Circ Sys

Question 1

Function of the circ. system

Answer 1

1.Transportation of O2, CO2,wastes, nutrients, and hormones
2.Maintain body temperature
3.Maintain body fluid levels

Question 2

Parts of the circ. system

Answer 2

The Heart: a muscular organ that continuously pumps blood through the body, generating blood flow. 2.The Blood Vessels: a system of hollow tubes through which the blood moves. 3.The Blood: The fluid that transports nutrients, O2, CO2and many other materials throughout the body.

Question 3

Location of the heart

Answer 3

slightly behind and left to the sternum

Question 4

Chambers of the heart

Answer 4

Atria- 2 top chambers that fill with blood returning from the body (RECEIVING)
Ventricles- 2 bottom chambers that receive blood from the atria and pump it out to the body/lungs (PUMPING)

Question 5

BLOOD FLOW OUT

Answer 5

Vena Cava brings O2 poor blood to Right Atrium which flows to Ventricle which pumps the o2 poor blood to the lungs via pulmonary arteries

Question 6

BLOOD FLOW IN

Answer 6

Pulmonary veins bring o2 rich blood back via left atrium, which flows to left ventricle, which pumps o2 rich blood through body via aorta

Question 7

Purpose of valves

Answer 7

to prevent backward blood flow

Question 8

LUB DUB SOUND

Answer 8

LUB-AV closing as blood is pumped from the atria to the ventricles

-“DUB” sound is caused by semilunar valves, as blood is pumped from the ventricles into the arteries

Question 9

Vassa vasorum

Answer 9

vessels of vessels (small blood vessels that supply oxygen to the layers of the large blood vessels)

Question 10

Nervi vasorum

Answer 10

nerve supply to large blood vessels, reg. via SNS

Question 11

What are varicose veins?

Answer 11

enlarged veins caused by weak vein walls

Question 12

What happens if circulation slows down

Answer 12

blood can clot in a deep vein leading to fatal pulmonary embolism if the clot goes to the lungs

Question 13

Continuous vs fenestrated vs discontinuous/sinusoid capillaries

Answer 13

contin- least permeable (nerves, muscles, fat)
fenestrated- somewhat permeable (intestinal villi, endocrine glands, kidney glomeruli
sinusoid- very permeable (in liver, bone marrow, spleen; any large bodily exchange, such as protein or tissue)

Question 14

Composition of blood

Answer 14

55%-plasma (fluid, 90% water), transports co2
45%-cells (solid), rbc-lose nucleus to carry more hemoglobin
1% of blood volume- wbc

Question 15

leukocytes and lymphocytes

Answer 15

leukocytes (macrophages)- ingest foreign pathogens
- innate response, can pass via capillary walls

lymphocytes- recognize specific pathogens and fend them off if they attack again
- acquired response

Question 16

what are platelets

Answer 16

non cell structures that help with blood clotting
fragments of large cells that break down in the bone marrow

Question 17

Blood clotting process

Answer 17

Blood vessel Is broken=trigger
substances released attract platelets that release chemical agents called THROMBOPLASTIN
THROMBOPLASTIN reacts with PROTHOMBRIN to produce THROMBIN
THROMBIN reacts with FRIBRINOGEN to produce FIBRIN
FIBRIN- mesh strands and catches any escaping material to form a clot

Question 18

Function of WBC and formation

Answer 18

locate the site of infection and other wbc to defend your body to produce antibodies for protection

They are formed in bone marrow, lymphocytes grow in thymus gland (T cells) and lymph node and spleen (B cells)

Question 19

neutrophils

Answer 19

help protect your body from infections by killing bacteria, fungi, and foreign debris

Question 20

lymphocyte

Answer 20

T cells, natural killer cells, and B cells to protect against viral infections and produce proteins

Question 21

eosinophil

Answer 21

identify and destroy parasites, cancer cells and assist basophils with allergic responses

Question 22

basophil

Answer 22

allergic response is producing; sneezing, coughing

Question 23

monocytes

Answer 23

defend against infection by cleaning damaged cells

Question 24

how many wbc are produced per day?

Answer 24

over 100 billion

Question 25

What is stroke volume

Answer 25

volume of blood leaving the heart

Question 26

What is heart rate

Answer 26

number of bpm (contractions)

Question 27

blood pressure

Answer 27

120/80mmHg
systolic- highest pressure when heart beats and pushes blood around body
diastolic- heart relaxes btwn beats

Question 28

what is cardiac output

Answer 28

amount of blood pumped from the heart per minute
= HR(SV), increased cardiac output, increased bp, increased hr

Question 29

what is artierolar resistance

Answer 29

diameter of the Arteriole determines the amount of blood flow, increased diameter, means decreased bp

Question 30

what is the diameter of blood vessels regulated by?

Answer 30

medulla oblongata

Question 31

vasoconstriction

Answer 31

nerve impulses contract muscles, and vessels thin to reduce flow to tissues, increases pressure

Question 32

vasodilation

Answer 32

nerve impulses expand/relax muscles, and vessels dilate to increase flow to tissues, decreases pressure

Question 33

What is the SA node

Answer 33

sinoatrial node; stimulates the muscle cells to contract and relax rhythmically, also called a pacemaker (sets pace for cardiac activity), located in right atrium wall
the SA node generates and electrical signal forcing the two atria to contract together, and the signal reaches the AV node

Question 34

What is the AV node

Answer 34

The AV node transmits the electrical signal through specialized fibres (purkinje fibres) that run down and around the septum and ventricles

initiates the simultaneous contraction of all cells including the right and left ventricles