Cardio & Resp Histology Flashcards
what type of tissue is mainly found in the media of muscular arteries
Sm muscle (also elastic fibers but less dominant)
what type of connective tissue fiber would you expect to find in the adventitia
collagen with elastic fibres
what does a, b, c represent
a = vasa vasorum
b = venule
c = nerve
what are the 3 main layers or tunics which form the wall of the medium sized muscular artery
- tunica intima
- tunica media
- tunica adventitia
what does c represent
lymphatics?
what are the characteristics of elastic arteries (5)
- size: large
- rounded appearance: yes
- relatively thick wall compared to its luminal diameter: yes
- conspicuous internal elastic lamina: no
- any valves: no
what are the characterisitcs of muscular arteries
- size: small, med, large
- rounded appearance: yes
- relatively thick wall compared to its luminal diameter: yes
- conspicuous internal elastic lamina: yes
- any valves: no
what are the characteristics of arterioles
- size: small
- rounded appearance: yes
- relatively thick wall compared to its luminal diameter: yes
- conspicuous internal elastic lamina: yes but only in larger arterioles
- any valves: no
what are the characteristics of the capillary
- size: very small
- rounded appearance: varies
- relatively thick wall compared to its luminal diameter: 2-4 endothelial cells line the lumen
- conspicuous internal elastic lamina: no
- any valves: no
what are the characterisitics of venules
- size: very small, larger lumen in comparison to accessory artery
- rounded appearance: no
- relatively thick wall compared to its luminal diameter: no but some development of other tunics is apparent
- conspicuous internal elastic lamina: no
- any valves: yes
what are the characteristics of small, medium and large veins
- size: larger lumen in comparison to accessory artery
- rounded appearance: no
- relatively thick wall compared to its luminal diameter: no but some development of other tunics is apparent
- conspicuous internal elastic lamina: no
- any valves: yes
what are the characteristics of the vena cava
- size: large
- rounded appearance: yes
- relatively thick wall compared to its luminal diameter: yes but the adventitia is the thickest tunic
- conspicuous internal elastic lamina: no
what are the characteristics of lymphatic vessels
- size: variable
- rounded appearance: no usually collapsed
- relatively thick wall compared to its luminal diameter: no mainly consists of endothelium and poorly developed media
- conspicuous internal elastic lamina: no
- any valves: yes more numerous than veins
what is the functional significant of these structural differences between medium sized vein and muscular arteries
arteries have much more smooth muscle in the tunica media –> high pressure, carry blood away from the heart
the multiple layers of elastic lamina are fenestrated, why?
to allow diffusion of nutrients from blood to nourish structures
what functional role do elastic lamina in large conducting arteries such as aorta
to allow aorta to stretch and undergo high variations
elastic recoil/dampening pulsatory flow
what other type of tissue is found in association with the elastic lamina in the media of elastic arteries
media contains smooth muscle cells
what is the vena cava is characterized by
large muscle bundles running longitudinally in the adventitia
the media is relatively narrow in comparison
coarse collagen fibers are circularly oreintated in the inner adventitia and form sheaths around the muscle bundles
label the structures of the elastic arteries
identify the structures muscular arteries
identify the structures of the arterioles
identify the structures of the venule
what are the structures of veins
identify the structures of the vein
- tunica intima
- tunica media
- tunica adventitia
identify the three layers of the muscular veins
identify the structures of purkinje fibres
how are capillaries structurally adapted to suit their function which is to act as exchange vessels
thin walls
high SA:volume ratio
maybe fenestrated, leaky cellular junctions
what is an arterio-venous anastomosis and give an example where you might expect to find this
pre-capillary arteriovenous anastomosis
the skin and small intestine
Skin- direct link between arterial and venous system without intervening capillary bed.
what is another example of an unusal form of microcirculation
- arterial portal system (kidney glomerulus)
- venous portal system (hepatic portal system ex. liver)
what are the two types of capillaries
- continuous capillary
- fenestrated capillary
what is the functional difference between the two types of capillaries
continuous have variable permeability
Fenestrated increased exchange cf. continuous- the presence of pores increase the permeability of a capillary
what is a sinusoid and give an example where you would expect to find this type of vessel
sinusoids have a discontinuous endothelium, no basal laminae
ex. liver and spleen
what are the structures of the trachea
A: respiratory epithelium (pseudostratified ciliated columnar epithelium with goblet cells)
B: seromucosal glands in lamina propria
C: hyaline cartilage
what is the epithelium in the trachea
pseudostratified columnar ciliated epithelium
what are the types of glands in the trachea
goblet cells
what type of cartilage comprises the tracheal cartilage
hyaline cartilage
is there any smooth muscle present in the trachea and where would it be
yes
under the cartilage
what does C represent
hyaline cartilage
what type of tissues are the arrows pointing to
smooth muscle in lamina propria
smooth muscle is present in the entire bronchial tree including the respiratory bronchiole
how is it innervated and what function does it perform
mediates broncho constriction
vagus nerve (parasympathetic) causes the smooth muscle to contract and reduce the diameter of the bronchioles
what type of connective tissue fibre is abundant in the lamina propria of the bronchial tree
elastic connective tissue
what do MALT and BALT stand for
mucosa associated lymphoid tissue
bronchus associated lymphoid tissue
what type of cells predominates in this type of tissue (BALT, MALT)
lymphocytes:
T and B cells
plasma cells
macrophages
give four reasons how you know that you are looking at a section of a bronchus and not a bronchiole
- cartilage present
- epithelium pseudostratified
- BALT
- goblet cells
which blood vessel deoxygenated blood to the lungs
pulmonary trunk –> pulmonary arteries
which cell type gradually replaces the mucous cell in the bronchiolar epithelium to become the dominant cell type in the terminal bronchiole
clara cell
what does A, B, C represent and what part of the distal resp system does A represent and give two reasons to justify your decision
A: bronchiole
B: alveolar ducts
C: alveolar ducts
terminal bronchiole (size, simple cuboidal epithelium, lamina propria smooth and elastic fibers)
name the cell type that predominates the wall of lung
type 1 pneumocyte
what is the principle cell type which forms the wall of the alveolus
ciliated cuboidal epithelium
what type of cell gives rise to the surfactant
type 2 pneumocyte
Illustrate how a medium sized vein differs structurally from its corresponding muscular artery?
what is the functional significance of these structural differences
Arteries= high pressure blood= thick muscular wall- regulate amount of blood being delivered to tissues; veins= capacitance vessels- blood at low BP- thick wall not required.
illustrate the difference in shape and wall thickness between these 2 types of blood vessel.
Venule and arteriole
Draw a labelled sketch of the aorta at low magnification to illustrate the relative extent of the tunica intima, media and adventitia. Are these limits easy to see in your H&E section?
Difficult to see limits of intima, media and adventitia with H&E- internal and external elastic lamina of the media difficult to distinguish from other laminae associated with the media.
By means of another labelled diagram, illustrate the main components of the blood-gas barrier across which respiratory gases are exchanged.
what is this representing
where would any smooth muscle be located in the trachea
below C shaped edges of cartilage if sheep
above is feline
Smooth muscle is present in the entire bronchial tree including the respiratory bronchiole. How is it innervated and what function does it perform?
Innervation- vagus and sympathetic nervous system- decreases /increases and diameter
