Connective Tissue - Hyperexcision

Last updated: November 12, 2024

Describe the general classification of connective tissue
- Embryonic Connective Tissue
  - Mesenchyme
  - Mucous Connective Tissue (Wharton’s Jelly)
- Connective Tissue Proper
  - Loose Connective Tissue
  - Dense Connective Tissue
    - Regular
    - Irregular
- Specialized Connective Tissue
  - Cartilage
  - Bone
  - Adipose Tissue
  - Blood
  - Haematopoietic Tissue
  - Lymphatic Tissue

Distinguish between resident and non-resident connective tissue cells and give examples in each class

	Resident cells	Non-resident cells
Characteristics	Stable – exhibit little movement and stay permanently in the tissue	These cells have migrated into the tissue from blood in response to specific stimuli
Examples	Fibroblasts, myofibroblasts, macrophages, adipocytes, mast cells, adult stem cells	Lymphocytes, plasma cells, neutrophils, eosinophils, basophils, monocytes

List down at least 5 connective tissue resident cells
- Fibroblasts
- Myofibroblasts
- Macrophages
- Adipocytes
- Mast cells
- Adult stem cells
List down at least 5 connective tissue non-resident cells ***Basically white blood cells
- Lymphocytes
- Plasma cells
- Neutrophils
- Eosinophils
- Basophils
- Monocytes
Briefly describe the stages of collagen synthesis
- Intracellular events
  - Collagen a-chains are synthesized in the Rough Endoplasmic Reticulum (RER) as long precursors containing large globular amino and carboxy terminus propeptides called pro-a-chains (preprocollagen)
  - Pre-procollagen undergoes post-translational modification in the cisternae of the RER to form procollagen molecules. These modifications include:
    - Cleavage of the amino-terminus signal
    - Hydroxylation of proline and lysine residues (Requires Vitamin C)
    - O-linked glycosylation of hydroxylysine residues and N-linked glycosylation at the two terminal positions
    - Formation of a triple helix consisting of 3 a-chains
    - Intrachain and interchain hydrogen and disulfide bonds are added to the triple helix
    - Heat shock proteins stabilize the triple helix and prevent their premature aggregation in the cells
  - Procollagen molecules pass to the Golgi apparatus where there are packed into secretory vesicles and transported to the cell surface
- Extracellular events
  - Procollagen is converted into Mature collagen molecules by procollagen peptidases. They cleave the uncoiled ends of the procollagen molecules
  - Aggregated collagen molecules align together to form collagen fibrils in a process known as fibrillogenesis. They are cross-linked by covalent bonds between lysine and hydroxylysine aldehyde groups.
State the connective tissue fiber affected in the following diseases: Osteogenesis imperfecta, Ehlers Danlos Type 4, Achondrogenesis, Marfan syndrome
- Osteogenesis imperfecta: Type I collagen
- Ehlers-Danlos type 4 syndrome: Type III collagen
- Achondrogenesis: Type II collagen
- Marfan Syndrome: Elastin fibers
List examples of cells of mononuclear phagocytic system and state their respective locations
- Monocytes: Blood and Bone marrow
- Macrophage: Connective tissue, spleen, lymph nodes, Bone marrow, thymus
- Kupffer histiocytes: Liver
- Alveolar macrophages: Lungs
- Hofbauer cell: Placenta
- Pleural and peritoneal macrophages: Serous cavities
- Osteoclast: Bone
- Microglia: CNS
- Langerhans cell: Epidermis of skin, oral mucosa, foreskin, female genital epithelium
- Fibroblast-derived macrophage: Lamina propria of intestine, endometrium of uterus
- Dendritic cell: Lymph nodes, spleen
- Multinucleated giant cells (Foreign body giant cells, Langhans giant cell): Fused macrophages in Granulomas

As regards leukocytes, distinguish between granulocytes and agranulocytes

	Granulocytes	Agranulocytes
Specific granules in cytoplasm	Yes	No
Examples	Neutrophils, Eosinophils, Basophils	Lymphocytes, Monocytes

State the predominant connective tissue fibers of the following: Hyaline cartilage, Elastic cartilage, Fibrocartilage
- Hyaline cartilage: Type II collagen
- Elastic cartilage: Elastic fibers and Type II collagen
- Fibrocartilage: Type I collagen and Type II collagen
Name 2 sites that contain elastic cartilage
- External ear
- The walls of the external acoustic meatus
- The Eustachian tube
- The epiglottis
Name 2 major components of the extracellular matrix and their subclassification
- Fibers: Collagen, Elastic fibers
- Ground substance: Proteoglycans, Multiadhesive glycoproteins, glycosaminoglycans

Reference Intervals ›

Biochemistry

ACTH	P: <80 ng/L
ALT	P: 5–35 U/L
Albumin	P: 35–50 g/L
Aldosterone	P: 100–500 pmol/L
Alk. phosphatase	P: 30–130 U/L
α-Amylase	P: 0–180 IU/dL
α-Fetoprotein	S: <10 kU/L
Angiotensin II	P: 5–35 pmol/L
ADH	P: 0.9–4.6 pmol/L
AST	P: 5–35 U/L
Bicarbonate	P: 24–30 mmol/L
Bilirubin	P: 3–17 μmol/L
BNP	P: <50 ng/L
CRP	P: <10 mg/L
Calcitonin	P: <0.1 mcg/L
Calcium (ionized)	P: 1.0–1.25 mmol/L
Calcium (total)	P: 2.12–2.60 mmol/L
Chloride	P: 95–105 mmol/L
Cholesterol	P: <5.0 mmol/L
VLDL	P: 0.128–0.645 mmol/L
LDL	P: <2.0 mmol/L
HDL	P: 0.9–1.93 mmol/L
Cortisol AM	P: 450–700 nmol/L
Cortisol Midnight	P: 80–280 nmol/L
CK ♂	P: 25–195 U/L
CK ♀	P: 25–170 U/L
Creatinine	P: 70–100 μmol/L
Ferritin	P: 12–200 mcg/L
Folate	S: 2.1 mcg/L
FSH	P: 2–8 U/L ♂; >25 menopause
GGT ♂	P: 11–51 U/L
GGT ♀	P: 7–33 U/L
Glucose (fasting)	P: 3.5–5.5 mmol/L
Growth hormone	P: <20 mu/L
HbA1C (DCCT)	B: 4–6%
HbA1C (IFCC)	B: 20–42 mmol/mol
Iron ♂	S: 14–31 μmol/L
Iron ♀	S: 11–30 μmol/L
Lactate (venous)	P: 0.6–2.4 mmol/L
Lactate (arterial)	P: 0.6–1.8 mmol/L
LDH	P: 70–250 U/L
LH	P: 3–16 U/L
Magnesium	P: 0.75–1.05 mmol/L
Osmolality	P: 278–305 mosmol/kg
PTH	P: 0.8–8.5 pmol/L
Potassium	P: 3.5–5.3 mmol/L
Prolactin ♂	P: <450 U/L
Prolactin ♀	P: <600 U/L
PSA	P: 0–4 mcg/mL
Protein (total)	P: 60–80 g/L
Red cell folate	B: 0.36–1.44 μmol/L
Renin (erect)	P: 2.8–4.5 pmol/mL/h
Renin (recumbent)	P: 1.1–2.7 pmol/mL/h
Sodium	P: 135–145 mmol/L
TBG	P: 7–17 mg/L
TSH	P: 0.5–4.2 mU/L
T4	P: 70–140 nmol/L
Free T4	P: 9–22 pmol/L
TIBC	S: 54–75 μmol/L
Triglycerides	P: 0.50–2.3 mmol/L
T3	P: 1.2–3.0 nmol/L
Troponin T	P: <0.1 mcg/L
Urate ♂	P: 210–480 μmol/L
Urate ♀	P: 150–390 μmol/L
Urea	P: 2.5–6.7 mmol/L
Vitamin B12	S: 0.13–0.68 nmol/L
Vitamin D	S: 50 nmol/L

Arterial Blood Gases

pH	7.35–7.45
PaCO₂	4.7–6.0 kPa
PaO₂	>10.6 kPa
Base excess	±2 mmol/L

Urine

Cortisol (free)	<280 nmol/24h
Hydroxyindole acetic acid	16–73 μmol/24h
Hydroxymethylmandelic acid	16–48 μmol/24h
Metanephrines	0.03–0.69 μmol/mmol cr.
Osmolality	350–1000 mosmol/kg
17-Oxogenic steroids ♂	28–30 μmol/24h
17-Oxogenic steroids ♀	21–66 μmol/24h
17-Oxosteroids ♂	17–76 μmol/24h
17-Oxosteroids ♀	14–59 μmol/24h
Phosphate (inorganic)	15–50 mmol/24h
Potassium	14–120 mmol/24h
Protein	<150 mg/24h
Protein/creatinine ratio	<3 mg/mmol
Sodium	100–250 mmol/24h

Haematology

WCC	4.0–11.0 ×10⁹/L
RBC ♂	4.5–6.5 ×10¹²/L
RBC ♀	3.9–5.6 ×10¹²/L
Hb ♂	130–180 g/L
Hb ♀	115–160 g/L
PCV ♂	0.4–0.54 L/L
PCV ♀	0.37–0.47 L/L
MCV	76–96 fL
MCH	27–32 pg
MCHC	300–360 g/L
RDW	11.6–14.6%
Neutrophils	2.0–7.5 ×10⁹/L (40–75%)
Lymphocytes	1.0–4.5 ×10⁹/L (20–45%)
Eosinophils	0.04–0.44 ×10⁹/L (1–6%)
Basophils	0–0.10 ×10⁹/L (0–1%)
Monocytes	0.2–0.8 ×10⁹/L (2–10%)
Platelets	150–400 ×10⁹/L
Reticulocytes	0.8–2.0% / 25–100 ×10⁹/L
Prothrombin time	10–14 s
APTT	35–45 s

Paediatric

Pulse Rate (bpm)
Neonate	140–160
Infant <1yr	120–140
1–5 years	110–130
5–12 years	80–120
>12 years	70–100
Respiratory Rate (tachypnoea)
0–2 months	≥60/min
2–12 months	≥50/min
1–5 years	≥40/min
>5 years	≥30/min
Blood Pressure (mmHg)
Term	65/45
1 year	75/50
4 years	85/60
8 years	95/65
10 years	100/70
Weight Formulas
3–12 months	(a + 9)/2 kg
1–6 years	2a + 8 kg
>6 years	(7a − 5)/2 kg
Haemoglobin (g/dL)
Term newborn	13–20
1 month	11–18
2 months	10–15
1–2 years	10–13
>2 years	11–14
MUAC (6 months–5 years)
Obese	>17.5 cm
Normal	13.5–17.4 cm
At risk	12.5–13.4 cm
Moderate malnutrition	11.5–12.4 cm
Severe malnutrition	<11.5 cm
Developmental Milestones
Social smile	1.5 months
Head control	4 months
Sits unsupported	7 months
Crawls	10 months
Stands unsupported	10–12 months
Walks	12–13 months
Talks	18 months
CSF WBC (/mm³)
Term newborn	0–25
>2 weeks	0–5

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