Blood and Lymph Flashcards
What are the fluid connective tissues?
Blood and lymph
What are the characteristics of blood? (4)
Composed of blood cells and plasma
Distributes nutrients, oxygen and hormones to body cells
Carries metabolic wastes away from cells and to the kidneys for excretion
Transports specialized cells that provide protection against infection and disease
What are the physical characteristics of blood? (4ish)
Volume in body: 5-6L in males and 4-5L in females
pH: 7.35-7.45, very sensitive
Temperature: 38C at core
Normovolemic is normal volume, hypovolemic is volume too low, and hypervolemic is volume too high
What are the formed elements in blood? (3) and the subtypes.
Red blood cells (erythrocytes): carry O2 and CO2, 99% of cells in blood
White blood cells (leukocytes): neutrophils destroy bacteria, eosinophils are anti-inflammatory and allergic response, basophils are inflammatory response, monocytes become macrophages, and lymphocytes are immune response
Platelets: clotting reaction, stems outflow of blood, not a cell, they are pieces of a cell
What is the structure of red blood cells? (3)
Biconcave disc-shaped cells
Plasma membrane surrounds cytoplasm containing water (66%) and proteins (33%): intracellular structures, including nucleus, are ejected from cell during development (not needed for main purpose of gas transport)
No machines makes it hard to repair anything therefore they usually die when damaged, want to transport O2 and these machines use O2 therefore not efficient if they had them
What is the structure of platelets? (3)
Formed from large stem cells called megakaryocytes in the red bone marrow
Platelets are membrane-bound enzyme packets that pinch off from the cytoplasm of the megakaryocytes
Responsible for the clotting reaction in the blood
What is the structure of blood vessels? What way does blood flow in which vessels?
Pathways for blood to circulate throughout the body
Blood flows in two directions: away from the heart (arteries, arterioles, continuous capillaries), towards the heart (veins, venules, fenestrated capillaries)
What are the three layers if the vessel walls?
Tunica interna: composed of simple squamous epithelium (endothelium) and thin layer of connective tissue, many folds to increase SA
Tunica media: thickest layer, composed of elastic fibers and smooth muscle
Tunica externa: composed of connective tissues, attaches vessel to surrounding connective tissue
What are the 4 types of arteries in order of closest to heart to farthest away?
- Elastic artery: largest diameter, closest to the heart due to big bolus of blood gets pushed therefore vessel is mobile, large tunica interna
- Muscular artery: lots of muscle in tunica media, large control in dilating and constricting
- Arteriole: limited tunica externa, high media, many of them
- Continuous capillary: actual exchange and diffusion of gas across membrane occurs
What are the 4 types of veins in order of closest to heart to farthest away?
- Large vein: large tunica externa, close to heart to bring lots of blood back
- Medium sized vein: big tunica media
- Venule: large tunica externa, bit bigger than arteriole
- Fenestrated capillary: more pores in walls between cells therefore debris can get in and go back to heart
What is the structure of the elastic (conducting) vessels? (4)
Largest diameter of arteries
Tunica media contains high density of elastic fibers
Stretch and recoil in response to pumping of heart
Even out pressure surges
What is the structure of muscular (distributing) arteries? (4)
Medium sized arteries
Distribute blood to skeletal muscles and internal organs
Tunica media contains predominantly smooth muscle
Able to vasoconstrict (close) and vasodilate (open)
What are the structure of arterioles? (5)
Small to microscopic vessels
Poorly defined tunica externa
Tunica media composed of few smooth muscle cells
Deliver blood to capillaries
Change in luminal diameter regulates blood pressure
What is the structure of capillaries? (3)
Smallest blood vessels
Connect arterioles to venules
Mediate exchange between blood and surrounding tissues
What are some differences between continuous and fenestrated capillaries?
Fenestrated capillaries have pores to allow for more diffusion
What structure allows for more control over what gets into vasculature in the endothelial cells?
Diaphragm
How does control of blood flow work in capillary beds?
Precapillary sphincters control blood flow through capillaries (small and large opening)
Metarterioles shunt blood through capillary bed, shunt blood directly arteriole to venule when there is no high O2 demand in particular tissue
What is the structure and function of veins? And venules? And medium and large veins?
Collect blood from organs and tissues and return it to the heart
Venules: collect blood from capillaries, wall composed primarily of tunica interna
Medium and large veins: tunica externa thickest layer, blue veins more superficial b/c want to protect arteries in the event of injury
What is the purpose of valves? (4)
Valves in the walls of veins prevent backflow of blood
Venous compression caused by contraction of adjacent muscles aids in maintaining blood flow
Mostly in extremities because fighting gravity to return to heart
May break down as we age
How are the major arteries and veins divided?
By region: thorax, head and neck, abdominopelvic cavity, upper and lower extremities
What are the right arteries in the thorax?
Aortic arch with the brachiocephalic trunk branching off of it and bifurcating into the right subclavian and right common carotid, and off the subclavian is the vertebral which feeds parts of the brain
The internal thoracic comes off the brachiocephalic trunk and branches come off (intercostal arteries)
The aorta is called the thoracic aorta
What are the left arteries in the thorax?
The left common carotid artery branches off the aorta as well as left subclavian artery, and axillary
Intercostal branch off the aorta and travel intercostal space
Descending aorta ends in diaphragm
What are the arteries in the head and neck?
The brachiocephalic trunk which branches into carotid sinus (reads blood pressure, signals brain, brain fine tunes BP) and the external carotid
Also the internal thoracic branch off, thyrocervical trunk branches off subclavian and feeds thyroid and cervical regions, as well as vertebral and internal carotid
In the abdomen what are the branches on the RT side of the abdomen?
Abdominal aorta and into the celiac trunk, and then off of this comes the common hepatic , splenic, and gastric arteries, then comes the superior mesenteric which branches down. Off the superior mesenteric artery there are branches to the colon and small intestine
Then the right common iliac, right internal iliac and right external iliac
What are the left abdominal arteries?
Inferior mesenteric goes to colon, anal, rectum, branches to colon, then the left common iliac and left external iliac
What are the arteries in the upper extremities?
Subclavian, axillary, then deep brachial and brachial, then radial and ulnar, palmar arches and digital
What are the arteries of the lower extremities?
Common iliac, branches off into the internal iliac and external iliac, femoral as well once past the ligament, then there is a branch to the knee and popliteal, posterior and anterior tibial, fibular , pedal arches and digital
What are the branches of the veins in the thorax that come off the superior vena cava in the upwards direction? What does the superior vena cava turn into being called?
Internal jugular, external jugular, then the SVC turns into being called the subclavian
What veins come off the SVC downwards? What is the large vein that comes out the bottom of the heart?
Azygos, internal thoracic, hemiazygos, intercostals
Inferior vena cava
What are the veins in the neck and head?
Superior vena cava branches into the right brachiocephalic , then into subclavian.
Off the RT BC comes the internal jugular, external jugular and the vertebral
What are the major veins below the diaphragm coming from the inferior vena cava?
Hepatics, renals, gonadals
RT/LT common iliac, RT/LT internal iliac, RT/LT external iliac
What are the components of the hepatic portal system? What is the purpose of this system?
Hepatic portal vein, which branches into the gastrics and splenics, as well as the superior mesenteric vein and inferior mesenteric vein
Blood from the digestive tract drains directly to the liver
What are the veins in the upper extremity?
Subclavian, branches into the axillary and cephalic, axillary branches into the brachial and basilic, then radial and ulnar and palmar arches and digitals
What are the veins in the upper extremties?
External iliac and common iliac/ internal iliac as well as deep femoral and femoral, great saphenous (superficial drainage), and popliteal, posterior and anterior tibial, small saphenous and fibular, as well as pedal arches and digitals
What are the two bodily fluids?
Intracellular fluid: cytoplasm, nucleoplasm
Extracellular fluid: blood plasma (in circulatory system), interstitial fluid (bathes the cells of the body, filtrate of fluid and small solutes out of capillaries to the areas surroundings, called lymph when it enters the lymphatic vessels, composed of lymphocytes and lymph fluid, lymph fluid is a dilute solution of proteins and excess of interstitial fluid)
What is the comparison between lymph flow and blood flow?
Blood is actively pumped through vessels by heart
Lymph flows passively along a pressure gradient (NO PUMP)
What are the structure of the lymphatic vessels?
Lymphatic system is extremely low pressure, vessels are very thin (not a lot of integrity between cells)
What are the valves in the lymph system?
Large number of valves because passive flow allows pressure to be easily changed, therefore prevents backflow of lymph
What is the lymphatic system?
Produce, maintain and distribute lymphocytes: function in immune response
Assists with maintaining normal blood volume: vascular pressure forces water and solutes across capillary membrane into interstitial space (3.6L, 72% of blood volume, enters interstitial fluid every day) and fluid is returned to the vasculature by lymph vessels
Alternate route for transport of hormones, nutrients, metabolic waste (some lipids absorbed by digestive tract enter bloodstream via lymph rather than capillaries of the vasculature, thus these lipids do not go to liver for processing, go straight to the heart)
What are the two lymphatic ducts?
Right lymphatic duct which drains right upper extremity and RT head/neck and RT thorax
Thoracic duct which drains LT head/neck, LT upper extremity, LT thorac and all lower abdomen extremities
These empty into large thoracic veins such as azygos vein and cisterna chyli
What are the three types of lymphocytes?
B-lymphocytes, T-lymphocytes and NK cells
What are the B-lymphocytes?
Originate and become immunocompetent in bone marrow, reside in lymph nodes, spleen and lymphoid tissue
Produce antibodies targeted to specific antigens: antibody-mediated immunity
What are the T-lymphocytes?
Originate in the bone marrow and continue development and become immunocompetent in the thymus gland
Cytotoxic T-cells destroy pathogens and abnormal cells (cell mediated immunity)
Regulatory T-cells regulate the immune responses, reside in spleen, other lymphoid organs, bone marrow
What are the natural killer cells?
Originate and become immunocompetent in the bone marrow and continuously circulate through peripheral tissue (immunological surveillance cells)
Respond to cancer cells
What are the lymphatic organs?
Discrete structures enclosed by a fibrous connective tissue capsule
Primary- produce, maintain and store lymphocytes, contain stem cells that generate B, T, and NK cells
Secondary (peripheral) structures: where most immune responses are initiated, activated lymphocytes divide to produce additional lymphocytes of the same type, the front line where invading bacteria were first encountered
What is the thymus gland?
Lies posterior to manubrium in the superior mediastinum, two lobes, large in early life, it undergoes involution in later life, source of T lymphocytes
What is the spleen?
Located along lateral curvature (left) of stomach between ribs 9-11
Largest lymphoid organ
Filters the blood, removing abnormal blood cells and components by phagocytosis
Stores ions recycled from metabolized RBC
Initiates immune response by B and T cells in response to circulating antigens
What is a lymph node?
Oval lymphoid organs 1-25 mm in diameter
Many afferent vessels penetrate fibrous tissue
A single efferent vessel exits the node
Lymph nodes filter the lymph, removing 99%+ of antigens
Resident T cell, B cells and macrophages (major site of immune response to antigens)
Lymph glands: large nodes at the base of neck, axillae, groin
Swollen glands: enlarged nodes due to the inflammation of infection
What are the lymphoid tissue?
Connective tissues dominated by lymphocytes
Diffuse (mucous membranes of respiratory and urinary tract)
Nodules: oval shaped aggregations of densely packed lymphocytes (1mm in diameter) supported by dense reticular fibres, boundaries often indistinct due to lack of fibrous capsules
Mucosa of digestive tract: wall of pharynx (tonsils), lining of small intestine (peyer’s patches), appendix (mass of fused lymphoid nodules, lymphocytes not always effective against infection (tonsillitis, appendicitis)
What are lymphoid nodules?
Densely packed accumulations of lymphocytes, mount an immune response to antigens
What are the tonsils?
Aggregates of lymphocytes nodules in the pharynx, remove pathogens from inspired air and food
What is involved in the drainage of the breast?
Axillary lymph nodes (75% of breast drainage)
Lymph nodes and mammary glands
Cancer cells metastasize (migrate) along lymphatics and become trapped in lymph nodes
