Circulatory & Lymphatic Systems Flashcards
the vascular system must be _______ to adjust to varying needs of tissues in the body and maintain appropriate BP and blood flow. this is achieved by vessels being able to _______ & _______
dynamic
• Constrict and relax
what is the function of the vascular system?
to deliver materials and remove waste products to tissues
-perfusion of tissues & organs
what components make up the blood vesssels?
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
the ____ ____ is the inner lining of arteries &
veins composed of endothelium (simple squamous epithelium) which is continuous with the endothelium of the heart
tunica intima
the tunica media is the middle layer of arteries & veins which is made of elastic tissue & _____ _____
smooth muscle
_____ has a thinner layer of smooth muscle compared to arteries
veins
the ____ ______ is the outer layer of blood vessels made of connective tissue
Tunica externa/adventitia
the tunica externa/adventitia is infiltrated with ____ fibers, _____ vessels, & ______
- nerve
- lymphatic
- vaso-vasorum
Depolarization of smooth muscle via fast sodium channels depends largely on extracellular _____
calcium
the smooth muscle contractions in the vasculature of blood vessels are ____ & _____, requiring ___ energy
- slow
- sustained
- low
what are the actions of smooth muscle involved the body’s vasculature?
- Few fast sodium channels
* SNS activation or inhibition
________ receptors are excitatory which result in SNS activation, causing sodium channels to open → vasoconstriction
α-adrenergic
what type of receptors are inhibitory in the sympathetic nervous system, causing sodium channels to close → vasodilation?
beta-adrenergic
the arterioles are predominantly _____ ______ which are responsible for regulating flow into capillaries & ___ _______
smooth muscle
-SNS innervation
the large & medium sized arteries in the arterial system are elastic aka ____ & muscular aka _____
- conducting
- distributing
capillary exchange involves____, _____, & ____ between blood & cells that occurs at the capillary bed
nutrients
gases
wastes
what are the 3 types of capillary membranes?
● Continuous
● Fenestrated
● Sinusoidal
what structures make up the capillary bed/plexus?
● Precapillary sphincters
● Metarterioles
● Thoroughfare channel
____ are not present in thoracic or abdominal veins
valves
what is the structural makeup & functions of the venous system? what innervates them?
Structure: Thin-walled, distensible, and collapsible
– Valves prevent backward-blood flow
Functions: contract or expand to handle variable
amount of blood
Innervation: sympathetic nervous system
what are the parts that make up the venous system?
venules
veins
what are the types of venous sinuses?
– Dural
– Coronary
– Hepatic
how does blood circulate in arteries?
– Pressure within the arteries
– Contraction of smooth muscle in tunica media
how does blood circulate in veins?
– Respiratory (pressure changes)
-skeletal (muscle contraction) pumps
– Valves: one way blood flow
where do veins drain into?
superior or inferior vena cava
____ are capable of enlarging and storing large
quantities of blood
veins
what is blood flow determined by?
- BP
- resistance
what factors contribute to resistance of blood flow in hemodynamics?
- Blood viscosity
- Total blood vessel length
- Blood vessel diameter
what generates blood flow and what does it flow along?
- pumping action of the heart
- pressure gradient
____ results when blood flow is opposed by resistance
pressure
____ ______ reflects how much blood vessels can stretch, volume & viscosity of blood in vessels
arterial blood pressure
what factors contribute to the humoral control of vascular function?
● Norepinephrine & epinephrine ● Angiotensin II ● Histamine ● Serotonin ● Bradykinin ● Prostaglandins
what is autoregulation in regards to vascular function?
automatic adjustment of blood flow
to each tissue in proportion to the tissue’s
requirements at any given time
what factors are responsible for local control of organs in regulating blood flow by varying resistance in their arterioles?
● Nitrous oxide
● Angiotensin II
● Collateral circulation
how does the lymphatic system help balance fluid levels?
by transporting excess fluid out of interstitial spaces
and returning it to bloodstream
what are the functions of the lymphatic system & what precursor cells are involved? where do these cells develop?
Lymphocyte:
> Production (lymphopoiesis)
> maintenance
> distribution
Development in the bone marrow:
- Precursor B lymphocytes -> B cells
- Precursor T lymphocytes -> T cells
where do T cells mature & what is their primary function?
thymus gland
-differentiate into helper and cytotoxic T cells
»_space;> proliferation in lymph nodes
where do B cells mature & what is their primary function?
bone marrow
- differentiate into plasma cells
- move into lymph nodes -> proliferate and produce antibodies
aside from lymphocytes, what other cells are involved in the lymphatic system?
- macrophages
- dendritic cells
- reticular cells
how do cells in the lymphatic system defend against infection & disease?
– Invading bacteria, viruses
– Recognizes & attacks specific foreign
molecules (i.e. toxins released by bacteria)
– Defends against abnormal cells
what structures make up the network of lymphatic vessels?
- Capillaries
- Collecting vessels
- Trunks
- Ducts
what are the main components of the lymphatic system?
> Lymph
Network of lymphatic vessels
Lymphoid tissues/organs
Lymphocytes & phagocytes
interstitial fluid that enters the lymphatic system is considered ___.
lymph
what is lymph made of?
water and dissolved substances from blood
what dissolved substances are contained in lymph?
> Gases > hormones > nutrients > proteins > pathogens > tumor cells
____ pressure from cardiovascular capillaries & _____ pressure in lymph capillaries forms the dissolved substances from blood in lymph
- hydrostatic
- osmotic
what happens to the openings of lymphatic capillaries in the presence of inflammation?
openings get bigger
lymphatic capillaries are made of a ____ layer of squamous epithelium which merge to form _____ vessels
single
-larger
how are lymphatic capillaries distributed throughout the body? what parts of the body do they not involve?
connective tissue
> CNS
> bone
> teeth
______ is a specialized type of lymphatic capillaries
lacteals
lymphatic vessels, also known as ______ vessels, is where lymph capillaries feed into & where the smooth muscle layer and valves start to be seen
collecting
how are lymphatic collecting vessels formed and what are they made of? what do they feed into?
multiple lymphatic capillaries feeding into larger vessels
- thin layer of smooth vessels
- contain valves
> lymph nodes
the lymphatic trunks consist of ____ paired lymphatic vessel branches that are named according to their anatomical location
four
what are the major trunks involved where lymphatic vessels converge?
- Lumbar
- Bronchomediastinal
- Subclavian
- Jugular
- Intestinal
where are the jugular lymphatic trunks located?
Cervical nodes in neck
where are the subclavian lymphatic trunks located?
Apical lymph nodes in axilla in the upper extremities
where are the bronchomediatinal lymphatic trunks located?
Heart lungs trachea mediastinum mammary glands
where are the lumbar lymphatic trunks located?
legs
pelvic region
kidneys
what are the major ducts involved in the lymphatic system?
> thoracic duct
> right lymphatic duct
where is the thoracic duct located and where does it collect lymph from?
Left side of body superior to diaphragm
Lymph collected from:
• Both sides of body inferior to diaphragm
– Cisterna chyli
where does the right lymphatic duct collect lymph from?
right side of body superior to diaphragm
where does the right lymphatic & thoracic ducts empty into?
venous circulation at or near junction of internal jugular vein and subclavian vein on that side of the body
what pressure is lymph constantly under & how is lymph moved throughout the lymphatic system?
low hydrostatic pressure
– Muscle contraction (skeletal or smooth)
– Pressure changes in abd. and chest from breathing
what increases lymph flow?
Increased passive movements and physical activity
what occurs when lymph flow is interrupted?
lymphedema
what organs are considered lymphoid organs & what organ is an exception to being made up of lymphoid tissue?
> lymph nodes > spleen > tonsils > lymphoid nodules in small intestine > appendix
exception: thymus
what is the function of lymphoid organs?
designed to gather & destroy infectious microorganisms
lymphoid tissues are where ______ are able to conduct surveillance
macrophages
what are lymphoid tissues made of?
loose, reticular connective tissue network of intertwined fibers
– Containing macrophages and lymphocytes
what is Mucosa-Associated Lymphoid Tissue (MALT)?
lymphoid tissue located in mucus membranes of digestive, respiratory, urinary, reproductive tracts
where are lymphoid tissues located in the pharynx?
tonsils
what specific organ structure in the digestive tract is made of lymphoid tissue which specifically helps destroy bacterial pathogens when they enter the digestive tract?
Peyer’s patches?
where in the digestive tract are Peyer’s patches located?
small intestine (entrance of digestive tract)
what are lymph nodes made of?
- Surrounded by fibrous capsule
- Extensions of fibrous strands into interior node separate node into compartments
- Sinus opening w/ in compartments
what are intertwined w/ in the lymph capillaries and what is their function?
macrophages
> to phagocytize pathogens
what structures are involved in lymph nodes?
- Afferent vessels
- Efferent vessels
- Cortex
- Medulla
what is the function of lymph nodes?
- Filter potentially harmful substances & monitor body fluids
- Contain lymphocytes & macrophages that fight invading organisms
