lecture 13

Question 1

what are the three general functions of blood

Answer 1

transportation, immune response, coagulation

Question 2

what sort of transport does blood do

Answer 2

transports oxygen and nutrients to the tissues, takes away wastes and CO2. carries lipid soluble hormones to the effector cells, also transports heat around the body.

Question 3

what in blood helps it to coagulate

Answer 3

platelets and coagulation factors

Question 4

what does coagulation mean

Answer 4

blood can coagulate when we need it to, like stopping bleeding

Question 5

what are formed elements

Answer 5

the cells and cell fragments which we find in cells

Question 6

what in blood is in greatest proportion

Answer 6

plasma, just over half of it

Question 7

what do plasma proteins do

Answer 7

Maintain osmotic pressure
Immune response
Coagulation factor
Lots of functions; varies by person

Question 8

what do plasma electrolytes do

Answer 8

Maintain pH and ion balance
Cells need these to function!
Cells are getting rid of this

Question 9

what do platelets do

Answer 9

Cell fragments that participate in
clotting to stop bleeding

Question 10

define haematopeisis and where does it occur

Answer 10

formation of blood cells, Initiated in red bone
marrow, which contains blood stem cells

Question 11

Blood stem cells are the progenitors for all blood
cells, what does this mean

Answer 11

All formed elements of blood originate from the “blood stem cell” the haemocytoblast. The haemocytoblast cells divide into lymphoid stem cells- which give lymphocytes. The Hemocytoblasts also divide into myeloid stem cells which give the platelets, white blood cells and red blood cells.

Question 12

define progenitor

Answer 12

Progenitor cells are those that descend from a stem cell and further divide into more specialised cells, an intermediate cell if you will.

Question 13

what are the division pathways for the haemoblastocyte

Answer 13

The haemocytoblast cells divide into lymphoid stem cells- which give lymphocytes. The Hemocytoblasts also divide into myeloid stem cells which give the platelets, white blood cells and red blood cells.

Question 14

when is the nucleus lost from the red blood cell

Answer 14

erythroblast cell stage

Question 15

What does erythropoietin (EPO) do?

Answer 15

RBC is stimulated by EPO, erythropoietin. EPO goes to the bone marrow and stimulates the production of more RBC to carry more blood.

Question 16

what releases EPO

Answer 16

the kidneys in low oxygen state

Question 17

what does the biconcave shape of red blood cell allow

Answer 17

This shape is adventageous as it gives a large SA:V ratio. This ratio allows for efficient diffusion of gases to tissues as it creates a short diffusion distance.
The shape also allows the Red Blood cells to become flexible as they move through capillaries. So they can bend and fold as the move through. Squeezing into tight capillaries makes a good short diffusion distance.

Question 18

red blood cell has no nucelus, what does this mean. also what makes 1/3 RBC weight

Answer 18

haemoglobin makes 1/3 weight, As red blood cells have no nucleus they cannot divide to generate more red blood cells. Instead once the lifespan of one of the cells is complete the cells will just be regenerated vie haematopoiesis.

Question 19

what is the generation of red blood cells called?

Answer 19

Erythropoiesis is the generation of red blood cells.

Question 20

what is the hematocrit level

Answer 20

The fraction of blood occupied by the red cells is called the haematocrit or packed cell volume (PCV).

Question 21

how do we get haemocritic levels and what are normal levels

Answer 21

To determine this we can centrifuge blood. Spinning it fast results in the formed elements separating from plasma. With the heaviest RBCs going to the bottom. From there we can determine RBC component by looking at the blood. Typically about 50%, so haematocrit is around 0.5.

Question 22

what is anemia and give causes and consequences

Answer 22

Low haemoglobin levels = Anaemia
This means our blood carries less oxygen, which reduced amount of O2 tissues receive, which reduces exercise ability and makes us more fatigued.
This low haemoglobin count can come from Fe deficiency in our diets.

Question 23

what is needed to make a red blood cell

Answer 23

iron for the haemoglobin

Question 24

why do males have more haemoglobin

Answer 24

process of making RBC and haemoglobin can be increased by testosterone, men have more testosterone