Biology Health and Disease

Module 3

Blood

• Transportation

• Regulation

• Projection

Components of Blood

• Blood Plasma: liquid; 91.5% water; 8.5% solutes

• Formed Elements: RBCs, WBCs, platelets

Hematocrit

The percentage of total blood volume occupied by RBCs

Polycythemia

The percentage of RBC is abnormally high (raises viscosity/thickness of blood). Makes blood flow difficult

Hemopoiesis

Formation and development of blood cells

Erythropoietin

Hormone that increases RBCs

RBCs/Erythrocytes

• Contain hemoglobin

• “Biconcave disc”

• Strong, flexible plasma membrane

• Mature RBC lacks nucleus

WBCs/Leukocytes

• Do not contain hemoglobin

• Granular leukocytes: Basophils; Eosinophils; Neutrophils

• Agranular leukocytes: Lymphocytes and Monocytes

• WBCs are far less numerous than RBCs

Neutrophils

• 60-70% of WBC

• Phagocytic

• Neutrophils respond most quickly to tissue damage by bacteria

Monocytes

Take longer to arrive but come in large numbers and destroy more microbes

Basophils

• Contain histamine

• Involved in allergies

Eosinophils

Parasitic Worms

WBC Diseases

Leukocytosis: high WBCs - normal response to invaders

Leukopenia: low WBCs; never beneficial

Platelets/Thrombocytes

Forms blood clot

Sickle Cell Disease (Sickle Cell Anemia)

• Most common genetic disorder in the U.S

• RBCs are stiff; fragile; deliver less oxygen; sickle shaped

Blood Vessels and Circulation

• Angiogenesis: growth of new blood vessels

• Lumen: interior opening of the blood vessel

Order of Vessels Leaving the Heart

• Arteries: carry blood AWAY from heart

• AAA

• Arterioles

• Capillaries: site of exchange

• Venules

• Veins: carry blood TO the heart

Tunica Interna

Form the inner layer of a blood vessel

Tunica Media

• Greatest variation among vessel types

• Middle Layer

Tunica Externa

Outer Layer

Veins

• Not designed to withstand high pressure

• More numerous than arteries

• Lumen is larger than arteries

• Have Valves

• Largest portion of blood at rest is in systemic veins and venules

• Systole/Diastole: 110/70

Vascular Resistance

Depends on: size of lumen; blood viscosity; total blood vessel length

Pulse

• Rhythmic beating in the arteries caused by the beating of the heart

• Tachycardia: rapid pulse or heartbeat

• Bradycardia: slow heartbeat or pulse

Blood Pressure

• Measured in the brachial artery

• Sphygmometer

• Korotkoff Sounds

Hypovolemic Shock

• (low) Decreased blood volume

• Causes: acute hemorrhage, loss of body fluids, inadequate intake of fluids

Cardiogenic Shock

Heart fails to pump adequately

Vascular Shock

• Inappropriate vasodilation of vessels

• Ex: Anaphylactic Shock

• Septic Shock

Obstructive Shock

• Blood flowing through circulatory system is blocked (obstructed)

• Ex: pulmonary embolism

Signs and Symptoms of Shock

• Systemic BP less than 90 mm Hg

• Resting HR rapid/Pulse weak and rapid

Heart

• Located in the mediastinum (think sternum) - region between the lungs

• The Apex: inferior surface

• The heart points to the left; rests on the diaphragm and is directed anteriorly

• The Base: superior surface

Endocardium

• The thin innermost layer

• Smooth lining for chambers of heart; valves

Mitral Valve

• Bicuspid valve/Left atrioventricular

• Between left atrium and left ventricle

• Blood flows from left atrium into left ventricle and travels through this valve

Tricuspid Valve

• Right Atrioventricular

• Between right atrium and right ventricle

• Blood flows from right atrium into right ventricle and travels through this valve

Heart Issues

• Narrowing of a heart valve; restricts blood flow

• Rheumatic fever: usually occurs after a streptococcal infection of the throat; very often damages mitral and aortic valves

• Myocardial Infarction: heart attack

• Congestive Heart Failure: loss of pumping efficiency to the heart

• Congenital Defects: tetralogy of Fallot; Blue Baby

Auscultation

Listening to sounds within the body (stethoscope)

Hormones

• Epinephrine (Adrenaline) and Thyroid Hormones: increases heart rate and contractility

The Respiratory System

Nasal conchae: cause air to swirl; removes debris, prevents dehydration (moistens air)

Pharynx (Throat)

• Passageway for air and food

• Resonating chamber (Three Regions): Nasopharynx; Oropharynx; Lingual, Palatine tonsils; Laryngopharynx

Larynx

• Voicebox

• Thyroid cartilage or Adam’s Apple

• Epiglottis: flap of tissue; closes when we swallow to prevent food from getting into the larynx and trachea

Phonation

Produce Sounds

Enunciate

Produce Words

Trachea

• Windpipe

• Divides into right and left bronchi

• Composed of 16-20 C-shaped rings of cartilage

Bronchi

• The right and left bronchus enter the lungs

• They divide to form the bronchial tree

• Bronchial tree is in the lungs

Lungs

• Cardiac notch: concavity on the left lung

• Heart makes left lung 10% smaller than the right lung

• Lobes: each lung divided by 1 or 2 fissures

• Each Lung has oblique fissure

• Right Lung has horizontal fissure

• Right lung: 3 lobes

• Left Lung: 2 lobes

Alveoli

Main site of gas exchange

Order of Airflow

• Nasal (nose) cavity or oral (mouth) cavity

• Pharynx (throat)

• Larynx (voicebox)

• Trachea (windpipe)

• Bronchi

• Lungs

Lung Compliance

• High Compliance: lungs expand easily

• Low Compliance: resist exansion

The Endocrine System

• Pituitary Gland (Anterior Lobe)

• Human Growth Hormone - promote cell growth

• Thyroid Stimulating Hormone: stimulates synthesis and secretion of thyroid hormones by thyroid gland

• Follicle Stimulating Hormone

• Luteinizing Hormone

• Prolactin: promotes mammary gland development (increases during pregnancy); promotes milk production by the mammary glands

Pituitary (Posterior Lobe)

• Oxytocin: contraction of smooth muscle in walls of uterus during childbirth

• Milk ejection from mammary glands

• Antidiuretic hormone (vasopressin)

Thyroid Gland

• Hormones:

• T4

• T3

Hypothyroidism

• Fatigue

• Cold Intolerance

• Slow Heartbeat

• Weight Gain

Pancreas

• Pancreatic Islets or Islets of Langerhans

• Hyposecretion: low hormone release

• Hypersecretion: too much hormone release

Pituitary Gland Disorders

• Gigantism: hypersecretion of human growth hormone during childhood

• Acromegaly: hypersecretion of human growth hormone during adulthood

• Large hands, feet, frontal, zygomatic, mandible, maxilla bones