Histology Flashcards
What is the tunica adventitia
the outer layer of the blood vessel made up of connective tissue, much larger in veins for protection as they tend to be more superficial in the body
what is the tunica media
the middle layer of blood vessels consisting of smooth muscles and some elastic fibres, much larger in arteries
what are the three conformations of the capillaries
continous
fenestrated
discontinuous
what are the properties of continuous capillaries
epithelial cells line side by side with no gaps, pericytes in the lining and a continuous basal membrane
what are the properties of discontinuous capillaries
larger gaps and discontinuous basal membrane, therefore providing a leaky function
what are the properties of fenestrated capillaries
There are pores in them but the basal membrane remains continuous
Where are fenestrated capillaries found
gut mucosa, endocrine and kidney
what capillaries would you find in the spleen, liver and bone marrow
discontinuous
where are continuous capillaries found
lung, nerve, skin and muscle tissue
describe the flow of blood in the context of blood vessels
heart - arteries - arterioles - terminal arteriole, meta-arteriole - pre capillary sphincters - capillary bed - lymphatics - post-capillary venules - venules -veins - back to the heart
what structures control blood flow in the capillaries
pre-capillary sphincters
what is the tunica intima
inner most layer of blood vessel and is comprised of simple squamous epithelial cells supported by the basal laminate and connective tissue
What are the components of blood
45% formed elements (erythrocytes, leukocytes and platelets) 55% plasma (water, proteins and nutrients)
List the leukocytes in order of proportion (most to least abundant)
neutrophils
lymphocytes
eosinophils
monocytes
basophils
Give an account of veins
carry deoxygenated blood, small/thin TM but thicker TA and have valves to prevent backflow of blood
Give an example where valves are defective in the veins of the limbs
varicose veins
What separates the tunica intima from the tunica media
internal elastic membrane
What is the vasa vasorum
Vasculature in arteries that provide nutrients to the tunica adventitia because the thickness is so large
What are meta arterioles?
blood vessels that it before the capillaries and have a discontinuous layer of smooth muscle with pericytes wrapped around the endothelial cells allowing more flexibility
What are terminal arterioles
contain continuous smooth muscle, because of this muscular wall allows for contraction and dilation to regulate bloodflow
What is Fascia?
the connective tissue that covers all the structures of the body
loose connective tissue that is a meshwork of collagen and elastic fibres and space in between filled with adipose tissue. Which type of fascia is it?
superficial fascia
What is deep fascia?
dense and tightly packed connective tissue lacking in adipose tissue
Fascia around the body is separated into different regions and is non-continuous, true or false?
False, fascia runs continuously throughout the body
Where is deep fascia absent in the body?
In the face
What does septae mean?
deep fascia that separates limbs into compartments
What processes is the fascia active in
- Thermoregulation
- Protective padding
- Support for tissues / organs
- Reduces friction
- Transmits mechanical force
- Proprioceptive feedback (rich nerve supply)
- Myofascial system (muscles and fascia are tightly woven and interdependent )
What is compartment syndrome
because the fascia is structured in compartments, if there is a bleed or fluid release it can increase the pressure in one compartment and cause tissue necrosis
What is plantar fasciitis
inflammation of the plantar fascia which supports the arches of the foot
Name the types of voluntary and involuntary muscles
smooth muscle - involuntary
skeletal muscle - voluntary
what kind of muscle has striations?
skeletal muscle and cardiac but stations are less prominent in the latter
Name three forms of connective tissue
soft connective, hard connective and muscle
tendons and ligaments are examples of which connective tissue?
soft
cartilage is smooth connective tissue, true or false?
false, it is considered hard connective tissue
A neuron that has one axon and one dendrite is described as?
bipolar
What are pseudo-unipolar neurons?
neurons that have a single process that branches out from the cell body and then splits into one end which is the axon and the other the dendrite
multipolar neurons have one axon and multiple dendrites, true or false?
true
what are dendrites
they receive sensory stimulus and transmit it to the axon
What is the role of an axon
sends signals to the central nervous system typically the spinal cord
what are microglia
macrophages of the brain
what are astrocytes
most abundant glial cells in the brain and responsible for maintaining the blood-brain barrier and supporting ion transport
Name 3 types of glial cells
astrocytes
oligodendrocytes
microglia
Which glial cell is responsible for the production of myelin sheath
oligodendrocytes
Give examples of structures that are made out of microtubules
flagella, cilia and spindle fibres
What are microtubules
part of the cytoskeleton that is composed of two alpha and beta-alternating tubulin subunits
microfilaments are composed of actin fibres, true or false
true
which part of the cytoskeleton is responsible for the mechanical strength and stability of the cell
intermediate filaments
which part of the cytoskeleton is responsible for dividing the cell during cytokinesis
the microfilaments
Where is regular soft connective tissue found
tendon
in the dermis, loose soft connective tissue is found irregularly, true or false?
false, it is dense connective tissue in the dermis but it is an irregular manner
where can loose connective tissue be found?
the mesentery because there are cells packed amongst the fibres
What kind of secretions are found in the parotid gland?
serous secretions so watery
What secretions are found in the submandibular gland?
more serous secreting than mucus secreting
more serous secretions are found in the sublingual gland than mucus secretions, true or false?
false, there are more sticky secretions (mucus)
What kind of glands are endocrine and exocrine glands considered
endocrine (ductless)
exocrine (ducted)
What are ductless glands?
glands that secrete hormones directly into the bloodstream - goes towards the basal end of the membrane and into the vascular system
What are ducted glands
hormones are secreted to the apical end of the cell - sends it to specific body surfaces and cavities - tends to serve a localised function
