Cardiac Cycle, Blood Vessels, Blood, Partial Pressures EXAM #3

The majority of plasma is made from what?

Water (90-92%)

How do red blood cells carry oxygen? How many molecules of oxygen can each red blood cell carry?

- Red blood cells carry oxygen bound to hemoglobin
- Each hemoglobin molecule can carry up to 4 molecules of Oxygen

Abundance Of WBC in Normal Blood Smear

Neutrophils : 50-70%
Lymphocytes: 20-40%
Monocytes: 2- 8%
Eosinophils: 1- 4%
Basophils: 0.5-1%

Granulocytes

Neutrophils
Eosinophils
Basophils

Agranulocytes

Lymphocytes
Monocytes

What happens to the diameter of arteries as you get farther away from the heart?

Arteries branch into smaller arterioles and then capillaries, their diameters decrease, by branching and narrowing of arteries it helps regulate blood flow and distribute blood to various tissues throughout the body.

What happens to the diameter of veins from the Venules to the Vena Cava?

Veins gradually increase in diameter as they merge from venules to larger veins and eventually into the Vena Cava. This gradual increase in diameter helps veins accommodate increasing blood volume and lower pressure as blood returns to the heart

If the Arterioles are under Vasodilation, what happens to the amount of blood flow to the capillaries?

Vasodilation of Arterioles increases blood flow to the Capillaries

What is the purpose of valves in Veins?

- Prevent back flow of blood

What is the percentage of how we carry CO2 as Bicarbonate (HCO3-) ? What is the function of Bicarbonate?

- Approximately 70%
- Function of Bicarbonate: acts as a buffer in the blood, helping to maintain the pH of blood within a normal range (7.35-7.45)
- Crucial for maintaining acid-base balance in body

What happens to the pressure of an artery during Vasoconstriction?

The diameter of the artery decreases, which increases resistance to blood flow, and a result pressure within the artery increases

What effect does Vasoconstriction have on overall blood pressure?

Increases overall blood pressure- because the narrowing of the blood vessels increase resistance throughout the circulatory system, causing the heart to exert more force to maintain blood flow, thereby raising blood pressure

Artery

A

Arteriiole

B

Capillaries

C

Venule

D

Veins

E

Which blood vessel would have a higher pressure, Venules or the Superior Vena Cava?

Venules

Which Leukocyte can become a Macrophage?

Monocytes- they migrate from the bloodstream into tissues they differentiate into macrophages, which are crucial for phagocytosing pathogens and cellular debris

Partial Pressure of O2 in a Systemic Artery

Around 95-100 mm/Hg

Which neurotransmitter is released from the Sympathetic Nervous System at the SA node to increase heart rate?

Norepinephrine (Noradrenaline)

What is the normal pH of blood?

7.35-7.45 (slightly basic)

What is the partial pressure of CO2 in the systemic veins returning blood into the Right Atrium?

Around 45 mm/Hg

Which two white blood cells can achieve phagocytosis?

Neutrophils and Monocytes

Which neurotransmitter from the Parasympathetic Nervous System is released at the SA node to decrease Heart Rate?

Acetylcholine

What percentage of CO2 is carried in the plasma?

About 7-10% of CO2 is carried dissolved in the plasma

What are the first blood vessels that branch off the Ascending Aorta?

L + R Coronary Arteries

3 Layers of Veins (Systemic Circuit)

- Tunica Intima

- Tunica Media

- Tunica Externa (Adventitia)

contains DEOXYGENATED BLOOD

Pressure Level : Low Pressure

Carrying blood from where? Away from heart

3 Layers of Arteries (Systemic Circuit)

- Tunica Intima

- Tunica Media

- Tunica Externa (Adventitia)

contains OXGENATED BLOOD

Pressure Level: High Pressure

Carrying blood from where? Toward the heart

1 Layer of Capillaries (Systemic Circuit)

Endothelium

What is happening in the Capillaries?

Gas Exchange O2-> CO2 between blood and tissues

Nutrient Delivery: to tissues

Waste Removal: from tissues

Fluid Exchange: between blood and Interstitial fluid

Carrying blood from where? Arterial System to the Venous System, facilitating the exchange of O2, CO2, Nutrients, waste products between the blood and surrounding tissues. They connect arterioles (small arteries) to venules (small veins)

ORDER OF VESSELS THAT BLOOD TRAVELS IN ANY CIRCUIT

ARTERIES --> ARTERIOLES--> CAPILLARIES--> VENULES--> VEINS

FENESTRATED CAPILLARIES

"Leaky" capillaries- have pores (fenestrations) in their endothelial lining that allow for increased permeability. These pores enable rapid exchange of small molecules and fluids between

What is Oxygen bound to in a red blood cell?

Hemoglobin- can carry up to 4 O2 molecules

Name this white blood cell:
What is the abundance in a normal blood smear?
What is its function?

Monocyte

Abundance: 2-8%

Function: Phagocytosis, Differentiation into Macrophages, Antigen Presentation, Cytokine Production

Systemic Arteries Partial Pressure of Oxygen
Systemic Arteries Partial Pressure of Carbon Dioxide

PO2--> 95-100 mm/Hg

PCO2--> 40 mm/Hg

Systemic Tissues Partial Pressure of Oxygen
Systemic Tissues Partial Pressure of Carbon Dioxide

PO2--> 40 mm/Hg

PCO2--> 45 mm/Hg

Systemic Veins Partial Pressure of Oxygen
Systemic Veins Partial Pressure of Carbon Dioxide

PO2--> 40 mm/Hg

PCO2--> 45 mm/Hg

Which way will oxygen diffuse at the systemic tissues? From the tissues into the blood or blood into tissues?

From the blood into the tissues (O2 diffuses from areas of higher partial pressure to areas of low partial pressures)

Describe a Continuous Capillary

- most common + least permeable type of capillary
- found in lungs, skin, nervous system, connective tissue + blood brain barrier
- has intact endothelial lining that forms a tube, only interrupted by intercellular clefts + joined by tight junctions
- rich in transport vesicles ➜ endocytosis or exocytosis

How much Oxygen is carried in the plasma?

1.5% is carried to dissolve in plasma

How many molecules of oxygen can one hemoglobin molecule bind with?

4

What is the skeletal muscle pump and how does it help with blood return?

Skeletal Muscle Pump- (Venous Return) refers to the mechanism by which contracting muscles compress veins, pushing blood back towards the heart

Why is it important for large arteries to be elastic?

- Absorbs the pressure
- Maintains blood flow
- Reduces workload on the heart

Basophil

Abundance: Less than 1% in a normal blood smear

Function: Releases Histamine to promote inflammation and helps in allergic reactions and defense against parasites

What two vessels bring blood into the Superior Vena Cava?

R + L Brachiocephalic Vein

Phase 4 of Cardiac Cycle (Systemic Circuit): ISOVOLUMETRIC VENTRICULAR DIASTOLE

Valves Open : None

Valves Closed : Atrioventricular Valves (Mitral & Tricuspid), Semilunar Valves (Aortic & Pulmonary)

Phase 5 of Cardiac Cycle (Systemic Circuit): PASSIVE VENTRICULAR FILLING

Valves Open: Atrioventricular Valves (Mitral & Tricuspid),

Valves Closed: Semilunar Valves (Aortic & Pulmonary)

SYMPATHETIC EFFECTS ON HEART RATE:

Increases heart rate by releasing Noradrenaline at the SA node, which increases the rate of depolarization and enhances contractility of the heart

PARASYMPATHETIC EFFECTS ON HEART RATE:

Decreases heart rate by releasing Acetylcholine at the SA node, which decreases the rate of depolarization and slows down the heart rate

What is Atherosclerosis?

Condition which fatty deposits (plaques) build up on the inner walls of arteries, leading to hardening and narrowing of the arteries. Can restrict blood flow and lead to Cardiovascular complications such as Heart Attacks and Strokes

Causes of Atherosclerosis

- Lifestyle
- Hypertension
- High Cholesterol
- Genetic Factors
- Obesity
- Diabetes

T/F: Capillaries work in groups called "beds"

True- networks called capillary beds

Which Leukocyte is responsible for making antibodies?

B- Lymphocytes (B cells)

If the arterioles are under vasoconstriction , what happens to the blood flow to the capillaries?

Arterioles decreases their diameter, which increases resistance to blood flow. As a result, blood flow to the capillaries decreases

What percentage of Oxygen is carried in a red blood cell?

98.5%

What are the formed elements of blood?

Red Blood Cells- Erythrocytes
White Blood Cells- Leukocytes
Platelets- Thrombocytes

T/F: The plasma proteins make up about 70% of Plasma

False- Plasma proteins make up about 7-9% of plasma volume

Which way would CO2 diffuse between the systemic capillaries and tissues: would it diffuse from the capillaries into the tissues, or from the tissues into the capillaries

CO2 would diffuse from the tissues into the capillaries

Neutrophil

Abundance: Approximately 50-70% in a normal blood smear (most abundant)

Function: Primary role is phagocytisis--engulfing and digesting bacteria, fungi and other pathogens.

(1st responders to infections and play a crucial role in immunity

Eosinophil

Abundance: Typically 1-4% in a normal blood smear

Function: Involved in combating parasitic infections and modulating allergic reactions by releasing enzymes that target parasites and chemicals that reduce inflammation

Granulocyte

T/F : Capillaries consist of three layers

False- Single layer

3 Different ways CO2 is carried in the blood

1) Dissolved in plasma - (7-10%)

2) As Bicarbonate ions- (70%)

3) Bound to Hemoglobin- (23%)

If Sympathetic stimulation increased to the arterioles , what happens to the diameter of the Vessel?

Sympathetic stimulation causes Vasoconstriction of arterioles , leading a decrease in their diameter

Which blood vessel would you expect to be under the highest amount of pressure?

Subclavian Artery

What is the partial pressure of oxygen in a systemic circuit vein returning blood to the heart

PO2--> 40 mm/Hg

Phase 1 of Cardiac Cycle (Systemic Circuit): ATRIAL CONTRACTION

Valves Open: AV valves (Mitral, Tricuspid)

Valves Closed: Semilunar Valves (Aortic, Pulmonary)

Phase 2 of Cardiac Cycle (Systemic Circuit): ISOVOLUMETRIC VENTRICULAR CONTRACTION

Valves Open: NONE

Valves Closed: AV valves (Mitral, Tricuspid), Semilunar (Aortic, Pumonary)

Phase 3 of Cardiac Cycle (Systemic Circuit): VENTRICULAR EJECTION

Valves Open: Semilunar valves (Aortic, Pulmonary)

Valves Closed: AV valves (Mitral, Tricuspid)