week 11

Lymphatic System

            One way system

            Made of

                        Lymph

                        Lymph vessels

                        Lymph nodes

                        Tonsils

                        Thymus

                        Bone marrow

                        Spleen

                        Appendix

                        Peyer's patches (or aggregated lymphoid nodules)

            Functions

                        Produces lymphocytes

                        Filters lymph

                        Absorbs fats into lymph vessels

                        Alternate route for return of tissue fluids

                        Assists with Immune system

                               

Lymph Capillaries

            Begin blind essentially

            Not continuous with anything

            Has no pump

                        Skeletal muscles, valves & respiration act as an indirect pump

            Small vast network

            Thin walled

            Valved

2 major lymph vessels

            thoracic duct

            right lymphatic duct

Thoracic duct

            Abdominal region

            Cisterna chili

                        is a dilated sac at the lower end of the thoracic duct into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow

            goes through the diaphragm

            left side of the vertebrae

            empties into subclavian vein just before it ends

            drainage system for left half of head neck left arm and lower extremities

Right Lymphatic duct

            Smaller

            Drains right half of head and neck and right arm only

Lymph Nodes

            Made of lymphatic tissues

            Encapsulated

            Scattered along vessels

            Afferent vessels enter nodes & more numerous

            Efferent vessels leave node & less numerous

            Lymph moves slowly through node to give it time to be filtered

            Part of RES (reticuloendothelial system)

           

Appendix

            Experimentally verified as being rich in infection-fighting lymphoid cells, suggesting that it might play a role in the immune system

Tonsils

            Pharyngeal (adenoids)

                        Incompletely encapsulated

                        Located  on Roof of pharynx

            Palatine

                        Incompletely encapsulated

                        Sides of oropharynx between palatoglossal and palatopharyngeal arches

            Lingual

                        Incompletely encapsulated

                        Behind tongue

           

            Produce Lymphocytes

            Infections of tonsils can lead to breathing problems and hearing loss

Peyer’s Patches

            Collections of Lymphatic Tissue

            In Ileum of instesting

Thymus

            In mediastynum superiorly

            Bi lobbed

            Max development occurs in puberty

            Starts to degenerate after puberty

            Produces T-Cell Lymphocytes (critical cells of the adaptive immune system)

            2 hormones

                        Thymosin

                        Thymopoesin

Spleen

            12 cm long

            under diaphragm

            slit like opening à hylus for the artery, veins & nerves entering

            Made of red and white pulp

                        White pulp = typical lymphatic tissue

                        Red pulp = venous sinuses & cord of splenic cells

            Purposed with filtering blood

Digestive system to follow

Week 10

SA node

            starts the heart beat

            Automatic

            Sends stimulus that causes both atria to contract at the same time

            What pacemakers do

AV node

            Close to coronary sinus

            Between atria and ventricles

            Right & left sides are bundled up and branch out over each ventricle

            Purkinje fibers transmit the impulse that cause the ventricles to contract at the same time

Contractions start at the apex and travel to the base

Blood Vessels

            3 Layers in a vessel

                        called tunics

            Tunica Interna

                        Thin surface layer of endothelium & elastic CT

            Tunica Media

                        Smooth muscle with some elastic CT

                        Circular arrangement

                        Contractions constrict flow of blood, increasing Blood Pressure (BP)

                        Relaxing dilates the vessels decreasing BP

            Tunica Externa

                        Thin white fibrous elastic CT

Ellastic Arteries

            Conducting Vessels

            Aorta is an example

            Expand and recoil

            Delivers to muscular arteries

Musclar arteries

            Conduct blood to location or distribute

            Continuous flow

Autoregulation

            Automatic local adjustment of blood flow in a given region of the body in            

            response to needs of over tissues à need for oxygen is stimulus

Colateral Circulation

            2 arteries serving the same location

Anastomosis

            2 arteries joining at distal end

Infarction

            Death of cell due to lack of oxygen

NO VALVES IN ARTERIES

Capillaries

            Layer of simple squamous epithelium

            Slows the flow of blood

            Purpose of the cardiovascular system is to serve these

            More numerous in tissues that need/use more oxygen

            Can be closed of with sphincters

            Interconnector between arterioles and venules

Veins

            3 layers

            Same as arteries but less distinct

            Minimal elastic tissue

            Thinner walls

            Greater diameter

            Vena comitans

                        2 veins following a common artery

            Surface veins

                        Cutaneous

            Valves are use to carry blood up against the force of gravity

            Low Pressure

            Pressure gradients help move blood

            Skeletal muscles can act as a pump

            Respiratory can act as a pump

Pulmonary Circuit

            Receives oxygen deficient blood

            Purpose is to oxygenate blood

            Begins Right Ventricle

                        Conus arteriosus

            Ends in the Left Atrium

Pulmonary trunk

            In front of ascending aorta

            To the left & under the arch

            Short wide vessel

            Is an Artery

            Divides into right and left arteries

            Right side delivers blood to right side of lung

                        Branches in lower and superiors branches

                                    Lower branch is larger and delivers to lower lobes

                                    Superior branch delivers to upper lobe

            Left side delivers blood to left side of lung

                        Branches into lower and superior

                                    Lower branch delivers to lower lobe

                                    Superior branch delivers to upper lobe

                                   

            2 Pulmonary veins from each lung empty into left atrium

Systemic Circuit

            More extensive

            Starts in Left ventricle

            Ends in right atrium

            Dispenses from Aorta

            Delivers Oxygen to all systemic arteries

            Aorta has 3 regions

                        Ascending

                        Arch

                        Descending (2 parts)

                                     Thorassic

                                    Abdominal

Ascending Aorta          

            2 coronary arteries

            only branches of ascending Aorta

            Right side receives first

            Left side divides more

                        Anterior ventricular artery

                        Posterior ventricular artery

                        Circumflex artery         

                                   

Arch of the Aorta

            Region that leaves the pericardial sac

            Leave out & heads back

            Ends ~ T4

            3 branches on the top of the arch

                        1^st and largest is Brachiocephalic

                        Left Common Carotid 2^nd

                        Left Subclavian 3^rd

Descending Aorta

            Begins ~ T4 ~ T6

            Thorassic branch

            Has parietal & visceral branches

           

            Abdomincal branch

            Has parietal & visceral & terminal branches

Systemic veins

            Drainage system of blood

            Lots of valves to prevent backflow of blood

            Brings back nutrients waste and lacks oxygens

            Tributaries instead of branches

            Tributaries of origin

                        2 veins merging into 1 common vein

            Superficial

                        Under skin

                        No companion arteries

                        Empty into deep veins

            Deep

                        Travel with artery

                        Artery usually has the same name

            Venus Sinus

                        Space between layer of dura mater (outer layer)

                        Endothelium lined

                        Empty into internal jugular vein

Coronay Sinus

            Heart wall return

Superior Vena Cava  à SVC

            7cm long

            Receives blood from right and left brachiocephalic

                        Right side is shorter

            Receives blood from head neck thorax and upper extremities

Inferior Vena Cava à IVC

            Recieves blood from trunk and lower limbs

           

All 3 empty into Right Atrium

Portal Sytems or Hephatic (Liver) system

            Artery

            Arteriole

            Capillary (sinusoid)

            Venule

            Capillary (sinusoid)

            Venule

            Vein

           

            Recieves blood from digestive tract and spleen

            Portal vein takes blood to liver

            Feeds capillary beds

                        Which filter the blood

                        What gets filtered depends on what the body needs at the moment

Fetal Circulation

            5^th week the fetal heart can start beating

            Foramen Ovale

                        Oval shaped hole between right and left atrium

                        Allows blood to skip going to the lungs since a baby doesn’t use it lungs

                        Decreases in size after birth

                        Becomes fossa ovale

            Large Eustachian valve in IVC

                        Prevents blood from going into ventricle prematurely

            Ductus Arteriosus

                        Allows blood in right ventricle to skip lung

                        Becomes ligamentum arteriosum

            2 umbilical arteries

                        lack oxygen

                        goes to placenta to be oxygenated and get nutrients

                        becomes lateral umbilical ligament

            1 umbilical vein

                        goes back to liver/IVC

                        becomes ligamentum teres

            Ductus venosus

                        Between umbilical vein & IVC

                        Skips liver

                        Becomes ligamentum venosum

week 8

Circulatory System

            Internal environment provides the fluid environment needed

                        ECF or interstitial fluid

            Main function is to transport blood & lymph

                        Blood carries nutrients oxygen enzymes hormones among other things

            Closed system

                        Whole blood contained entirely within heart & vessels

                        Lymph picks up unneeded fluid & returns it to the lymphatic system for                                      cleaning and filtering which is also a part of bodily defense

            FUNCTIONS

                        Maintains homestasis

                        Transportation of oxygen, water, hormones, enzymes & antibodies

                        Regulation

                        Coordination

                        Water & other substance regulation

                        Temperature control

                        Phagocytosis à white blood cells

2 parts to the circulatory system

            Cardiovascular

            Lymphatic

Cardiovascular System

            Adequate blood needed for all body systems/organs at different times for different                     reasons making the circulatory very complex since it can redirect blood                               flow to parts of the body that need or don’t need it very quickly

            Ateries

            Arterioles

                        Both carry blood away from the heart and have higher pressure

            Veins

            Venules

                        Both carry blood to the heart and have a lower pressure

            Capillaries

                        What the circulatory system is designed around

                        Is the exchange zone for bloods nutrients and the organs used nutrients

                                    Blood moves slowly through capillaries to allow time for nutrients                                                           and waste to move into and out of the blood for use or                                                  transport

Internal inviroment

                        Blood

                                    Fluid & formed elements that are confined to organs of                                                              cardiovascular system

                        Tissue Fluid

                                    Interstitial fluid or ECF

                        Lymph

                                    Fluid in vessels of lymphatic system

Blood in detail

            Should have a pH value of 7.35 ~ 7.45

                        Making it a slightly basic fluid under normal conditions

            ~ 8% of body weight

            4 is normal Relative viscosity

                        depends on hematocrit temperature & flow rate

            4 ~ 6 Liters of blood on average in an adult

Plasma in detail

            90% water

            7 ~ 9% proteins

                        fibrin is a protein that helps blood clot

                                    made from fibrinogen

                        serum is plasma with Fibrin removed à all proteins except those used in                                               blood clotting

                                    55% of  all proteins are Serum Albumen (egg white) which is what                                             makes blood viscous & regulates blood volume

                                    38% are immunoglobulens à the bodies defense         

            1% salt sugars fats urea & other thing

            accounts for 50 ~ 60% of blood volume

            other 40 ~ 50% are formed elements

                        formed elements of the blood are erythrocytes (red blood cells),                                                leukocytes (white blood cells), and thrombocytes (platelets)

           

Eurythrocytes

            Red blood cell simply

            Mature cells lack a nucleus

            Hemoglobin gives the red color

                        Oxygen binds to Iron in the blood to be carried

            4 ~ 6 million/mm^3

Hematopoiesis

            The production of red blood cells

            Occurs in red bone marrow

            2 million/second produced to keep up with the bodies demand

Stem cell: One of the human body's master cells, with the ability to grow into any one of             the body's more than 200 cell types.

Reticulocyte

            Immature red blood cell

            Leaves bone marrow & enters blood stream & losses its nucleus

Luekocyte

            True cell

            6,000 ~ 10,000 /mm^3 of blood

            2 groups

                        Granular à granulocyte à white blood cell

                                    Has staining granules

                                    Polymorphonuclear

                                    Nuetrophil

                                    Eosinophil

                                    Basophil

                        Agranular

                                    Monocyte

                                                Can develop in macrophages

                                    Lymphocyte

                                                B cells

                                                T cells

                                                NK cells

Thrombocytes

            Platelets

            250,000 / mm^3 of blood

            fragments of megakaryocyte cell

            rounded

            colorless

            sticky à to adhere to cuts or breaks in a vessel

Hemostasis

            Stopping of blood flow

            Smooth muscle spasms to constrict blood flow

            Platelet plug should form at the site of the damage to start to the repairing process

THE HEART

            2 purposes

                        Completes the Pulmonary circuit for oxygenation of blood

                        Completes the systemic circuit for getting the rest of the body the it needs

            Double Pump

            Maintains flow & pressure

            70 ~ 75 beats/contractions a minute in the average human

            highly efficient to maintain its output

            weigh 340 grams ~ 11 ounces

            12cm long à 9cm wide à 6cm thick

                        less than 648 cm^3 because its not a perfect cube

                        Roughly the size of ones clinched fist

            Located in the mediastynum

            2/3 of it lies to the left of the bodies midline

            1/3 of it lies to the right of the bodies midline

            Posterior to the sternum

            Anterior to the vertebrae & descending aorta & esophagus

            Parietal pericardium adheres to the diaphragm

            Medial to the lungs

            Endocardium

                        Fibrous tissue that supports the endothelium

                        Inner most layer that lines the heart

            Myocardium

                        CT & cardiac muscles

                        Supports lymph

                        Thinner in the walls of the Atrias

                        Right Ventricle 1/3 inch thick

                        Left Ventricle 1 inch thick

                        Arrangement of whirls helps to empty blood

                        Not smooth

                                    Trabeculae carneae

                                                are rounded or irregular muscular columns which project                                                           from the whole of the inner surface of the ventricle

            Capillary bed

                        A dense network of tiny blood vessels that enables blood to fill a tissue or                                  organ

            Epicardium

                        Visceral layer of pericardium

                        the outermost of the three layers of tissue that form the heart wall

                        The inner layer of the pericardium that is in contact with the surface of the                                  heart

           

            Parietal cardium

                        Outer layer of pericardium

                        forms the sac and is lined with a serous membrane. Also called heart sac

            Pericardial cavity

                        Lies between the epicardium and parietal cardium

                        Serous or watery membrane

                        Serous fluid is used as lubrication for the heart

                                    Provides almost 0 friction

            4 chambers to the Heart

                        2 atrium both are superior used to receive blood

                        2 ventricles both are inferior use to pump blood away

            the hearts veins & artery locations

                        Coronary sulcus

                                    Lies between the atrium & ventricle

                        Anterior interventricular sulcus

                                    Between the ventricles

                        Posterior interventricularu sulcus

                                    Between the ventricles

            RIGHT ATRIUM

                        Gets blood returning from systemic route

                        3 openings

                                    Superior vena cava

                                                Superior & posterior

                                                Returns blood from shoulders and up

                                                Directed downward

                                                No valve

                                    Inferior vena cava

                                                Posterior & inferior

                                                Directed upward

                                                Brings in blood from the trunk down

                                                Has foramen ovale

                                                            Fossa ovalus forms after birth

                                                Eustachion valve

                                                            Only seems to be active while a fetus

                                                            No known function for adults

                                    Coronary Sinus

                                                Large veinous

                                                Brings blood back to the heart from the heart

                                                Thebesian valve

           

            RIGHT VENTRICLE

                        Opening between the right atrium & right ventricle

                        Controlled by Tricuspid valve

                                    Tough fibrous tissue

                                    Opens during diastole (relaxation)

                                    Closes duing systole (contraction)

                                    Preventing backflow

                                                Has 3 chordae tendoneae

                                                Attached to 3 papillary muscles

                        Opens to pulmonary trunk

                                    Flow controlled by pulmonary semilunar valve

            LEFT ATRIUM

                        Small in size

                        Walls are thicker than right atrium

                        4 pulmonary veins

                        No valves

            LEFT VENTRICLE

                        Same size as right ventricle

                        Walls are 3x thicker than the right side

                                    To accommodate the higher pressure needed

                        Opening between left ventricle & atrium

                        Controlled by Bicuspid valve (mitral)

                                    2 flaps

                                    2 tendons

                                    2 papillary muscles

                                    All stronger and thicker than the right ventricle

                        Pumps into the aorta

                        Controlled by Aortic Semilunar Valve

                                    Opens with systole

                        Aortic sinuses

                                    For coronary arteries

                                    Receives blood in Diastole