Quiz 11 - Blood Flashcards Preview

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Flashcards in Quiz 11 - Blood Deck (30):
1

composition and functions of blood

blood acts as transport medium to distribute substances to and from body tissues

2

basis functions of blood

distribution
regulation
protection

3

distribution by blood

transports:
- O2 from lungs and nutrients from GI tract to cells
- metabolic wastes from cells to lungs and kidneys for elimination
- hormones from endocrine glands to target organs

4

regulation by blood

maintains:
- body temperature by absorbing and distributing heat
- pH in body tissues using buffer systems
- fluid volume in circulatory system

5

protection by blood

prevents:
- blood loss by initiating clot formation when a vessel is broken
- infections by synthesizing and utilizing antibodies and white blood cells against pathogens

6

components of blood

plasma plus formed elements and hematocrit (Hct)

7

hematocrit

% of RBCs in centrifuged blood sample
- when centrifuged, blood separates into heavier formed elements on bottom and lighter plasma on top

8

average Hct for men and women

men ~46%
women ~ 42%

9

physical characteristics of blood

- more dense than water (viscous)
- alkaline pH = 7.4
- temp = 38C
- accounts for ~7% of body weight
- avg volume: males ~5L, women ~4L

10

components of plasma

water (90% of plasma)
plasma proteins (8%)

11

types of plasma proteins

albumin
fibrinogen
globulins

12

albumin

regulates osmotic pressure (water balance)

13

fibrinogen

clotting proteins

14

globulins

transport lipids and antibodies

15

substances transported by blood

respiratory gasses
nutrients
hormones
electrolytes

16

formed elements

erythrocytes
leukocytes
platelets

17

structure of erythrocytes

- biconcave shape (increases surface area, stackable, flexible)
- no nucleus (unable to divide, grow, or synthesize proteins)
- >97% hemoglobins
- no mitochondria (ATP is generated anaerobically)

18

function of erythrocytes

carry O2 from lungs to tissue and carry CO2 from tissues to lungs

19

hemoglobin

major protein of RBCs that carries oxygen
- reg pigment: oxygenated (red), deoxygenated (dark red)
- 4 heme molecules: each with an iron that can bind one oxygen

20

erythropoietin

hormone released by kidneys which stimulates red blood cell production

21

release of erythropoietin is triggered by...

- hypoxia due to decreased RBCs
- decreases in oxygen availability
- increase tissue demand for oxygen

22

fate and destruction of erythrocytes

- life span of a RBC = 100-120 days
- dying and damaging RBCs are engulfed by macrophages in spleen or liver
- heme and global are separated and the iron recycled

23

leukocytes

- important in body's defense against foreign invaders
- less numerous than RBCs
- make up 1% of total blood volume

24

types of leukocytes

neutrophils
eosinophil
basophil
lymphocyte
monocyte

25

neutrophils

- multi-lobed nuclei
- most abundant of WBCs
- phagocytize bacteria
- 1st of the WBCs to arrive at injury site during inflammation

26

eosinophil

- bi-lobed nuclei
- 1-4% of WBCs
- release enzymes that digest large parasites
- lessen severity of allergies

27

basophil

- most rare of WBCs
-

28

lymphocyte

- >25% of WBCs
- primary cells of lymphatic system found mostly in lymphoid tissues (some circulate in blood)
- become B and T cells, important in immune system

29

monocyte

- 4-*% of WBCs
- largest of leukocytes
- arrive at injury site shortly after neutrophils, entering tissue and become macrophages

30

platelets

cell fragments
- structure: small fragments broken off from megakaryocytic in bone marrow
- function: forms platelet plug that seals injured blood vessel wall