Question | Answer |
What is Tunica Intima? | AKA endothelium; layer of simple squamous epithelium; allows for smooth and frictionless flow of blood. |
What is Tunica Media? | Helps adjust blood pressure because of the smooth muscle; regulated by autonomic nerves. |
What is Tunica (Externa) Adventitia? | Tough supportive layer of connective tissue that anchors blood vessels to surrounding tissues. Infiltrated with nerve fibers and lymphatic vessels. |
Vasoconstriction | Arteries are capable of this. Decreases blood flow by decreasing the diameter of blood vessel. |
Vasodilation | Arteries are capable of this. Increases blood flow by increasing the diameter of a blood vessel. |
Capillaries | Have thin walls made of endothelium for diffusion. Blood vessel diameter is one-cell wide meaning RBC can enter one at a time. Allows deposit of nutrients and oxygen while picking up waste and other by-products. |
Blood flow through capillaries are regulated by? | Precapillary sphincters( faucets) which constricts or dilate them. |
How does blood move through veins? | 1. Valves prevent back flow.
2. Contraction of muscles.
3. Breathing |
What is the aorta? | Largest artery in the body. |
What are the 3 parts of the aorta? | 1. Ascending aorta
2. Aortic arch
3. Descending aorta |
What branches off of the aortic arch? | 1. Brachiocephalic (becomes right common carotid and right subclavian artery)
2. Left common carotid artery (blood to left side head/neck)
3. Left subclavian artery (blood to upper left limb) |
What branches off the ascending aorta? | Coronary artery ( blood to the heart) |
What branches off the descending aorta? | Thoracic aorta to the abdominal aorta to the common iliac |
What is the Circle of Willis? | AKA Cerebral arterial circle, group of blood vessels(mainly internal carotid arteries) that supply blood to the brain. |
What are vertebral arteries? | Branch off subclavian arteries. Runs through foramina of the cervical vertebrae and up to the foramen magnum. Unite to form basilar artery. |
What are basilar arteries? | Feed blood to the pons, cerebellum, midbrain. |
The brain won't be able to maintain life without what? | Vertebral arteries and common carotids. |
What is the celiac trunk? | Branch of abdominal aorta. Made up of common hepatic, splenic, left gastric arteries. Feeds blood to the stomach, pancreas, spleen, upper duodenum and liver. |
What does the external iliac artery feed? | Lower limbs. |
What does the internal iliac artery feed? | Pelvic area. |
The external iliac artery becomes femoral artery which then becomes the popliteal artery which feeds? | Lower limbs. |
What collects blood from the head, neck, thorax, and upper limbs? | Superior vena cava |
What collects blood from the abdomen, pelvis, and lower limbs? | Inferior vena cava |
Veins of the head and neck | External/internal jugular veins drain blood from head/neck into subclavian vein to (right/left) brachiocephalic vein to superior vena cava. |
Veins of the thorax | Azygos system |
Veins of the abdomen | Hepatic portal system drains nutrient rich blood from viscera to the inferior vena cava. |
Veins of the lower limbs | Great saphenous vein is taken from lower limb and used for coronary by-pass surgery. |
What is blood pressure? | Measure of the force that blood exerts against the walls of blood vessel.
Systolic: maximum pressure exerted when ventricles contract (best example is left ventricle) |
What is the relationship between blood pressure and resistance in blood vessels? | If resistance goes up, blood pressure goes down. |
What is stroke volume? | Volume of blood ejected from the ventricles per beat. |
What is vascular compliance? | Elasticity of the vessel |
What allows capillaries to exchange nutrients? | Blood pressure, and osmosis |
What is local control? | Use of pre-capillary sphincters of capillaries. When they are relaxed: increase blood flow. When they are contracted: decrease blood flow. |
What heart rate x stroke volume? | Cardiac output. |
What do baroreceptors do? | Monitor blood pressure, located in neck and thorax arteries, sends action potentials to medulla oblongata. |
What do chemoreceptors do? | Sense changes in chemicals like 02, C02, pH.
If 02 is low, it'll send signals to the vasomotor center/medulla oblongata. |
What is congestive heart failure? | Heart is not pumping right. |
What is shock? | Abnormal circulation of blood. |