Fundamentals of body structure Flashcards
What are the 6 body regions?
Head Neck Thorax Abdomen Pelvis Limbo's
What does superior mean?
Towards the head
What does inferior mean?
Towards the feet
What does medial mean?
Towards the centre
What does lateral mean ?
To the side / away from middle of The Body
What does proximal mean?
Nearer to the point of reference
What does distal mean?
Further away from the point of reference
What does superficial mean?
Closer to the surface/ more externally
What does deep mean?
Away from the surface further into the body
What does palmer mean?
Palm of hand
What does planter mean?
Sole of the foot
What is the median sagittal plane?
Middle line down the body
What is the para sagittal plane?
Any plane parallel to the median sagittal plane
What is the axial/ transverse plane?
Separates the upper and lower body (top and bottom)
What is the coronal plane
Separates front and back (anterior and posterior)
How does the number of chromosomes change during reproduction?
2 haploid cells with 23 chromosomes combine to form a zygote (diploid cells with 46)
Describe the sperm (structures)
Haploid cell
Head of the sperm is covered by an acrosome cap which contains enzymes for fertilisation
- middle piece provides energy for swimming
-tail - microiubeles for movement
Describe the ovum structure egg
Haploid cell - cytoplasm holds all organelles used for cell function
- zone pullicida - outer membrane of the cell
- corona radiata = outermost layer of cells
Sperm must penetrate both layers
What layers must the sperm penetrate to fertalise the egg
Corona radiata
Zone pellucida
Describe the process of fertilisation
Intercourse → sperm is in vagina
- Sperm penetrates the corona radiata
- Sperm makes contact with zona pellucida and binds to receptors - initiates acrosomal reaction
- Sperm penetrates zona pellucida by secreting enzymes that breakdown the layer
- Sperm makes contact with oocytes plasma membrane and fuses with oocyte
- Sperm releases its nucleus into oocyte cytoplasm
What is the cleavage of cells?
After fertilisation zygote initiates a rapid series of mitotic divisions
→ cleavage increases the number of cells but the size of the cell remains the same
→ occurs up to morulla stage which is 16 cells
What 3 processes happen during the first week of development?
Cleavage
Blastocyst formation
Initiating implantation
When can totipotency occur and what is it?
Cells ability to divide and produce all differentiated cells in an organism
- it is possible at 8 cell stage
When is toripotency lost?
At 16 cell stage (morulla) as differentiation of cells begins to occur