Blood and Circulatory System pt.2 Flashcards

Arterial system:
1. Arteries

carry blood away from heart

2. Arterioles

Arterioles and precapillary sphincters control pressure

Venous system

1. Veins

carry blood toward the heart

2. Venules

small veins:
Mechanisms in blood return-
Contraction of skeletal muscles One-way
valves Pressure changes associated with breathing
�abdominal : thoracic veins

Veins and Arteries:
In Pulmonary and Systemic Circuits

1) Veins in systemic
circuit: deoxygenated blood
Veins in pulmonary circuit:
oxygenated blood
2) Arteries in systemic circuit: oxygenated blood
Arteries in pulmonary circuit: deoxygenated blood

I) Red Blood Cells (Erythrocytes):
a) Function:

transport oxygen and carbon dioxide

b) Hemoglobin:

oxygen-binding protein-
Oxyhemoglobin (bright red): (arrow
up)[O2], arteries Deoxyhemoglobin (dark
purple): (arrow down)[O2], veins

c) Bohr Effect:

body�s blood � gas exchange mechanism

II) White Blood Cells (Leucocyte)
a) Function
b) Ratio

protection from infection; regulation of the
inflammatory reaction production of RNA � proteins
Ratio: RBC : WBC 1000:1

5 Types of WBC in 2 groups:

Granular: neutrophils, eosinophils, basophils
Agranular: lymphocytes, monocytes

1) Granular:
i) Neutrophils
a) Function:

mediating immune responses against infectious organism (virus/bacteria)
Neutrophilia: abnormal high number of
neutrophils circulating in the blood Neutropenia: abnormal low number of neutrophils
circulating in the blood

ii) Eosinophils
a) Function:

mediating certain types of allergic reactions, or against large parasites
Eosinophilia: parasites
stress, corticosteroid treatments

iii) Basophils:
a) Function:

mediating hypersensitivity reactions (indicators of allergies)
Basophilia: food, asthma Basopenia: urticaria,

2) Angular
iv) Monocytes
a) Function (3)

Protect tissues from foreign substances:
Phagocytosis Induce immune response:
P resentation of Antigen
Production of anti-inflammatory proteins: Cytokines
(proteins for cell communication)
Monocytophilia: inflammatory processes
Monocytopenia: stress, acute infections, leukemia

v) Lymphocytes
a) Function
b) Types (3)

Important for the immune system response

B-lymphocytes: Humoral immunity � Produce
T-lymphocytes: Cell mediate immunity -
Natural killer: Cytotoxic innate immunity � destroy
viruses and cancerous cells by causing lysis or forced
Lymphocytophilia: Infections
Lymphocytopenia: uses of corticosteroids, chemotherapy

III) Platelets
a) Function

- Reduce blood clotting
- Respond to an abnormality in vessel wall
- Production regulated by the hormone
thrombopoietin (liver/kidney)

b) Hemostasis
A) Def:
B) Steps (4)

A) Set of mechanisms to prevent blood loss-
B) Steps-

Blood vessel breaks/cuts: Signals platelets to form
blood clot
Vascular Spasm (Vasoconstriction): Reduces blood
Platelets plug formation: Platelets attach to each
other and the damaged vessels
Clot formation: Soluble/insoluble fibrinogen mesh to fibrin, trapping
RBCs and platelets
Fibrin- Biological glue

Comp: (3)

Erythroblast: begins hemoglobin formation Late
Erythroblast: accumulation of hemoglobin Reticulocytes: no
nucleous, biconcave shape

Process of

Origin: Stem cells --> Erythroblast --> Erythrocyte
Erythropoiesis (7 days)

Regulation of Blood:
a) Purpose

a) a negative feedback control loop that
maintain homeostasis
b) Erythropoietin stimulates the stem
cells to produce more RBCs