Anatomy :( Flashcards
From the inside out what are the four major sections of blood vessels
Lumen, Tunica intima, Tunica media, Tunica adventitia
What are the main components of the tunica intima
Endothelium (simple squamous), Basal laminate of the epithelial cells, Subendothelial connective tissue
What are the main components of the Tunica Media
Smooth muscle fibres in loose connective tissue and potentially elastic fibres
What are the main components of the Tunica Adventitia
Connective tissue which merges with surrounding connective tissue and may also contain vasorum.
What are the main differences between arteries and veins.
Blood pressure, wall thickness, presence of valves
When comparing corresponding arteries and veins how does the artery compare
Arteries have thicker walls, appear to have a smaller lumen, will maintain its shape, more resilient and does not contain valves.
What are the three main types of arteries (and their purposes)
Elastic (conducting), Muscular (distributing), Arterioles (resistance vessels)
How large are elastic arteries and what structural adaptations are present. (Name 3 examples of elastic arteries)
They can be up to 2.5cm diameter and contain a thick tunica media with many elastic fibres and few smooth muscle cells. E.g. aorta brachiocephalic & common carotid.
What is the size range and the structural adaptations of muscular arteries. (Any examples of muscular arteries)
Diameter ranges between 0.5mm - 0.4cm, contain lots of smooth muscle cells in tunica media, distinct internal and external elastic laminae and a thick tunica externa.
How large are arterioles and what structural adaptations do they possess
They are <= 30 μm in diameter and contain only one or two layers of smooth muscle in the tunica media with a poorly defined tunica adventitia
What are the purposes of each of the types of arteries?
Elastic must withstand changes in blood pressure during the cardiac cycle while ensuring blood flow, muscular distribute blood to muscles and organs and will dilate/constrict in order to control blood flow, Arterioles also dilate/constrict and control blood flow and pressure.
What are the structures and purpose of the capillaries
Capillaries connect arterioles and venules (microcirculation) while acting as sites of gaseous exchange. They have slow blood flow and thin walls allowing efficient 2 way exchange of substances. They are only 8μm in diameter.
What are the three types of capillaries and what are their purposes/structures
Continuous (Make up the majority e.g. muscles, CT and lungs)
Fenestrated (pores penetrate endothelial lining which allows for rapid exchange of water and large solutes, mainly used for absorption e.g. kidney, choroid plexus and endocrine glands)
Sinusoidal (Gaps between endothelial cells with an incomplete or absent BM, blood moves slowly through them and large solutes can move in and out. Mainly important in specialised lining e.g. liver)
What is the importance of Metaarterioles and the precapillary sphincter.
A Metarteriole will continue as a thoroughfare channel throughout a capillary bed and has numerous capillaries leading from it, constriction of the metarteriole will reduce blood flow to the entire capillary bed. The Precapillary sphincter can contract and reduce blood flow or relax to increase to the capillary bed.
What is the name and importance of the direct channel from Arteriole to venule
Ateriovenous anastomoses is the channel that connects them and is important as when it dilates it can make blood bypass the capillary bed.
What are the structures and purpose of Venules
They average ~20μm in diameter and will connect capillary beds and small veins, smaller venules are just endothelium on basement membrane and as they get larger they have increasing amounts of smooth muscle outside endothelium
What are the sizes of veins and what are their structural importance
They have 3 categories, small <2mm, medium 2-9mm, large >9mm. They operate at low blood pressure so they are thin walled with a predominant Tunica adventitia with valves to aid flow and prevent back flow.
How do muscles aid blood flow in veins
As muscles especially in the legs contract they will compress the vein slightly and help to “pump” the blood.
In what type of blood vessel is the greatest loss of pressure
Arterioles
In what type of blood vessel is the greatest loss of pressure
Arterioles
Define all locational anatomical terms
Anterior/ventral - The front side of the body
Posterior/dorsal - The real side of the body
Superior - Top half of the body
Inferior - Lower half of the body
Medial - Central pillar of the body
Lateral - To the sides of the body
Proximal - Close to the center of the body
Distal - Far from the centre of the body
What are the three anatomical planes
Transverse/Horizontal - Splits body into lower and upper
Sagittal - Passes from front to back splitting body into left and right
Coronal/frontal - passes from side to side splitting from front to back
What are the different levels of organisation in the body
Cell<Tissue<Organ<System<Organism
What are the 4 types of tissues
Epithelia Connective Muscle Nervous
What are the different types of epithelia
Simple squamous
Keratinised stratified squamous
Stratified squamous
Simple cuboidal
Simple columnar
Pseudostratified columnar with goblet cells
What is the structure and functions of simple squamous epithelia
Flat cells with oval nuclei comprised of one layer. Mainly used for nutrient and gas exchange in blood vessels and alveoli.
What is the structure and function of Keratinised stratified squamous cells
Flat surface with oval nuclei with many layers. Reinforced with keratin making it act as a waterproof barrier e.g. skin.
What is the structure and function of Stratified squamous cells
Flat surface with oval nuclei comprised of many layers, acts as a barrier but non waterproof e.g. oral cavity/oesophagus.