A & P II Exam 1: Key Terms

• Study notes for Exam 1 A & P II

Vasodilation

• Widening of blood vessels.

Vasoconstriction

• Narrowing of blood vessels.

Pathogen

• Microorganism (e.g., bacterium, virus) that can cause disease.

Tropic Hormone

• Hormone stimulating the secretion of another hormone.

Anemia

• Condition of deficient red blood cells, hemoglobin, or total blood volume.

Agglutinins

• Antibodies formed that react against agglutinogens.

Interstitial

• Pertaining to spaces between cells in a tissue or organ.

Differentiation

• Process where cells become specialized in structure and function.

Viscosity

• A liquid's resistance to flow.

Endocrine System

• Controls reproduction, growth and development, blood nutrients, cellular metabolism, and body defenses.

Hormone Secretion and Transport

• Hormones are secreted from endocrine glands into the bloodstream to reach specific receptors.

Endocrine Glands

• Include pituitary, thyroid, parathyroid, adrenal, and pineal glands.

Hormone Target Recognition

• Target cells have specific receptors that bind to the hormone.

Stimuli for Hormone Release

• Humoral, neural, and hormonal stimuli.

Humoral Stimuli

• Changing levels of ions/nutrients in blood directly stimulate hormone secretion.

Neural Stimuli

• Preganglionic sympathetic fibers stimulate hormone release in few instances.

Hormonal Stimuli

• Hormones from one endocrine organ stimulate a different endocrine gland to release hormones.

Thyroid Gland Structure

• Isthmus connects two lateral lobes.
• Follicles are hollow spheres of epithelial follicular cells, which produce thyroglobulin.
• Colloid is fluid containing thyroglobulin bound to iodine, a precursor to thyroid hormone.
• Parafollicular cells produce calcitonin.

Posterior Pituitary Gland

• Composed of neural tissues that secretes prestored neurohormones and does not produce any hormones.

Anterior Pituitary Gland

• Known as the master endocrine gland.

Oxytocin

• Hormone released by the pituitary gland.
• Causes increased contraction of the uterus during labor.
• Stimulates milk ejection in the breasts.
• Also known as the cuddle hormone.

Antidiuretic Hormone (ADH)

• Produced by neurosecretory cells in the hypothalamus.
• Stimulates water reabsorption from kidney tubule cells into the blood.
• Stored in the posterior pituitary gland.

Growth Hormone (Somatotropin)

• Triggers liver, skeletal muscle, and bone to produce insulin-like growth factors.
• Stimulates uptake of nutrients for DNA and protein synthesis needed for cell division.
• Major targets are bone and skeletal muscle.
• Regulated by GHRH and GHIH.

Thyroid Hormone (Thyrotropin)

• Stimulates normal development and secretory activity of thyroid.
• Release is triggered by TRH from the hypothalamus.
• Inhibited by rising thyroid hormone levels in the blood.

Aldosterone

• Released in response to low Na+ levels and high K+ levels.

Parathyroid Hormone

• Essential for maintaining calcium (Ca2+) levels in the blood.
• Controlled by calcium levels in the blood.

Calcitonin

• Produced by parafollicular cells in the thyroid gland when Ca2+ blood levels are high.
• Antagonist to parathyroid hormone.
• High levels can cause damage.

Glucagon

• Produced by pancreas alpha cells.
• Increases blood sugar levels.
• Antagonist to insulin.

Insulin

• Created by Pancreas Beta cells.
• Released in response to high glucose levels by promoting glycogen formation and glucose fat conversion rates.
• Antagonist to glucagon.

Glucocorticoids

• Produced within the adrenal cortex.
• Helps regulate blood glucose levels and blood pressure.
• Cortisol is the most abundant form.

Mineralocorticoids

• Produced within the adrenal gland.
• Regulates electrolyte concentration.
• Has a short-lived reaction time.

Gonadocorticoids

• Weak hormones mostly produced within the gonads during puberty.
• Converted into testosterone or estrogen to help create secondary sex characteristics.
• Also produced within the adrenal gland.

Diabetes Mellitus Cardinal Signs

• Polyuria: huge urine output due to glucose acting as osmotic diuretic.
• Polydipsia: excessive thirst from water loss due to polyuria.
• Polyphagia: excessive hunger and food consumption because cells cannot take up glucose and are "starving".

Diabetes Mellitus Type 1

• Pancreas produces very little to no insulin.

Diabetes Mellitus Type 2

• Cells in body become resistant to insulin.

Blood Composition

• Matrix of nonliving plasma and living cells called formed elements.
• Includes erythrocytes, leukocytes, and platelets.

Blood as a Tissue

• It is a tissue and the only one in a fluid state.

Blood Centrifugation

• Separates into three layers.

Separated Blood Components

• Erythrocytes (45%) form the large bottom layer.
• White blood cells and platelets make up the buffy coat (1%).
• Plasma sits on top in another large layer (55%).

Main Functions of Blood

• Transporting respiratory gases.
• Defending against disease.
• Regulating nutrient movement.

Hematocrit

• Percentage of blood volume occupied by red blood cells.
• Low hematocrit leads to tissue hypoxia.
• High hematocrit increases blood viscosity.

Erythrocytes

• Main purpose is to transport oxygen.
• Life span of 100-120 days.
• Made and mature in bone marrow.

Erythropoietin

• Hormone produced and released by the kidney.
• Stimulates red blood cell production by the bone marrow.

Erythrocyte Structure

• Biconcave shape provides large surface area for gas exchange.
• Four peptide chains and heme groups.

Erythrocyte Differentiation

• Proerythroblasts differentiate and transform into erythrocytes.

Hematopoietic Stem Cell

• The type of cell an erythrocyte is right before it is fully mature.

Leukocytes

• White blood cells that fight infection.
• Made in the bone marrow.
• All types have nuclei and organelles.
• Live from a few hours to a few days, depending on the type.

Leukocyte Subtypes

• Neutrophils, eosinophils, basophils, lymphocytes, and monocytes.

Neutrophils

• Most abundant leukocyte.
• Multilobed nucleus and pale red and blue cytoplasmic granules.
• Very phagocytic and increase in number during acute infection.
• Granulocyte.

Eosinophils

• 2-4% of leukocytes.
• Nucleus has two lobes connected by a broad band.
• Deals with parasitic worms, allergies, and asthma.
• Granulocyte.

Basophils

• Rarest type of leukocyte.
• Produces histamine.
• Acts as a pseudo mast cell.
• Granulocyte.

Lymphocytes

• About 25% of leukocytes.
• Large, dark purple, circular nuclei with thin rim of blue cytoplasm.
• Mostly found in lymphoid tissue.
• T cells act as white blood cells, and B cells give way to plasma.
• Agranulocyte.

Monocytes

• Largest of the leukocytes, about 3-4%.
• Nucleus is dark purple-staining, U- or kidney-shaped.
• Leave circulation, enter tissues, and differentiate into macrophages.
• Agranulocyte.

Platelets

• Fragments of larger megakaryocytes formed in the myeloid lining.
• Help seal breaks in blood vessels.

Hemostasis

• Step 1: Vascular spasm.
• Step 2: Platelet plug formation.
• Step 3: Coagulation (blood clotting).

Vascular Spasm

• Vessel responds to injury with vascular spasms, involving vasoconstriction.

Platelet Plug

• Platelets stick to exposed collagen fibers of damaged blood vessels.

Coagulation Phases

• Phase 1: Intrinsic or extrinsic pathway to form prothrombin activator.
• Phase 2: Prothrombin activator converts prothrombin to thrombin.
• Phase 3: Thrombin converts fibrinogen to fibrin to make the mesh.

Blood Types

• Determined by the antibodies attached to the red blood cells which react to foreign blood types.

Rh Factor

• RH positive people do not develop RH antibodies.
• Rh negative people do develop RH antibodies as their blood recognizes it as a foreign object.

Transfusion Reactions

• Adverse responses to blood transfusions due to antibodies within the blood reacting to one another and causing agglutination.

Heart Wall Layers

• Fibrous pericardium, parietal layer serous pericardium, pericardial cavity, epicardium, myocardium, endocardium.

Heart Wall Blood Supply

• Supplied by coronary arteries.

Interrupted Myocardium Blood Supply

• No nutrients or oxygen being delivered, resulting in cardiac muscle damage.

Cardiac Muscle Cells

• Different from skeletal muscle because they have cells that are self-excitable (contractile and pacemaker cells).

Heart Chambers

• Right atrium, right ventricle, left atrium, left ventricle.

Right Atrium

• Receives unoxygenated blood.

Right Ventricle

• Receives unoxygenated blood.

Left Ventricle

• Receives oxygenated blood.

Left Atrium

• Receives oxygenated blood.

Left vs. Right Side of Heart

• Differ in oxygenation, musculature, and valves.
• Right has the tricuspid valve, left has the bicuspid valve.
• The left is more muscular because of the difference in distance the blood they pump must reach.

Atrioventricular vs. Semilunar Valves

• Atrioventricular valves are located between atria and ventricles.
• Semilunar valves are located between ventricles and major arteries.

Tricuspid Valve

• AV valve with three cusps.
• Sits between the right atria and ventricle.
• Anchored by chordae tendineae.

Mitral Valve

• AV valve with two cusps.
• Sits between the left atria and ventricle.
• Anchored by chordae tendineae.

Pulmonary Semilunar Valve

• Located between the right ventricle and the pulmonary artery.

Aortic Semilunar Valve

• Located between the left ventricle and the aorta.

Intrinsic Conduction System Components

• Pacemaker polarization, depolarization, repolarization.

Pacemaker Polarization

• K+ channels are closed, but slow Na+ channels are open, causing interior to become more positive.

Depolarization

• Ca2+ channels open (around 40 mV), allowing huge influx of Ca2+, leading to rising phase of action potential.

Repolarization

• K+ channels open, allowing efflux of K+, and cell becomes more negative.

Intrinsic Conduction System Parts

• Sinoatrial (SA) node → Atrioventricular (AV) node → atrioventricular (AV) bundle right and left bundle branches → subendocardial conducting network (Purkinje fibers).

Heart Sounds

• Lub-dub. 1st sound: a-v valves close, second sound: aortic and pulmonary valves close.

Fetal Heart Structures

• Foramen ovale and ductus arteriosus.

Foramen Ovale

• Hole in interatrial septum of fetal heart.

Ductus Arteriosus

• Connects the pulmonary trunk to the aorta.

Cardiac Output

• Amount of blood pumped out by each ventricle in 1 minute.

Stroke Volume

• Volume of blood pumped out by one ventricle with each heartbeat.

Vagal Tone

• Heart at rest exhibits vagal tone (from vagus nerve innervation).

Systole

• Period of heart contraction.

Diastole

• Period of heart relaxation.

ECG

• Composite of all action potentials at a given time, not a tracing of a single AP

QRS Complex

• Ventricular depolarization andatrial repolarization

T Wave

• Ventricular repolarization

P=R Interval

• Beginning of atrial excitation tobeginning of ventricular excitation

S=T Segment

• Entire ventricular myocardium depolarized

Q-T Interval

• Beginning of ventricular depolarization through ventricular repolarization

Electrolytes and Cardiac Function

• Calcium - contraction
• Potassium - relax
• Sodium - fluid balance
• Magnesium - maintains excitability

Hypocalcemia

• (↓Ca2+): depresses heart. ECG change: prolonged QT interval.

Study notes covering essential terms for Anatomy and Physiology II Exam 1. Key terms covered include vasodilation, vasoconstriction, pathogens, tropic hormones, and anemia. Also includes, agglutinins, interstitial, differentiation, viscosity, and the endocrine system.