SEM01_Introduction_NO

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the dictionary definition of the term 'embryo'?

Developing animals that are already born

Developing animals that are unhatched or not yet born (correct)

Plants in the early stages of growth

Fully grown animals

Why do many embryologists prefer the term 'developmental biology' over 'embryology'?

To study the development of organisms beyond prenatal stages (correct)

To focus only on prenatal stages of development

To escape from studying animal embryology

To confine their studies to plants

How is life described in terms of stages?

As a single continuous stage

As a random collection of stages

As a succession of stages (correct)

As separate isolated stages

Why are there discussions about the concept of 'human embryo'?

Due to tagging developmental periods with moral or ethical values Signup and view all the answers

What does the conceptus refer to?

The embryo or fetus along with the tissues that nourish it Signup and view all the answers

When does the fetal stage begin?

When an embryo is recognizable as belonging to its species Signup and view all the answers

How is human pregnancy typically divided?

Embryonic (first 8 weeks) and fetal (remaining 32 weeks) Signup and view all the answers

What are teratogens?

Environmental factors that can impair prenatal development Signup and view all the answers

"Atresia" is a condition where:

An orifice or passage in the body is abnormally closed or absent Signup and view all the answers

"Fistula" is:

An abnormal passageway in the body that can go between two internal organs or from the body surface to an internal organ. Signup and view all the answers

What are congenital defects?

Structural or functional anomalies that occur during intrauterine life. Signup and view all the answers

What do malformations refer to?

Primary defects due to underlying genetic, epigenetic, or environmental factors. Signup and view all the answers

What influences the duration of gestation period in different species?

Animal size and level of development at birth. Signup and view all the answers

How are birth defects caused?

By genetic, environmental, or a combination of factors. Signup and view all the answers

What does the embryonic period in humans consist of?

23 Carnegie stages based on morphologic features. Signup and view all the answers

What is the difference between hyperplasia and hypertrophy?

Hyperplasia is an increase in the number of cells, while hypertrophy is an increase in cell size Signup and view all the answers

What is metaplasia?

Transformation of one differentiated cell type to another, normal or abnormal Signup and view all the answers

What is dysplasia?

Disorder in which cellular architecture of a tissue is not normally maintained Signup and view all the answers

What is the difference between agenesis, aplasia, and hypoplasia?

Agenesis is complete absence, aplasia is defective development, and hypoplasia is underdevelopment Signup and view all the answers

What are oesophageal atresia and tracheoesophageal fistula related to?

Absence or decrease in the development of the oesophagus and its connection to the trachea Signup and view all the answers

What is a sequence?

A primary anomaly determining additional defects that develop in cascade as a consequence of the primary malformation Signup and view all the answers

During which stage do blastomeres form the three germ layers?

Gastrulation Signup and view all the answers

When does the embryonic period end in humans?

After 8 weeks Signup and view all the answers

What is the defining characteristic of the foetal stage?

Recognition as a foetus Signup and view all the answers

Which stage involves the delimitation of body and differentiation of embryonic and extra-embryonic organs and structures?

Embryonic stage Signup and view all the answers

What happens immediately after fertilisation in embryonic development?

Formation of blastomeres Signup and view all the answers

What is the primary characteristic of the early embryo stage or germinal period?

Zygote composition of an increasing mass of cells without recognisable body boundaries or organs Signup and view all the answers

When does organogenesis occur in embryonic development?

After the three germ layers are established Signup and view all the answers

What marks the transition from embryo to foetus?

Formation of body organs Signup and view all the answers

What characterizes the developmental stages in embryology?

Continuous development with no distinct boundaries or changes Signup and view all the answers

At what point does an embryo become recognisable as a foetus?

After organogenesis Signup and view all the answers

What occurs after mitotic division slows down in embryonic development?

Blastomeres undergo rearrangements to form germ layers Signup and view all the answers

What is the dictionary definition of the term 'embryo'?

A developing animal that is unhatched or not yet born Signup and view all the answers

Why do many embryologists prefer the term 'developmental biology' over 'embryology'?

To escape from the need to confine their studies to prenatal stages Signup and view all the answers

What can embryology be defined as in the modern sense?

The study of the development of organisms, considering developmental aspects of life as a whole Signup and view all the answers

What does the term 'embryology' encompass?

Developmental aspects of life as a whole, not just a concrete period of time Signup and view all the answers

What is the primary difference between malformations, disruptions, and deformations in the context of congenital defects?

Malformations are primary defects due to underlying genetic, epigenetic, or environmental factors, while disruptions and deformations are secondary disturbances. Signup and view all the answers

What influences the duration of gestation period in different species?

Animal size and level of development at birth Signup and view all the answers

What is the defining characteristic of the fetal stage?

Organ systems continue to develop and grow Signup and view all the answers

What do teratogens refer to in prenatal development?

Environmental factors that can impair prenatal development and lead to congenital defects Signup and view all the answers

What does atresia refer to in medical terminology?

A condition where an orifice or passage in the body is abnormally closed or absent Signup and view all the answers

What characterizes the embryonic period in humans?

It is typically divided into the first 8 weeks of pregnancy Signup and view all the answers

What are congenital defects primarily caused by?

Genetic, environmental, or a combination of factors Signup and view all the answers

What does fistula refer to in medical terminology?

An abnormal passageway in the body that can go between two internal organs or from the body surface to an internal organ Signup and view all the answers

What marks the transition from embryo to fetus in human pregnancy?

Recognition as belonging to its species and continued organ system development Signup and view all the answers

What characterizes errors in embryonic development?

They can result in embryonic loss, fetal death, fetal mummification, abortion, stillbirth, or the birth of viable offspring with congenital defects. Signup and view all the answers

What do malformations refer to in the context of congenital defects?

Structural or functional anomalies that occur during intrauterine life due to underlying genetic, epigenetic, or environmental factors. Signup and view all the answers

What is the difference between hyperplasia and hypertrophy?

Hyperplasia is an increase in the number of cells, while hypertrophy is an increase in cell size Signup and view all the answers

What is metaplasia?

The transformation of one differentiated cell type to another differentiated cell type Signup and view all the answers

What is dysplasia?

A disorder in which the intrinsic cellular architecture of a certain tissue is not normally maintained throughout growth and development Signup and view all the answers

What characterizes a sequence?

A primary anomaly determines additional defects that develop in cascade as a consequence of the primary malformation Signup and view all the answers

What are oesophageal atresia and tracheoesophageal fistula related to?

The absence or decrease in the development of the oesophagus and its connection to the trachea Signup and view all the answers

What does agenesis refer to?

Complete absence of an organ or structure Signup and view all the answers

What does aplasia refer to?

Complete absence of an organ or structure Signup and view all the answers

What occurs during the gastrulation stage in embryonic development?

Blastomeres undergo extensive rearrangements to form the three germ layers Signup and view all the answers

What characterizes the foetal stage in embryonic development?

Continued growth and functional development of organ systems Signup and view all the answers

At what point does an embryo become recognisable as a foetus?

When it is developed to the point of being recognisable as the species to which it belongs Signup and view all the answers

What marks the transition from embryo to foetus in human development?

When it is recognisable as its species Signup and view all the answers

What is the primary characteristic of the early embryo stage or germinal period?

Zygote composition of an increasing mass of cells without recognisable body boundaries or organs Signup and view all the answers

What does the foetal stage in human embryonic development involve?

Continued growth and functional development of organ systems Signup and view all the answers

What characterizes the embryonic period in humans?

The period covering the first 8 weeks during which body organs and systems arise from three primary layers. Signup and view all the answers

What happens after mitotic division slows down in embryonic development?

Blastomeres undergo extensive rearrangements to form the three germ layers. Signup and view all the answers

What is involved in organogenesis during embryonic development?

Cells interact and form tissues and organs. Signup and view all the answers

What is embryology?

The study of the development of embryos in animals and plants Signup and view all the answers

Why do many embryologists prefer the term 'developmental biology' over 'embryology'?

To avoid confining their studies to prenatal stages only Signup and view all the answers

What is the dictionary definition of 'embryo'?

Developing animals that are unhatched or not yet born Signup and view all the answers

How can life be described in terms of stages?

As a succession of stages with no specific boundaries between them Signup and view all the answers

During which stage of development do cells interact and rearrange to produce tissues and organs?

Organogenesis Signup and view all the answers

What marks the transition from the embryonic period to the fetal period in human development?

End of the eighth week after conception Signup and view all the answers

Which stage involves the establishment of the three germ layers, ectoderm, endoderm, and mesoderm?

Gastrulation Signup and view all the answers

What characterizes the early embryo stage or germinal period?

Rapid division of zygote cytoplasm into blastomeres Signup and view all the answers

What is the gestation period defined as?

The time from fertilization to birth Signup and view all the answers

What happens during the fetal stage in human pregnancy?

All organ systems continue to develop and grow Signup and view all the answers

What are congenital defects primarily caused by?

Genetic or environmental factors, or a combination of the two Signup and view all the answers

What is atresia in medical terminology?

An abnormal closure or absence of an orifice or passage in the body Signup and view all the answers

What characterizes malformations in the context of congenital defects?

Primary defects due to intrinsically abnormal development of an organ or body part Signup and view all the answers

"Fistula" in medical terminology refers to:

An abnormal passageway in the body Signup and view all the answers

What do disruptions refer to in the context of congenital defects?

Secondary defects caused by vascular, infectious, mechanical, or metabolic factors that interfere with development of an organ or body part. Signup and view all the answers

What does conceptus refer to?

The embryo or fetus along with the tissues that nourish it, such as the placenta. Signup and view all the answers

What occurs during embryonic period in humans?

Formation and initial differentiation of embryonic and extra-embryonic organs and structures. Signup and view all the answers

What characterizes fetal mummification?

A condition where a fetus dies and becomes preserved within the uterus. Signup and view all the answers

What are deformations in the context of congenital defects?

Secondary disturbances caused by mechanical forces resulting in abnormal shape or position of an organ or body part. Signup and view all the answers

What is hypertrophy?

Enlargement of an organ or tissue from the increase in the size of its cells Signup and view all the answers

What is metaplasia?

Transformation of one differentiated cell type to another differentiated cell type Signup and view all the answers

What is dysplasia?

Anomaly in which the intrinsic cellular architecture of a tissue is not maintained, resulting in abnormal growth and development Signup and view all the answers

What is hypoplasia?

Underdevelopment or incomplete development of a tissue or organ due to a decreased number of cells in its structure Signup and view all the answers

What is aplasia?

Defective development or complete absence of an organ due to the failure of its primordial tissues or cells Signup and view all the answers

What is agenesis?

Complete absence of an organ and its primordia Signup and view all the answers

Study Notes

Human embryos are defined as developing humans during the first eight weeks after conception, but this boundary is not definitive.
Developmental stages in embryology: Fertilisation and cleavage, gastrulation, and organogenesis.
Fertilisation and cleavage: Immediately after fertilisation, cleavage occurs, dividing zygote cytoplasm into numerous smaller cells called blastomeres, forming a hollow sphere known as blastula or blastocyst.
Gastrulation: After mitotic division slows down, blastomeres undergo extensive rearrangements, forming the three germ layers: ectoderm, endoderm, and mesoderm.
Organogenesis: After the three germ layers are established, cells interact and form tissues and organs.
Early embryo stage or germinal period: Zygote composition of an increasing mass of cells without recognisable body boundaries or organs; only some cells will become the actual embryo, while others form extra-embryonic organs (placenta).
Embryonic stage: Delimitation of body and differentiation of embryonic and extra-embryonic organs and structures; most organ systems are formed during this stage.
Embryonic period: Covers the first 8 weeks in humans, during which the body organs and systems arise from the three primary layers.
Foetal stage: An embryo is developed to the point of being recognisable as the species to which it belongs, and is then called a foetus. In foetal development, organ systems continue to grow and become functional.
All stages are part of continuous development, with no distinct boundaries or changes.
Human embryos are defined as developing humans during the first eight weeks after conception, but this boundary is not definitive.
Developmental stages in embryology: Fertilisation and cleavage, gastrulation, and organogenesis.
Fertilisation and cleavage: Immediately after fertilisation, cleavage occurs, dividing zygote cytoplasm into numerous smaller cells called blastomeres, forming a hollow sphere known as blastula or blastocyst.
Gastrulation: After mitotic division slows down, blastomeres undergo extensive rearrangements, forming the three germ layers: ectoderm, endoderm, and mesoderm.
Organogenesis: After the three germ layers are established, cells interact and form tissues and organs.
Early embryo stage or germinal period: Zygote composition of an increasing mass of cells without recognisable body boundaries or organs; only some cells will become the actual embryo, while others form extra-embryonic organs (placenta).
Embryonic stage: Delimitation of body and differentiation of embryonic and extra-embryonic organs and structures; most organ systems are formed during this stage.
Embryonic period: Covers the first 8 weeks in humans, during which the body organs and systems arise from the three primary layers.
Foetal stage: An embryo is developed to the point of being recognisable as the species to which it belongs, and is then called a foetus. In foetal development, organ systems continue to grow and become functional.
All stages are part of continuous development, with no distinct boundaries or changes.
Conceptus refers to the embryo or fetus along with the tissues that nourish it, such as the placenta.
Fetal stage begins when the embryo becomes recognizable as the species to which it belongs. all organ systems are formed during embryonic development but continue to develop and grow during fetal stage.
Gestation period is the time from fertilization to birth. The length varies depending on animal size and level of development at birth.
Human pregnancy is divided into an embryonic period (A) lasting 8 weeks and a fetal period (B) from the 9th week to birth, i.e., 30 weeks.
Congenital defects, also known as birth defects or malformations, are structural or functional anomalies that occur during intrauterine life and can range from minor to life-threatening conditions.
Birth defects can be caused by genetic or environmental factors, or a combination of the two. Environmental factors, or teratogens, include viruses, drugs, chemicals, stressors, and malnutrition.
Malformations are primary defects due to intrinsically abnormal development of an organ or body part, often caused by genetic or epigenetic factors.
Disruptions are secondary defects caused by vascular, infectious, mechanical, or metabolic factors that interfere with the development of an organ or body part.
Deformations are secondary disturbances caused by mechanical forces, often due to uterine constraint, resulting in abnormal shape or position of an organ or body part.
Errors in development can result in embryonic loss, fetal death, fetal mummification, abortion, stillbirth, the birth of nonviable neonates, or the birth of viable offspring with congenital defects.
Atresia is a condition where an orifice or passage in the body is abnormally closed or absent, and fistula is an abnormal passageway in the body.
Agenesis, aplasia, hypoplasia, atrophy, hypertrophy, metaplasia, and dysplasia are all conditions related to the development or structure of organs and tissues
Agenesis is the complete absence of an organ and its primordia, such as renal agenesis where the kidney and the ureter are absent
Aplasia is the defective development or complete absence of an organ due to the failure of its primordial tissues or cells, such as renal aplasia where there is a primordium of renal tissue but the kidney is not developed
Hypoplasia is the underdevelopment or incomplete development of a tissue or organ due to a decreased number of cells in its structure
Hyperplasia is an organ enlargement caused by an increase in the number of its cells, such as congenital adrenal hyperplasia where there is excessive production of sex steroid hormones by the adrenal glands
Hypertrophy is the enlargement of an organ or tissue from the increase in the size of its cells
Metaplasia is the transformation of one differentiated cell type to another differentiated cell type, which may be part of a normal maturation process or caused by an abnormal stimulus
Dysplasia is another type of anomaly in which the intrinsic cellular architecture of a tissue is not maintained, resulting in abnormal growth and development
Sequence and syndrome are recognizable patterns of multiple defects, with sequence occurring when a primary anomaly determines additional defects in cascade and syndrome being a recognizable pattern of multiple defects presenting together
Comparative morphological terminology is used to standardize the anatomical nomenclature and includes terms such as cranial, caudal, dorsal, ventral, medial, and lateral. These terms describe the relative position of structures in the body.
Anatomical position refers to the position of the body in normal standing or resting position, with the palms facing forward and the toes pointing straight ahead. This position is used as a reference point for describing the location of structures in the body.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge about the stages of embryonic and fetal development, including the formation of organ systems and the period of gestation in mammals.

SEM01_Introduction_NO_history

Podcast Beta

Questions and Answers

What is the dictionary definition of the term 'embryo'?

Why do many embryologists prefer the term 'developmental biology' over 'embryology'?

How is life described in terms of stages?

Why are there discussions about the concept of 'human embryo'?

What does the conceptus refer to?

When does the fetal stage begin?

How is human pregnancy typically divided?

What are teratogens?

"Atresia" is a condition where:

"Fistula" is:

What are congenital defects?

What do malformations refer to?

What influences the duration of gestation period in different species?

How are birth defects caused?

What does the embryonic period in humans consist of?

What is the difference between hyperplasia and hypertrophy?

What is metaplasia?

What is dysplasia?

What is the difference between agenesis, aplasia, and hypoplasia?

What are oesophageal atresia and tracheoesophageal fistula related to?

What is a sequence?

During which stage do blastomeres form the three germ layers?

When does the embryonic period end in humans?

What is the defining characteristic of the foetal stage?

Which stage involves the delimitation of body and differentiation of embryonic and extra-embryonic organs and structures?

What happens immediately after fertilisation in embryonic development?

What is the primary characteristic of the early embryo stage or germinal period?

When does organogenesis occur in embryonic development?

What marks the transition from embryo to foetus?

What characterizes the developmental stages in embryology?

At what point does an embryo become recognisable as a foetus?

What occurs after mitotic division slows down in embryonic development?

What is the dictionary definition of the term 'embryo'?

Why do many embryologists prefer the term 'developmental biology' over 'embryology'?

What can embryology be defined as in the modern sense?

What does the term 'embryology' encompass?

What is the primary difference between malformations, disruptions, and deformations in the context of congenital defects?

What influences the duration of gestation period in different species?

What is the defining characteristic of the fetal stage?

What do teratogens refer to in prenatal development?

What does atresia refer to in medical terminology?

What characterizes the embryonic period in humans?

What are congenital defects primarily caused by?

What does fistula refer to in medical terminology?

What marks the transition from embryo to fetus in human pregnancy?

What characterizes errors in embryonic development?

What do malformations refer to in the context of congenital defects?

What is the difference between hyperplasia and hypertrophy?

What is metaplasia?

What is dysplasia?

What characterizes a sequence?

What are oesophageal atresia and tracheoesophageal fistula related to?

What does agenesis refer to?

What does aplasia refer to?

What occurs during the gastrulation stage in embryonic development?

What characterizes the foetal stage in embryonic development?

At what point does an embryo become recognisable as a foetus?

What marks the transition from embryo to foetus in human development?

What is the primary characteristic of the early embryo stage or germinal period?

What does the foetal stage in human embryonic development involve?

What characterizes the embryonic period in humans?

What happens after mitotic division slows down in embryonic development?

What is involved in organogenesis during embryonic development?

What is embryology?

Why do many embryologists prefer the term 'developmental biology' over 'embryology'?

What is the dictionary definition of 'embryo'?

How can life be described in terms of stages?

During which stage of development do cells interact and rearrange to produce tissues and organs?

What marks the transition from the embryonic period to the fetal period in human development?

Which stage involves the establishment of the three germ layers, ectoderm, endoderm, and mesoderm?

What characterizes the early embryo stage or germinal period?

What is the gestation period defined as?

What happens during the fetal stage in human pregnancy?

What are congenital defects primarily caused by?

What is atresia in medical terminology?

What characterizes malformations in the context of congenital defects?

"Fistula" in medical terminology refers to: