Anatomy Final

Monday May 8

Physical location

within thoracic cavity

mediastinum=

region between pulmonary cavities

heart size

approximately the size of closed fist

* varies with age, height, weight, gender
* important to consider for treatment

Pericardium

surrounds heart, protection, roots, great vessels

Fibrous pericardium-

made of dense and loose CT, fairly non-pliable

anchors heart, prevents overdistension, protects against blunt force

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Serous pericardium (2 layers)

parietal layer- outer/ fused to fibrous pericardium

Visceral layer- inner/ aka epicardium, covers heart

* pericardial fluid between layers

Visceral pericardium

superficial, thin, smooth layer

Myocardium

middle, very thick, composed of cardiac myocytes (contractility)

endocardium

deep, somewhat thin, simple squamous epithelium over CT layer

4 chambered heart

2 superior chamber: right atrium and left atrium

2 inferior chambers: right ventricle, left ventricle

4 heart chambers separated by

interatrial septum and interventricular septum

* separation of O2 Rich and O2 poor Blood

heart valves

allow one-way blood flow and prevent black flow of blood

Cusps/leaflets

flaps that make up valves

Atrioventricular valves (AV Valves)

Tricuspid valve (Right) 3 cusps

Bicuspid valve (left) 2 cusps

Chordae tendineae

connects AV Valves to papillary muscle within heart

prevents inversion of valves during ventricular contraction

Coronary arteries

originate from aorta, supply O2 rich blood to heart tissue

Left coronary artery, right coronary artery- both exit aorta

Left coronary artery

Left anterior descending a.

Left marginal a.

circumflex a.

Right coronary artery

right marginal a

Posterior descending a.

cardiac veins

Drain O2 poor blood from heart tissue

Major veins

Great cardiac vein- Left side

Middle cardiac vein- posterior

Small cardiac vein- Right side

coronary sinus

collects O2 poor blood from above and empties into R atrium

Coronary blockage

cholesterol and fatty deposits (plaques)

infarction

* necrosis due to insufficient blood flow

Myocardial infarction (heart attack)

Necrosis of myocardium due to one or more coronary blockage

Widowmaker

blockage of left anterior descending artery

* supplies the L ventricle

Characteristics of Cardiac Muscle

Branched and networked

Joined by intercalated discs

High levels of communication between cardiac myocytes

Allows for coordinated contraction of cardiac muscle tissue

Cardiac syncytium

Arrangement of cardiac myocytes to form an interconnected mass

* when one cell becomes excited, all cells become excited and heart can contract as one unit
* “all or none principle”

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Two syncytia

atrial syncytium- coordinated contraction of both atria

Ventricular syncytium- coordinated contraction of both ventricles

blood components

Plasma (55-65%)

Formed elements (35- 45%)

Formed elements of blood

Erythrocytes (RBC)

Leukocytes (WBC)

Thrombocyte (platelets)

functions of blood

Transport

PH balance

Extracellular fluid volume

Body temperature regulation

blood transport

Gases

Nutrients

Regulatory molecules

* hormones
* enzymes

plasma

Mostly water

Colloid

Plama proteins in suspension

colloid

liquid that contains suspended substances

Plasmsa protiens in suspension

Albumin

Globulins

Fibrinogen

Albumin

regulates water balance between tissues and blood and osmotic pressure

Transport of hormones (T3 and T4) and other molecules

Globulins

Transport of hormones (E2, CORT) and other molecules

Fibrinogen

Clotting

serum

Let blood clot, then centrifuge sample

Liquid fraction= serum

Does not contain clotting factors

Plasma

Blood is collected with anticoagulant (no clotting), and is centriguged 

* liquid fraction= plasma 
* contains clotting factors

RBC: Erythocytes

O2 transport

White blood cells. leukocytes

Involved with immune function

Platelet/ thrombocytes

Cell fragments

Necesary for clot formation

Granulocytes

Neutrophils

Eosinophils

Basophils

Agranulocytes

Lymphocytes

Monocytes

WBC chemotaxis

Movement of WBC between circulation and tissueC

Chemotaxis in response to:

Toxins

Chemicals released form damaged/ infected tissue

WBC chemotaxis inflammation

vasodialation (histamines)

Increased capillary permeability

Neutrophil and macropphage accumulation

Neutrophils

Most common (60-70%)

Multi-lobed nuclei

First responders to infections

Phagocytize bacteria, antigen A antibody complexes, and other foreign bodies

Eosinophils

less common (2-4%)

Defense against parasites

Attach to parasite and release chemicals to kill it

* no phogocytosis

Regulation of inflammatory response

Aggregate in tissues during allerfic reaction

Destroy inflammatory chemicals, prevent spread of allergic inflammation

Basophils

Rare (0.5-1%)

Proliferate during allergic reaction

* release heparin
* Release histamines
* Vasodilation, itching, swelling

Lymphocytes

Fairly common (20-25%)

B Lymphocytes

* differentiate into plasma cells or memory cells

T cells
* cytotoxic T cells: destroy tumor and Virus-infected cells
* Helper T cells: activate B cells and cytotoxic cells

Natural killer cells: destroy tummor and virus- infected cells

Monocytes

Less common (3-8%)

When leave circulation→ macrophages

* phagocytize bacteria, debris, etc.
* stimulate chemotaxis of other cells
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RBC primary function

oxygen and carbon dioxide transport

Hemoglobin

Protien with four subunits

* each subunit= global (polypeptide) bound to heme
* Heme: red pigment molecule, contains one fe atom

Oxygen binds to heme, at fe center

How many 02 can each hemoglobin molecule carry?

Also transports CO2, attaches to global, not Fe

Hemoglobin Major types:

Embyonic hemoglobin, fetal hemoglobin, adult hemoglobin

Embryonic hemoglobin

3 week to 3 months of pregnancy

Fetal hemoglobin

3 months until birth

Adult hemeglobin

Takes about 2 years to fully transition from fetal to adult hemoglobin

sickle cell disease

abnormality of hemoglobin gene

Irregular RBC shape

Cells block blood flow or break

Reduced oxygen delivery to tissues

sickle cell carriers:

some protection from plasmodium parasites (malaria)

Anemia

Hemoglobin deficiency

Blood loss: chronic bleeding, menstruation

Iron deficiency

Vitamin B12 and folate deficiency

Sickle cell anemia

Reduced O2 delivery due to sickling of RBCs

Polycythemia

Excess RBC

Hypoxia: Compensatory polycythemia- low O2 content due to high altitude

Polycythemia Vera: Rare blood disorder, overproduction of blood cells especially RBCs (thickening of blood, poor blood flow)

Hematopoiesis

blood cell production

Fetal hematopoiesis

occurs in yolk sac, liver, thymus, spleen, lymph nodes, and red marrow

Post natal/ adult hematopoiesis

occurs mostly in red marrow

hemocytoblasts

stem cell origin of all formed elements

blood cell production

Hemocytoblast division→

one daughter cell reamins as hemocytoblast, other daughter becomes either:

myeloid stem cell: Develop into RBCs, platelets, and most WBCs

Lymphoid stem cell: develop into lymphocytes (another WBC)

Hemostasis

Stoppage of bleeding


1. vascular spasm
2. platelet plug formation
3. coagulation

Vascular spasm

immediate temporary constricution of blood vessel

Damage to vessels activates reflexes

stops blood flow

platelet plug formation

Accumulation of platelts to seal breaks in vessel

Platelet adhesion

VWF helps platelets bind to damaged vessel platelet activation

Platelet release reaction

Release of ADP and thromboxanes by activated platelets

→ leads to additional platelet activation

positive feedback loop!

Platelet aggregation

Platelet shape change, fibrinogen bridges platelets forming plug

coagulation

formation of a clot

Network of fibrin, traps blood cells, platelets, and fluid

Clot formation depends on clotting factors ( protiens in plasma)

coagulation- Activation of clotting factors:

extrinsic pathway- initiated by chemicals outside the blood

Intrinsic pathway- intiated by chemicals within the blood

Conversion of fibrinogen (from platelet plug!) to fibrin

* fibrin makes up clot

blood type based on which antigen on surface of RBCs

Antibodies associated with each blood group!

ABO blood group

If you have type A bllod you:

Have antigen A on RBCs

produce anti-B antibody

If blood is not compatible in transfusion…

if you got type B blood (with Antigen B and Anti-A antibody), the anti-A antibodies would bind with your Antigen A== Bad Reaction

Antigen + antibody reaction= agglutination (clumping)

Rapid hemolysis, coagulation, shock, renal failure, death

Rh blood group

first studied in rhesus monkeys

Based on antigen D on RBCs

Genetically determine

Rh antigen develop in Rh negative person is exposed to Rh positive blood

through transfusion

Blood crossing placenta from mother to fetus

Respiratory system function

Respiration

* ventilation
* external respiration (O2 enters and CO2 leaves through lungs)
* Gas transport
* Internal respiration- gas exchange in tissues

Regulation of Ph

changing CO2 levels

Production of chemical mediatiors

angiotensin-converting enzyme (ACE), Bp regulation

Upper respiratory tract

External nose

Nasal cavity

Pharynx

Larynx

Lower respiratory tract

Trachea

Bronchi and Bronchioles

Lungs

Alveoli

Upper respiratory infection

usually symptoms above the neck (coughing, sneezing, sore throat, etc.) and less serious

Lower respiratory infections

bronchitis, pneumonia, etc. usually last longer and are more serious

conducting zone

where air movements occure

Nose to bronchioles

Respiratory zone

site of gas exchange

alveoli

Air movement (nasal cavity)

Turbinates force air into slow steady pattern to contract surface area with epithelium

clean air (nasal cavity)

pseaudostratified cilitated columnar epithelium w/ goblet cells

\-mucous production

olfactory epithelium

scent detection

Pharynx

common opening for digestive and respiratory system

nasopharynx

connects to nasal cavity

oropharynx

connects to oral cavity

laryngopharynx

route food/drink to esophagus, and air to larynx

larynx

rigid and strong

* 9 cartilages connected by muscle and ligaments
* biggest is thryroid catrilage

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