Name the layers of the blood vessels. How many cells thick are the capillaries and why? Compare and contrast the structure of veins and arteries.

Name the major arteries of the following areas: head, arms, legs. How are the precapillay sphincter muscles controlled? What is the difference between hydrostatic pressure & osmotic pressure? If someone’s blood pressure is 140/80, what is their pulse pressure?

What do the two numbers represent in your blood pressure? What is an example of a normal blood pressure? Which blood vessels have the highest and lowest blood pressure? Why? Explain how baroreceptors and chemoreceptors help maintain normal blood pressure.

Blood Vessel and Circulation Functions 1. Carry Blood 2. Exchange of nutrients 3. Transport 4. Regulate blood pressure 5. Direct blood flow

I Blood Vessels - Forms a closed circulatory system (Arteries ->Capillaries ->Veins) Made up of three layers a. Lumen - space for the flow of blood. b. Tunica Intima - inner lining. c. Tunica Media - smooth muscle, contractibility. d. Tunica Adventitia – anchoring

A. Arteries - Carries blood away from the heart Strong & Elastic 1. Elastic Arteries – Largest in diameter. Mainly elastic 2. Muscular arteries – medium sized and small diameter. Mainly smooth muscle 3. Distributing arteries – vasoconstriction - Vasomotor fibers of the sympathetic (autonomic) . vasodilatation - nerve impulse is inhibited - muscle relaxes & elastic fibers recoils. 4. Small arteries 5. Arterioles - 0.5 mm in diameter

1. Connect arteries to veins 2. 0.01 mm in diameter - lumen B. Capillaries - Thin wall blood vessels that permit exchanges of material. 1. Connect arteries to veins 2. 0.01 mm in diameter - lumen 3. Can only fit 1 RBC at a time. 4. Form capillary beds or networks. Thoroughfare channels - connect arterioles directly to veins True Capillaries - 10-100 per bed Precapillary Sphincter - valve that regulates flow of blood into those capillaries.

C. Veins - Carries blood toward the heart 1. Thinner & collapse. 2. Holds 65% of the body’s blood. 3. Low blood pressure, too low to be pumped back to the heart. 1 way valves Body movement - Skeletal contraction, breathing. 4. Made up of three layers - same as arteries 5. Varicose veins - overstretched veins from blood pooling , hemorrhoids. 6. Venules – thinner versions of veins

Blood flow through the circulatory system

Arteries

Major arteries of the body

Veins

Major veins of the body

II. Blood Pressure - force exerted by blood against the inner walls of vessels A. Influenced by: Cardiac Output Blood Volume Peripheral Resistance which is regulated by nerve, kidneys, hormones. B. Moves from regions of higher pressure to lower pressure Systolic - Peak pressure - 120 mmHg Diastolic - Resting - 70 - 80 mmHg Sphygmomanometer - measures blood pressure. Stethoscope – Hearing Korotkoff - tapping sound sounds

C. Pulse - rhythmic expanding & recoiling of an arterial wall Average Adult 70 - 90 bpm Child 80 - 140 bpm tachycardia - heart rate is above 100 bpm at rest bradycardia - heart rate is lower than 60 bpm at rest Auscultatory Method Sphygmomanometer Stethoscope Korotkoff sounds

D. Blood Pressure

Pulse Pressure Pulse pressure – the difference between systolic & diastolic pressure. 120/80 – 40 pulse pressure. Factors effecting pulse pressure. Activity - increase Arteriosclerosis- decrease

III Capillary Exchange 10 Billion capillaries Materials (gases, nutrients) move across capillary walls by diffusion, osmosis, facilitated diffusion & active transport. Small amount of fluid also moves across the capillary walls: Hydrostatic pressure - blood pressure within the capillaries Osmotic pressure - movement of fluid from cells to plasma 90% reabsorbed back into the blood 10% returned back by the lymphatic system

Control of vasomotor center (MAP) IV. Regulation of blood pressure - regulation of steady pressure is important. A. Nervous Control - Adjusts cardiac output & peripheral resistant by autonomic fibers to the SA node & reflex center (vasomotor center in the medulla oblongata & pons). 1. Peripheral resistance - control by activity of vasomotor between the smooth muscle & reflex center of Medulla (Vasomotor tone, increases = constriction). Control of vasomotor center (MAP) Map = CO X PR Baroreceptors – located in major vessels above the heart & detect changes in the blood pressure. Moment to moment control

b. Chemoreceptors - Sensitive to changes in oxygen levels or hydrogen ions (pH) level. carotid bodies – carotid sinus aorta bodies - aorta

B. Hormone Control 1. Epinephrine & norepinephrine a. Activated by the sympathetic division of the autonomic division b. Fight or flight response - times of stress c. Epinephrine - increases cardiac output d. Norepinephrine - increases peripheral resistance 2. Atrial natriuretic factor - secreted by the atria of the heart a. Reduces blood volume b. Stimulates the kidney to secrete more sodium & water c. Less water d. Drop in blood volume

3. Antidiuretic hormone (vasopressin) a. Produced by the hypothalamus b. Stimulates the kidneys to increase water absorbtion c. Increase in blood volume C. Kidney Control - Main mechanism of long term control 1 High blood pressure - excretes more water Low blood pressure - conserve more water 2. Release of special chemicals a. Reduced blood flow causes renin to be released by the kidney and causes the formation of Angiotensin I. Angiotensin I + angiotensin-converting enzyme makes angiotension II = vasoconstrictor. b. Angiotensin II - Aldosterone release by the adrenal glands to stimulate the reabsorbtion of sodium & water.

V. Cardiovascular diseases Aneurysm - formation of a sac within the heart or blood vessels due to stretching B. Arteriosclerosis - Loss of elasticity in arterial walls C. Atherosclerosis - narrow of arteries by plaque build up

Cardiovascular diseases

Cardiovascular diseases

D. Congestive heart failure - failure of the heart to pump blood to the body tissues E. Heart Block - Failure of the SA or AV. to generate impulses F. Heart fibrillation - Heart beats at a irregular pace G. Heart flutter - heart race up to 300 bpm H. Hypertension - elevated blood pressure I. Murmur - Leaking of blood through a closed valve J. Myocarditis - infection of the heart muscle K. Pericarditis - Infection of the pericardial sac which results in thicken or scarring

Circulation

II. Circulatory Pathways A. Pulmonary Circulation - Heart ->Lungs -> Heart Drop off CO2 & pick up oxygen 1. Pulmonary artery 2. Pulmonary vein

B. Systemic Circulation - Heart ->Body ->Heart Nutrients to cells & remove metabolic wastes Transports: gases, nutrients, wastes, blood cells, proteins (enzymes), hormones 1. Major Arteries a. Carotid Artery (internal & external) b. Brachiocephalic artery (arms) c. Subclavian (shoulder) d. Aorta e. Common iliac artery f. renal artery kidney g. Axillary (armpit) h. Brachail artery i. Radial artery J. ulnar artery k. femoral l. posterior/anterior tibial artert m. fibular artery

2. Major Veins a. Jugular veins (internal & external) b. Right & Left Brachiocephalic veins c. Inferior & superior vena cava d. Common Iliac vein e. Subclavin vein f. renal vein kidney g. Axillary (armpit) h. Brachail vein i. Radial vein J. ulnar vein k. femoral vein l. posterior/anterior tibial vein m. fibular vein n. hepatic portal vein

Circulation