Hematopoiesis, Blood Components, and Hormonal Regulation in Human Physiology

Osmolarity

Concentration of dissolved particles that determines water movement

Albumin

Plasma protein with greatest impact on osmolarity and colloid osmotic pressure

Edema

Excess fluid accumulation in interstitial space

Hydrostatic pressure

Pressure that pushes fluid out of capillaries

Colloid osmotic pressure (oncotic pressure)

Pressure created by plasma proteins that pulls fluid into capillaries

Heme group

Iron-containing portion of hemoglobin that binds oxygen

Globin portion

Protein portion of hemoglobin that binds some carbon dioxide

Main transport form of carbon dioxide

Bicarbonate ion in plasma

Blood type determined by

Antigens on red blood cell surface

Antigens

Surface markers that trigger an immune response

Antibodies

Plasma proteins that attack specific antigens

Erythropoietin (EPO)

Hormone from kidneys that stimulates red blood cell production

Trigger for EPO release

Low oxygen levels (hypoxia)

Red blood cell lifespan

Approximately 120 days

Erythrocyte graveyard

Spleen

Megakaryocyte

Large bone marrow cell that produces platelets

Thrombopoietin

Hormone that stimulates platelet production

Polycythemia

Excess red blood cells leading to increased viscosity and clot risk

Anemia

Decreased red blood cells or hemoglobin causing reduced oxygen delivery

Three steps of hemostasis

Vascular spasm, platelet plug formation, coagulation

Serotonin in hemostasis

Causes vasoconstriction

Thromboxane A2

Promotes platelet aggregation

ADP in clotting

Recruits additional platelets to the plug

Thrombus

Stationary clot attached to vessel wall

Embolus

Traveling clot that can obstruct a vessel elsewhere

Aspirin action

Blocks COX enzyme reducing thromboxane A2 and platelet aggregation

Granulocytes

Neutrophils, eosinophils, basophils

Agranulocytes

Lymphocytes and monocytes

Hormone

Chemical messenger released into bloodstream to regulate target cells

Endocrine glands

Ductless glands that secrete hormones into blood

Exocrine glands

Glands that secrete substances through ducts to surfaces or cavities

Nervous system speed

Rapid onset and short duration

Endocrine system speed

Slower onset and longer lasting effects

Hormone range

Acts on distant target cells through bloodstream

Paracrine range

Acts on nearby cells

Autocrine range

Acts on the same cell that secreted it

Anterior pituitary tissue type

Glandular epithelial tissue

Posterior pituitary tissue type

Nervous tissue

Anterior pituitary hormones

GH, TSH, ACTH, FSH, LH, Prolactin

Posterior pituitary hormones

ADH and Oxytocin

Thyroid hormones

T3 and T4 increase metabolism, calcitonin lowers blood calcium

Parathyroid hormone (PTH)

Raises blood calcium levels

Adrenal cortex hormones

Cortisol, aldosterone, and androgens

Adrenal medulla hormones

Epinephrine and norepinephrine

Pancreas hormones

Insulin lowers blood glucose, glucagon raises blood glucose

Ovarian hormones

Estrogen and progesterone

Testes hormone

Testosterone

General adaptation syndrome (GAS)

Body's three-stage stress response

Stages of GAS

Alarm, resistance, exhaustion

Alarm stage hormones

Epinephrine and norepinephrine

Resistance stage hormone

Cortisol

Glucose sparing effect

Body uses fats instead of glucose to preserve glucose for the brain

Protein hormones

Water soluble, bind to membrane receptors, fast acting

Steroid hormones

Lipid soluble, bind intracellular receptors, slower but longer lasting

Synergistic interaction

Two hormones produce amplified effect together

Antagonistic interaction

Hormones produce opposite effects

Permissive interaction

One hormone enhances the effect of another

Up-regulation

Increase in receptor number due to low hormone levels

Down-regulation

Decrease in receptor number due to prolonged high hormone levels

Heart valves

Prevent backflow of blood and ensure one-way flow

Tricuspid valve

Between right atrium and right ventricle

Pulmonary valve

Between right ventricle and pulmonary artery

Mitral valve

Between left atrium and left ventricle

Aortic valve

Between left ventricle and aorta

Widowmaker artery

Left anterior descending artery supplying most of left ventricle

Preload

Ventricular stretch before contraction

Contractility

Strength of ventricular contraction

Afterload

Resistance ventricle must overcome to eject blood

Effect of increased preload

Increases cardiac output to an optimal point

Effect of increased contractility

Increases cardiac output

Effect of increased afterload

Decreases cardiac output

Contractile cell depolarization

Sodium moves into the cell

Plateau phase

Calcium moves into the cell

Repolarization

Potassium moves out of the cell

Plateau significance

Prevents tetany and ensures coordinated contraction

P wave

Atrial depolarization

QRS complex

Ventricular depolarization

T wave

Ventricular repolarization

Sympathetic effect on heart

Increases heart rate and contractility

Parasympathetic effect

Decreases heart rate

Blood pressure trend

Highest in arteries, lower in capillaries, lowest in veins

Continuous capillaries

Tight junctions found in muscle and brain

Fenestrated capillaries

Pores for filtration found in kidneys and endocrine organs

Sinusoidal capillaries

Large gaps found in liver and spleen

Capillary sphincters

Smooth muscle rings controlling capillary blood flow, usually closed at rest

Baroreceptors

Detect changes in blood pressure

Chemoreceptors

Detect oxygen, carbon dioxide, and pH levels

Anastomosis

Connection between blood vessels providing alternate pathway

Portal system

Blood flows through two capillary beds before returning to heart

Velocity of blood flow

Inversely related to total cross-sectional area

Medullary ischemic reflex

Emergency increase in blood pressure due to brain ischemia

Arteriosclerosis

General hardening of arteries

Atherosclerosis

Plaque buildup within arterial walls

Shock treatment

Oxygen, IV fluids, vasopressors, and treat underlying cause

Venous return mechanisms

Skeletal muscle pump, respiratory pump, venous valves, sympathetic venoconstriction

Hydrostatic pressure effect

Pushes fluid out of capillaries

Colloid osmotic pressure effect

Pulls fluid into capillaries

Hemodynamics

Force that affects blood flow

Blood Flow = ___

Cardiac Output