Arterioles
- small blood vessels in microcirculation
- extend and branch out from arteries and lead to capillaries
- like arteries, arterioles carry blood away from the heart to tissues -
arterioles play an important role in blood pressure regulation
- arterioles generally have one to two layers of smooth muscle
Venules
- small blood vessel in microcirculation
- carry oxygen-deprived blood from the capillaries back to the veins
- have 3 layers
3 Layers of Venules
-the endothelium (inner layer) is made up of squamous endothelial cells that
act as a membrane
- the middle layer is made up of elastic tissue
- the outer layer is made up of fibrous connective tissue
Capillaries
- smallest of the blood vessels in microcirculation
- connect arterioles and venules
,- enable the exchange of oxygen, water, carbon dioxide, waste, and other
nutrients between blood and
body tissues
- capillaries don't function on their own but as a "supply cell"
Two main capillary types
Continuous
Fenestrated
Continous
- endothelial cells provide continuing lining, therefore allowing only small
molecules to spread through junctions of intercellular clefts (unjoined
membrane)
Fenestrated
- pores in the endothelial cells are present
- these pores allow small molecules and restricted amounts of protein to
spread through
Supine Position
patient is lying face-up on their back
Prone Position
,patient is lying face-down on their stomach
What is important to remember about glucose testing
patient must be fasting for 12 hours
3 Types of blood draws
Venipuncture
Capillary Puncture
Arterial Puncture
Venipunture
collection of blood through needle or syringe
Used when large amounts of blood are needed
What type of veins lack resistance
thromboses
How can blood be forced into veins
massaging arm from elbow to wrist
tapping site with finger
applying warm cloth
, lowering extremity over bedside
Elements of requisition form
Patients full name and ID number
DOB and sex of patient
name of physician requesting procedure
source of specimen
Date and Time of collection and initials of phlebotomist
Labels
Patients full name
Patients ID number
Date and Time of Collection
Initials of phlebotomist
Capillary puncture
Also known as dermal puncture
Used on infants are anemic patients
Penetration should be less than 2.0mm
Often performed for white blood cell differential