BIO 12 UNIT 4: Study Notes

PLASMA

Major Components:

1. Water (90-92%): maintains blood volume and transports molecules [source: absorbed from intestine]
2. Proteins (7-8%): maintains osmotic pressure and pH [source: liver]
1. Albumin (maintains blood volume and pressure)
2. Globulins (transport cholesterol); fight infection)
3. Fibrinogen (clotting)
3. Salts (>1%): metabolism; maintains osmotic blood pressure and pH [source: absorbed from intestine]
4. Gases (O2 and CO2): cellular respiration, end products of metabolism [source: lungs and tissues]
5. Nutrients (lipids, glucose, amino acids): provides food/energy for cells [source: absorbed from intestine]
6. Wastes (Urea): excretion by kidneys [source: liver]
7. Hormones, Vitamins, etc.: Aid in metabolism [source: varied]

BIO 12 UNIT 4: Study Notes

PATHWAY OF BLOOD

Aorta-->Arteries-->Arterioles-->Capillaries at major body organs and regions-->Venules-->Veins-->Inferior/Superior Vena Cava-->RA-->(via tricuspid AV valve) RV-->(via Pulmonary semi-lunar valve) Pulmonary Trunk-->Pulmonary Arteries-->Pulmonary Arterioles-->Pulmonary Capillaries (lungs)-->Pulmonary Venules-->Pulmonary Veins-->LA-->(via bicuspid/mitral AV valve) LV-->(via Aortic semi-lunar valve) Aorta

Video... Excellent and informative explanation of blood flow in heart:

http://www.youtube.com/watch?v=mH0QTWzU-xI

BIO 12 UNIT 4: Study Notes

FETAL VS ADULT CIRCULATION 

FETAL: Receives O2ated blood from the placenta and bypasses pulmonary circulation, 4 structures that adult does not have:

1. Oval Opening (Foramen Ovale): Between L and RA (flap acts as a valve), blood from the RA is shunted into the LA (does not need to go through the process of moving to the RV)
2. Arterial Duct or Ductus Arteriosus: Connection between pulmonary artery and aorta, reroutes blood away from lungs and sends it directly to the aorta
3. Umbilical Arteries and Veins: Arteries send deO2ated blood and wastes away from the heart and towards the placenta, Veins send O2ated blood and nutrients from the placenta to the fetus (heart)
4. Venous Duct or Ductus Venosus: Connection between umbilical vein and vena cava (liver), mixture of O2ated blood (umbilical vein) and deO2ated blood   (Vena Cava)

PATHWAY OF BLOOD: UMBILICAL VEIN-->VENOUS DUCT-->INFERIOR VENA CAVA-->RA-->OVAL OPENING-->LA-->LV-->AORTA


or UMBILICAL VEIN-->VENOUS DUCT-->INFERIOR VENA CAVA-->RA-->RV-->PULMONARY TRUNK/ARTERY-->ARTERIAL DUCT-->AORTA-->BODY (UMBILICAL ARTERIES-->PLACENTA)




A Great Video explaining Fetal Circulation:
http://www.youtube.com/watch?v=uwswhoKfkmM

ADULT: Has none of the fetal structures mentioned above AND has both Pulmonary and Systemic Circulation (uses lungs)

BIO 12 UNIT 4: Study Notes

PULMONARY VS SYSTEMIC CIRCULATION

PULMONARY-- Circulates blood from the heart to the lungs and from the lungs to the heart

**Right side of heart: RA-->RV-->PULMONARY TRUNK-->PULMONARY ARTERIES-->PULMONARY ARTERIOLES-->LUNGS (GAS EXCHANGE, BLOOD BECOMES O2ATED, CAPILLARIES)-->PULMONARY VENULES-->PULMONARY VEINS--> HEART (LA)

• ARTERIES (PULMONARY)- DeO2ated blood (away from heart)
• VEINS (PULMONARY)- O2ated blood (towards heart)

SYSTEMIC-- Circulates blood from the heart to the body (tissues and organs)

**Left side of heart: LA-->LV-->AORTA-->BRANCHES OF AORTA (ONE OF THE MANY PATHS)-->ORGANS AND BODY REGIONS 

• VEINS- DeO2ated blood (towards heart)
• ARTERIES- O2ated blood (away from heart)

BIO 12 UNIT 4: Study Notes

BLOOD VESSELS

1. ARTERIES: Thick walls, inside layer (endothelium), move blood away from heart and towards arterioles (O2ated) 

1. Inner Layer: Epithelial cells
2. Middle Layer: Elastic tissue and smooth muscle
3. Outer Layer: Fibrous connective tissue **Walls help with function to expand after heartbeat/maintain blood pressure**
2. ARTERIOLES: Smaller arteries, middle layer=smooth muscle, fibers of muscle contract and relax relating to blood pressure, transports O2ated blood towards capillaries (away from heart)
3. CAPILLARIES: Narrow, one-cell thick, endothelium walls, form capillary beds, regulates blood flow from the arterioles to the venules (bridge), gas exchange/nutrient exchange site--> O2 and other nutrients leaves thin capillary walls and joins tissue fluid, wastes diffuse into capillary                                     
4. VENULES: Small veins that drain capillary bed and join to form a vein, moves blood towards heart (deO2ated towards veins)   
5. VEINS: Has valves, brings deO2ated blood from capillary (venules) to the heart, valves allow for blood to flow in the right direction in the heart and prevent backflow, blood reservoirs (contain much of blood volume) 

                          

BIO 12 UNIT 4: Study Notes

SYSTOLE AND DIASTOLE PRESSURES

• SYSTOLE: Highest arterial pressure while heart is pumping (ventricles are contracting)
• 110-150 (normal for adult)--> fluctuates and differs depending on individual and activity/stress
• DIASTOLE: Lowest arterial pressure when heart is at rest (ventricles are relaxing)
• Should be 90 < (remains constant) 

The norm is 115/75 (Systolic/Diastolic)

VIDEOTIME... THE CARDIAC CYCLE: 

http://www.youtube.com/watch?v=jLTdgrhpDCg

BIO 12 UNIT 4: Study Notes

FACTORS AFFECTING BP: HYPERTENSION AND HYPOTENSION

• HYPERTENSION: High blood pressure (mild systole > 140 BUT severe systole > 180)
• Causes: Diet (fatty foods), obesity, hormone malfunction, arteries hardening, smoking, proper functioning kidneys help regulate this increase, reduction of stress, avoiding smoking, and eating healthy are factors that help regulate/counteract hypertension
• HYPOTENSION: Very low blood pressure (systole < 100)
• Causes: Weak pumping of heart (Often genetic or hereditary), kidneys regulate BP [ensure it does not get too low], ADH (increases BP), Renin (increases BP), and Aldosterone (increases BP)--> Response/regulation factors of Hypotension (counteract effects)