histology Flashcards
The walls of arteries and veins are composed of
endothelial cells, smooth muscle cells and extracellular matrix
extracellular matrix including
collagen and elastin
layers of walls of arteries and veins
intima, media and adventitia
The intima is
the inner layer lining the vessel lumen
The adventitia is
the outer layer of the blood vessel.
The media is
sandwiched between the intima and adventitia.
sandwiched between the IEL and EEL.
the thinnest layer
intima
intima is composed of
single layer of endothelial cells and a small
amount of subendothelial connective tissue.
The intima is separated from the media by
a dense elastic membrane called the internal elastic lamina (IEL)
a dense elastic membrane called
the internal elastic lamina (IEL)
the external elastic lamina (EEL)
the internal elastic lamina (IEL) separates
The intima from the media
the thickest layer
The media especially in artery.
The media function
structural support, vasoreactivity and elasticity
The media is composed of
smooth muscle cells, elastic fibres and connective tissue( collagen fibers.)
things vary in amount depending on
the type of vessel.
smooth muscle cells, elastic fibres and connective tissue
Smooth muscle cells function
contract (vasoconstriction) or relax (vasodilatation) controlling lumen diameter and regional blood flow.
Smooth muscle cells is controlled by
- autonomic nerves (nervi vasorum)
2. local metabolic factors
Elastic fibres allow the vessel to
1.expand with systole (dilation) ,when ventricles contracts
2.contract with diastole, after ventricle contraction
and back to the origin shape for propelling blood forward.
The media is separated from the adventitia by
dense elastic membrane called the external elastic lamina (EEL)
dense elastic membrane called
the external elastic lamina (EEL)
the external elastic lamina (EEL) separates
media from the adventitia
The adventitia is composed of
connective tissue, nutrient vessels (vasa vasorum) and autonomic nerves
(nervi vasorum)
The intima and inner part of the media are nourished by
diffusion of oxygen and nutrients from blood in the lumen
the adventitia and outer part of the media are nourished by
vasa vasorum
Metabolic factors include
the acidity and alkalinity in the media
type of endothelial cells that lining intima
squamous which sitting on basement membrane.
epithelial cells line
external surfaces of the vessel “cover it”
endothelial cells line
the internal surfaces of the vessel
lumen
Cardiac Muscle developed from
mesoderm cells of the primitive heart tube
Contraction of cardiac muscle is
involuntary, vigorous, and rhythmic.
Cardiac muscle cell are
elongated
branched
bound to one another at structures called intercalated discs
intercalated discs.
خلايا عضلات اللقلب بربطو مع بعض خلاله
Cardiac muscle has
cross-striations
Each cardiac cell عدد الانوية
one or two ,centrally ,located, pale-staining nuclei
damage cardiac cells are
not renewable, if they died, they will convert into fibrous tissue.
The striated appearance comes from
the arrangement of proteins inside the cell; actin and myosin.
The intercalated discs represent
the interface between adjacent muscle cells and contain many junctional complexes.
intercalated discs are
- Transverse regions of the step-like discs
2. have many desmosomes and fascia adherentes
desmosomes and fascia adherentes functions
bind cardiac muscle cells firmly together to prevent their pulling apart under
constant contractile activity.
endomysium
- delicate sheath surrounding each cardiac muscle cell
- rich capillary network
- (a thin layer of areolar connective tissue 4.it contains capillaries and nerves).
contractile proteins
actin and myosin
Cardiac muscle cells اكتر اشي موجود فيها
mitochondria, which occupy 40% or
more of the cytoplasmic volume (reflecting their need for continuous aerobic metabolism).
the major fuel of the heart
Fatty acids
Glycogen granules may also be present
بالبيو كيم اخدنا انو كميته قليلة
Fatty acids, transported to cardiac muscle cells by
lipoproteins
Fatty acids are stored in cardiac muscle cells
triglycerides (lipid droplets)
Lipofuscin are لونهم
fine yellowbrown pigment granules
Lipofuscin found
near the nuclei of cardiac muscle cells
Lipofuscin composed of
lipid-containing residues of lysosomal digestion
