Bio209 - term test 2

What are the 4 types of hormone interactions?

• Antagonistic/opposite effects

• Additive effects

• Permissive effects

• integrative effects

What is the antagonistic/opposing effects? with examples

• Net results depends on the balance between hormones which are opposites.

• Example

  • PTH versus calcitonin

  • Insulin vs glucagon

What is the additive effect? With examples

• Net result from 2 hormones is greater than each acting alone (it’s basically an addition), sometimes creating a synergistic effect

• Example

  • Glucose-sparing action of GH is enhanced in the presence of glucocorticoids

What is the synergistic effect?

The effect produced by 2 hormones that is greater than the additive effect

What is the permissive effect? With example

• one hormone is needed for the second hormone to produce its effect (increasing the sensibility of the cell to the second hormone basically)

• Example

  • Epinephrine changes rate of cellular energy consumption only in the presence of thyroid hormones

What is the integrative effect? With example

• Hormones produce different but complementary effects, important in coordinating activities of diverse physiological systems (Both of them are using different pathways)

• Example

  • Effects of calcitriol and PTH on tissues in calcium metabolism

What are the 3 main components of the cardiovascular system and their sub-components?

• Heart

• Blood vessels

  • Arteries

  • Capillaries

  • veins

• blood

What are the functions of each type of blood vessels?

• Arteries carry blood away from the heart

• Capillaries permit exchange between blood and interstitial fluids

• Veins return blood to the heart

What are the 5 functions of blood?

• Transport → dissolved gases, nutrients, hormones and metabolic waste

• Regulate → the pH and ion composition of interstitial fluids

• Restrict → fluid losses at injury sites

• Defend → against toxins and pathogens

• Stabilize →. body temperature

What is the regular pH of blood?

7.3 to 7.4, alkaline

What is hematocrit?

the percentage of formed elements within the blood

What is the composition of blood?

• 55% plasma (7% plasma proteins, 1% solute, 92% water)

• 45% formed elements (<0.1% platelets, <0.1% white blood cells, 99.9% red blood cells)

What is Albumins?

a plasma protein, makes up around 60% of the plasma proteins in blood. It maintains the volume of the blood and the osmotic pressure

What is globulin?

A plasma protein, that makes up about 35% of the plasma proteins in the blood. It includes immunoglobulins and transport globulins

What is fibrinogen?

A plasma protein, that makes up about 4% of the plasma proteins in the blood. It is involved in blood clotting

What are platelets aka thrombocytes?

small membrane-bound cell fragments involved in clotting

what are the 5 types of white blood cells?

Neutrophils

Eosinophils

Basophils

Lymphocytes

Monocytes

What are leukocytes?

white blood cells

Where are stem cells located?

within the red bone marrow

what are hemocytoblasts?

multipotent stem cells that give rise to all mature blood cells in the body

how are lymphocytes formed?

hemocytoblasts → lymphoid stem cells → lymphoblastic (blast cells) → pro lymphocyte → lymphocytes

What is the stem cell that forms all other blood cells?

myeloid stem cell

what are progenitor cells stimulated by?

colony-stimulating factors

progenitor cells that are stimulated by colony-stimulating factors form what?

monoblasts and myeloblasts

monoblast?

monocytes - in our tissues and eat pathogens

what are progenitor cells stimulated by to form red blood cells?

erythropoietin (EPO) which are secreted by the kidneys

where is red bone marrow?

inside the spongy tissue of our bones

what are the 3 types of progenitor cells?

monoblasts and myeloblasts, megakaryocytic, proerythroblasts

What is the amount of red blood cells in a human

between 4.2 to 6.3 millions red blood cells/mm³ or uL

What is the shape of red blood cells?

biconcave discs, it is facilitating all the functions that rbc perform in our bodies

What are characteristics of red blood cells?

• Large surface area-to-volume ratio (like 2000x the body surface)

• can form stacks called rouleaux (uninterrupted flow that doesn’t bump into the blood vessel)

• flexibility

• lose most organelles during development

• enucleate and no ribosome

• 120 days life span (spleen is the graveyard of the body)

• Primary function is the transport of respiratory gases

• 95% of rbc intracellular proteins are hemoglobin molecules

Each hemoglobin molecule has…?

• two alpha chains

• two beta chains

• 4 heme molecule (1 per chain)

What is heme molecule

a non-protein part of hemoglobin molecules that has a iron atom that can bond with oxygen

how many hemoglobin molecules are typically found in a single rbc?

280 million

What are antigens?

A substance that can elicit immune response

what is the blood type determined by?

the presence of absence of surface antigens (A, B or D aka Rh)

Antigens and antibodies by blood types

type A → antigen A, anti-B antibodies in plasma

type B → antigen B, anti-A antibodies in plasma

Type AB → antigen A and B

Type O → anti-A and anti-B antibodies in plasma

antigens are also known as what when they are present on the surface of rbc?

agglutinogens

What is agglutination?

clumping together or rbcs, it occurs when surface antigens are exposed to corresponding antibodies from another blood type

antibodies are also known as?

agglutinins

What is hemolysis

the destruction or rupture of red blood cells

+or - blood types are determined by what?

the presence of either Rh positive antigen or Rh negative antigens

clumping with anti-Rh antibodies means what?

that the blood type is positive

Rh-negative person will not have any anti-Rh antibodies until?

exposed to Rh-positive RBC, then develops anti-Rh anti bodies, through a process called Rh sensitization

hemolytic disease of the newborn

the mother’s blood supply breaches the placenta during birth and the antibodies destroy the blood of the newborn. basically, the antibodies (rh+) are developed during the first pregnancy and during the second pregnancy the antibodies cross the placenta

what is erythroblastosis fetalis?

hemolytic disease of the newborn

what are the 5 white blood cells?

• neutrophils

• lymphocytes

• monocytes

• eosinophiles

• basophils

the number of wbc in the body is dependent on what?

inflammation, pathogens or like allergic reactions

what is positive chemotaxis?

the directed movement of a cell towards a higher concentration of chemical attractant

what is emigration or diapedesis?

white blood cells squeezing through the lining of the blood vessel and pass through and enter into the tissue.

on average the blood contains how many WBCs?

7000 white blood cells per uL

what is differential count?

the percentage of each type of white blood cells in a sample

what are the 2 classes of white blood cells?

• Granular leukocytes or granulocytes (abundant cytoplasmic granules that absorb histological stains

• agranular leukocytes or agranulocytes (smaller secretory vesicles/lysosomes that don’t absorb stains

which cells are granular leukocytes?

• neutrophils - 50 to 70% - phagocytic

• eosinophils - 2 to 4% - allergies and parasite infections

• basophils - <1% - enter damaged tissues and release histamine

which cells are agranular leukocytes?

• monocytes- 2 to 8% - enter tissue and become macrophages

• lymphocytes- 20 to 40% - lymphatic system

what is hemostasis?

the process responsible for stopping b blood loss through walls of damaged blood vessels

What are the 3 phases of hemostasis (cardiovascular system)?

• vascular phase

• platelet phase

• coagulation phase

Describe the vascular phase of hemostasis

endothelial cells release chemicals and local hormones, including endothelins. the smooth muscle have a vascular spasm which partially closes the blood flow and becomes sticky

Describe the platelet phase of hemostasis

it begins with attachment of platelets to sticky endothelial surfaces, basement membrane, exposed collagen fibres and other platelets. It then releases chemicals (ADP, PDGF and Ca²⁺)

Describe the coagulation phase of hemostasis

Coagulation involves complex sequence of steps leading to conversion of circulating fibrinogen to insoluble fibrin. Blood cells and platelets are trapped in fibrin network

What are the 2 pathways of the coagulation phase of hemostasis?

• Extrinsic pathway: release of tissue factor III from damaged endothelial cells → tissue factor combines with Ca²⁺ to activate factor X (first step in the common pathway)

• Intrinsic pathway: activation of proenzymes → PF-3 (factor released by aggregating platelets) → sequence of enzyme activations lead to factor X

Where is the heart located?

directly behind the sternum, in the pericardium

where is the base of the heart?

it is the superior part of the heart and is 0.5 inches to the left behind the 3rd costal cartilage

what is the apex of the heart?

it is the pointed tip of the heart, 3 inches to the left and behind the 5th intercostal space

Describe the anatomy of the heart

• the heart is 2 sided pump with 4 chambers

  • Right atrium (receive systemic circuit)

  • Right ventricle (pumps into pulmonary circuit)

  • Left atrium (receive pulmonary circuit)

  • Left ventricle (pumps into systemic circuit)

What are the 4 borders of the heart?

• Superior border = base

• right border = right atrium

• left border = left ventricle and part of left atrium

• inferior border = right ventricle

What are the membranes in the pericardium?

• Fibrous pericardium

• Parietal layer of serous pericardium

  • areolar tissue

  • mesothelium

what is pericardial fluid?

a small amount of lubricant located inside the pericardial sac that surrounds and cushions the heart

What is the pericardium?

sac-like structure wrapped around the heart

what is pericarditis?

the inflammation of the pericardium

what is cardiac tamponade?

excess accumulation of pericardial fluid

What are 4 characteristics of cardiac muscles?

• small size

• single, centrally located nucleus

• branching interconnections between cells

• presence of intercalated discs

What are some boundaries between the 4 heart chambers?

• Auricle (each atrium)

• Coronary sulcus (groove separating atria and ventricles)

• Anterior inter ventricular sulcus (groove marking boundary between the 2 ventricles)

• Ligamentum arteriosum (fibrous remnant of fetal connection between aorta and pulmonary trunk)

Describe the heart surface anatomy on the posterior surface

• 4 pulmonary veins (returning blood to left atrium)

• Superior and inferior venae cavae (returning blood to right atrium)

• Coronary sinus (returns blood from myocardium to right atrium)

• Posterior inter ventricular sulcus (groove boundary between the 2 ventricles)

What are 5 main arteries?

• Marginal arteries (supply right ventricle)

• Posterior interventricular artery (supplies inter ventricular septum and adjacent parts of ventricles)

• Circumflex artery (follows coronary sulcus to the left and meets branches of right coronary artery posteriorly)

• Right coronary artery

• left coronary artery

What are 6 main veins around the heart?

• anterior cardiac veins

• great cardiac vein

• coronary sinus

• posterior vein of left ventricle

• middle cardiac vein

• small cardiac vein

What is coronary heart disease?

the main blood vessels to the heart become narrow or blocked

fat or plaque build up

interatrial septum vs interventricular septum

• Interatrial septum: right and left atria

• Interventricular septum: right and left ventricles, much thicker

Atrioventricular valves (AV) vs Semilunar valves

• Atrioventricular valve: between each atrium and ventricle, allows only one-way blood flow from atrium into ventricle. right AV valve has 3 cusps with left AV valve has 2 cusps

• Semilunar valves: at exit from each ventricle, allows only one-way blood flow from ventricle out into aorta or pulmonary trunk. Right to pulmonary trunk and left to aorta

What is chordae tendineae?

Strong, inelastic, fibrous cords of connective tissue in the heart

What are the 4 functions of the connective tissue fibres in the heart?

• Providing physical support for the cardiac muscle fibres, blood vessels and nerves of myocardium

• Helping distribute the forces of contractions

• Add strength and prevent over expansion of the heart

• Provide elasticity that helps return the heart to its original size and shape after contraction

When the left ventricle contracts what happens?

• the distance between the base and apex decreases

• the diameter of the ventricular chamber decreases

What are the “steps” of the cardiac cycle?

Atrial systole → ventricular systole and atrial diastole → ventricular diastole and atrial diastole

What is the cardiac cycle?

The period between the start of one heartbeat and the beginning of the next. It includes alternating periods of contraction and relaxation

Skeletal muscles vs Cardiac muscles

• Skeletal muscles

  • brief action potential (ends as short twitch)

  • Contraction ends when sarcoplasmic reticulum reclaims Ca²⁺

  • Short refractory period ends before peak tension develops

  • Twitches can summate; tetanus can occur

• Cardiac muscles

  • long action potential

  • Ca²⁺ enters cells over prolonged period

  • long contractions

  • Refractory period continues into relaxation

  • No tetanic contractions occur

what is fossa ovalis?

the remnants of the fetal heart

what are coronary blood vessels?

a circulatory pathway that supplies blood to the heart muscles itself. inferiorly located to the ascending aorta

how much blood is pumped by the heart into the heart itself?

5% because the heart requires abundant O₂ and nutrients

Angina pectoris vs myocardial infarction

both are defects of coronary circuit.

Angina pectoris is just chest pain

myocardial infraction is also known as heart attack,

which vessel sends blood into the right atrium?

Coronary sinus

11 steps of the blood pathway through the heart

• blood enters. right atrium from superior and inferior venae cavae

• blood in right atrium flow through right AV valve into right ventricle

• contraction of right ventricle forces pulmonary valve open

• blood flows through pulmonary valve into pulmonary trunk

• blood is distributed to the lungs where it unloads CO₂ and loads O₂

• Blood returns from lungs via pulmonary veins to left atrium

• blood in left atrium flows through left AV valve into left ventricle

• contraction of left ventricle forces aortic valve open

• blood flows from aortic valve into ascending aorta

• blood in aorta is distributed to every organ in body

• blood return to right atrium from venae cavea

What’s another name for left AV valve?

mitral valve or bicuspid valve

what are the 2 subphrases of ventricle diastole?

isovolumetric contraction: semilunar valves not opened yet

ventricular ejection: semilunar valves opened

Does the blood pressure within the respective chambers remain stable?

no, to ensure flow of blood in the entire body

what are 2 heart sounds you can hear in adults?

• S1 aka “lubb”: when AV valves close

• S2 aka “dupp”: when semilunar valves close

systole vs diastole

• systole is contraction

• diastole is relaxation

what is action potential?

changes in the charge of the cell that can result in initiation of the action potential and the result or outcome of action potential is the contraction of muscle

what is an absolute refractory period?

the period during which no further stimulation can initiate an action potential

what is the relative refractory period?

time duration during which if muscles are stimulated with a powerful stimulation then it can initiate an action potential

what are the 2 different types of heart muscle cells?

• Contractile cells which produce the powerful contractions that propel the blood

• Nodal tissue: specialized muscle cells of the conducting system, which control and coordinate the heartbeat