1AA3 - WEEK 2

Cardiac Output

amount of blood pumped by the heart per minute

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CO = HR x SV

Cardiac Reserve

the difference between CO at rest and at max (exercise)

Heart Regulation

intrinsic: regulates from normal functional control

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extrinsic: involves neural and hormonal control

Stroke Volume Regulation

preload: amount of stretch of ventricular walls before contraction

after load: pressure in contracting ventricles must produce to overcome aortic pressure

contractility: forcefulness of contraction of ventricle muscle fibres / controlled by positive or negative inotropic agents

Heart Rate Regulation

PNS: vagus nerve decreases HR with acetylcholine hyperpolarization

SNS: cardiac accelerator nerves increase HR by opening Ca2+ channels

hormones: epinephrine and norepinephrine from adrenal medulla

Heart and Homeostasis

homeostasis of blood pressure, pH/CO2/O2, extracellular ion concentration, body temperature

Plama Composition

albumins, globulins, fibrinogen

Erythrocytes

red blood cells / biconcave disks / no nucleus and mitochondria / contains hemoglobin

Hemoglobin

4 globin and 4 heme

Heme Breakdown

biliverdin → bilirubin (blood → liver → bile → small intestine) → urobilogen → stercobilin → feces

Carbonic Anhydrase

converts water and carbon dioxide to carbonic acid

Erythropoiesis

production of red blood cells / 4 days / 2 million degenerated per second / 120 days in circulation

Leukocyte Movements

diapedis and chemotaxis

Types of Leukocytes

granulocytes

* neutrophils
* eosinophils
* basophils

agranulocytes

* lymphocutes
* monocytes

Thrombocytes

platelets / have glycoproteins for platelet adhesion / form platelet plugs

Red Blood Cell Recycling

1. natural degeneration
2. separation of components
* globin: protein that recycles amino acids
* heme: iron removed and recycled

Cell Origins

proerythroblasts → erythrocytes

myeloblasts → granulocytes

lymphoblasts → lymphocytes

mono blasts → monocytes

megakaryoblasts → thrombocytes

Vasa Vasorum

blood vessels that supply arteries and veins

Portal Veins

2 capillary networks in series / hepatic (GI and spleen → liver) and hypophyseal (hypothalamus → anterior pituitary gland)

Types of Arteries

elastic, muscular, arterioles

Metarterioles

terminal end / last area with smooth muscle

Veins

thin, less elastic tissue, increased diameter, do not dilate or constrict

Types of Capillaries

continuous, fenestrated, sinusoid

Fenestrae

where cytoplasm is absent and membrane is made of thin porous diaphragm

Layers of Blood Vessels

tunica intima, tunica media, tunica adventitia