Lecture Notes

Blood vessel walls

• Tunica interna

• Tunica media

• Tunica externa

• permeated by vasa vasorum

Arteries maintain round and oval structure well

Veins are not as uniform

Arteries are resistant vessels

• conducting: are the biggest, stiffen with age - arteriosclerosis

• distributing arteries: have specific names (i.e. femoral artery)

• resistance: a lot of smooth muscle, major point of control to how much blood an organ receives

Arterial Sense Organs

• Carotid sinuses - baroceptors

• Carotid bodies - chemoreceptors

• Aortic Bodies - arch of the aorta, are chemoreceptors, transmit singals via the vagus to the brainstem

Capillaries

• Take nutrients to the tissues and get rid of the bas stuff

• Only in three places that nutrients, wastes, hormones, and leukocytes can pass into the tissues - the capillaires, some venules, and sinusoids

• Microciruclation

• Capillary bed

• Absent in epithelia, cartilages, the cornea and lens of the eye

• scarce in tendons and ligaments

Types of capillaries

• continuous capillaries - BBB, pericytes

• fenestrated capillaries - engage in rapid filtration, have pores

• sinusoids - big, irregularly shaped vein. most common and bone marrow and spleen

Capillary Beds

• webs of capillaries supplied by sigle arteriole

• At any given time, about ¾ of the beds capillary beds are shut down as there is not enough blood to fill them all at once.

• precapillary sphincter, regulates blood flow to the capillary bed

Venis

• capacitance vessels

• are not subjected to significant pressures

• continuous flow

• post-capillary venules

• muscular venules

• medium veins

• large veins - vena cava

• venous sinuses

Pericytes:

• blood flow regulation

• vessel stability

• angiogenesis

• wound healing

• inflammation control

Skeletal muscles act as a pump - when they contract they squeeze blood to the heart

Varicose veins

• in people who stand up too much

Circulatory routes

• heart to arteries to capillaries to veins to heart

• portal systems - 3 portal systems in the body - good exam questions

• anastomosis

• AV anastomosis to shunt

• collateral circulation

Circulatory system

• flow is the amount of blood passing through a tissue or blood vessel

• perfusion

• greater of flow the greater the resistance

Blood pressure

• ratio of systolic over diastolic

• pulse pressure

• MAP

• SPO2

Blood flow is pulsatile

Peripheral resistance

• opposition to flow in the vessels

• viscosity - mainly from plasma proteins & RBCs = polythemia vera

• vessel length - longer tube the more friction/resistance

• vessel radius

Laminar flow

Diffusion and transcyotsis

tissue fluid surrounds capillaries

Skeletal muscles

Lungs

• Pulmonary arteries thinner than other ones

• BP in the pulmonary circuit is only 25/10

• Oncotic pressure overides hydrostatic pressure

• Pulmonary arteries constrict in response to hypoxia in poor ventilated area shunting the blood to better ventilated areas

• Right has three lobes and left lung has two lobes

Learn the Thoracic Aorta slide

• Left subclavian artery

• left common carotid

• right subclavian

• right common carotid

Common carotid arterties

• right side the barchiocephalic artery divides into the R cosmmon and R subclavian

Extracranial arterties slide - anterior view

• Circle of Willis

  • for blood circulation to the brain

  • can be useful if one artery gets plugged off, one can take over

Internal carotid artery supplies 80% of blood flow to the brain

Basilar artery supplies blood to the back of the head

Veins

• Dural sinuses

  • like veins but holes in the dura

  • Cavernous sinus

Major veins in the neck

• internal jugular vein

• external jugular vein

• vertebral vein

• subclavian vein

Arteries of the Thorax Parietal Branches of the Thoracic Aorta

Branches of the Subclavian and Axillary Arteries

Tributaries of the SVC

KNOW ALL MAIN VEINS AND ARTERIES

Phrenic = Diaphragm

Renal arteries

Organ specific arteries - gonadal, renal, etc.

The Mesentery

• sheet that arteries and veins connect to