ANAT2341 Lab 7

Endocrine and Integumentary

Introduction

1. The first half of this laboratory will be a presentation by Dr Annemeik Beverdam.
2. The second part of the practical will briefly cover Endocrine and Integumentary Development.

Developmental and Regenerative Dermatology Unit

The presentation will discuss current research in Dr Annemeik Beverdam's laboratory on Skin development and stem cells. There will also be preparation for an assessment item to be prepared for the Stem Cells Practical later in the course.

Dr. Beverdam studies the genetic processes that govern development, homeostasis and regeneration of the skin in the mouse. Her research aims at understanding the genetic and molecular basis of developmental and human regenerative skin diseases such as skin cancer, which affects 2 out of 3 Australians in their life time.

Contact: A.Beverdam@unsw.edu.au

Links: Dr Annemeik Beverdam | Research Projects | Publications | PubMed - YAP (Yes-Associated Protein)

Endocrine

Developing Pituitary - Human Embryo Carnegie stage 22

• Begin by working through Endocrine Development by week 8.
• Then look at the information on each endocrine organ on their related specific page.

Integumentary

Teeth

Fetal Head (12 weeks) lateral

Deciduous teeth

Permanent teeth

• integumentary system specialization by epitheilal/mesenchymal interactions in development and develops with a major contribution from the neural crest.
  • ectoderm of the first pharyngeal arch and neural crest, ectomesenchymal cells.

• week 6 - odontogenesis begins, tooth bud
• 4 morphological stages describing the early tooth development: bud, cap, bell, and terminal differentiation
• 2 sets of teeth: 20 deciduous teeth, 32 permanent teeth
• differential rates of growth, shed at different times over 20 year period
• inductive influence of neural crest with overlying ectoderm
• tooth growth occurs in ossifying jaws

odontoblasts - neural crest-derived mesenchymal cells which differentiate under the influence of the enamel epithelium. Cells secrete predentin, calcifies to form dentin.

ameloblasts - inner enamel epithelium forms pre-ameloblasts differentiate and produce enamel

periodontal ligament - tooth is not anchored directly onto its bony socket (alveolar bone) but held in place by the periodontal ligament (PDL), a specialized connective tissue structure that surrounds the tooth root coating of cementum.

• ligament also act as; a shock absorber, transmitter of chewing forces (from tooth to bone), sensory information (heat, cold, pressure and pain).
  • collagen fiber bundles within the ligament are called "Sharpey's fibres".

Tooth Stages

Tooth development stages

Stage	Image	Human (weeks)
lamina		Week 6
placode		Week 7
bud		Week 8
cap		Week 11
bell		Week 14

Teeth Postnatal

Deciduous teeth

• 6 - 24 months - erupt from gums by pushing toward surface
• 2 years - all deciduous teeth present

Permanent teeth

• 6 years until early adult
• tooth bud lie in gums beneath deciduous teeth
• osteoclasts resorb deciduous teeth roots
• growth affects face shape

Links: Tooth Development

Individual Assessment

1. Identify and write a brief description of the findings of a recent research paper on development of one of the endocrine organs covered in today's practical.
2. Identify the embryonic layers and tissues that contribute to the developing teeth.

References

2015 Course: Week 2 Lecture 1 Lecture 2 Lab 1 | Week 3 Lecture 3 Lecture 4 Lab 2 | Week 4 Lecture 5 Lecture 6 Lab 3 | Week 5 Lecture 7 Lecture 8 Lab 4 | Week 6 Lecture 9 Lecture 10 Lab 5 | Week 7 Lecture 11 Lecture 12 Lab 6 | Week 8 Lecture 13 Lecture 14 Lab 7 | Week 9 Lecture 15 Lecture 16 Lab 8 | Week 10 Lecture 17 Lecture 18 Lab 9 | Week 11 Lecture 19 Lecture 20 Lab 10 | Week 12 Lecture 21 Lecture 22 Lab 11 | Week 13 Lecture 23 Lecture 24 Lab 12 | 2015 Projects: Three Person Embryos | Ovarian Hyper-stimulation Syndrome | Polycystic Ovarian Syndrome | Male Infertility | Oncofertility | Preimplantation Genetic Diagnosis | Students | Student Designed Quiz Questions | Moodle page