Unit 12: Cardiovascular system (anatomy of blood vessels and blood) Flashcards
(15 cards)
What is the general structure of blood vessels (except capillaries) and what are the different types.
General structure (except capillaries):
1) Tunica externa - CT
2) Tunica media - smooth muscle, elastic fibers (CT)
3) Tunica intima/interna - endothelium (simple squamous epithelium), continuous w/ endocardium
4) Lumen - contains blood (NOT A LAYER!)
Blood vessel types (following path from heart and back to heart):
1. Arteries (highways)
2. Arterioles (roads)
3. Capillaries (driveways - drop and pick up things at houses [cells] - and only one that contains ONE layer - all others = 3)
4. Venules
5. Veins
Info on arteries (highways)
Carry blood AWAY from heart (does NOT refer to oxygenated or deoxygenated blood).
2 types:
1. elastic arteries - large conducting arteries exiting the heart
- elastic CT in all 3 layers
- largest arteries (near heart)
- e.g. aorta
2. muscular arteries - smaller distributing arteries
- a LOT of smooth muscle
- most arteries
- e.g. coronary artery
Info on arterioles (roads)
- little arteries
- regulate blood flow and blood pressure
Info on capillaries
- ONLY tunica intima - endothelium (1 cell layer) and basement membrane
- allow exchange of gases and nutrients
- most have gaps btw. cells that allow exchange of fluid and solutes w/ the interstitial fluid
Info on venules
- collect blood from capillaries
- intima (endothelium) w/ thin media/externa layers
Info on veins
- carry blood INTO heart (veIN) (does not refer to oxygenated or deoxygenated blood)
- large lumen
- can have one-way valves that prevent backflow of flood
- thin media - more CTs but less smooth muscle than arteries
What are the characteristics of blood?
- higher viscosity than H2O (about 5X thicker)
- pH 7.35-7.45
- 4-6 L in an adult
- 37 degrees Celsius
What is the composition of blood?
1) plasma (matrix) makes up about 55-60% of blood volume
- fluid portion w/ solutes
2) formed elements makes up about 40-45% of blood volume
- cellular portion
Info on plasma (matrix)
= blood minus formed elements, and is composed of:
a) H2O - 90%
b) proteins - 8%
i. albumins
- most plentiful plasma protein
- carries substances like hormones, enzymes, and
medicines throughout the body
- helps control tissue water balance
ii. fibrinogen - clot formation
iii. globulin - antibodies (immunity) - detect and bind
foreign invaders (bacteria, viruses, etc.)
iv. protein based hormones and enzymes
c) other solutes - 2%
- nutrients, vitamins, wastes, electrolytes, blood gases - oxygen (O2) and carbon dioxide (CO2)
What are the parts of the formed elements?
Red blood cells, white blood cells - leukocytes, and platelets
Info about red blood cells
RBC = erythrocytes = most abundant cell type in the body
- binds to and transports most of oxygen in the blood
- hematocrit = % of blood volume that is made up of RBCs (usually about 45%)
= have a biconcave disc shape
- are Anucleate (lack a nucleus and all other organelles) when mature
- life span = 120 days
- old cells destroyed in liver and spleen
- contain hemoglobin (iron-containing pigment protein):
i. 4 globin chains (protein)
ii. 4 iron (Fe) containing heme groups (gives blood its red
colour) - 1 iron per heme
Info on WBC - leukocytes
- nucleated
- life span varies - days to years
- defend against disease
- 2 types:
i. Granulocytes - CONTAIN VISIBLE protein granules; include:
- neutrophils (about 60%) - all phagocytic (engulf and digest invaders and kill bacteria
- eosinophils (about 3%) - mostly attack blood parasites
- basophils (about 1%) - release chem.s involved in inflammation and reduction of blood clotting during immune responses
ii. Agranulocytes - LACK VISIBLE protein granules; include:
- lymphocytes (about 35%) - for immunity (resistance to disease)
- mostly found w/in lymphatic tissues
- 2 types:
i. T lymphocytes - activate immune response - kill tumor
or virus infected/diseased cells directly
ii. B lymphocytes - become plasma cells that release
antibodies that circulate in the plasma
- and monocytes (about 5%) - enter tissue and enlarge to become macrophages (meaning “big eaters”) phagocytic
Info on plateles
- = FRAGMENTS of cells called megakaryocytes
- involved in clotting
- life span = about 10 days if not used for clotting
What are 2 medical conditions related to this unit?
- Atrial septal defect = a hole in the interatrial septum
- most common type occurs b/c of incomplete closure of the foramen ovale - Atherosclerosis = build up of fat deposits in the tunica intima that leads to narrowing or blockage of arteries
What is hemopoiesis/hematopoiesis?
- = formation of blood cells
- all blood cells arise INDIRECTLY from hemocytoblast cells (which are a type of stem cells) in red bone marrow
- red bone marrow in an adult is located in:
- axial skeleton
- pelvic and pectoral girdles
- proximal ends of humerus and femur
