IMMS: Week 6 Flashcards
How can metabolic acidosis take place
Due to excess production of organic acids (usual cause) or reduced levels of HCO3- to buffer H+ ions
Reduced arterial oxygen content
Hypoperfusion
Diabetic ketoacidosis
How can metabolic alkalosis take place
Excessive re-absorption of HCO3- ions
Excess H+ secretion at tubules
What cells produce bone and cartilage
Chondrocytes and chondroblasts
What fibres do bone and cartilage consist of
Collagen and elastic fibres
What is the bone matrix made of
GAG
Why are collagen fibres arranged parallel to each other
Gives extra strength
What is the role of osteoblasts
Synthesise bone
Role of osteoclasts
Resorb bone and aid in remodelling
Role of osteocytes
Break down bone and aid remodelling bone
What is the first type of bone to be synthesised
Woven bone
What happens to woven bone
Remodelled to lamellar bone which is lighter and stronger
What two ways can bone formation occur
Membrane: Formed directly in a mesenchyme
Endochondral: Formed by replacement of cartilage
Where are osteons found
In the compact bone
What is appositional deposition of bone
Deposition of bones in layers on external surface of bones
What is stratified epithelia needed for
Protective function and composed of many cell layers
It is a WATERPROOF layer
How many layers are there in pseudo stratified epithelia
1
Cells are all joined to the basement membrane
What does the epithelia need a basement membrane for
Survival
What is the basement membanre made of
Type IV collagen and fibronectin
What do fibroblasts secrete
Tropocollagen units (pro collagen)
When does the embryo become a foetus
At the end of week 8
What organs start functioning after week 8
Kidneys, liver, brain and lungs
What is the intramural part of the fallopian tube
The part of the tube that crosses the uterine musculature
What is the tubal sodium of the fallopian tubes
Where the tubal canal meets the peritoneal cavity
How long does a typical pregnancy last
280 Days after last menstrual period
266 Days after fertilisation
When does fertilisation take place
15th day in cycle
What is the time period from fertilisation to the end of the 8th week called
Embryonic period
What is the time period from the beginning of the 9th week to birth called
Foetal period
What happens in the 1st week
Fertilisation and formation of a blastocyst
What happens in the second week
Implantation and bilaminar disk
What happens in the third week
Gastrulation
What happens in the fourth week
Embryo folding (F for folding)
What happens during the 5th to the end of the 8th week
Development of organs
What is the function of the male reproductive organs
- Produce, maintain and transport the sperm and semen
- Discharge sperms within the female reproductive tract
- Produce and secrete male sex hormones
What are three consequences of fertilisation
- Restoration of diploid number of chromosomes
- Determination of chromosomal sex
- Initiation of cleavage/division of cells
How many cells are there in a morula
16
What happens to the morula as it enters the uterus on the 3rd or 4th day after fertilisation
Blastocyst formation
When does implantation occur
at the end of the first week
What does the inner cell mass develop into
Embryo
What does the outer cell mass develop into
Trophoblast
What two layers does the embryo blast develop into
Epiblast
Hypoblast
This is the bilaminar disc
What does the epiblast give his ego
amnioblasts that line the amniotic cavity
What does the hypoblast give rise to
Cells that line the blastocyst cavity and inner surface of the trophoblast
What are cells derived from the hypoblast and lining the inner surface of the trophoblast called
Primitive yolk sack
What two layers does the extra embryonic mesoderm form
The splanchnic layer
Somatic Layer
What is the extra embryonic mesoderm responsible for
The formation of blood vessels that will connect the embryo to the placenta
What area of the embryo forms endodermal cells
The hypoblast
These form a new cavity in the yolk sack
What is the cavity produced by endodermal cells called
Secondary yolk sac which replaces the primary
