Connective Tissue 3 Flashcards
(41 cards)
1
Q
Blood Components
A
Erythrocytes (RBCs and Platelets)
Leukocytes (Monocytes, Lymphocytes, Eosoniphils, Basophils and Neutrophils)
2
Q
General Facts
A
.38 degrees
* 5X viscosity water –
dissolved proteins, formed
elements
* PH average 7.4 slightly
alkaline (expand here)
* 4-5L
3
Q
Formed Elements
A
- Blood cells and cell fragments suspended in
plasma - RBCs, WBCs and platelets
- Formed elements produced through
hematopoiesis - Hemocytoblast (PSCs)
→ myeloid stem cells
→ Lymphoid stem cells
4
Q
Transport
A
Dissolved gases
Nutrients
Hormones
Metabolic waste
5
Q
Regulation
A
PH/Ion composition of interstitial
fluid….
-Regulates ion levels
-Eliminates acid build up
6
Q
Restricts Fluid Loss
A
- Enzymes that respond to breaks in
vessels - Clotting
7
Q
Defence against pathogens/toxins
A
- WBC’s
- Antibodies
- Special proteins
8
Q
Stable body temperature
A
- Absorbs heat generated by skeletal
muscles
9
Q
Plasma Proteins
A
Proteins in solution
* Similar to interstitial fluid
* 7.6g/100ml in plasma
* X5 less in interstitial fluid
* Three protein classes:
- Albumins (60%); osmotic
pressure; transporter
- Globulins (35%);
antibodies/immuno and
transport globulins
- Fibrinogen – Clotting
- Molecules can interact making
insoluble fibrin strands
→>framework for a blood clot.
- 1% other proteins with
specialised functions
10
Q
Blood haematocrit - % of whole blood
occupied by red blood cells
A
- 42% females
- 46% males
- Male sex hormones (androgens) stimulate red blood cell production
- Blood can be separated out by centrifugation
11
Q
Clinical Relevance of Haematocrit
A
Anaemia
- Decreased
hematocrit
*Polycythemia
- Increased
hematocrit
(>65%)
12
Q
RBCs
A
- 99% formed elements
- Red pigment – haemoglobin – binds O2/CO2
- RBC/ul – 4-6 million!!!
- Biconcave disc
- Large surface area:volume - efficient gas exchange (total 3800 sqm!!!)
- Stack and flow!
- Very flexible
13
Q
Haemoglobin
A
- 95% of RBC protein
- Grams of Hb/100ml of whole blood
- 2 alpha and 2 beta polypeptides
- Each Hb chain has a haem (pigment)
- Binds O2 – shade difference
14
Q
Erythropoiesis
A
- Erythropoiesis – formation of RBCs
- Red bone marrow
- In extreme situations yellow marrow
converts to red marrow
15
Q
Blood production
A
Haematopoiesis
16
Q
Clinical Relevance of Hb
A
- Sickle cell anaemia
- Autosomal recessive
- Mutant Hb gene leads
to mutant Hb protein
Hb-S - When Hb-S gives up O2
it forms rodlike structures - ‘Crisis’- pain and
damage due to
blocked capillaries
17
Q
Leucocytes (WBC)
A
- Nucleus
- 6-9000/ul
- Larger than RBC
- Role in immune system, removal of foreign substances
& defective cells/debris, inflammation. - Mostly located in connective tissue proper or lymph
organs
18
Q
Granulocytes (Leukocytes)
A
- Neutrophils; eosinophils and basophils
- Granules are vesicles and lysosomes
19
Q
Agranulocytes (Leukocytes)
A
- Monocytes and lymhocytes
- Non-granular cytoplasm
20
Q
normal differential count for white
blood cells:
A
Neutrophils (60-70%)
Lymphocytes (20-40%)
Monocytes (3-10%)
Eosinophils (1-4%)
Basophils (~1%
21
Q
Granulocytes- Neutrophils
A
- Most common
(50-70% of WBC) - 10-12μm
diameter - 2-5 lobed nucleus
- Lysosomal and bactericidal
granules - First to injury site
- Cell scavengers
/phagocytes
22
Q
Granulocytes- Eosinophils
A
- Eosin +ve granules
- Rare (2-4% of WBC)
- 10-12μM diameter
- Exocytosis of toxic compounds
- Attack antibody coated objects
- Increased in allergic
conditions (e.g. asthma)
and internal parasitic
infections (e.g. worms)
23
Q
Granulocytes- Basophils
A
- 0-5-1% (most rare!)
- 8-10μm diameter
- Migrate to injury site
- release histamine
dillates blood vessels
and heparin
prevents blood clotting
24
Q
Agranulocytes- Monocytes
A
- 12-20μm diameter
(largest) - 3-8% of WBC
- Kidney shaped nucleus
- Circulate in Blood for 2
days, then mature in
tissues - Mature into macrophages
- Cell-mediated immunity
25
Agranulocytes- Lymphocytes
* Smallest WBC
* Diameter 8-10μm
* 20-30% of WBC
* Large nucleus
* B-cells – differentiate into plasma
cells (antibody production).
* T-cells – CD4 and CD8
* NK (natural killer) – immune
surveillance and destruction of
abnormal tissue (cancer).
26
Platelets
* Can look spindle shaped in smear
* Fragments shed from cytoplasm of
megakaryocytes (slide17!)
* In BM, slowly sheds cytoplasm in
membrane enclosed packages
* Around 4000!
* 2-4μm diameter
* Role in blood clotting – make clotting
factors (III,IV, V, VIII and XIII)
* Lifespan of 9-12 days
* Removed in spleen by phagocytes
27
Clinical Significance of Platelets
- Hereditary disorder mostly
affecting males
- Inadequette clotting factor
formation (VIII)
- Delayed clot
formation
- Haemorrhage
28
Lymphatic SYSTEM
* Lymphatic capillaries and vessels
Lymphocyte producers:
* Lymphoid tissue – e.g. tonsils
* Lymphoid organs – spleen and
thymus
* Production/distribution of
lymphocytes
* Lymphopoiesis
29
lYMPH
Blood plasma components (not large plasma
proteins) pass through capillary walls into interstitial fluid.
* Concentration gradient prevents flow from interstitial fluid to
blood.
* Passes into permeable lymph capillaries = lymph.
30
Collecting drainage – lymphatic capillaries
* Capillaries deliver more liquid to tissues than they carry away.
* The residual liquid (15%) is returned via lymphatic system.
* Helps distribute lymphocytes, hormones, nutrients etc…from
interstitial fluid
31
Lymphatic capillaries
* Branch through peripheral tissues
* Not present in CNS, BM or cornea
* Originate in blind pockets – cul-de-
sac!
* Large diameter
* Thin walls – endothelial cells
* Absent/incomplete basement
membrane
* Not tightly packed but overlap
* This creates a valve for the one
directional flow of lymph
32
Lymphatic vessels
* Small lymphatic vessels contain valves
* Ensure flow from trunk to thoracic cavity
* Present in almost every tissue
* Often associate with blood vessels
* Plasma →interstitial fluid → lymph
33
Lymphoid tissues
* Specialised connective tissue dominated by
lymphocytes.
* Example – tonsils.
* These are large nodules in pharynx wall.
* Germinal centres contain dividing lymphocytes
34
Lymphoid organs
* A fibrous connective tissue
capsule separates these
organs.
* Lymph nodes, the thymus
and the spleen.
35
Lymph nodes
* Kidney bean!
* Small, oval, 1-2mm.
* Collagen fibres extend in –
trabeculae.
* Helium – point of attachment
for blood vessels and nerves
* Afferent lymphatics – carry in
lymph.
* Efferent lymphatics – carry
lymph away
36
Lymph node function
.filter
* Purify lymph before entry to venous system.
* Remove 99% antigens.
* Macrophages phagocytose
* Antigen presentation to lymphocytes.
* Strategically positioned to avoid infection – groin, digestive and
respiratory tract protection.
43
37
Thymus
* Right and left lobes
* Septa separate out the lobes into lobules.
* Contains many lymphocytes.
* Produces hormone Thymosin
38
Spleen
* Largest collection of tissue.
* Preforms the same function as
lymph nodes…but for blood.
* Recycling red blood cells.
* Initiation of immune responses – B
and T cells
45
39
Spleen histology and function
* 12cm
* Capsule - collagen/elastin
* Trabecula – blood vessels.
* Red pulp – blood+ fixed
macrophages in network of
reticular fibres
- Removes abnormal blood
cells.
- Immune cell activity
* White pulp – Rich in variety of
immune cells
40
What aids lymph flow?
1)Smooth muscle contraction
2)Skeletal muscle contraction
3)Inhalation
41
Clinical Significance of Lymph Fllow
* BLOCKAGE OF
LYMPH VESSELS
- Fluid accumulates
in interstitial fluid,
proteins retained
* FILARISIS
- Nematodes infect
lymph nodes
- Elephantiatis
