- Information
- AI Chat
Blood Vessels (CHP 18) - important key notes for exams
Basic Anatomy & Physiology II (BIO-118-51 )
Camden County College
Preview text
Blood Vessels (CHP 18)
Different Types of Blood Vessels
- Arteries --> carry blood AWAY from the heart ○ Pulmonary arteries --> transport blood that has a low oxygen content from the RIGHT VENTRICLE to the LUNGS ○ Systemic arteries --> transport oxygenated blood from the LEFT VENTRICLE to the BODY TISSUES ○ Elastic arteries --> elastin enables these vessels to withstand and smooth out pressure fluctuations due to heart action ○ Arterioles --> SMALLEST arteries that regulate blood flow into capillary beds through vasoconstriction & vasodilation ○ Muscular arteries --> deliver blood to specific body organs 1. Structure: 3 layers within artery walls 2. Tunica intima (innermost layer) --> reduces friction between the vessel walls & blood 3. Tunica media --> controls vasoconstriction and vasodilation of the vessel 4. Tunica externa--> protects, reinforces, and anchors the vessel to surrounding structures
- Veins --> return deoxygenated blood from your organs back to your heart ○ Venules formed where capillaries converge; allow fluid & white blood cells to move easily between the blood & tissues ○ Venules join to form veins; 65% of total body volume 1. Structure: 3 main layers 2. Tunica intima (inner layer) --> lined with endothelial cells 3. Tunica media --> made up of smooth muscle 4. Tunica externa --> consists chiefly of connective tissue and is the thickest layer of the vein
- Capillaries --> SMALLEST BLOOD VESSELS; allow for exchange of substances between the blood and interstitial fluid ○ Continuous capillaries (MOST COMMON) --> allow passage of fluids and small solutes ○ Fenestrated capillaries --> more permeable to fluids and solutes than continuous cap. ○ Sinusoidal capillaries --> leaky capillaries that allow large molecules to pass between the blood & surrounding tissue
○ Precapillary sphincter (a cuff of smooth muscle)--> acts as a valve to regulate blood flow into the capillary; surrounds each capillary at the metarteriole
**Oxygen-poor blood returns from the body to the heart
through the superior vena cava (SVC) and inferior vena cava
(IVC), the two main veins that bring blood back to the heart.
The oxygen-poor blood enters the right atrium (RA), or the
right upper chamber of the heart**
Pulse
Pulse --> your heart rate, or the number of times your heart beats in one minute
● Pulse rates vary from person to person* ● Pulse is lower when you are at rest ● Increases when you exercise (more oxygen-rich blood is needed by the body when you exercise ● How to measure a pulse: ○ Generated by the alternating stretch and recoil of elastic arteries during each cardiac cycle
Blood Pressure
● Blood Pressure --> the pressure of circulating blood on the walls of blood vessels ○ How to measure blood pressure: ■ Measured indirectly using the ascultatory method, which relies on the use of a blood pressure cuff to alternately stop and reopen blood flow into the brachial artery of the arm ○ *Alterations in blood pressure may result in hypertension (low blood pressure), transient, or persistent hypertension (high blood pressure) ○ How is blood pressure regulated? --> ■ Short-term regulation is controlled by the autonomic nervous system ■ Changes in blood pressure are detected by baroreceptors
Blood Vessels (CHP 18) - important key notes for exams
Course: Basic Anatomy & Physiology II (BIO-118-51 )
University: Camden County College
