar cells and the capillary endothelial cells 3. the cytoplasm of the endothelial cells * total thickness= .1-1.5 uM * oxygen from the alveolar air diffused through layers of the alveolar wall toward the capillary while carbon dioxide diffuses in the opposite direction