2) Cardiovascular System - Blood Vessel & Lymphatic System

which arteries have thick muscular walls? what’s their purpose

medium-sized muscular arteries that allow for vasoconstriction and vasodilation to deliver blood to organs or muscles

which vessels have very thin walls consisting of endothelium only? 

capillaries

describe 2 types of capillary pressures

these are the pressures that drive substances in/out of capillaries

1. osmotic/oncotic pressure: pulls fluid into capillaries

2. hydrostatic pressure: pushes fluid out of capillaries 

which pressure pulls fluid INTO the capillaries

osmotic/oncotic 

which pressure pushes fluid out of capillaries 

hydrostatic

what is “bulk flow” in capillary exchange? how else can things move in/out of capillaries

consists of filtration and reabsorption

• filtration: mvmd of fluid out of capillaries (o2, nutrients) 

• reabsorption: mvmd of fluid into capillaries (co2, wastes) 

-diffusion also happens for gases and small molecules

this is the force exerted by blood onto vessel walls of arteries

blood pressure - 120/80 mmHg 

blood pressure is influenced by cardiac output (= HRxSV), blood volume, and peripheral resistance. how is peripheral resistance increased?

more resistance can be due to decrease in diameter of arteries/arterioles or the stretchiness of these arteries

this term refers to the ability of tissue (heart) to automatically adjust its blood flow to match its demands (metabolic needs)

auto regulation

neural regulation of the heart involves what part of the nervous system

autonomic - sympathetic and parasymp.

which hormones affect blood pressure? (hormonal regulation)

adrenaline, aldosterone, anti-diuretic (ADH)

where do you find baro-receptors? what do these do

found in internal carotid arteries & aortic arch

function: detect changes in blood pressure - then relay this info to the cardiovascular center in the brainstem

in fetal circulation which arteries/vein carry oxygenated and which carry deoxygenated blood?

• umbilical vein carries OXYGENATED blood from the placenta to the fetus heart

• 2 umbilical arteries carry DE-oxygenated blood (co2/wastes) from the fetus to the placenta

describe these 3 shunts in the fetal circulation:

• ductus venosus

• foramen ovale

• ductus arteriosus

• ductus venosus: umbilical vein skips the liver (bc its already filtered and oxygenated)

• foramen ovale: pushes the o2 blood from right atrium straight into left atrium (bc it doesn’t need to go to the lungs)

• ductus arteriosus: by-passes the pulmonary artery to go straight to aorta (bc doesn’t need to go to the lungs)

what is the red bone marrow’s role in the lymphatic system?

produces mature T and B cells

where is the thymus located? what is its role in the lymphatic system?

located behind the sternum

T-cell maturation

what is the spleen’s function for the lymphatic system?

filter pathogens in blood and immune response

3 functions of the lymphatic system

1. absorb excess interstitial fluid (from capillary exchange) and return it to blood stream

2. immunity: filter pathogens from lymph and initiate immune response

3. absorb lipids from digestive system and return to blood stream

describe the flow of lymph from lymphatic capillaries to blood stream

lymphatic capillaries > lymph vessels + lymph nodes > lymphatic ducts (thoracic & right lymphatic ducts) > drains into the subclavian/internal jugular veins > back into blood

what are the 2 main lymphatic ducts that drain lymph fluid back into veins

thoracic duct and right lymphatic duct

which of these are false:

1. lymphatic capillaries have a basement membrane

2. lymph vessels have valves

3. lymph fluid moves via skeletal muscle contractions and respiratory movements

number 1 - lmyph caps don’t have a basement membrane

which WBCs do lymph nodes contain

lymphocytes: T and B cells

macrophages