Chapter 14: Autonomic Nervous System (ANS)

The Effects of Activation of the Sympathetic Division of the ANS

The sympathetic division of the autonomic nervous system prepares the body for stressful or emergency situations, often referred to as the "fight-or-flight" response.

• Triggers: Increased heart rate, dilated pupils, increased blood flow to muscles, decreased digestive activity.

• Neurotransmitters: Norepinephrine and epinephrine are primarily released.

The Effects of Activation of the Parasympathetic Division of the ANS

The parasympathetic division promotes the "rest and digest" response, conserving energy and maintaining daily bodily functions.

• Triggers: Decreased heart rate, increased digestive activity, constricted pupils.

• Neurotransmitter: Acetylcholine is primarily released.

Similarities and Differences Between the Somatic Motor Nervous System and the ANS

Both systems are divisions of the peripheral nervous system (PNS) and originate from the brain and spinal cord, but they control different types of effectors and functions.

• Somatic System: Controls voluntary movements via skeletal muscles.

• ANS: Manages involuntary functions such as heart rate, digestion, and respiratory rate.

• Neurotransmitter: Both use acetylcholine, but the ANS also uses norepinephrine.

Key Concepts of the Autonomic Nervous System

• The ANS is a motor division of the PNS, moderating visceral function and homeostasis.

• Pathways consist of a two-neuron chain: preganglionic and postganglionic neurons.

• Neurotransmitters: Acetylcholine (parasympathetic), acetylcholine and norepinephrine (sympathetic).

• Preganglionic parasympathetic fibers originate in the craniosacral CNS; sympathetic fibers in the thoracolumbar CNS.

• ANS neurons can be excitatory or inhibitory depending on the receptor type.

Chapter 17: Blood

Definition and Functions of Blood

Blood is a connective tissue with multiple functions essential for homeostasis.

• Transportation: Oxygen, nutrients, hormones, and waste products.

• Regulation: Body temperature, pH, and fluid/electrolyte balance.

• Protection: Clotting and defense against disease.

Hematopoiesis

Hematopoiesis is the formation of blood cells, occurring in the red bone marrow.

Composition of Blood

• Plasma: 55% of blood; mostly water, with proteins (albumin, globulins, fibrinogen), nutrients, hormones, and electrolytes.

• Formed Elements: 45% of blood; includes erythrocytes (RBCs), leukocytes (WBCs), and thrombocytes (platelets).

Blood Plasma: Composition, pH, and Function

• pH: Slightly basic, .

• Volume: 5-6 liters in males, 4-5 liters in females.

• Functions: Transport, osmotic balance, pH buffering, and clotting.

Serum

Serum is the clear, liquid portion of blood after clotting, lacking clotting factors like fibrinogen.

Formed Elements of Blood

• Erythrocytes (RBCs): Biconcave, anucleate cells filled with hemoglobin (97%). Function: transport respiratory gases. Life span: 100-120 days.

• Leukocytes (WBCs): Only complete cells; function in defense and immunity. Two major categories: granulocytes and agranulocytes.

• Thrombocytes (Platelets): Small cell fragments involved in clot formation. Normal count: 150,000-400,000/μL.

Hemoglobin

• Structure: Red pigment = heme + globin protein.

• Function: Each Hb molecule can transport 4 O2 molecules.

• Normal values: Male: 13-18 g/100mL; Female: 12-16 g/100mL.

• Each RBC contains about 250 million Hb molecules.

Erythropoiesis

Erythropoiesis is the production of erythrocytes, regulated by erythropoietin (EPO), a hormone produced by the kidneys in response to hypoxia.

Leukocytes: Types and Functions

• Granulocytes: Neutrophils (most numerous, phagocytize bacteria), Eosinophils (attack parasites, mediate inflammation), Basophils (release histamine, mediate allergic responses).

• Agranulocytes: Lymphocytes (produce antibodies, mediate immune response), Monocytes (differentiate into macrophages).

Mnemonic: Never Let Monkeys Eat Bananas (Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils).

Antibodies

Antibodies are proteins produced by B lymphocytes that bind to specific antigens, marking them for destruction.

Hemostasis

Hemostasis is the process of stopping bleeding, involving three major steps:

1. Vascular spasm: Vasoconstriction in response to injury.

2. Platelet plug formation: Platelets adhere to exposed collagen, become sticky, and release chemicals (positive feedback cycle).

3. Coagulation: Cascade of reactions converting fibrinogen to fibrin, forming a stable clot.

Role of the Liver in Hemostasis

• Produces clotting factors and plasma proteins.

• Thrombopoietin: Hormone stimulating platelet production.

• Bile: Needed for vitamin K absorption, which is essential for clotting factor synthesis.

Blood Typing and Transfusion Reactions

• ABO and Rh blood groups: Determined by antigens on RBC surfaces.

• Transfusion reaction: Occurs if mismatched blood is transfused; recipient's antibodies attack donor RBCs, causing agglutination and hemolysis.

Type O: Universal donor (no A or B antigens). Type AB: Universal recipient (no anti-A or anti-B antibodies).

Blood Disorders

• Anemia: Low RBC count or hemoglobin, reducing O2-carrying capacity. Symptoms: Fatigue, pallor, dyspnea.

• Polycythemia: Excess RBCs, increasing blood viscosity.

• Leukocytosis: High WBC count.

• Leukopenia: Low WBC count.

• Thrombocytosis: High platelet count.

• Thrombocytopenia: Low platelet count.

Chapter 18: The Heart

The Basic Function of the Heart as a Pump with Four Chambers

The heart is a muscular organ that pumps blood through two main circuits:

• Pulmonary circuit: Right side of the heart pumps deoxygenated blood to the lungs.

• Systemic circuit: Left side of the heart pumps oxygenated blood to the body.

The Structure and Function of the Heart Valves and Chordae Tendineae

• Heart valves: Ensure unidirectional blood flow; open and close in response to pressure changes.

• Chordae tendineae: Tendinous cords anchoring AV valves to papillary muscles, preventing valve prolapse.

The Importance of Coronary Circulation

Coronary circulation provides the heart muscle (myocardium) with a functional blood supply, essential for its activity and survival.

Additional info: Some explanations and table formatting were expanded for clarity and completeness based on standard Anatomy & Physiology content.