Unit D2: The Circulatory System T3-7

Layers of arteries

connective tissue, smooth muscle, endothelium

Capillaries

Microscopic vessel through which fluid, gas, & nutrient exchanges take place between the blood and cells of the body

Capillary beds

A network of capillaries that surround every organ and tissue, supply oxygen and nutrients

Precapillary sphincter

a band of smooth muscle fibers that encircles the capillaries at the arteriole-capillary junctions and controls blood flow to the tissues

Skeletal muscular contraction

help push blood through veins

blood reservoir (veins)

Store ~65% of total blood in the body, redirect blood when needed

endothelial cells

The thin layer of cells that line the interior surface of all blood vessels. Only one cell thick in capillaries.

autonomic nervous system

A subdivision of the peripheral nervous system. Controls involuntary activity of visceral muscles and internal organs and glands.

Peripheral Nervous System (PNS)

connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body

vasoconstriction

Reduces blood flow and heat transfer by decreasing the diameter of arterioles (e.g when exposed to cold)

Radial artery

The major artery in the forearm; it is palpable at the wrist on the thumb side.

Carotid artery

The major artery that supplies blood to the head and brain.

vasodilation

increase in diameter of a blood vessel to increase blood flow (e.g during excercise)

fight or flight response

activation of the sympathetic division of the autonomic nervous system, blood redirected to muscles & vital organs

Atherosclerosis

Narrows walls due to lipid deposits/plaque buildup on artery walls. Reduces blood flow

valves in the veins

cause venous blood flow to go in only one direction

aneurysm

an excessive localized enlargement of an artery caused by a weakening of the artery wall. Can lead to a stroke

stroke

A sudden attack of weakness or paralysis that occurs when blood flow to an area of the brain is interrupted

Varicose veins

weakened valves in large veins, especially in the lower legs, lead to enlarged, twisted, and bulging veins

Cardiac Output (CO)

measurement of the amount of blood ejected per minute from either ventricle of the heart

Stroke volume

the volume of blood pumped out by a ventricle with each heartbeat

blood pressure

the pressure that is exerted by the blood against the walls of blood vessels

Regulators of blood pressure

cardiac output, arteriolar resistance

arteriolar resistance

Resistance to blood flow in arterioles.

baroreceptors

Detect changes in blood pressure

Located in the aorta and carotid arteries

medulla oblongata

Part of the brainstem that controls autonomic, life-sustaining functions such as heartbeat, blood pressure, and digestion.

Hypertension

abnormally high blood pressure, damages arteries (become less elastic)

stethoscope

instrument used for listening to internal body sounds

sphygmomanometer

blood pressure cuff wrapped around arm and inflated to block blood flow, air is released while listening with a stethoscope

Korotkoff sounds

series of sounds that correspond to changes in blood flow through an artery as pressure is released

pulmonary embolism

A blood clot that breaks off from a large vein and travels to the blood vessels of the lung, causing obstruction of blood flow.

systolic pressure

Blood pressure in the arteries during contraction of the ventricles.

diastolic pressure

occurs when the ventricles are relaxed; the lowest pressure against the walls of an artery

Thermoregulation

the maintenance of body temperature within a range that enables cells to function efficiently.

Peripheral temperature

temperature of outer layers - skin, subcutaneous tissue, fat

core temperature

The temperature of the central part of the body (eg, the heart, lungs, and vital organs).

hypothalamus function

Part of the brain for homeostasis, sends messages when equilibrium disrupted

pituitary

at the base of the brain; stimulates growth and controls functions of other glands

Normal systolic pressure

~ 95-120 mmHg

Normal diastolic pressure

≤ 80 mmHg

autonomic

controls self-regulated action of internal organs and glands- sympathetic & parasympathetic

Hair follicles

Message sent to these, causing hair to stand on end to reduce heat loss & trap hair during thermoregulation

sweat glands

The glands that secrete sweat to reduce body temperature

Cardiac output formula

stroke volume x heart rate

Shivering

Muscles start to contract and relax to help heat up the body, involuntary

Extracellular fluid

body fluids located outside of cells, includes plasma & interstitial fluid

Filtration

pressure-driven movement of fluid and solutes from blood capillaries into interstitial fluid

reabsorption

- movement of fluid from interstitial fluids back into the capillaries

- driven by osmotic pressure

arteriole end

Filtration, driven by pressure gradient, high pressure

venule end

Hydrostatic pressure is LOW

Osmotic pressure is HIGH

Fluid moves IN, reabsorption

hemorrhage

excessive bleeding, decreased blood volume lowers blood pressure, osmotic pressure the same

Edema

puffy swelling of tissue from the accumulation of fluid, can be from starvation

plasma proteins in blood used as last source for energy, reducing osmotic pressure

Inflammation

chemical histamine released, believing they are under attack, increasing capillary permeability, so proteins enter ECF & lower osmotic pressure

plasma

Fluid, clear portion of blood. Not viscous

platelets

blood clotting, thrombocytes

lymphatic system

Composed of a network of vessels, ducts, nodes, and organs. Provides defense against infection.

Lymph vessels

vessels that receive lymph from the lymph capillaries and circulate it to the lymph nodes

unidirectional (valves)

muscle contraction & low pressure for movements

lymph nodes

small oval clumps of lymphatic tissue located at grouped intervals along lymphatic vessels, filter bacteria, damaged cells

contain lymphocytes to remove harmful invaders thru phagocytosis

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

Urea

major nitrogenous waste excreted in urine

Buffer

compound that prevents sharp, sudden changes in pH

Lymphoid organs

Lymph nodes, spleen, appendix, adenoids, thymus, tonsils, red bone marrow

red bone marrow

produces red and white blood cells and platelets

thymus gland

located above the heart; secretes thymosin, where T lymphocytes mature

thymosin

stimulates the maturation of lymphocytes into T cells of the immune system

T cells

Cells created in the thymus that produce substances that attack infected cells in the body.

Spleen

An organ that is part of the lymphatic system; it produces lymphocytes, filters the blood, stores blood cells, and destroys old blood cells.

macrophages

Found within the lymph nodes, they are phagocytes that destroy bacteria and other foreign matter in the lymphatic stream.

lymphocytes

A type of white blood cell that make antibodies to fight off infections

monocytes

A type of white blood cell that is able to migrate into tissues and transform into a macrophage.

Phagocyte

A white blood cell that destroys pathogens by engulfing them and breaking them down

eosinophil

a granular leukocyte that increases in allergic and some infectious reactions

Neutrophil

A type of white blood cell that engulfs invading microbes and contributes to the nonspecific defenses of the body against disease.

biconcave

shape of red blood cells, increases surface area

red blood cells

Blood cells that carry oxygen via hemoglobin from the lungs to the body cells.

no nucleus in mature cells

hemoglobin

iron-containing protein in red blood cells that carries oxygen for delivery to cells

heme group

iron-containing structures on hemoglobin, the sites of oxygen binding

Globin protein

protein composed of four highly folded polypeptide chains

Oxyhemoglobin

a bright red substance formed by the combination of hemoglobin with oxygen, present in oxygenated blood.

Deoxygenated hemoglobin

Hemoglobin not carrying oxygen, maroon colour

carbaminohemoglobin (HbCO2)

a form of hemoglobin that transports carbon dioxide.

Bicarbonate ions in blood

act as a buffer to prevent sudden changes in blood pH

erythropoiesis

Production of red blood cells in bone marrow.

bile pigments

substances derived from the breakdown of hemoglobin, produced by the liver, and excreted in the form of bile

hemoglobin breakdown

globin gets broken down to amino acids, which are released into the blood and used by cells for protein production

Hematopoesis

production of blood cells

Stem cells

unspecialized cells that retain the ability to become a wide variety of specialized cells

bilrubin

pigment excreted in the bile

Anemia

A condition in which the blood is deficient in red blood cells, in hemoglobin, or in oxygen dedicient

Erythropoietin

A hormone produced and released by the kidney that stimulates the production of red blood cells by the bone marrow.

Karl Landsteiner

Discovered that blood can be grouped into different types, A, B, AB and O.

Blood doping

A technique for temporarily improving athletic performance in which oxygen-carrying red blood cells previously withdrawn from an athlete are injected back just before an event

Glycoprotein markers/ Antigens

"flag" on surface of cells used to signal

Universal donor

Type O blood can donate to any type.

Agglutination

Clumping of microorganisms or blood cells, typically due to an antigen-antibody interaction (incompatible blood types mix)

Rhesus factor

Surface protein on red blood cells in the ABO blood group: people can be Rh+ or Rh-

Universal recipient

Type AB blood can receive any blood type.

erythroblastosis fetalis

a disorder that results from the incompatibility of a fetus with Rh-positive blood and a mother with Rh-negative blood, causing red blood cell destruction in the fetus

RhoGAM

Used to prevent an immune response to Rh positive blood in people with an Rh negative blood type

megakaryocytes

Enormous cells in the bone marrow that release packets of cytoplasm (platelets) into the circulating blood.