- Closed siculatory system

- Blood flows is important for oxygen, nutrients, and removal of wastes.

- It is a blood vessel

- Innermost layer

- Endothelial lining and an underlying layer of connective tissue.

- Contains variable amounts of elastic fibers.

- It is a blood vessel

- Middle layer

- Concentric layers of smooth muscle in a framework of connective tissue.

- Can be stimulated by the sympathic  nervous system.

- Collegen fibers bind the media to the intima and adventitia.

- Thin band of elastic fibers located between the media and adventitia.

- The outer layer.

- Connective tissue sheath around the vessel.

--Collagen fibers and some elastic fibers.

- Fibers of the adventitia blend into those of adjacent tissue.

-- Stabilize and anchor the blood vessel.

- Layered wall gice arteries and veins considerable strenght.

- Elastic and collagen components allow for stretching and recoiling.

-Muscular components permit controlled alterations in diameter.

-- Blood pressure changes

-- Blood volume changes

- Elastic (conducting arteries)

-- Large vessels: Diameters up to 2.5 cm

-- Transport large volumes of blood away from the heart.

-- Extremely resilient

--- Highdensity of elastic fibers

--- Few smooth muscle fibers

--- Tolerate pressure changes that occur during the cardiac cycle.

--Example: Aorta, Pulmonary arteries, Common carotid artery.

- Transports blood to the  skeltal muscle and internal organs

- Average diameter of approcimately 0.4 cm

- Thicker media woth a greater percentage of smooth muscle fibers than elastic arteries.

-Examples: External corotid brachial, and femoral arterles.

- Controls blood flow between arteries and capollaries.

- Average diameter of 30,um.

- Poorly defined adventitia.

- Media consists of scattered smooth muscle cells. 

-- Don't form a complete layer.

- Greatest resistance to blood flow.

- Exchange of material occurs in the capillaries.

- Continouous

- Fenestrated

-Sinusolds 

- Most places in the body

- Endothelium is a complete lining

- Have pores in their walls

- May have an incomplete endotheilial lining

- Chorold plecus, hypothalmus, pituitary and pineal glands, kidney.

- Resemble  fensdtrated capillaries but have larger pores.

- Liver, bine marrow, adrenal gland.

- Walls of the capillaries are thin so diffusion distances are small and diffusion can occur quickly

-- Diffusion across the edothelial cells (ECs)

-- Diffusion through gaps bewteen adjacent ECs

-- Diffusion through pores in fenstrated and sinusolds

-- Vesicular transpirt by ECs

- Capacitance vessels

- Collect blood from all tissues and return it to the heart 

- Walls are thinner than corresponding arteries.

-- pressure is lower in veins tha arteries

- Expept for the venules, veins have the same three layers as the arteries.

- Collect blood from capillarles

- May lack a media layer

- Average luminal size of 20,um

- Thin tunica medai (few SM sells, dominated by connective tissues)

- Largest layer is the advertitia (contains bundles if elastic and collagen fibers)

- Average diameter between 2-9 mm

- Examples- Great veins, superior and inferior vena cava.

- Slender media and thick adcentitia

-- Collagen and elastic fibers.

- Pressure is too low to oppose the force of gavity.

- Presents backflow of blood

- Formed by infolding of the initma 

- Any movements that distort of compress a vein will push blood toward the heart.

- Walls of arteries are generally thicker that those of veins.

-- Media of an artery contain more elastic fibers

-- Arteries contain more elastic fibers

- Walls of the arteries contract when not opposed by blood pressure

-- In sectional views arteries apper smaller than veins 

-- Arteries will retain a cirular shape in section.

- Veins have valves.

- The veins and arteries contain the most blood.

- Veins are capacltance vessels

- Venous system acts as a blood reseroir.

- Begins at the pulmonary truck and endas at the left artium.

- Arteries carry deoxygenated blood.

-- Pulmonary trunk ( pulmonary semilunar valve)

- Right and left pulonary arteries

-- Pulmonaryu arterioles

--- Provide blood to the capillary networks around the air pockets of the lungs

-- Pulmonary capillaries

--- Where gas exchange between inspired air and blood occurs

-- Pulmonary veins.

- Begins at the aortic semilunar valve and ends at the entrance to the right atrium.

- Ascending aorta

-- Connects the ascending aorta  with the descending aorta

- Aortic Arch

All in highlighted is the Delicer blood to the head, neck, shoulders and upper limbs

-- Brachiocephalic trunk

--- Right subclavian

--- Right common carotid

-- Left common carotid

-- Left subclavain

- Its a arterie.

- Vertebral arteries. 

- Provides blood to the brain and spinal.

- Runs through the transverse foramen of the cervical vertebrae.

- Supplies blood to the upper limbs

- Deep brachial

--Supplies the deep structures along the posterior suface of the arm.

Supply blood to the forearm

---Radial 

--- Ulnar

- Superficial palmar arch

-- Supplies blood to the palm

- Deep palmar arch

-- Supplies blood to the digital arterles of the thumbs and fingers.

- Joining of two vessels without a capillaru bed

-- Ensures there is a blood supply to tissues

-- Prevents the interruption of blood flow due to changes in body position (arterlivenous anatomosis)

- Branches around C4 or C5 into the :

-- External corotid- Neck, pharynx, esophagus, larynx, lower jaw and face.

-- Intrnal carotid= delivers blood to the brain.

---Enter through the carotid canals

- Ascends to the level of the optic nerves then divides into:

-- Opthalmic artery- supplies the eyes

-- Anterior cerbral- supplies the frontal and parietal lobes

-- Middle cerebral- supplies the midbrain and lateral surfaces of the cerebral hemispheres.

- Circle of wall

- Ring-shaped anastomosis that reduces the chances for serious interruption of cirulation.

- Divides around the posterior surface of the mandible into the:

-- Maxillary: supplies  deep  structures of the face

-- Superfircial temporal

-- Facial: Delivers blood to superficial strutures of the face

- Begins at T5 and penetrates  the diaphragm at T12

- Travels within the mediatinum

- Delivers blood to the viscera of the thorax, muscles of the chest (intercostals), the diaphragm (superior phrenic) and the thoracic portion of the spinal cord.

- Delivers blood to all the abdominopelvic organs and structures.

- Major branches to viseral organs are unparied.

-- Celiac truck.

-- Superior mecsenteric artery.

-- Inferir mecenteric artery.

- Delivers blood to the liver, stomach, esophagus, gallbladder, duodenum, pancreas and spleen.

- Divides into 3 branches.

-- Left gastric artery

-- Splenic artery

-- Common hepatic artery

- Surfactant cells (type II cells)

= Produce and oily serection containing a mixture of phospholipids called surfactant

= Reduces suface tension

- They are near Alveoli.

- Roaming cells that patrol the epithelium, phagocytizing any particulate matter that has eluded resportory defenses.

- In with Alveoli.

- Blood vessel endothelium fuses with alveolar epithelium.

- Small distance allows for rapid gas exchange.

- Diaphragm

- External and internal intercostal muscles

- Eupena- quiet breathing

= Inspirtation is active, expiration is passive

= Diaphragmatic breathing (deep breathing)

= Costal breathing (shallow breathing)

- Hyperpnea- Forced breathing

= Active inspiration and active expiration (internal intercostals and abdominal muscles)

- Dorsal respirtatory group (DRG): Inspitatory center

- Ventral respirtatory group (VRG): Expiratory enter

- Apneustic centerpromotes inspiration by stimulating neurons in the medulla oblogata

- Pneumotaxic centerinhibits the apneustic center (inhibits inspiration)