BIOS 255 Exam 2 Review with expert curated questions and answers-Chamberlain

Tunica externa (tunica adventitia)

epithelial cells, connective tissue, elastic fibers

Tunica media

elastic fibers and smooth muscle (usually the largest layer- controls the diameter)

Tunica intima (interna)

endothelial cells, connective tissue

Aneurysm

is a weak point in the wall of a vessel, bulging sac that pulsates with each heartbeat.

Capillaries

vessels that allow for the exchange of substances between blood and interstitial space

Sinusoidal

large openings allow the passage of larger molecules such as proteins and formed elements; found in the liver

Veins

vessels that carry blood TOWARDS from the heart

Carotid bodies

responsible for monitoring blood pH

Blood pressure (BP)

is the force exerted by blood against a vessel’s wall as it flows through. • BP = systolic pressure/diastolic pressure

Systolic blood pressure

refers to the pressure in the arteries when the heart contracts and pumps blood into the circulation.

Diastolic blood pressure

• represents the pressure in the arteries when the heart is at rest between beats.

Pulse Pressure

systolic pressure - diastolic pressure

Mean Arterial Pressure: MAP

diastolic pressure + 1/3pulse pressure

Arteriosclerosis

stiffening of the arteriole walls due to degradation of elastic tissues.

Atherosclerosis

stiffening of blood vessel walls due to lipid deposits.

Vascular Resistance (R)

• Three factors determine systemic vascular resistance: blood vessel diameter, blood vessel length, blood viscosity

Blood vessel diameter

CONSTRICTED VS DIALATED

▪ A decrease in vessel diameter increases resistance and requires an increase in pressure to maintain the original flow rate.

Blood vessel length

An increase in blood vessel length increases resistance and require an increase in blood pressure to maintain the original flow rate

Blood viscosity

An increase in viscosity results in thicker blood that is harder to move and requires an increase in blood pressure to maintain the original flow rate

BHP = Blood hydrostatic pressure

facilitates the filtration of fluid and small molecules out of the blood capillaries and into tissues

Vasoconstriction

Definition: Vasoconstriction is the narrowing of blood vessel diameter due to contraction of the smooth muscle in the vessel wall.

Effect on Blood Flow: Decreases blood flow to the area downstream of the constricted vessel.

Effect on Blood Pressure: Increases resistance to blood flow, which leads to an increase in blood pressure. The heart must work harder to push blood through the narrower space.

How it Happens: Often triggered by the sympathetic nervous system, certain hormones (like angiotensin II and catecholamines), or reflexes responding to low blood pressure or stress.

Vasodilation

Definition: Vasodilation is the widening of blood vessel diameter due to relaxation of the smooth muscle in the vessel wall.

Effect on Blood Flow: Increases blood flow to the area downstream of the dilated vessel.

Effect on Blood Pressure: Decreases resistance to blood flow, which leads to a decrease in blood pressure. Blood moves more easily through the wider vessel.

How it Happens: Can be triggered by local chemicals (like histamine or prostaglandins), decreased sympathetic stimulation, or certain hormones (like natriuretic peptides).

EDEMA

accumulation of excess fluids in a tissue

Increased capillary filtration

increase in hydrostatic pressure or an increase in capillary permeability may increase the amount of water that filters out into surrounding tissues

Reduced capillary reabsorption

lack of albumin in blood plasma reduces the reabsorption of tissue fluid (Remember osmosis: wherever solutes are, water follows!).

Obstructed lymphatic drainage

If the lymphatic vessels have a blockage, then lymph is unable to return to the bloodstream and accumulates in tissue fluids.

Flow of blood into the right atrium

axillary vein, subclavian vein, brachiocephalic vein, superior vena cava, right atrium

Hepatic portal vein

carries oxygen-poor but nutrient-rich blood from the intestines to the liver

Internal jugular vein

drains blood from most of the brain

need to know

Blood in the axillary artery will flow to the Brachial artery

need to know

Axillary vein and Hepatic vein carry deoxygenated blood

Circle of Willis

The internal carotid artery is a key artery that contributes along with vertebral artery to a loop of vessels located at the base of the brain

Celiac Trunk

a major unpaired artery that branches off the abdominal aorta just below the diaphragm

Immune System

cell population that inhibits all organs and defends the body from agents of disease

Lymphatic System

network of organs, tissues, and vessels densely populated with immune system cells

Fluid recovery

85% of tissue fluid is reabsorbed by blood capillaries and put into venous circulation; remaining 15% is reabsorbed by the lymphatic system

Immunity

lymphatic fluid is inspected for foreign invaders as it passes through lymph nodes

Lipid absorption

lymphatic vessels called lacteals in the small intestine absorb dietary lipids and transport them to the bloodstream

Lymph: recovered extracellular fluid

Clear, colorless fluid similar to blood plasma, but much less protein; same composition as interstitial fluid

Lymphatic Organs: Primary

-site where B & T cells are generated and mature

- red bone marrow and thymus

Lymphatic Organs: Secondary

-mature cells migrate to play a role in immunity

-lymph nodes, tonsils, and spleen

Lymphatic Vessels

• Vein-like vessels that transport lymph

• Penetrate nearly every body tissue except cartilage, cornea, bone, and bone marrow

• Closely associated with blood capillary beds

Right lymphatic duct

receives lymph from right arm, right head, and right thorax → empties into right subclavian vein

Thoracic duct

larger and longer, receive lymph from below diaphragm, left arm, left head, left neck, and left thorax → empties into left subclavian vein

Lymphatic Route

Lymphatic Capillaries >Collecting Vessels: thin walls, many valves >Lymph Trunks:

lumbar, intestinal, bronchomediastinal, subclavian, jugular >Collecting Ducts - right

lymphatic duct, thoracic duct (left lymphatic duct)> Subclavian vein(left)

Mucosa-associated lymphatic tissue (MALT)

respiratory, digestive, urinary, and reproductive tracts

Lymphatic nodules (follicles)

temporary dense masses of lymphatic cells (lymphocytes and macrophages) that form in response to pathogens

Tonsils

found in pharynx and oral cavity - helps to trap inhaled or ingested foreign substances

Pharyngeal tonsils

wall of the nasopharynx

Palatine tonsils

pair at posterior oral cavity, tonsilitis

Lingual tonsils

pair at root of tongue

Spleen

largest lymphatic tissue in the body; upper right quadrant; surrounded by a capsule

Red Pulp

blood reservoir; helps to rid the body of old or damaged RBCs

White Pulp

consists of B-cells, T-cells, and macrophages and functions similar to a large lymph node

Thymus

site of T cell maturation

Cervical (neck)

monitor lymph from head and neck

Axillary (armpit)

monitor lymph from upper limb and female breast

Thoracic (chest)

monitor lymph from mediastinum, lungs, and airway

Abdominal (posterior abdominopelvic wall)

monitor lymph from the urinary and reproductive systems

Intestinal/Mesenteric (adjacent to intestines)

monitor lymph from the digestive tract

Inguinal (groin)

monitor lymph from the entire lower limb

Popliteal (back of knee)

monitor lymph from the foot and leg proper

Arteries

vessels that carry blood AWAY from the heart

Carotid sinuses

helps control blood pressure and HR

Aortic Bodies

a small cluster of chemoreceptors located near the aortic arch, responsible for sensing changes in blood oxygen and carbon dioxide levels, as well as pH

portal system

•consists of blood vessels that have a capillary bed at either end.

Hypophyseal portal

connects the hypothalamus to the anterior pituitary

Hepatic portal

connects the lower GI tract to the liver

Factors affecting blood pressure

1. cardiac output

2. Blood volume

3. Vascular resistance or resistance to flow

thrombus

a blood clot that forms within a blood vessel and remains attached to the vessel wall.

brachiocephalic trunk

•delivers blood towards the upper right limb via the right subclavian artery branch and blood towards the head via the right common carotid artery.