Unit III Flashcards
Which part of the tilaminar disc do the kidneys develop from?
Intermediate mesoderm
What is the smallest area of The mesoderm?
Intermediate mesoderm
What is the intermediate mesoderm continuous with?
Periaxial
What happens at the nephrotome stage?
The intermediate mesoderm looses contact with the periaxial mesoderm.
After the nephrotome stage, the solid mass of cells gets ___________ _____. This is then called the _________ __________.
Hollowed out
nephritic tubule
Branches from the aorta will push into the _________ _________. There are called the __________ _________
Splanchnic mesoderm
External glomerulus
The aortic branches that push into the top of the nephritic tubule is called the…?
Internal glomerulus
What happens to the external glomerulus?
It disappears with no adult derivatives.
First 3 parts you will see from the internal glomerulus lateral to medial.
Lateral:
Will see a dilated area called the ________ _______, which is a round shaped structure
Nephrotic duct
First 3 parts you will see from the internal glomerulus lateral to medial.
Intermediate:
Will see the continuation with the ________ ________
Nephric tubule
First 3 parts you will see from the internal glomerulus lateral to medial.
Medial:
A cap that is a precursor to ________ ________
Bowman’s Capsules
Bowman’s Capsule goes all the way around the ________ ________. It will then _______ ____ until it rounds out at the ____.
Internal glomerulus
narrow out
Duct
Bowman’s Capsule
Stage 1 of 4 of kidney development:
Pronephros
Approx what is the timeframe of the pronephros stage, and what happens? What are the adult derivatives?
Around beginning of week 4 until the end of week 4. Still in nephrotome stage.
Body is practicing Kidney development.
There are no adult derivatives.
Stage 2 of 4 of Kidney Development:
Mesonephros
When does the mesonephros develop?
Just as the pronephros kidney is dying off.
Stage 3 of 4 of kidney development:
Mesonephric kidney develops and loses contact with the periaxial mesoderm.
What forms after the mesonephric kidney develops and loses contact with the periaxial mesoderm?
Mesonephric tubule. And mesonephric duct.
Between mesonephric tubule and mesonephric duct, which one is the only one to persist?
Mesonephric duct
Stage 4 of 4 of kidney development.
Will see metanephros kidney
Which of the kidneys that form will be the adult kidney?
Metanephros
True/False:
There is no time where we will see two sets of kidneys at once, even for short period
False
How does the kidney move from the pelvis up to the appropriate area?
It doesn’t. As the body elongates, the kidneys stay in the same place. It only looks as though the kidneys move.
_______ are the filtering part of the kidney, found in the ________ ________. They are made up of ________ _______.
Nephrons
Metanephros kidney
Bowman’s Capsule
What does a nephron contain?
Proximal and distal convoluted tubules
Loop of Henle
The second part of the adult kidney is called the _________ ______. This is an outgrowth of the ________ ______, and acts as a ____________ ____ ____ _____.
Ureteric bud
Grows from the mesonephric duct
Acts as a transporter of the urine
Adult derivatives of the ureteric bud (4 structures):
Minor culyx
Major culyx
Renal pelvis
Ureter
2 parts of the adult kidney:
Metanephros (filtering) and ureteric (transport)
Kidney of the fetus is:
Functional
Where does the embryo poop and pee?
Amniotic sac
What happens to the toxic fluids in the amniotic sac?
Mom’s blood filters it out
For bladder development:
Urorectal septum will mitose and grow towards the __________ _________
Cloacal membrane
From the cloacal, a ______ ________ develops. This will rupture and become the _______ _______
Urogenital membrane
Urethral opening
From top to bottom, what are the 2 parts of the urogenital sinus that go for both male and female?
1- A large dilated area that grows and rounds out.
Becomes the urinary bladder.
2- A narrow section that will have two sections (pelvic and genital)
Where does the pronephros develop?
In the throat
Where does the mesonephros develop?
In the thorax/abdomen
The mesenephros begins as a ______ of structures, which will eventually _______ into ______ ______ _____
series
collapse
one large kidney
The genital portion of the UG sinus:
Opens up to the UG membrane
For males, what does the pelvic portion of the UG sinus give rise to?
prostatic and membranous urethra
The prostatic urethra will have an _______ and give rise to the ________.
outgrowth
prostate
For males, what does the genital portion of the UG sinus give rise to?
The penile urethra
The lower part of the urinary system is derived from:
Cloaca/endoderm
For females, what happens to the pelvic and genital portions of the US sinus?
They both become the urethra
______ _____ will attach to the posterior portion of the bladder.
As the bladder grows this will be pulled into it.
mesonephric duct
The mesonephric duct will form the:
Trigon
What is the trigon?
The sensory part of the bladder. Tells us when our bladder is full.
The trigon derives from the _____-
Mesoderm
The detrusor muscle (AKA ____ ______ of the bladder), derives from the
Endoderm
SRY gene is found on
short arm of the Y chromosome
SRY gene codes for
Testis Determining Factor (TDF)
Genital ridge originates from the _________, and develops on the ______ side of the _______ kidney
mesoderm
medial
mesonephric
2 populations of cells found in the genital ridge
Support Cells
Hormone producing cells
The ________ ____ ____ develop in the yolk sac, then walks to the genital ridge, and are moved by _____ _____.
primordial germ cells
amiboid actions
Primordial germ cells walk to develop:
uncommited gonad (cannot determine if male or female)
If SRY gene is present:
Primordial Germ Cells become:
Hormone producing cells become:
Support cells become:
Sperm cells
Leydig cells
Sertoli cells
If SRY gene is NOT present:
Primordial germ cells become:
Hormone producing cells become:
Support cells become:
Egg cells
Thecal cells
Follicle cells
Route of the primordial germ cells: They originate in \_\_\_\_\_ \_\_\_\_\_ portion of the yolk sac. Then migrate to behind the \_\_\_\_\_\_\_ then cross over the \_\_\_\_\_\_ \_\_\_\_\_\_ Then into the \_\_\_\_\_ \_\_\_\_\_\_
posterior superior
hindgut
dorsal mesentary
genital ridge
What does the connective tissue covering the genitals do?
Primarily dilates the structural ridge
also produces the septa
Septa develops into:
Sex cords
If SRY gene present:
CT will become ______ _____ (to ______ the testis)
Sexcords become the ______ _____
tunica albugenea–protect
seminiferous tubules
When do the seminiferous tubules open up and form a lumen?
during puberty in the presence of mature sperm cells.
If NO SRY gene:
CT _____ ____.
Sex cords ____ __ and form the ____ ____.
remains thin
break up— egg nest
Testis produce ____ ____ ____ which comes from the sertoli cells
mullerial inhibitory factor
2 duct systems are forming in male and female:
Mesonephric duct
and paramesonephric duct
Males primary duct is _____ ____
while the _____ ___ disappears
mesonephric duct
paramesonephric duct
Females primary duct is ______ _____
while the ______ _____ disappears
Paramesonephric duct
mesonephric duct
In males, before the paramesonephric duct disappears, it will give rise to:
Appendix testis
appendix epididymis
Prostatic utricle
In females, the param. duct forms 3 parts (bilateral):
1- Vertical section
2- horizontal section
3- 2nd vertical section
The first vertical section:
fuses together and will become the uterus
The horizontal and 2nd vertical sections become the:
uterine tubes
The posterior portion of the UG sinus will mitose and become the ______ ___
sinovaginal buld
Once the sinovaginal bulb and the parame.duct become 1 solid mass….
programmed cell death will occur to form the vagina
The lower part of the vagina is derived from the
mesoderm
the upper part of the vagina is derived from the
endoderm
Genital tubricle
Single midline structure from the surface epithelium
Genital folds
Raised surrounding the UG opening
Genital swellings
Lateral to the folds. Not as raised, although wider than the folds
For males:
Genital tubricle becomes:
Genital folds become:
Genital swellings become
Glands penis (head of penis)
shaft of penis
scrotum
Raph
fine of fusion where the genital folds met
For females:
Genital tubricle becomes:
Genital folds become:
Genital swellings become
Clitoris
Labia minora
labia majora
Space between the genital folds is called
vestibule
(T/F)
The scrotum is homogulous to the labia majora
True`
Lungs develop from
endoderm
2 major respiratory developmental events
Organogenesis
Differenciation
Organogenisis of respiratory development
Where the resp system really develops
Differenciation of respiratory development
specialized cells and tubes are introduced
5 stages of respiratory development
1- embryonic 2- Pseudoglandular 3-Canulicular 4-Saccular 5-Alveolar
Embryonic stage of respiratory development
Where lungs first start to form.
An outgrowth of the foregut
Will see trachea and bronchi develop here
Pseudoglandular stage of respiratory development
airsacs develop at end of the tubules.
Avoili look serous
Canulicular stage of respiratory development
Tubes develop as solid stuctures and open up to form a lumen
Saccular stage of respiratory development
little structures open up. Surfactant also seen here.
Alveolar stage of respiratory development
Alveola are introduced. THIS STAGE CONTINUES AFTER BIRTH!
Lungbud grow off of the ________ and moves and grows ________
foregut
anterior
Split between esophagus and trachea
esophageal tracheal septum
in _____ bronchi, the right side has _____ ___, while the left side has _____ _____
secondary
three lobes
two lobes
Tertiary bronchi form the _________ ______
bronchopulmonary segments
smaller tubes from the bronchi are called ______ ______ __ _____. Here, there is no ____ ____.
Conducting zone of the lung
gas exchange
When and where does gas exchange take place
Canulicular stage
in the resp. bronchioles, alveolar ducts, and teh aveolar sacs.
Surfactant is resp for
Decreasing surface tension in the lung, making gas exchange more efficient.
2 major cell types in the cell
Type 1 pneumocyte
Type 2 pneumocyte
Type 1 pneumocyte
thin squamous cells that exchange gas
Type 2 pneumocyte
cuboidal cells that secrete surfactant
Four different sources that form the diaphragm
Mesentary of esophagus
Thoracic body wall growths
Septum transverse
Pleuroperitoneal membrane
Mesentary of esophagus
layer of ct that holds various pieces in place
thoracic body wall growths
where the muscle comes from
Septum transverse
large structure CT that forms the central tendon. This develops by itself from the mesoderm
Pleuroperitoneal membrane
part of the perietal peritoneum
Osteocytes are all associated with ________ _____.
Protein synthesis
Bone is originally _____ and allow for ____.
Soft
Diffusion
What causes the bone to harden?
Osteoclasts take on calcium and phosphate
Mesenchyme differenciates into _________ which will form _______
Chondrocytes
Cartilage
Cartilage relays on _______ to get blood and nutrients
Diffusion
Osteocytes synthesize _______
Protein
Two types of bone development:
intramembranous
and endochondral
Intramembranous Development is the development of
Flat bones such as the skull
Endochondral development is the development of
Long bones, like limbs
In intramembranous development, mesenchyme cells differenciate into _____, which will then transform into ______.
Osteoblasts
osteocytes
Osteoblasts take on ______ and ______ to harden
Calcium and phospate
What happens the the osteocytes once the bone hardens?
They go from cuboidal shaped to star shaped. They reach out and touch each other, while one is touching a capillary, which will then transfer blood and nutrients.
In endochondral development, mesenchyme cells differenciate into _______, which then form __________, which is ________
Chondrocytes
cartilage
avascular
Endochondral development: How does the cartilage ossify?
Cartilage eventually is vascularized. Blood vessel brings osteoblasts along with it, which will create osteocytes and eventually calcify
Bone utilizes cartilage to grow called ______ ______.
Epiphyseal plates
2 major parts of the skull
Neurocranium and Visocranium
What does the neurocranium form?
Bones that surround the brain
What does the visocranium form?
Facial bones- primarily from the pharyngeal arches.
Superior portion of the skull, around the brain:
Intramembranous
Base of the skull
Cartilaginous- endochondral
Soft spots, AKA:
Fontanelles
Purpose of Fontanelles:
To allow the skull to collapse when being pushed out of the vaginal canal
The vertebral column develops from the:
Paraxial mesoderm (most medial part of the mesoderm)
The paraxial mesoderm forms 42-44 pairs of ______, which has 3 derivatives. Name the three.
somites
Dermatome
Myotome
Sclerotome
Dermatome is the most _____ part of the somites and forms:
Superficial
Forms the dermis of the skin.
Myotome develops:
paraxial muscle
Sclerotome develops:
The vertebrae
To develop the vertebra, the sclerotomes must first ______, then ___ with the one above
split
fuse
Once the sclerotomes fuse with the superior ones, they will the move _____ to
medially to fuse with the adjacent pair
1 vertebra is the result of _____ (number) sclerotome
4
The sternum is developed from the:
Somatic mesoderm
To form the sternum, you first have:
2 circular masses and 2 elongated masses
The 2 elongated masses that form the sternum are called:
Sternal bars
In sternum development, the 2 circular masses fuse and form:
The manubrium of the sternum
Name the 2 parts of the thoracic TVP
True TVP
and costal process (outer, anterior portion)
How do the ribs develop?
They grow from the costal process of the TVP
Ribs develop from: (trilaminar disc)
Paraxial mesoderm
Primary inducer of the limb development
Apical ectodermal ridge (AER)
The bones and connective tissue of the limbs derives from:
Mesoderm
The AER induces the ______, and causesmesenchyme cells to differenciate into: (4 cell types)
mesoderm
osetoblasts, fibroblasts, myoblasts and chondroblasts.
Mitoses in the limbs begins in the:
Progress zone
The thumb develops _____, while the little finer develops ______.
Laterally
medially
The lower limb rotates _______, causing the big toe to be _____.
inward
medial
Axial muscles develop from the:
Paraxial mesoderm
Number of somites in Occipital cervical thoracic lumbar sacral and coccygeal
4 occipital 8 cervical 12 thoracic 5 lumbar 5 sacral 8-10 coccygeal
As development continues, what somites dissapear?
1st occipital
5-7 coccygeal
Which part of the somite forms the axial muscles?
myotome
Each mytome separates into _____, which is dorsal, and ______, which is ventral
epimere
hypomere
The hypomere form:
Ventral trunk muscles like the abdominal muscles
The epimere form:
Back axial muscles like erector spinalis
What are the hypomere innervated by?
Ventral ramus of the spinal nerve
What are the epimere innervated by?
Dorsal ramus of the spinal nerve
In the AER, mesenchyme cells differenciate into _______.
Myoblast
2 areas of limb development:
Ventral, AKA preaxial
and Dorsal AKA Postaxial
The preaxial and postaxial are separated by:
CT Septum
In the upper limb, the flexors are formed by _____, while the extensors are formed by _____.
preaxial
postaxial
In the lower limb, flexors are formed by ______, while the extensors are formed by the _______.
postaxial
preaxial
Why the the preaxial and postaxial have different roles in the upper and lower limbs?
This is due to the rotation of th lower limbs.
The nervous system develops from the:
Ectoderm
What happens that causes the formation of the neural plate? What induces this?
Surface ectodermal cells go from being flattened to columnar. Induced by the notochord
How is the neural groove formed?
The neural plate expands and starts to fold inward
Once the grooves of the neural groove meet, the ___ ____ is formed
neural tube
During the 4th week of development, the cranial end will _____ to form the:
dilate
3 vesicle brain
3 vesicle brain consists of:
Prosencephalon
mesencephalon
rhombencephalon
In the 5 vesicle brain, the prosencephalon creates the
telencephalon and the diencephalon
In the 5 vesicle brain, the mesencephalon creates the
mesencephalon
In the 5 vesicle brain, the rhombencephalon creates the
metencephalon and the myencephalon
The telencephalon forms the
Cerebrum
The diencephalon forms the
thalamus
The mesencephalon forms the
midbrain
the metencephalon forms the
pons and cerebellum
the myencephalon forms the
medulla
What flexure is at the midpoint of the mesencephalon?
Cephalic flexure
What separates the mesencephalon and the metencephalon?
Rhombencephalic isthmus
What separates the metencephalon and the myencephalon?
pontine flexure
What separates the myencephalon and the spinal cord?
cervical flexure
2 major layers of the neural tube
Mantle layer and marginal layer
The mantle layer is made up of _____ _____, and becomes the _____ matter of the CNS
cell bodies
grey
What are the 2 plates of the mantle later, and what structures do they form?
1- Dorsal alar plates (sensory structures)
2- Ventral basal plates (motor structures)
The marginal layer is made up of ______, and forms the ___ matter of the CNS
axons
white
