SlideShare a Scribd company logo
Embryology part 6
Jón Kolbeinn Guðmundsson
Folding of the embryo and formation of the gut tube.
Lateral folding of the embryo gives us the gut tube. The gut tube is now dividied into 3
areas: foregut, midgut and hindgut. Each part giving rise to a separate structure.
The liver, gallbladder, pancreas and spleen all arise from the distal end of the foregut.
Transverse septum and the future diaphragm
Between the yolk stalk and the pericaridium there is a septum which
separates the abdomen from the thorax region. It is a transverse
mesodermal plate called the transverse septum, and will eventually form the
diaphragm.
Transverse septum
The development of the liver, biliary
ducts and gallbladder &
The development of the pancreas
Topic 22 & 23
LIVER - The liver bud (hepatic diverticulum)
At around 3rd week after fertilization a liver bud will start growing out from the distal
end of the forgut.
The liver bud starts to grow ventrally from the foregut. As the bud grows in size and
penetrates the septum, the connection between it and the foregut narrows forming
the bile duct.
From the liver bud the gallbladder emerges as a diverticulum.
The liver bud forks into left and right lobes. These grow in the cephalic direction until it
meets the transverse septum, forming hepatic cords as they go.
During further development the hepatic cords intermingle with the vitelline and
umbilical veins, which form the hepatic sinusoids (the venous system of the liver, which
drains into the inferior vena cava).
The hepatic cords differentiate into parenchyma (hepatocytes) and the lining of biliary
ducts.
Circulation of the fetal liver and the anatomical remnants in the adult
Two thirds of the oxygen rich blood from the placenta passes through the liver during
development. The rest passes directly to the Inferior vena cava via a shunt called the
ductus venosus. Once the baby is born, the ductus venosus closes and becomes the
ligamentum venosum.
The same thing occurs with the
umbilical vein. After birth the
umbilical cord is cut and the
umbilical vein degenerates into
the round ligament (Ligamentum
teres)
** Clinical correlation ** The remnant veins in the round ligament can
reopen during portal hypertension, this will result in caput medusae and is
an example of porta-caval anastomosis
As the liver grows it will press against the transverse septum (diaphragm).
Where the liver is pressed against the future diaphragm, this spot will become the
bare area of the liver, no visceral mesoderm covers the liver there, hence “bare area”.
The liver grows fast and starts taking a great amount of space. Due to the rotation of
the stomach, the liver moves towards the right side and starts to fill up alot of space in
the abdominal cavity.
In the fetus, the liver is twice the relative size compared to an adult. This is because
during development, the liver is the main site of hematopoesis.
Liver in relation to mesoderm
The developing liver is covered by mesoderm of the septum transversum.
It connects to the foregut (stomach & duodenum) via the lesser omentum and
to the ventral abdominal wall via the falciform ligament.
** remember that the falciform ligament contains the umbilical vein in the
developing fetus.
PANCREAS - The pancreatic buds
The soon after the liver bud and the gallbladder start to form, a dorsal pancreatic bud
appears at the dorsal end of the foregut, and a smaller ventral pancreatic bud at the
ventral end in close proximity to the gallbladder.
The two pancreatic buds
(dorsal and ventral) will
eventually join and fuse
together. This occurs due to
the rotation of the stomach
and the foregut.
Common
bile duct
Hepatic
duct
Gallbladder and biliary ducts
Cystic duct
Ventral
pancreatic bud
Dorsal
pancreatic bud
As the liver grows larger, the hepatic
duct forms along with the cystic duct.
Together the cystic duct and hepatic
duct drain into the common bile duct
which is in close proximity to the
ventral pancreatic bud.
The hepatocytes in the fetal
liver start to produce bile
around 12th week of
development, where the bile is
stored in the gallbladder and is
secreted into the duodenum.
* The first stool that the new-
born baby passes is called
meconium and is basically
green coloured due to the bile.
Common
hepatic duct
Left hepatic ductRight hepatic duct
Cystic duct
Common bile
duct
90 degree clockwise
rotation
Fusion of the ventral and dorsal pancreatic buds
Due to the 90 degree rotation of
the foregut (stomach mostly), the
ventral pancreatic bud swings to
the dorsal side and is now
situated below the dorsal bud.
Clearly the common bile duct
does so as well and is now
situated behind the duodenum
and the pancreatic buds.
The duodenum swings towards
the right side of the abdomen due
to the rotation of the foregut and
take on it’s characteristic “C”
shape.
The dorsal pancreatic bud becomes the head, neck, body and tail of the pancreas.
The ventral pancreatic bud becomes the uncinate process.
The pancreatic ducts
The parenchyma of the ventral and dorsal buds fuse, along with their ducts.
The duct from the dorsal bud joins the duct from the ventral bud forming the main
pancreatic duct (of Wirsung). Notice that the common bile duct and the main pancreatic
duct join together and open into the duodenum at the major papilla (Ampulla of Vater)
Main pancreatic duct
(of Wirsung)
Major papilla
(Ampulla of Vater)
*Accessory pancreatic
duct (of Santorini)
* Minor papilla
* The proximal part of the dorsal pancreatic duct either
disappears or persists as an accessory pancreatic duct.
There can be quite a bit of anatomic variation.*
Pancreas in relation to mesoderm.
Once the pancreas has formed in the dorsal mesogastrium. It will be pushed by
the growing viscera towards the dorsal abdominal wall and will fuse with it,
making it along with the duodenum retroperitoneal, the exception is the tail of
the pancreas which will be intraperitoneal.
The development of the
respiratory tract
Topic 8
LUNG – formation of the lung bud
Once folding of the embryo has occurred and the gut tube has
formed, at around 22 day (3rd week) a lung bud forms ventrally
from the upper part of the foregut (oesophagus region)
The lung bud grows ventrally and
caudally (downwards).
Small ridges start to pinch the lung
bud off from the oesophagus.
The lung bud is made from
endoderm and will become the
epithelial lining of the respiratory
tract, the surrounding lung
parenchyma and vasculature will
derive from mesoderm.
* The lung bud is sometimes called
respiratory diverticulum *
After separation, the developing trachea lies ventral to the oesophagus.
The left and right lung buds form.
Branching
Continued branching of the primary bronchi gives rise to secondary bronchi, 3 on
the right and 2 on the left.
During 6th week further branches result in the formation of tertiary branches. These
will each supply a bronchopulmonary segment.
Histological differentiation of the lungs
Maturation of the lungs is divided into 4 periods.
1. Pseudoglandular: 5-17 weeks
2. Canalicular: 16-25 weeks
3. Terminal sac: 24 weeks until birth
4. Alveolar: birth till about 8 years old.
Note that the lung continues to develop into long into childhood.
These maturation periods are important clinically, as they determine the
likelihood of survival of premature babies.
For embryology we are mostly concerned with the first 3 maturation periods
1. Pseudoglandular period
From weeks 5-17. Branching of the respiratory tree has occurred from
terminal bronchioles.
Respiration is not possible at this stage, therefore the fetus cannot survive if
born prematurely.
2. Canalicular period
16-25 weeks. Terminal bronchioles give rise to respiratory bronchioles, which in turn give
rise to respiratory bronchioles.
The surrounding mesodermal tissue becomes highly vascularized with capillaries.
Respiration is just possible towards the end of the canalicular period as some terminal
sacs (primitive alveoli) have developed at the ends of the respiratory bronchioles.
*the reason for this is because maturation starts slightly earlier in the cranial part of the
lungs*
3. Terminal sac period
24 weeks until birth. Further terminal sacs (primitive alveoli) develop. The
epithelium starts to thin and become squamous. Capillaries come into contact
with epithelium and the blood-air barrier is formed.
At this stage we have two types of pneumocytes, type 1 and type 2.
Type 1 is involved in gas exchange and type 2 produces surfactant.
Surfactant is necessary to reduce surface
tension in the alveoli and keep them open,
if surfactant is lacking there is a risk of the
alveoli collapsing. That is called Infant
respiratory distress syndrome (IRDS)
The formation of the pleural cavity.
Once the lung bud has branched into two separate lung buds and surrounded by
mesoderm. The pleuropericardial cavity begins to divide into two separate cavities.
The pleural and pericardial cavity.
This happens when pleuropericardial fold begin to move towards each other in the
midline.
Eventually the pleuropericardial folds have met in the midline and
fused, making the pleural and pericardial cavity completely separate
Later still, as the lungs develop and grow they begin to wrap around
the pericardial cavity.
Embryology part 6

More Related Content

What's hot

MUSCULAR SYSTEM DEVELOPMENT (Human Embryology)
MUSCULAR SYSTEM DEVELOPMENT  (Human Embryology)MUSCULAR SYSTEM DEVELOPMENT  (Human Embryology)
MUSCULAR SYSTEM DEVELOPMENT (Human Embryology)
Fasama H. Kollie
 
Anatomy of Anterior thigh
Anatomy of Anterior thigh Anatomy of Anterior thigh
Anatomy of Anterior thigh
Ammedicine Medicine
 
Posterior abdominal wall
Posterior abdominal wallPosterior abdominal wall
Posterior abdominal wall
Mohamed El Fiky
 
Surface marking lower limb
Surface marking lower limbSurface marking lower limb
Surface marking lower limb
Dr. Mushfiqul Hoque
 
Posterior abdominal wall
Posterior abdominal wallPosterior abdominal wall
Posterior abdominal wall
Suraj Dhara
 
Female reproductive system
Female reproductive systemFemale reproductive system
Female reproductive systemUE
 
Anatomy of the Radius Bone
Anatomy of the Radius BoneAnatomy of the Radius Bone
Anatomy of the Radius Bone
Dr Adnan Sami
 
Anterior compartment of leg and Dorsum of foot
Anterior compartment  of leg and Dorsum of foot Anterior compartment  of leg and Dorsum of foot
Anterior compartment of leg and Dorsum of foot
CIMS
 
Lower limb joints
Lower limb jointsLower limb joints
Lower limb joints
mohammed Qazzaz
 
General anatomy of muscles
General anatomy of muscles General anatomy of muscles
General anatomy of muscles
ritika patel
 
Muscle histology by dr. armaan singh
Muscle histology by  dr. armaan singhMuscle histology by  dr. armaan singh
Muscle histology by dr. armaan singh
Dr. Armaan Singh
 
Histology of tongue by Dr. Shubham Gupta
Histology of tongue by Dr. Shubham Gupta Histology of tongue by Dr. Shubham Gupta
Histology of tongue by Dr. Shubham Gupta
shubhamgupta1791
 
anatomy_lecture-19-ul.pdf
anatomy_lecture-19-ul.pdfanatomy_lecture-19-ul.pdf
anatomy_lecture-19-ul.pdf
shamie8
 
histology of Urinary system
histology of Urinary systemhistology of Urinary system
histology of Urinary system
Muhammad Amir Sohail
 
Vessels and nerves of sole of foot
Vessels and nerves of sole of footVessels and nerves of sole of foot
Vessels and nerves of sole of foot
drasarma1947
 
Ulna Bone Anatomy
Ulna Bone AnatomyUlna Bone Anatomy
Ulna Bone Anatomy
Dr Adnan Sami
 
General anatomy of muscle
General anatomy of muscleGeneral anatomy of muscle
General anatomy of muscle
Abdul Ansari
 
Embryology powerpoints
Embryology powerpoints Embryology powerpoints
Embryology powerpoints
Vikash Kumar
 
Trilaminar germ disc (week 3 embryology)
Trilaminar germ disc (week 3 embryology)Trilaminar germ disc (week 3 embryology)
Trilaminar germ disc (week 3 embryology)
Abdoulwahab Mahde
 
Blood vessels of upper limb - pdf lecture notes by Dr.N.Mugunthan
Blood vessels of upper limb  - pdf lecture notes by Dr.N.MugunthanBlood vessels of upper limb  - pdf lecture notes by Dr.N.Mugunthan
Blood vessels of upper limb - pdf lecture notes by Dr.N.Mugunthan
MUGUNTHAN Dr.Mugunthan
 

What's hot (20)

MUSCULAR SYSTEM DEVELOPMENT (Human Embryology)
MUSCULAR SYSTEM DEVELOPMENT  (Human Embryology)MUSCULAR SYSTEM DEVELOPMENT  (Human Embryology)
MUSCULAR SYSTEM DEVELOPMENT (Human Embryology)
 
Anatomy of Anterior thigh
Anatomy of Anterior thigh Anatomy of Anterior thigh
Anatomy of Anterior thigh
 
Posterior abdominal wall
Posterior abdominal wallPosterior abdominal wall
Posterior abdominal wall
 
Surface marking lower limb
Surface marking lower limbSurface marking lower limb
Surface marking lower limb
 
Posterior abdominal wall
Posterior abdominal wallPosterior abdominal wall
Posterior abdominal wall
 
Female reproductive system
Female reproductive systemFemale reproductive system
Female reproductive system
 
Anatomy of the Radius Bone
Anatomy of the Radius BoneAnatomy of the Radius Bone
Anatomy of the Radius Bone
 
Anterior compartment of leg and Dorsum of foot
Anterior compartment  of leg and Dorsum of foot Anterior compartment  of leg and Dorsum of foot
Anterior compartment of leg and Dorsum of foot
 
Lower limb joints
Lower limb jointsLower limb joints
Lower limb joints
 
General anatomy of muscles
General anatomy of muscles General anatomy of muscles
General anatomy of muscles
 
Muscle histology by dr. armaan singh
Muscle histology by  dr. armaan singhMuscle histology by  dr. armaan singh
Muscle histology by dr. armaan singh
 
Histology of tongue by Dr. Shubham Gupta
Histology of tongue by Dr. Shubham Gupta Histology of tongue by Dr. Shubham Gupta
Histology of tongue by Dr. Shubham Gupta
 
anatomy_lecture-19-ul.pdf
anatomy_lecture-19-ul.pdfanatomy_lecture-19-ul.pdf
anatomy_lecture-19-ul.pdf
 
histology of Urinary system
histology of Urinary systemhistology of Urinary system
histology of Urinary system
 
Vessels and nerves of sole of foot
Vessels and nerves of sole of footVessels and nerves of sole of foot
Vessels and nerves of sole of foot
 
Ulna Bone Anatomy
Ulna Bone AnatomyUlna Bone Anatomy
Ulna Bone Anatomy
 
General anatomy of muscle
General anatomy of muscleGeneral anatomy of muscle
General anatomy of muscle
 
Embryology powerpoints
Embryology powerpoints Embryology powerpoints
Embryology powerpoints
 
Trilaminar germ disc (week 3 embryology)
Trilaminar germ disc (week 3 embryology)Trilaminar germ disc (week 3 embryology)
Trilaminar germ disc (week 3 embryology)
 
Blood vessels of upper limb - pdf lecture notes by Dr.N.Mugunthan
Blood vessels of upper limb  - pdf lecture notes by Dr.N.MugunthanBlood vessels of upper limb  - pdf lecture notes by Dr.N.Mugunthan
Blood vessels of upper limb - pdf lecture notes by Dr.N.Mugunthan
 

Similar to Embryology part 6

05. midgut& hindgut embryo
05. midgut& hindgut embryo05. midgut& hindgut embryo
05. midgut& hindgut embryoAlok Saxena
 
GI presentation embryo
GI presentation embryo  GI presentation embryo
GI presentation embryo
naba al wazen
 
Development of GIT
Development of GITDevelopment of GIT
Development of GIT
Nirav Dhinoja
 
developmentofgit-copy-150530164223-lva1-app6892.pdf
developmentofgit-copy-150530164223-lva1-app6892.pdfdevelopmentofgit-copy-150530164223-lva1-app6892.pdf
developmentofgit-copy-150530164223-lva1-app6892.pdf
karthikeyan104187
 
Embryology liver,pancreas,spleen & respiratory system
Embryology   liver,pancreas,spleen & respiratory systemEmbryology   liver,pancreas,spleen & respiratory system
Embryology liver,pancreas,spleen & respiratory systemMBBS IMS MSU
 
Embryology liver,pancreas,spleen & respiratory system
Embryology   liver,pancreas,spleen & respiratory systemEmbryology   liver,pancreas,spleen & respiratory system
Embryology liver,pancreas,spleen & respiratory systemMBBS IMS MSU
 
Embryology part 5
Embryology part 5Embryology part 5
Embryology part 5
Amirrasa Kateb
 
Embryology Course V - Body Cavities, Respiratory System
Embryology Course V - Body Cavities, Respiratory SystemEmbryology Course V - Body Cavities, Respiratory System
Embryology Course V - Body Cavities, Respiratory System
Rawa Muhsin
 
Embryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdf
Embryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdfEmbryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdf
Embryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdf
elphaswalela
 
Abdomen.ppt
Abdomen.pptAbdomen.ppt
Abdomen.ppt
kenosewe1
 
Development of mid & hind guts
Development of mid & hind gutsDevelopment of mid & hind guts
Development of mid & hind guts
Sara Memon
 
Development Of Mid & Hind Guts
Development Of Mid & Hind GutsDevelopment Of Mid & Hind Guts
Development Of Mid & Hind Guts
Sara Memon
 
Embryology Course VIII - Digestive System
Embryology Course VIII - Digestive SystemEmbryology Course VIII - Digestive System
Embryology Course VIII - Digestive System
Rawa Muhsin
 
Embryology alimentary system 2
Embryology   alimentary system 2Embryology   alimentary system 2
Embryology alimentary system 2MBBS IMS MSU
 
Kidney developmentprint
Kidney developmentprintKidney developmentprint
Kidney developmentprintshalamabobbi
 
DEVELOPMENT OF DIGESTIVE SYSTEM.pptx
DEVELOPMENT OF DIGESTIVE SYSTEM.pptxDEVELOPMENT OF DIGESTIVE SYSTEM.pptx
DEVELOPMENT OF DIGESTIVE SYSTEM.pptx
wmdpr4x64f
 
Development of FOREGUT MIDGUT AND HINDGUT.ppt
Development of FOREGUT MIDGUT AND HINDGUT.pptDevelopment of FOREGUT MIDGUT AND HINDGUT.ppt
Development of FOREGUT MIDGUT AND HINDGUT.ppt
JairajSinghChauhan1
 
Embryology Respiratory System.ppt
Embryology Respiratory System.pptEmbryology Respiratory System.ppt
Embryology Respiratory System.ppt
MASHUDMORAA
 

Similar to Embryology part 6 (20)

05. midgut& hindgut embryo
05. midgut& hindgut embryo05. midgut& hindgut embryo
05. midgut& hindgut embryo
 
GI presentation embryo
GI presentation embryo  GI presentation embryo
GI presentation embryo
 
Development of GIT
Development of GITDevelopment of GIT
Development of GIT
 
developmentofgit-copy-150530164223-lva1-app6892.pdf
developmentofgit-copy-150530164223-lva1-app6892.pdfdevelopmentofgit-copy-150530164223-lva1-app6892.pdf
developmentofgit-copy-150530164223-lva1-app6892.pdf
 
Embryology liver,pancreas,spleen & respiratory system
Embryology   liver,pancreas,spleen & respiratory systemEmbryology   liver,pancreas,spleen & respiratory system
Embryology liver,pancreas,spleen & respiratory system
 
Embryology liver,pancreas,spleen & respiratory system
Embryology   liver,pancreas,spleen & respiratory systemEmbryology   liver,pancreas,spleen & respiratory system
Embryology liver,pancreas,spleen & respiratory system
 
Embryology part 5
Embryology part 5Embryology part 5
Embryology part 5
 
Embryology Course V - Body Cavities, Respiratory System
Embryology Course V - Body Cavities, Respiratory SystemEmbryology Course V - Body Cavities, Respiratory System
Embryology Course V - Body Cavities, Respiratory System
 
Embryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdf
Embryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdfEmbryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdf
Embryology_and_Anatomy_of_the_Gastrointestinal_Tract_NASPGHAN.pdf
 
12. git[1]
12. git[1]12. git[1]
12. git[1]
 
10.development of urogenital system
10.development of urogenital system10.development of urogenital system
10.development of urogenital system
 
Abdomen.ppt
Abdomen.pptAbdomen.ppt
Abdomen.ppt
 
Development of mid & hind guts
Development of mid & hind gutsDevelopment of mid & hind guts
Development of mid & hind guts
 
Development Of Mid & Hind Guts
Development Of Mid & Hind GutsDevelopment Of Mid & Hind Guts
Development Of Mid & Hind Guts
 
Embryology Course VIII - Digestive System
Embryology Course VIII - Digestive SystemEmbryology Course VIII - Digestive System
Embryology Course VIII - Digestive System
 
Embryology alimentary system 2
Embryology   alimentary system 2Embryology   alimentary system 2
Embryology alimentary system 2
 
Kidney developmentprint
Kidney developmentprintKidney developmentprint
Kidney developmentprint
 
DEVELOPMENT OF DIGESTIVE SYSTEM.pptx
DEVELOPMENT OF DIGESTIVE SYSTEM.pptxDEVELOPMENT OF DIGESTIVE SYSTEM.pptx
DEVELOPMENT OF DIGESTIVE SYSTEM.pptx
 
Development of FOREGUT MIDGUT AND HINDGUT.ppt
Development of FOREGUT MIDGUT AND HINDGUT.pptDevelopment of FOREGUT MIDGUT AND HINDGUT.ppt
Development of FOREGUT MIDGUT AND HINDGUT.ppt
 
Embryology Respiratory System.ppt
Embryology Respiratory System.pptEmbryology Respiratory System.ppt
Embryology Respiratory System.ppt
 

More from Amirrasa Kateb

Embryology part 1
Embryology part 1Embryology part 1
Embryology part 1
Amirrasa Kateb
 
Embryology part 2
Embryology part 2Embryology part 2
Embryology part 2
Amirrasa Kateb
 
Embryology part 3
Embryology part 3Embryology part 3
Embryology part 3
Amirrasa Kateb
 
Embryology part 4
Embryology part 4Embryology part 4
Embryology part 4
Amirrasa Kateb
 
Embryology part 7
Embryology part 7Embryology part 7
Embryology part 7
Amirrasa Kateb
 
Embryology part 8
Embryology part 8Embryology part 8
Embryology part 8
Amirrasa Kateb
 
Embryology part 9
Embryology part 9Embryology part 9
Embryology part 9
Amirrasa Kateb
 
Embryology part 10
Embryology part 10Embryology part 10
Embryology part 10
Amirrasa Kateb
 
Embryology part 11
Embryology part 11Embryology part 11
Embryology part 11
Amirrasa Kateb
 

More from Amirrasa Kateb (9)

Embryology part 1
Embryology part 1Embryology part 1
Embryology part 1
 
Embryology part 2
Embryology part 2Embryology part 2
Embryology part 2
 
Embryology part 3
Embryology part 3Embryology part 3
Embryology part 3
 
Embryology part 4
Embryology part 4Embryology part 4
Embryology part 4
 
Embryology part 7
Embryology part 7Embryology part 7
Embryology part 7
 
Embryology part 8
Embryology part 8Embryology part 8
Embryology part 8
 
Embryology part 9
Embryology part 9Embryology part 9
Embryology part 9
 
Embryology part 10
Embryology part 10Embryology part 10
Embryology part 10
 
Embryology part 11
Embryology part 11Embryology part 11
Embryology part 11
 

Recently uploaded

Chapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptxChapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptx
Mohd Adib Abd Muin, Senior Lecturer at Universiti Utara Malaysia
 
MARUTI SUZUKI- A Successful Joint Venture in India.pptx
MARUTI SUZUKI- A Successful Joint Venture in India.pptxMARUTI SUZUKI- A Successful Joint Venture in India.pptx
MARUTI SUZUKI- A Successful Joint Venture in India.pptx
bennyroshan06
 
1.4 modern child centered education - mahatma gandhi-2.pptx
1.4 modern child centered education - mahatma gandhi-2.pptx1.4 modern child centered education - mahatma gandhi-2.pptx
1.4 modern child centered education - mahatma gandhi-2.pptx
JosvitaDsouza2
 
Thesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.pptThesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.ppt
EverAndrsGuerraGuerr
 
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
MysoreMuleSoftMeetup
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
Sandy Millin
 
PART A. Introduction to Costumer Service
PART A. Introduction to Costumer ServicePART A. Introduction to Costumer Service
PART A. Introduction to Costumer Service
PedroFerreira53928
 
Basic phrases for greeting and assisting costumers
Basic phrases for greeting and assisting costumersBasic phrases for greeting and assisting costumers
Basic phrases for greeting and assisting costumers
PedroFerreira53928
 
How to Create Map Views in the Odoo 17 ERP
How to Create Map Views in the Odoo 17 ERPHow to Create Map Views in the Odoo 17 ERP
How to Create Map Views in the Odoo 17 ERP
Celine George
 
Sha'Carri Richardson Presentation 202345
Sha'Carri Richardson Presentation 202345Sha'Carri Richardson Presentation 202345
Sha'Carri Richardson Presentation 202345
beazzy04
 
Overview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with MechanismOverview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with Mechanism
DeeptiGupta154
 
ESC Beyond Borders _From EU to You_ InfoPack general.pdf
ESC Beyond Borders _From EU to You_ InfoPack general.pdfESC Beyond Borders _From EU to You_ InfoPack general.pdf
ESC Beyond Borders _From EU to You_ InfoPack general.pdf
Fundacja Rozwoju Społeczeństwa Przedsiębiorczego
 
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
Nguyen Thanh Tu Collection
 
Unit 2- Research Aptitude (UGC NET Paper I).pdf
Unit 2- Research Aptitude (UGC NET Paper I).pdfUnit 2- Research Aptitude (UGC NET Paper I).pdf
Unit 2- Research Aptitude (UGC NET Paper I).pdf
Thiyagu K
 
Digital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and ResearchDigital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and Research
Vikramjit Singh
 
Model Attribute Check Company Auto Property
Model Attribute  Check Company Auto PropertyModel Attribute  Check Company Auto Property
Model Attribute Check Company Auto Property
Celine George
 
Polish students' mobility in the Czech Republic
Polish students' mobility in the Czech RepublicPolish students' mobility in the Czech Republic
Polish students' mobility in the Czech Republic
Anna Sz.
 
Additional Benefits for Employee Website.pdf
Additional Benefits for Employee Website.pdfAdditional Benefits for Employee Website.pdf
Additional Benefits for Employee Website.pdf
joachimlavalley1
 
Palestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptxPalestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptx
RaedMohamed3
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
Pavel ( NSTU)
 

Recently uploaded (20)

Chapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptxChapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptx
 
MARUTI SUZUKI- A Successful Joint Venture in India.pptx
MARUTI SUZUKI- A Successful Joint Venture in India.pptxMARUTI SUZUKI- A Successful Joint Venture in India.pptx
MARUTI SUZUKI- A Successful Joint Venture in India.pptx
 
1.4 modern child centered education - mahatma gandhi-2.pptx
1.4 modern child centered education - mahatma gandhi-2.pptx1.4 modern child centered education - mahatma gandhi-2.pptx
1.4 modern child centered education - mahatma gandhi-2.pptx
 
Thesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.pptThesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.ppt
 
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
 
PART A. Introduction to Costumer Service
PART A. Introduction to Costumer ServicePART A. Introduction to Costumer Service
PART A. Introduction to Costumer Service
 
Basic phrases for greeting and assisting costumers
Basic phrases for greeting and assisting costumersBasic phrases for greeting and assisting costumers
Basic phrases for greeting and assisting costumers
 
How to Create Map Views in the Odoo 17 ERP
How to Create Map Views in the Odoo 17 ERPHow to Create Map Views in the Odoo 17 ERP
How to Create Map Views in the Odoo 17 ERP
 
Sha'Carri Richardson Presentation 202345
Sha'Carri Richardson Presentation 202345Sha'Carri Richardson Presentation 202345
Sha'Carri Richardson Presentation 202345
 
Overview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with MechanismOverview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with Mechanism
 
ESC Beyond Borders _From EU to You_ InfoPack general.pdf
ESC Beyond Borders _From EU to You_ InfoPack general.pdfESC Beyond Borders _From EU to You_ InfoPack general.pdf
ESC Beyond Borders _From EU to You_ InfoPack general.pdf
 
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
GIÁO ÁN DẠY THÊM (KẾ HOẠCH BÀI BUỔI 2) - TIẾNG ANH 8 GLOBAL SUCCESS (2 CỘT) N...
 
Unit 2- Research Aptitude (UGC NET Paper I).pdf
Unit 2- Research Aptitude (UGC NET Paper I).pdfUnit 2- Research Aptitude (UGC NET Paper I).pdf
Unit 2- Research Aptitude (UGC NET Paper I).pdf
 
Digital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and ResearchDigital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and Research
 
Model Attribute Check Company Auto Property
Model Attribute  Check Company Auto PropertyModel Attribute  Check Company Auto Property
Model Attribute Check Company Auto Property
 
Polish students' mobility in the Czech Republic
Polish students' mobility in the Czech RepublicPolish students' mobility in the Czech Republic
Polish students' mobility in the Czech Republic
 
Additional Benefits for Employee Website.pdf
Additional Benefits for Employee Website.pdfAdditional Benefits for Employee Website.pdf
Additional Benefits for Employee Website.pdf
 
Palestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptxPalestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptx
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
 

Embryology part 6

  • 1. Embryology part 6 Jón Kolbeinn Guðmundsson
  • 2. Folding of the embryo and formation of the gut tube. Lateral folding of the embryo gives us the gut tube. The gut tube is now dividied into 3 areas: foregut, midgut and hindgut. Each part giving rise to a separate structure. The liver, gallbladder, pancreas and spleen all arise from the distal end of the foregut.
  • 3. Transverse septum and the future diaphragm Between the yolk stalk and the pericaridium there is a septum which separates the abdomen from the thorax region. It is a transverse mesodermal plate called the transverse septum, and will eventually form the diaphragm. Transverse septum
  • 4. The development of the liver, biliary ducts and gallbladder & The development of the pancreas Topic 22 & 23
  • 5. LIVER - The liver bud (hepatic diverticulum) At around 3rd week after fertilization a liver bud will start growing out from the distal end of the forgut. The liver bud starts to grow ventrally from the foregut. As the bud grows in size and penetrates the septum, the connection between it and the foregut narrows forming the bile duct. From the liver bud the gallbladder emerges as a diverticulum.
  • 6. The liver bud forks into left and right lobes. These grow in the cephalic direction until it meets the transverse septum, forming hepatic cords as they go. During further development the hepatic cords intermingle with the vitelline and umbilical veins, which form the hepatic sinusoids (the venous system of the liver, which drains into the inferior vena cava). The hepatic cords differentiate into parenchyma (hepatocytes) and the lining of biliary ducts.
  • 7. Circulation of the fetal liver and the anatomical remnants in the adult Two thirds of the oxygen rich blood from the placenta passes through the liver during development. The rest passes directly to the Inferior vena cava via a shunt called the ductus venosus. Once the baby is born, the ductus venosus closes and becomes the ligamentum venosum. The same thing occurs with the umbilical vein. After birth the umbilical cord is cut and the umbilical vein degenerates into the round ligament (Ligamentum teres)
  • 8. ** Clinical correlation ** The remnant veins in the round ligament can reopen during portal hypertension, this will result in caput medusae and is an example of porta-caval anastomosis
  • 9. As the liver grows it will press against the transverse septum (diaphragm). Where the liver is pressed against the future diaphragm, this spot will become the bare area of the liver, no visceral mesoderm covers the liver there, hence “bare area”.
  • 10. The liver grows fast and starts taking a great amount of space. Due to the rotation of the stomach, the liver moves towards the right side and starts to fill up alot of space in the abdominal cavity. In the fetus, the liver is twice the relative size compared to an adult. This is because during development, the liver is the main site of hematopoesis.
  • 11. Liver in relation to mesoderm The developing liver is covered by mesoderm of the septum transversum. It connects to the foregut (stomach & duodenum) via the lesser omentum and to the ventral abdominal wall via the falciform ligament. ** remember that the falciform ligament contains the umbilical vein in the developing fetus.
  • 12. PANCREAS - The pancreatic buds The soon after the liver bud and the gallbladder start to form, a dorsal pancreatic bud appears at the dorsal end of the foregut, and a smaller ventral pancreatic bud at the ventral end in close proximity to the gallbladder. The two pancreatic buds (dorsal and ventral) will eventually join and fuse together. This occurs due to the rotation of the stomach and the foregut.
  • 13. Common bile duct Hepatic duct Gallbladder and biliary ducts Cystic duct Ventral pancreatic bud Dorsal pancreatic bud As the liver grows larger, the hepatic duct forms along with the cystic duct. Together the cystic duct and hepatic duct drain into the common bile duct which is in close proximity to the ventral pancreatic bud.
  • 14. The hepatocytes in the fetal liver start to produce bile around 12th week of development, where the bile is stored in the gallbladder and is secreted into the duodenum. * The first stool that the new- born baby passes is called meconium and is basically green coloured due to the bile. Common hepatic duct Left hepatic ductRight hepatic duct Cystic duct Common bile duct
  • 16. Fusion of the ventral and dorsal pancreatic buds Due to the 90 degree rotation of the foregut (stomach mostly), the ventral pancreatic bud swings to the dorsal side and is now situated below the dorsal bud. Clearly the common bile duct does so as well and is now situated behind the duodenum and the pancreatic buds. The duodenum swings towards the right side of the abdomen due to the rotation of the foregut and take on it’s characteristic “C” shape. The dorsal pancreatic bud becomes the head, neck, body and tail of the pancreas. The ventral pancreatic bud becomes the uncinate process.
  • 17.
  • 18. The pancreatic ducts The parenchyma of the ventral and dorsal buds fuse, along with their ducts. The duct from the dorsal bud joins the duct from the ventral bud forming the main pancreatic duct (of Wirsung). Notice that the common bile duct and the main pancreatic duct join together and open into the duodenum at the major papilla (Ampulla of Vater) Main pancreatic duct (of Wirsung) Major papilla (Ampulla of Vater) *Accessory pancreatic duct (of Santorini) * Minor papilla * The proximal part of the dorsal pancreatic duct either disappears or persists as an accessory pancreatic duct. There can be quite a bit of anatomic variation.*
  • 19. Pancreas in relation to mesoderm. Once the pancreas has formed in the dorsal mesogastrium. It will be pushed by the growing viscera towards the dorsal abdominal wall and will fuse with it, making it along with the duodenum retroperitoneal, the exception is the tail of the pancreas which will be intraperitoneal.
  • 20.
  • 21. The development of the respiratory tract Topic 8
  • 22. LUNG – formation of the lung bud Once folding of the embryo has occurred and the gut tube has formed, at around 22 day (3rd week) a lung bud forms ventrally from the upper part of the foregut (oesophagus region) The lung bud grows ventrally and caudally (downwards). Small ridges start to pinch the lung bud off from the oesophagus. The lung bud is made from endoderm and will become the epithelial lining of the respiratory tract, the surrounding lung parenchyma and vasculature will derive from mesoderm. * The lung bud is sometimes called respiratory diverticulum *
  • 23. After separation, the developing trachea lies ventral to the oesophagus. The left and right lung buds form.
  • 24. Branching Continued branching of the primary bronchi gives rise to secondary bronchi, 3 on the right and 2 on the left. During 6th week further branches result in the formation of tertiary branches. These will each supply a bronchopulmonary segment.
  • 25.
  • 26. Histological differentiation of the lungs Maturation of the lungs is divided into 4 periods. 1. Pseudoglandular: 5-17 weeks 2. Canalicular: 16-25 weeks 3. Terminal sac: 24 weeks until birth 4. Alveolar: birth till about 8 years old. Note that the lung continues to develop into long into childhood. These maturation periods are important clinically, as they determine the likelihood of survival of premature babies. For embryology we are mostly concerned with the first 3 maturation periods
  • 27. 1. Pseudoglandular period From weeks 5-17. Branching of the respiratory tree has occurred from terminal bronchioles. Respiration is not possible at this stage, therefore the fetus cannot survive if born prematurely.
  • 28. 2. Canalicular period 16-25 weeks. Terminal bronchioles give rise to respiratory bronchioles, which in turn give rise to respiratory bronchioles. The surrounding mesodermal tissue becomes highly vascularized with capillaries. Respiration is just possible towards the end of the canalicular period as some terminal sacs (primitive alveoli) have developed at the ends of the respiratory bronchioles. *the reason for this is because maturation starts slightly earlier in the cranial part of the lungs*
  • 29. 3. Terminal sac period 24 weeks until birth. Further terminal sacs (primitive alveoli) develop. The epithelium starts to thin and become squamous. Capillaries come into contact with epithelium and the blood-air barrier is formed. At this stage we have two types of pneumocytes, type 1 and type 2. Type 1 is involved in gas exchange and type 2 produces surfactant. Surfactant is necessary to reduce surface tension in the alveoli and keep them open, if surfactant is lacking there is a risk of the alveoli collapsing. That is called Infant respiratory distress syndrome (IRDS)
  • 30. The formation of the pleural cavity.
  • 31. Once the lung bud has branched into two separate lung buds and surrounded by mesoderm. The pleuropericardial cavity begins to divide into two separate cavities. The pleural and pericardial cavity. This happens when pleuropericardial fold begin to move towards each other in the midline.
  • 32. Eventually the pleuropericardial folds have met in the midline and fused, making the pleural and pericardial cavity completely separate Later still, as the lungs develop and grow they begin to wrap around the pericardial cavity.