Submitted To: Dr.Mujeeb Ur Rehman Sohoo

Submitted By: Waqas Nawaz

11-arid-975

DVM 1ST

Semester

“Embryology Of The Heart”

Middle Of 3rd Week Rotation Of Cardiogenic Area

18 Days

21 Days

22 Days

Fusion Of The Heart Tubes

Myoepicardial Mantle

1.Myoblast

2.Mesothelial CellsThe formation of Cardiac Loop

(“bending of the heart”)

The formation of Cardiac Loop

(“bending of the heart at 28th day)

The IV foramen and AV canal 4th-5th week Partitioning of AV canal 4th-5th week

The IV foramen and AV canal 4th-5th week Partitioning of AV canal 4th-5th week

The Sinus Venosus

Partitioning of Atrium

(end of 4th week)

Fate of the Sinus Venosus Fate of the Sino-atrial valves

5 weeks newborn

Development of Semilunar valvesThe Truncus Arteriosus

8th week

“Heart”

Size,Shape.Location of the heart

Approximately the size of your fist

Wt. = 250-300 grams

Location

In the mediastinum between the lungs]

Superior surface of diaphragm

⅔’s of it lies to the left of the midsternal line

Anterior to the vertebral column, posterior to the sternum

Heart Skeleton

Consists of plate of fibrous connective tissue between atria and ventricles

Fibrous rings around valves to support

Serves as electrical insulation between atria and ventricles

Provides site for muscle attachment

Pericardial Layers of the Heart

Pericardial Layers of the Heart

Heart Wall

Three layers of tissue:

Epicardium: This serous membrane of smooth outer surface of heart

Myocardium: Middle layer composed of cardiac muscle cell and responsibility for heart contracting

Endocardium: Smooth inner surface of heart chambers

“Cardiac Muscle”

Cardiac Muscle

Elongated, branching cells containing 1-2 centrally located nuclei

Contains actin and myosin myofilaments

Intercalated disks: Specialized cell-cell contacts

Desmosomes hold cells together and gap junctions allow action potentials

Electrically, cardiac muscle behaves as single unit

“Arteries,Veins”

Endothelium- prevents platelet aggregation

secretes substances that control diameter of blood vessel

Tunica media- smooth muscle and connective tissue. Innervated by sympathetic nerves (vasoconstriction)

Missing in smallest arteries

Tunica externa- connective tissue; is vascularized

Tunica interna-smooth continuous lining

Major Vessels of the Heart

Vessels conveying blood away from the heart include:

Pulmonary trunk

Carries deoxygenated blood from right ventricle to lungs

Splits into right and left pulmonary arteries

Ascending aorta

Carries oxygenated blood away from left atrium to body organs

Three major branches:

--Brachiocephalic

--Left common carotid,

--Left subclavian artery

Major Vessels of the Heart

Vessels returning blood to the heart include:

Superior and inferior venae cavae

Open into the right atrium

Return deoxygenated blood from body cells

Coronary sinus

Opens into the right atrium

Returns deoxygenated blood from heart

muscle (coronary veins)

Right and left pulmonary veins

Open into the left atrium

Return oxygenated blood from lungs

“To A Special Teacher”When I started a school,

This day seemed so far away,

Now it’s here & I can’t believe

That time has passed so quickly…

But through your encouragement & guidance.

I feel I’m ready for tomorrow’s challenges.

Teachers play such an important part in shaping & guiding…

Especially teacher like you.

(Dr.Mujeeb-