LAB Midterm Part 1 Flashcards
process where food is taken in, taken apart and taken up
animal nutrition
3 categories of animals
1) herbivores (eats manly plants and algae)
2) carnivores (eats other animals)
3) omnivores (regurarly consumes animals as well as plants and algae)
what type of feeders are more animals?
opportunistic
what are 3 things an animal diet must provide? (COE)
1) chemical energy (for cellular processes)
2) organic building blocks (for macromolecules)
3) essential nutrients
materials that an animal cannot assemble from simpler organic molecules that must be obtained from an animal’s diet
essential nutrients
four classes of essential nutrients (EEVM)
1) essential amino acids
2) essential fatty acids
3) vitamins
4) minerals
how many amino acids do animals require?
20
what can animals do with amino acids?
synthesize about half from molecules in their diet
the remaining amino acids which must be obtained from food in preassembled form
essential amino acids
examples of food that provide all the essential amino acid and are “complete proteins”
1) meat
2) eggs
3) cheese
what are most plants amino acid’s composition?
incomplete
what do individuals who eat only plant proteins need to eat to get all the essential amino acids?
specific plant combinations
what do some animals have that help them through periods when their bodies demand extraordinary amounts of protein?
adaptations
can animals synthesize most of the fatty acids they need?
yes
where must most essential fatty acids be obtained from and what do they include?
from the diet and include certain unsaturated fatty acids
fatty acids with one ore more double bonds
non saturated fat
are deficiencies in fatty acids rare or common?
rare
organic molecules required in the diet in very small amounts
vitamins
how many vitamins are essential for humans?
13
2 categories that vitamins are grouped into
1) fat-soluble
2) water-soluble
simple inorganic nutrients, usually required in small amounts
minerals
what can ingesting large amounts of some minerals upset?
homeostatic balance
failure to obtain adequate nutrition
malnutrition
what can have negative impact on on health and survival?
malnutrition
what can deficiencies in essential nutrients cause?
deformities, disease and death
how can cattle, deer and other herbivores prevent phosphourus deficiency?
by consuming concentrated sources of salt or other minerals
an engineered strain of rice with beta-carotene
“Golden Rice”
what is “golden rice” converted to in the body?
vitamin A
results when a diet does not provide enough chemical energy
undernutrition
characteristics of an undernourished invidivual (5) (UBLSD)
1) use up stored fat and carbohydrates
2) break down its own proteins
3) Lose muscle mass
4) suffer protein deficincy of the brain
5) die or suffer irreversible damage
what have many insights into human nutrition come from?
epidemiology
the study of human health and disease in populations
epidemiology
what were found to be the result of a deficiency in folic acid in pregnant mothers?
neural tube
order of digestion
1) ingestion
2) digestion
3) absorption
4) elimination
the act of eating or feeding
ingestion
4 types of feeders (4) (SSFB)
1) suspension feeders
2) substrate feeders
3) fluid feeders
4) Bulk feeders
many aquatic animals, which sift small food particles from the water (Baleen)
suspension feeders
animals that live in or on their food source (catepillar)
substrate feeders
suck nutrient-rich fluid from a living host (leech, hummingbird, mosquito)
fluid feeders
eats relatively large pieces of food (humans)
bulk feeders
the process of breaking food down into molecules small enough to absorb
digestion
digestion where chewing increases the surface area of food (movement)
mechanical digestion
splits food into small molecules that can pass through membranes; these are used to build larger molecules
chemical digestion
in chemical digestion, what splits bonds in molecules with the addition of water?
enzymatic hydrolysis
uptake of nutrients by body cells
absorption
the passage of undigested material out of the digestive system
elimination
what do most animals process food in?
specialized compartments
what do the specialized compartments in animals reduce the risk of?
digesting its own cells and tissues
food particles are engulfed by phagocytes
intracellular digestion
containing food, fuses with lysosomes, containing hydrolic enzymes
food vacuoles
how do a few animals such as sponges digest their food?
with intracellular digestion
the breakdown of food particles outside the cell. (more common)
extracellular digestion
where does extracellular digestion occur?
in compartments that are continous with the outside of the animal’s body
what do animals have with simple body plans that function in both digestion and distribution of nutrients?
gastrovascular cavity
how many openings do more complex animals have?
two, a mouth and an anus
the digestive tube
digestive tract or alimentary canal
what does the digestive tract have that carries out digestion and absorption in a stepwise fashion?
specialized regions
what does the mammalian digestive system consist of that secrete juices through ducts
alimentary canal and accesory glands
what do the mammalian accesory glands include? (4) (SPLG)
1) salivary glands
2) pancreas
3) liver
4) gallbladder
the way food is pushed along consisting of rhythmic contractions of muscles in the wall of the canal
peristalsis
valves that regulate the movement of material between compartments
sphincters
what is the first stage of digestion and where does it take place?
mechanical, in the oral cavity
delivers saliva to lubricate food
salivary glands
when the teeth chew the food into smaller particles what is it exposed to which initiates breakdown of glucose polymers?
salivary amylase
what else does saliva contain which is a viscous mixture of water, salts, cells and glycoproteins?
mucus
what does the tongue shape food into that provides help with swallowing?
a bolus
the junction that opens to the espophagus and the trachea
throat or pharynx
connects the stomach
espophagus
leads to the lung
trachea (windpipe)
where does the espophagus conduct good from and down to and how?
from the pharynx to the stomach by peristalsis
what does swallowing cause the epiglottis to block entry to?
the trachea
what is the bolus guided by?
the larynx (upper part of respiratory tract)
when does coughing occur?
when swallowing reflex fails and food or liquids reach the windpipe
stores food and begins digestion of proteins
stomach
what does the stomach secrete?
gastric juice
what does gastric juice convert a meal to?
chyme
what type of digestion is occuring in the stomach?
both chemical and mechanical
About what is Gastric juice’s pH?
very low, about 2
what is the benefit of gastric juice’s pH being low?
kills bacteria and denatures proteins
what is gastric juices made up of?
hydrochloric acid (HCI) and pepsin
a protease, or protein-digesting enzymes that cleaves proteins into smaller peptides
pepsin
secretes hydrogen and chloride ions separately into the lumen (cavity) of the stomach
parietal cells
secretes inactive pepsinogen which is activated to pepsin when mixed with hydrochloric acid in the stomach
chief cells
what does mucus protect the stomach lining from?
gastric juice
lesions in the lining
gastric ulcers
what are gastric ulcers caused mainly by?
the bacterium Helicobacter Pylori (H Pylori)
what churns the stomach’s contents?
coordinated contraction and relaxation of the stomach muscle
what do sphincters prevent chyme from entering and what does it regulate its entry into?
the espophagus and regulate its entry into the small intenstine
longest compartment of the alimentary canal
small intestine
where does most enzymatic hydrolysis of macromolecules from food occur?
in the small intestine
produces proteases trypsin and chymotrypsin that are activated in the lumen of the duodenum
pancreas
what is the solution of the pancreas and what does it neutralize
alkaline solution and neutralizes the acidic chyme
what aids digestion and absorption of fats in the small intestine?
bile
where is bile made and where is it stored?
it is made in the liver and stored in the gallbladder
what does bile destroy?
non functional red blood cells
when is enzymatic digestion complete?
as peristalsis moves the chyme and digestive juices along the small intenstine
where does most digestion take place?
the duodenum
what do the jejunum and ileum function mainly in?
absorption of nutrients
what type of surface area does the small intestine have and why?
a huge one because villi and microvilli are exposed to the intestinal lumen
what does the enormous microvillar surface create a brush border for?
to greatly increase the rate of nutrient absorption
what type of transport across the epithelial cells occur and what does it depend on?
passive or active depending on the nutrient
carries nutrient-rich blood from the capillaries of the villi to the liver, then to the heart
hepatic portal vein
functions of the liver (3) (RID)
1) regulate nutrient distribution
2) interconverts many organic molecules
3) detoxifies many organic molecules
where is the colon in the large intenstine connected to?
the small intestine
aids the fermentation of plant material and connects where the small and large intentstine meet
cecum
the human cecum that has an extension which plays a minor role in immunity
appendix
what does the colon complete?
the reabsorption of water that began in the small intenstine
what do feces including undigested material and bacteria become?
more solid as they move through the colon
where are feces stored until they can be eliminated through the anus?
the rectum
what control bowel movementns?
two sphincters between the rectum and anus
an animals assortment of teeth (an example of structural variation reflecting diet)
denition
what is the success of mammals due in part to?
dentition which is specialized for different diets
what do nonmammalian verterbrates have less of?
specialized teeth, though exceptions exist
what type of stomachs do many carnivores have?
large, expendable
what type of alimentary canals do herbivores and omnivores have and what does it reflect?
longer alimentary canals and it reflects the longer time needed to digrest vegitiation
the coexistence of humans and many bacteria
mutualistic symbiosis
characteristics of some intestinal bacteria (2)
1) produce vitamins
2) regulates the development of the intestinal epithelium and the function of the innate immune system
using a DNA sequencing approach based on the polymerase chain reaction, what have scientists found?
more than 400 bacterial species in the human digestive tract
what are the processes that enable an animal to obtain nutrients matched to?
the ogranism’s circumstances and need for energy
what part of the nervous system helps regulate the digestive process?
the enteric divison
how does the endocrine system regulate digestion?
through the release and transport of hormones
what does the body store that are not needed right away for metabolism?
energy-rich molecules
in humans where is energy stored?
first in the liver and muscle cells in the polymer glycogen
where is excess energy stored?
in fat in adipose cells
when fewer calories are taken in that expected what does the human body do?
expands liver glycogen first, then muscle glycogen and fat
what is a major fuel for cellular respiration and a key source of carbon skeletons for biosynthesis
glucose
what hormones regulate the breakdown of glycogen and glucose?
insulin and glucagon
what is the liver a site for?
glucose homeostasis
what does a carbohydrate-rich meal do to insulin levels and what does that trigger?
raises them and triggers the synthesis of glycogen
what does low blood sugar cause glucagon to stimulate the breakdown of?
glycogen and release glucose
what does insulin act on?
nearly all body cells to stimulate glucose uptake from food
what cells are an exception to stimulating glucose?
brain cells because they can take up glucose whether or not insulin is present
where is glucagon and insulin both produced?
in the islets of the pancreas
a disease caused by the dificiency of insulin or a decreased response to insulin in target issues
diabetes mellitus
when one has diebetes mellitus what are cells unable to take up enough of?
glucose to meet metabolic needs
when one has diabetes mellitus what may the level of glucose in blood exceed?
the capacity of the kidneys to reabsorb it
what is one test for diabetes?
sugar in urine
an autoimmune disorder in which the immune system destroys the beta cells of the pancreas. usually appears during childhood.
Type 1 diabetes
characterized by failure of target cells to respond normally to insulin
type 2 diabetes
what significantly increases the risk of type 2 diabetes?
excess body weight and lack of exercise
when does type 2 diabetes generally appear?
generally after age 40, but may develop earlier in younger people who are sedentary.
what does overnourishment cause and what does it result from?
causes obesity and resulted from excess intake of food energy with the excess stored fat
what does obesity contribute towards? (4) (TCHS)
1) type 2 diabetes
2) cancer of colon and breasts
3) heart attacks
4) strokes
what do hormones reulate long-term and short-term appetite by?
affecting a ‘satiety center’ in the brain
a hormone secreted by the stomach wall, triggers feelings of hunger before meals
ghrelin
a hormone secreted by the small intenstine after meals, both suppress apetite
insuline and PPY
produced by adipose (fat) tissue, also suppresses apetite and plays a role in regulating body fat levels
leptin
what must every organism exchange material with?
its environment
at what level do exchanges ultimately occur and how?
at the cellular level by crossing the plasma membrane
where do exchanges occur in unicellular organisms?
directly with the environment
what is NOT possible for most cells of multicellular organisms?
direct exchange with the environment
what is an example of specialized exchange system in animals?
gills
how do gills work?
1) O2 diffuses from the water in the blood vessels
2) CO2 diffuses from blood into the water
what is functionally related in most animals?
internal transport and gas exchange.`
the way small molecules can move between cells and their surroundings
diffusion
how is diffusion only efficient and why?
over small surfaces because the time it takes to diffuse is proportional to the square of the distance
what is an example of how we don’t diffuse over large areas?
we can’t diffuse oxygen from lungs to feet
in small or thing animals what can cells exchange materials directly with?
the surrounding medium
in most animals how does cells exchange materials with the environment?
via fluid-filled circulartory system
do all animals have a ciruclatory system?
no
functions in both digestion and distribution of substances throughout the body
gastrovascular cavity
how many cells thick is the wall that encloses the gastrovascular cavity?
2
what type of body do flatworms have?
a gastrovasular cavity and a flat body that minimizes diffusion
characteristics of a circulatory system (CSM)
1) a circulatory fluid
2) a set of interconnecting vessels
3) a muscular pump, the heart
what does the circulatory system connect the fluid that surrounds the cells with?
the organs that exchange gases, absorb nutrients and dispose wastes
what can a circulatory sytem be and vary in?
open or close and vary in the number of circuits in the body
circulatory fluid that bathes the organs directly founds in insects, other anthropod and some molluscs
hemolymph
what type of circulatory system do insects, other anthropods and some molluscs have?
an open one
what type of circulatory sytem do annelids, cephalopods and verterbrates have?
closed
closed circulatory system found in humans and other veterbrates
cardiovascular system
3 main blood vessels of the cardiovascular system
1) arteries
2) veins
3) capillaries
what is blood flow in the blood vessels of a vertebrate circulatory system?
one way
where do arteries branch into and what do they do?
they branch into arterioles and carry blood AWAY from the heart to capillaries
network of capillaries, sites of chemical exchange between the blood and interstitial fluid
capillary beds
what do venules converge into and what do they do?
they converge into veins and return blood from capillaries to the heart (back to heart)
how are arteries and veins distinguished and how are they not?
by the direction of blood and NOT by the O2 content.
how many chambers do vertebrate hearts contain?
2 or more
where does blood enter through and where is it pumped out through?
enter through an atrium and pumped out through a ventricle
what type of circulation do bony fishes, rays and sharks have?
single circulation with a two-chambered heart
when blood leaving the heart passes through two capillary bed before returning
single circulation
what type of circulation do amphibians, reptiles and mammals have?
double
how are oxygen-poor and oxygen-rich blood pump?
separtly from the right and left sides of the heart
the place where in reptiles and mammals, oxygen-poor blood flows through to pick up oxygen through the lungs
pulmonary circuit
the place where in amphibians, oxygen-poor blood flows through to pick up oxygen through the lungs and skin
pulmocutaneous circuit
the place where oxygen-rich blood delivers oxygen through
system circuit
what does double circulation maintain more than single circulation?
higher blood pressure in the organs
what type of heart do mammals and birds have?
a four-chambered heart with 2 atria and 2 ventricles
what does the left side of the heart pump and receive?
oxygen-rich blood (from lungs)
what does the right side of the heart receive and pump?
oxygen-poor blood (to lungs)
where does blood begin its flow with and where does it go?
with the right ventricle pumping blood to the lungs via the pulmonary arteries
what does the blood do in the lungs?
loads O2 and unloads CO2
where does oxygen-rich blood from the lungs enter te heart?
at the left atrium via the pulmonary veins
how is the blood pumped to the aorta to goto the rest of the body tissues?
by the left ventricle
what provides blood to the heart through the coronary arteries?
the aorta (biggest artery)
what does blood return to the heart through?
the superior vena cava (blood from head neck, and forelimbs) and inferior vena cava (blood from trunk and hind limbs)
where do the superior and inferior vena cava flow into?
the right atrium
what type of walls do the two atria have in a mammalian heart and why?
thin walls to serve as collection chambers for blood returning to the heart
what type of walls do ventricles have in mammalian heart and why?
thicker walls to contract much more forcefully
the heart contracats and relaxes in a rhythmic cycle
cardiac cycle
the contraction, or pumping, phase
systole
the relaxation, or filling, phase
diastole
the pulse, the number of beat per minute in the heart
heart rate
the volume of blood pumped in a single contraction
stroke volume
the volume of blood pumped into the systemic circulation per minute and depends on both the heart rate and stroke volume
cardiac output
what do the four valves of the heart prevent?
backflow
separate each atrium and ventricle
atrioventricular (AV) valves
control blood flow to the aorta and pulmonary artery
semilunar valves
what is the “lub-dup” sound of the heart beat caused by?
the recoil of blood against the AV valves (lub) then against the semilunar (dub) valves
backflow of blood through a defective valve
heart murmur
what type of sound does a heart murmur make?
a wooshy sound
what valves allow blood to enter the ventricles but keep blood from flowing back into the atria during a ventricular contraction
the tricuspid valve and the mitral valve
what valves allow blood to flow out of the heart during ventricular contraction but prevent blood from flowing back in during relaxation
the aortic and pulmonary valves
what are some cardiac muscles and what does that mean?
aautorhythmic, they contract without any signal from the nervous system
what does the SA node or pacemaker set?
the rate and timing at which cardiac muscles contract
recorded impulses that travel during the cardiac cycle
electrocardiogram (ECG or EKG)
where do impulses from the SA node travel to?
the atrioventricular (AV) node
what happens at the AV node?
impulses are delayed and travel to the purkinje fibers that make ventricles contract
what two portions of the nervous system is the pacemaker regulated by?
the sympathetic and parasympathetic
what does the sympathetic division do the pacemaker
speeds it up
what does the parasympathetic division do the pacemaker
slows it down
what else is the pacemaker regulated by?
hormones and temp
a vessel’s cavity
central lumen
the epithelial layer that lines blood vessels which is smooth and minimizes resistence
endothelium
how big are capillaries compared to a red blood cell?
slightly wider
why do arteries have thicker walls than veins?
to acomodate the high pressure of blood pumped from the heart
in thinner-walled veins, why does blood flow back to the heart?
as a result of muscle action
where is velocity of blood flow slowest and why?
in the capillary beds as a result of the high resistance and large total cross-sectional area
why is blood flow in capillaries necessarily slow?
to exchange materials
in regards to pressure how does blood flow?
from higher to areas of lower
the pressure that blood exerts in all directions, including against the walls of blood vessels
blood pressure
what plays a roll in in maintaining blood pressure
the recoil of elastic arterial walls
the pressure in the arteries during ventricular systole; highest pressure in the arteries
systolic pressure
the pressure in the arteries during diastole
diastolic pressure
the rhythmic bulging of artery walls with each heartbeat
pulse
what regulates arterial blood pressure and how?
homeostatic mechanisms by altering the diameter of arterioles
the contaction of smooth muscle in arterial walls; increases pressure
vasoconstriction
the relaxation of smooth muscles in the artieroles; causes pressure to fall
vasodialiation
how is blood pressure generally for an artery in the arm?
at the same height as the heart
what is a normal blood pressure for healthy 20-year old human at rest?
120mm Hg at systole and 70mm Hg at diastole
what has a significant effect on blood pressure?
gravity
what is fainting caused by?
inadequate blood flow to the head
what type of blood pressure do animals with very long necks have and why ?
very high systolic pressure to pup blood a great distance against gravity
how is blood moved through veins?
by smooth muscle contraction, skeletal muscle contraction, and expansion of the vena cava with inhalation
what prevents backflow of blood?
one-way valves in veins
how much of the body’s capillaries at any given time does blood flow through?
only 5-10%
how much are capillaries in major organs usually filled?
to capacity
two mechanisms that regulate distribution of blood in capillary beds (2) (CP)
1) constriction or dilation of arterioles that supply capillary beds
2) pre capillary sphincters that control flow of blood between arterioles and venules
how is blood flow regulated by?
nerve impusles, hormones and other chemicals
where does the exchange of substances between the blood and interstitial fluid take place?
across the thin endothelial walls of the capillaries
what does the difference between blood pressure and osmotic pressure drive fluids out of capillaries at?
the arteriole end and into capillaries at the venule end
what are most blood protein and all blood cells?
too large to pass through the endothelium
returns fluid that leaks out from the capillary beds
lymphatic system
fluid lost by capillaries
lymph
what does the lympahtic system drain into?
veins in the neck
what do valves in lymph vessels prevent?
backflow of fluid
the swelling caused by disruption in the flow of lymph
edema
organs that filter lymph and play an important role in the body’s defense
lymph nodes
when the body is fighting an infection what becomes swollen and tender?
lymph nodes
what is the fluid in an open circulatory system?
continuous with the fluid surrounding all body cells
blood in veterbrates contain which is a connective tissue consisting of cells suspended in a liquid matrix
plasma
how much of the volume of blood do cellular elements occupy?
about 45%
contained in plasma that consists of inorganic salts as dissolved ions
electrolytes
what do plasma proteins influence and help?
blood pH and help maintain osmotic balance between blood and interstitial fluid
what do particular plasma proteins function in?
lipid transport, immunity and blood clotting
what is plasma similar in compostion to?
interstitial fluid but plasma has a much higher protein concentraition
what two types of cells are suspended in blood plasma and what do they do?
1) Red blood cells (erythrocytes)- transport O2
2) White blood cells (leukocytes)- function in defense
fragments of cells that are involved in clotting
platelets
what are the most numerous blood cell?
erythocytes (red blood cells)
the iron-containing protein that transports O2 in RBC’s?
hemoglobin
what does each molecule of hemoglobin do?
binds up to four molecules of 02
in mammals, what do mature erythrocytes lack?
nuceli and mitochondria
caused by abnormal hemoglobin proteins that form aggregates
sick-cell disease
what can the aggreates in sickle-cell disease deform an erythrocyte into?
a sickle shape
what can sick cells do?
rupture or block blood vessels
5 major types of leukocytes (MNBEL)
1) monocytes
2) neutrophils
3) basophils
4) eosinphils
5) lymphocytes
erythrocytes, leukocytes and platelets all develop from this common source
stem cells
where are stem cells commonly found?
in the red marrow of bones, especially ribs, vertibrae, sternum and pelvis
a hormone that stimulates erythrocite production when O2 delivery is low
erythropoietin (EPO)
what can physicians use recombinant of EPO to treat people?
conditions such as anemia
formation of a solid clot from liquid blood
coagulation
what does a cascade of complex reactions convert?
inactive fibrinogen to fibrin, forming a clot
a blood clot formed within a blood vessel and can block blood flow
thrombus
cardiovascular disease that is caused by the buildup of fatty deposits (plaque) within arteries
atherosclerosis
what is a key player in the development of atherosclerosis?
cholesterol
characteristics about cholestorol (SPPP3W)
1) steroid manufactured by animals
2) precursor to many steriod compounds
3) part of cell membranes
4) produce 1 gram daily
5) 35gram reservoir
6) we eat more than we need
water soluble proteins that carry cholesterol through blood
lipoproteins
two types of lipoproteins
1) high density lipoprotein (HDL) “good cholesterol”
2) Low density lipoprotein (LDL) “bad cholesterol”
delivers cholesterol to cells for membrane productions
low desnsity lipoprotein (LDL)
scavenges excess cholesterol to return to the liver
high-density lipoprotein (HDL)
what does risk for heart disease increase with?
a high LDL to HDL ratio
besides cholesterol what is another factor in cardiovascular diseases?
inflammation
the damage or death of cardiac muscle tissue resulting from blockage of one or more cornonary arteries
heart attack or myocardial infarction
death of nervous tissue in the brain, usually resulting from rupture or blockage of arteries in the head
stroke
chest pain caused by partial blockage of the coronary arteries
angina pectoris
a balloon intserted into an obstructured artery
stent
high blood pressure, also contributes to heart attack and stroke as well as other health problems
hypertention
how can hypertension be controlled by?
1) dietery changes
2) exercise
3) medication
what is the main difference between malnutrition and undernutrition
with undernutrition you’re getting what you need but not enough
who has a gastrovascular cavity?
animals with simple body plans
who has an alimentary canal?
more complex animals such as mammals
where does most chemical digestions take place?
in the duodenum by chemicals secreted by the liver, pancreas and small intestine
where does mechanical digestion take place?
begins in your mouth and is continued by the walls of the espophagus, stomach and intestines
what part of the digestive system are proteins digested? (3) (SSS)
1) Stomach
2) small intestine (enzyme from pancreas)
3) small intestine (enzyme from intestinal epithelium)
what part of the digestive system are carbohydrates and sugars digested? (4) (OSSS)
1) oral cavity, pharnyx, esophogus
2) stomach
3) small intestine (enzymes from pancreas)
4) small intestine (enzymes from intestinal epithelium)
what part of the digestive system are nucleic acids digested? (2) (SS)
1) small intestine (enzymes from pancreas)
2) small intestine (enzymes from intestinal epithelium)
what part of the digestive system are fats digested?
the small intestine (enzymes from pancreas)
what happens during single circulation?
blood leaves the heart and passes through two capillaray beds before returning
what happens during double circulation?
oxygen-poor blood and oxygen-rich blood are pumped separatly from the right and left sides of the heart 66
order of blood flow (9) (RLPLLABVR)
1) right ventricle
2) lungs (loads up on O2 and unloads CO2)
3) pulmonary veins (oxygen rich blood)
4) left atrium
5) left ventricle
6) aorta
7) body tissues
8) vena cava
9) right atrium
what do the bundle fibers pass signals to?
the heart apex
