Brachial Plexus - Multiple Choice Questions

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

Multiple Choice Questions on Brachial Plexus

Which spinal nerves contribute to the formation of the brachial plexus?

a) C1-C4

b) C5-T1

c) T2-T6

d) T7-T12

Answer: b) C5-T1

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which brachial plexus trunk is formed by the fusion of the C5 and C6 spinal nerves?

a) Superior trunk

b) Middle trunk

c) Inferior trunk

d) Lateral trunk

Answer: a) Superior trunk

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves innervates the deltoid muscle?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: d) Axillary nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which brachial plexus cord is formed by the fusion of the anterior divisions of the superior and middle trunks?

a) Lateral cord

b) Medial cord

c) Posterior cord

d) Long thoracic cord

Answer: a) Lateral cord

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves is responsible for the motor innervation of the biceps brachii muscle?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Musculocutaneous nerve

Answer: d) Musculocutaneous nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which brachial plexus root(s) contribute(s) to the formation of the median nerve?

a) C5 and C6 only

b) C6 and C7 only

c) C5, C6, and C7

d) C8 and T1 only

Answer: c) C5, C6, and C7

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves supplies sensation to the lateral forearm?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Musculocutaneous nerve

Answer: d) Musculocutaneous nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which brachial plexus cord is formed by the fusion of the posterior divisions of all three trunks?

a) Lateral cord

b) Medial cord

c) Posterior cord

d) Long thoracic cord

Answer: c) Posterior cord

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves supplies sensation to the medial hand and digits 4 and 5?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: b) Ulnar nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves is responsible for the motor innervation of the triceps brachii muscle?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: c) Radial nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which brachial plexus root(s) contribute(s) to the formation of the ulnar nerve?

a) C7 and C8 only

b) C8 and T1 only

c) C7, C8, and T1

d) C6 and C7 only

Answer: c) C7, C8, and T1

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following nerves supplies sensation to the lateral upper arm and posterior forearm?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Musculocutaneous nerve

Answer: c) Radial nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves supplies sensation to the lateral hand and digits 1-3?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: a) Median nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following muscles is innervated by the axillary nerve?

a) Deltoid

b) Biceps brachii

c) Brachioradialis

d) Triceps brachii

Answer: a) Deltoid

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which brachial plexus root(s) contribute(s) to the formation of the radial nerve?

a) C6 and C7 only

b) C7 and C8 only

c) C5, C6, and C7

d) C8 and T1 only

Answer: c) C5, C6, and C7

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which brachial plexus cord is responsible for the motor innervation of the extensor muscles of the forearm?

a) Lateral cord

b) Medial cord

c) Posterior cord

d) Long thoracic cord

Answer: c) Posterior cord

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves supplies sensation to the tip of the thumb and index finger?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: a) Median nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves is responsible for the motor innervation of the muscles of the anterior forearm (except for the flexor carpi ulnaris and part of the flexor digitorum profundus)?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Musculocutaneous nerve

Answer: a) Median nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which brachial plexus root(s) contribute(s) to the formation of the musculocutaneous nerve?

a) C5 and C6 only

b) C7 and C8 only

c) C5, C6, and C7

d) C8 and T1 only

Answer: a) C5 and C6 only

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves supplies sensation to the medial aspect of the hand and digits 4 and 5?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: b) Ulnar nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which brachial plexus cord is responsible for the motor innervation of the muscles of the hand (except for the thenar eminence and the first two lumbricals)?

a) Lateral cord

b) Medial cord

c) Posterior cord

d) Long thoracic cord

Answer: b) Medial cord

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves is responsible for the motor innervation of the supinator muscle?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: c) Radial nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following nerves supplies sensation to the posterior aspect of the arm and forearm?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: c) Radial nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves is responsible for the motor innervation of the flexor carpi ulnaris and part of the flexor digitorum profundus muscles?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Musculocutaneous nerve

Answer: b) Ulnar nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which brachial plexus root(s) contribute(s) to the formation of the axillary nerve?

a) C5 and C6 only

b) C7 and C8 only

c) C5, C6, and C7

d) C8 and T1 only

Answer: a) C5 and C6 only

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves supplies sensation to the palmar aspect of the thumb, index finger, middle finger, and half of the ring finger?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Musculocutaneous nerve

Answer: a) Median nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which brachial plexus cord is responsible for the motor innervation of the flexor muscles of the arm (biceps brachii, brachialis, and coracobrachialis)?

a) Lateral cord

b) Medial cord

c) Posterior cord

d) Long thoracic cord

Answer: a) Lateral cord

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following nerves supplies sensation to the skin over the deltoid muscle and the teres minor muscle?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: d) Axillary nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following brachial plexus nerves is responsible for the motor innervation of the triceps brachii muscle?

a) Axillary nerve

b) Median nerve

c) Radial nerve

d) Ulnar nerve

Answer: c) Radial nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves supplies sensation to the skin over the little finger and part of the ring finger?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: b) Ulnar nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which brachial plexus nerve provides motor innervation to the deltoid and teres minor muscles?

a) Axillary nerve

b) Median nerve

c) Radial nerve

d) Ulnar nerve

Answer: a) Axillary nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

The brachial plexus is formed by the union of which nerve roots?

a) C1-C5

b) C5-T1

c) T1-T5

d) C5-C8

Answer: b) C5-T1

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following nerves supplies sensation to the skin over the lateral two-thirds of the dorsum of the hand?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: c) Radial nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following muscles is NOT innervated by the musculocutaneous nerve?

a) Biceps brachii

b) Coracobrachialis

c) Brachialis

d) Brachioradialis

Answer: d) Brachioradialis

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

The long thoracic nerve originates from which brachial plexus roots?

a) C5, C6, C7

b) C7-C8

c) T1-T2

d) T2-T3

Answer: a) C5, C6, C7

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following muscles is innervated by the dorsal scapular nerve?

a) Trapezius

b) Rhomboid major

c) Teres major

d) Supraspinatus

Answer: b) Rhomboid major

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which brachial plexus nerve provides motor innervation to the flexor pollicis longus muscle?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: a) Median nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following brachial plexus nerves provides motor innervation to the extensor carpi radialis muscle?

a) Axillary nerve

b) Median nerve

c) Radial nerve

d) Ulnar nerve

Answer: c) Radial nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

The suprascapular nerve originates from which brachial plexus roots?

a) C5-C6

b) C7-C8

c) T1-T2

d) T2-T3

Answer: a) C5-C6

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves supplies sensation to the skin over the medial side of the forearm and hand?

a) Median nerve

b) Medial cutaneous nerve of forearm

c) Radial nerve

d) Axillary nerve

Answer: b) Medial cutaneous nerve of forearm

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following nerves provides motor innervation to the teres minor muscle?

a) Radial nerve

b) Ulnar nerve

c) Axillary nerve

d) Musculocutaneous nerve

Answer: c) Axillary nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following muscles is innervated by the thoracodorsal nerve?

a) Latissimus dorsi

b) Serratus anterior

c) Pectoralis major

d) Subscapularis

Answer: a) Latissimus dorsi

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following brachial plexus nerves provides motor innervation to the flexor carpi ulnaris muscle?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: c) Ulnar nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves provides motor innervation to the extensor digitorum muscle?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: b) Radial nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves provides motor innervation to the coracobrachialis muscle?

a) Musculocutaneous nerve

b) Axillary nerve

c) Median nerve

d) Radial nerve

Answer: a) Musculocutaneous nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following brachial plexus nerves provides motor innervation to the flexor digitorum profundus muscle?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: c) Ulnar nerve and a) Median nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following brachial plexus nerves provides motor innervation to the pronator teres muscle?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: a) Median nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following nerves provides motor innervation to the extensor carpi radialis muscles?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: b) Radial nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following brachial plexus nerves provides innervation to the brachialis muscle?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Musculocutaneous nerve

Answer: d) Musculocutaneous nerve and b) Radial nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves provides sensory innervation to the skin over the medial aspect of the hand?

a) Median nerve

b) Ulnar nerve

c) Radial nerve

d) Axillary nerve

Answer: b) Ulnar nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following brachial plexus nerves provides motor innervation to the serratus anterior muscle?

a) Long thoracic nerve

b) Dorsal scapular nerve

c) Suprascapular nerve

d) Subscapular nerve

Answer: a) Long thoracic nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Which of the following nerves provides sensory innervation to the skin over the posterior aspect of the arm?

a) Median nerve

b) Radial nerve

c) Ulnar nerve

d) Axillary nerve

Answer: b) Radial nerve

Reference: Standring, S. (Ed.). (2016). Gray's Anatomy: The Anatomical Basis of Clinical Practice (41st ed.). Elsevier.

Which of the following brachial plexus nerves provides motor innervation to the rhomboid muscles?

a) Long thoracic nerve

b) Dorsal scapular nerve

c) Suprascapular nerve

d) Subscapular nerve

Answer: b) Dorsal scapular nerve

Reference: Drake, R. L., Vogl, W., & Mitchell, A. W. M. (2015). Gray's Anatomy for Students (3rd ed.). Churchill Livingstone.

Which of the following nerves provides motor innervation to the levator scapulae muscle?

a) Long thoracic nerve

b) Dorsal scapular nerve

c) Suprascapular nerve

d) Subscapular nerve

Answer: b) Dorsal scapular nerve

Reference: Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Lippincott Williams & Wilkins.

Embryology Problem Based Questions (Langman - Q10)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

The second week of development is known as 2’s. Formation of what structures support this statement?

Answer:

At the beginning of the second week of development, the blastocyst has already implanted into the endometrium of the uterus. The inner cell mass (ICM) of the blastocyst divides into two layers, the epiblast and the hypoblast, forming the bilaminar embryonic disc.

The epiblast gives rise to the three primary germ layers (ectoderm, mesoderm, and endoderm) and the hypoblast contributes to the formation of the yolk sac.

The amniotic cavity begins to form during the second week of development as the epiblast cells at the cranial (head) and caudal (tail) poles of the embryonic disc proliferate and migrate towards the center. These cells form a membrane called the amniotic membrane, which expands and eventually fuses to form the amniotic cavity. The amniotic cavity is lined by the amnioblasts, which are derived from the epiblast.

The amniotic cavity is important for protecting the developing embryo from mechanical shocks and temperature changes, and also allows for free movement and growth of the embryo.

The yolk sac cavity forms from the hypoblast cells that line the bilaminar embryonic disc. These cells migrate and form a layer of cells beneath the embryonic disc, creating a space between the hypoblast layer and the exocoelomic cavity called the primary yolk sac.

As the embryonic disc continues to grow and differentiate, the yolk sac is gradually incorporated into the developing embryo. The hypoblast cells of the yolk sac give rise to a variety of structures, including the gut, the respiratory tract, and the germ cells.

The chorionic sacs also begin to develop during the second week of development. The chorion is formed by the trophoblast, which surrounds the developing embryo and gives rise to the fetal portion of the placenta. The chorionic sacs are initially bilateral, but eventually fuse to form a single chorionic sac.

The chorionic sacs are important for the exchange of gases and nutrients between the embryo and the mother, and also play a role in protecting the embryo from the mother's immune system.

Overall, the "week of twos" is a critical time for the establishment of the bilateral body plan and the formation of the embryonic germ layers, which will go on to form all of the organs and tissues of the body. The development of the amniotic cavity, yolk sac, and chorionic sacs are also crucial for the growth and protection of the developing embryo.

The extraembryonic mesoderm is a layer of cells that surrounds the bilaminar embryonic disc during the second week of development, and it plays a critical role in supporting the developing embryo.

The extraembryonic mesoderm arises from the epiblast cells that migrate towards the outer edge of the bilaminar embryonic disc. These cells form a layer of mesoderm that surrounds the amniotic cavity, yolk sac, and exocoelomic cavity. The extraembryonic mesoderm is divided into two layers, the somatic (parietal) layer and the splanchnic (visceral) layer, which are separated by a space called the extraembryonic coelom.

The somatic layer of the extraembryonic mesoderm is in contact with the cytotrophoblast layer of the chorionic sacs and eventually gives rise to the fetal part of the placenta. The splanchnic layer is in contact with the yolk sac and will eventually form the blood vessels that supply the yolk sac and embryo.

The extraembryonic mesoderm also plays a critical role in the formation of the umbilical cord, which connects the developing embryo to the placenta. As the connecting stalk elongates, it incorporates the extraembryonic mesoderm and the yolk sac into its structure. The extraembryonic mesoderm will eventually differentiate into the umbilical cord, which contains blood vessels that transport nutrients, gases, and wastes between the embryo and the placenta.

Overall, the extraembryonic mesoderm is an essential tissue that provides mechanical and nutritional support for the developing embryo during the second week of development, and its contribution is crucial for the proper growth and development of the embryo.

Reference:

Sadler, T. W. (2019). Langman's medical embryology. Wolters Kluwer.

Embryology Problem Based Question (Langman - Q9)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

A woman has had several bouts of pelvic inflammatory disease and now wants to have children; however, she has been having difficulty becoming pregnant. What is likely to be the problem, and what would you suggest?

Answer:

If a woman has a history of pelvic inflammatory disease (PID) and is having difficulty becoming pregnant, it is possible that the scarring and damage caused by the infection has blocked or damaged her fallopian tubes. This can prevent the sperm from reaching the egg or prevent the fertilized egg from reaching the uterus, making it difficult or impossible to conceive.

In this case, it would be important for the woman to undergo fertility testing to determine the underlying cause of her infertility. This may include a physical exam, blood tests, and imaging studies such as a hysterosalpingogram (HSG) to evaluate the condition of her fallopian tubes.

If the woman's fallopian tubes are found to be blocked or damaged, there are several fertility treatments that may be recommended, depending on the severity of the blockage. These may include:

Surgery: In some cases, surgery can be performed to remove scar tissue or repair damaged fallopian tubes.

Intrauterine Insemination (IUI): IUI involves placing washed sperm directly into the uterus using a catheter. This can bypass blocked fallopian tubes and increase the chances of conception.

In Vitro Fertilization (IVF): IVF involves retrieving eggs from the ovaries and fertilizing them with sperm in a laboratory. The resulting embryos are then transferred to the uterus.

It's important for the woman to work closely with her healthcare provider to determine the best course of treatment for her individual needs and circumstances.

References:

American Society for Reproductive Medicine. (2018). Pelvic inflammatory disease. https://www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/documents/fact-sheets-and-info-booklets/pelvic-inflammatory-disease-pid/

Mayo Clinic. (2021). Female infertility. https://www.mayoclinic.org/diseases-conditions/female-infertility/symptoms-causes/syc-20354308

Embryology Problem Based Questions (Langman - Q8)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

What are the primary causes of infertility in men and women?

Answer:

There are many factors that can contribute to infertility in both men and women. Here are some of the primary causes of infertility in each sex:

Causes of Infertility in Women:

Ovulation Disorders: Irregular or absent ovulation is a common cause of infertility in women. Polycystic ovary syndrome (PCOS) is the most common ovulation disorder.

Age-related Infertility: As women age, their fertility declines. This is because the number and quality of eggs decrease over time.

Endometriosis: Endometriosis is a condition in which the tissue that normally lines the uterus grows outside of it, causing scarring and damage to the reproductive organs.

Blocked Fallopian Tubes: Blockages or damage to the fallopian tubes can prevent the sperm from reaching the egg or prevent the fertilized egg from reaching the uterus.

Pelvic Inflammatory Disease (PID): PID is an infection of the female reproductive organs that can cause scarring and damage to the fallopian tubes.

Causes of Infertility in Men:

Low Sperm Count: Low sperm count, or oligospermia, is a common cause of male infertility. This can be caused by a variety of factors, including hormonal imbalances, genetic factors, and environmental factors.

Abnormal Sperm: Abnormalities in sperm morphology (shape) or motility (movement) can also contribute to male infertility.

Varicocele: Varicocele is a condition in which the veins in the scrotum are enlarged, leading to decreased sperm quality and production.

Testicular Trauma or Cancer: Trauma to the testes or testicular cancer can also affect sperm production and quality.

Erectile Dysfunction: Erectile dysfunction can prevent a man from achieving or maintaining an erection, making it difficult or impossible to conceive.

It's important to note that infertility can also be caused by a combination of factors, and in some cases, the cause may be unknown. If you are struggling with infertility, it's important to speak with a healthcare provider who can help determine the underlying cause and recommend appropriate treatment options.

References:

American Society for Reproductive Medicine. (2020). Causes of infertility. https://www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/documents/fact-sheets-and-info-booklets/causes-of-infertility/

Mayo Clinic. (2021). Female infertility. https://www.mayoclinic.org/diseases-conditions/female-infertility/symptoms-causes/syc-20354308

Mayo Clinic. (2021). Male infertility. https://www.mayoclinic.org/diseases-conditions/male-infertility/symptoms-causes/syc-20374773

Embryology Problem Based Questions (Langman - Q7)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

What are the three phases of fertilization, and what reactions occur once fusion of the sperm and oocyte membranes takes place?

Answer:

The phases of fertilization include

● Phase 1, penetration of the corona radiata

● Phase 2, penetration of the zona pellucida

● Phase 3, fusion of the oocyte and sperm cell membranes

After fusion of membranes-

Cortical and zona reaction

Resumption of second meiotic division

Metabolic activation of egg

During the fertilization process, there are several molecular and cellular events that occur in a specific sequence to ensure successful fusion and formation of the zygote. Here are some additional details about the different phases of fertilization:

Penetration and Activation:

After reaching the oocyte, the sperm binds to its receptors, which triggers intracellular signaling cascades leading to the release of calcium ions in the oocyte. The sudden influx of calcium ions into the oocyte cytoplasm is a critical step that activates the oocyte and initiates the cortical reaction.

The cortical reaction causes the release of cortical granules from the oocyte's cortex, which modifies the zona pellucida to make it impermeable to other sperm. The cortical granules also cause the oocyte's membrane to separate from the zona pellucida, preventing any further sperm from entering.

Fusion:

After the cortical reaction, the sperm undergoes the acrosome reaction, which involves the release of enzymes that digest the zona pellucida, enabling the sperm to penetrate the oocyte. Once the sperm penetrates the zona pellucida, it binds to the oocyte membrane, and the two membranes fuse. The fusion of the sperm and oocyte membranes allows the sperm to enter the oocyte's cytoplasm and initiate oocyte activation.

Activation of the Oocyte:

Oocyte activation involves a series of events that prepare the oocyte for fertilization and subsequent embryonic development. After the fusion of the sperm and oocyte membranes, the sperm nucleus enters the oocyte's cytoplasm and forms the male pronucleus. At the same time, the oocyte's meiotic spindle reorganizes, and the second meiotic division is completed, forming the female pronucleus.

The male and female pronuclei then migrate towards each other and fuse, forming the diploid zygote. This process is essential as it leads to the formation of a genetically distinct individual. The newly formed zygote undergoes rapid cell division, forming the morula, which then develops into a blastocyst that implants in the uterus.

References:

Wassarman, P. M. (2017). Fertilization. Current Biology, 27(17), R870-R875.

Ducibella, T., Fissore, R., & Heindryckx, B. (2019). The cortical reaction and development of activation competence in mammalian oocytes. Journal of Assisted Reproduction and Genetics, 36(2), 221-231.

Johnson, M. H., & Everitt, B. J. (2018). Essential reproduction (7th ed.). Hoboken, NJ: John Wiley & Sons. Chapter 4, Fertilization.

Embryology Problem Based Questions (Langman - Q6)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

What is the role of the corpus luteum, and what is its origin?

Answer:

The corpus luteum is a temporary endocrine gland that forms in the ovary after ovulation. Its primary function is to produce hormones such as progesterone and estrogen, which are essential for preparing the uterus for pregnancy and supporting early pregnancy if fertilization occurs.

The corpus luteum forms from the remains of the ovarian follicle that releases the ovum during ovulation. After ovulation, the ruptured follicle fills with blood and forms a structure called the corpus hemorrhagicum. The corpus hemorrhagicum then transforms into the corpus luteum, which is a highly vascularized glandular structure.

If fertilization does not occur, the corpus luteum begins to regress after approximately two weeks, resulting in a drop in hormone levels that triggers menstruation. If fertilization does occur, the corpus luteum continues to produce hormones to support early pregnancy until the placenta takes over hormone production.

References:

Hillier, S. G., & Tetsuka, M. (2005). Anatomical and functional heterogeneity of the follicular environment. Human Reproduction Update, 11(1), 47-56.

Schmidt, K. L., & Derman, R. J. (2007). Physiology, corpus luteum. In StatPearls [Internet]. StatPearls Publishing.

Stocco, C., & Telleria, C. (2015). Gibberellins and their role in the regulation of ovarian development and function in mammals. Reviews of Reproduction, 20(2), 77-88.

Embryology Problem Based Questions (Langman - Q5)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

What is mosaicism, and how does it occur?

Answer:

Mosaicism is a genetic condition that arises when an individual has two or more populations of cells with different genetic compositions within their body. In other words, some of the individual's cells have one set of genetic information, while others have a different set.

Mosaicism occurs due to genetic mutations that occur during early stages of embryonic development. During this time, the fertilized egg divides repeatedly to form a group of cells that will eventually develop into an entire organism. If a mutation occurs during one of these early cell divisions, then the resulting organism will have a mixture of cells with the mutation and cells without the mutation.

Mosaicism can occur in any type of cell, including those that give rise to tissues and organs, which can lead to a wide range of physical and developmental abnormalities depending on the type of mutation involved and which tissues are affected. Some examples of conditions caused by mosaicism include certain types of cancer, skin disorders, and developmental disorders such as Down syndrome.

Here are some examples of mosaicism:

Down Syndrome Mosaicism: Down syndrome is typically caused by an extra copy of chromosome 21, but in some cases, individuals have a mixture of cells with the extra chromosome and cells without it. This is known as mosaic Down syndrome. Mosaic Down syndrome can result in a milder phenotype and fewer health problems than the typical form of Down syndrome.

Reference:

Hook, E. B. (1981). Mosaicism for trisomy 21: a review. Human Genetics, 58(1), 1-12.

Segmental Neurofibromatosis Type 1 Mosaicism: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder characterized by the growth of benign tumors along nerves throughout the body. Segmental NF1 mosaicism is a rare form of the disorder in which only certain parts of the body are affected due to mosaicism.

Reference:

Kluwe, L., Friedrich, R. E., & Mautner, V. F. (2011). Segmental neurofibromatosis type 1: a rare manifestation with a possible risk of malignancy. Acta Dermato-Venereologica, 91(6), 686-687.

Pigmentary Mosaicism: Pigmentary mosaicism refers to a group of disorders in which there is a mosaic distribution of skin pigmentation. One example is hypomelanosis of Ito, which is characterized by a distinctive pattern of hypopigmentation along the lines of Blaschko.

Reference:

Happle, R. (2010). Mosaicism in human skin: understanding the patterns and mechanisms. Archives of Dermatology, 146(7), 859-876.

Mosaic Turner Syndrome: Turner syndrome is a genetic disorder that affects females and is caused by the absence of all or part of one X chromosome. In some cases, females with Turner syndrome have a mosaic pattern of cells with the missing X chromosome and cells with two X chromosomes.

Reference:

Sybert, V. P. (2016). Turner syndrome. New England Journal of Medicine, 376(8), 743-752

Embryology Problem Based Question (Q4 - Langman)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

In addition to numerical abnormalities, what types of chromosomal alterations occur?

Answer:

In addition to numerical abnormalities, there are several types of chromosomal alterations that can occur, including structural abnormalities and genomic imprinting disorders.

Structural abnormalities involve changes in the structure of chromosomes, such as deletions, duplications, inversions, and translocations. Deletions occur when a part of a chromosome is missing, while duplications occur when a segment is copied. Inversions involve a segment of the chromosome that is reversed in orientation, and translocations occur when segments of non-homologous chromosomes are exchanged.

Genomic imprinting disorders are caused by changes in the epigenetic marking of genes, which can result in the silencing of certain genes. These disorders can result in various clinical conditions, such as Angelman syndrome and Prader-Willi syndrome.

Deletions involve the loss of a segment of a chromosome, resulting in the absence of the genetic material contained in that segment. This can lead to various genetic disorders, depending on which genes are missing. For example, cri-du-chat syndrome is caused by a deletion of part of chromosome 5 and is characterized by a distinctive cry, intellectual disability, and other physical and developmental abnormalities.

Duplications occur when a segment of a chromosome is duplicated, resulting in the presence of extra genetic material. Depending on the size and location of the duplication, this can lead to various developmental and intellectual disabilities.

Inversions occur when a segment of a chromosome is flipped around 180 degrees, changing the orientation of the genetic material within that segment. Inversions can have varying effects depending on the location and size of the inverted segment, but may cause no significant clinical effects in some cases.

Translocations occur when a segment of one chromosome breaks off and becomes attached to another chromosome. This can lead to a rearrangement of genetic material and can cause various clinical syndromes, depending on the specific chromosomes involved. For example, the Philadelphia chromosome, which is a translocation between chromosomes 9 and 22, is associated with chronic myeloid leukemia.

In addition to these structural abnormalities, there are also chromosomal disorders that are caused by changes in the epigenetic marking of genes. Genomic imprinting disorders occur when certain genes are silenced due to abnormal epigenetic modifications, resulting in clinical syndromes such as Angelman syndrome and Prader-Willi syndrome.

References:

Sadler, T. W. (2019). Langman's medical embryology (14th ed.). Wolters Kluwer.

Lewis, R. (2020). Human genetics: concepts and applications (12th ed.). McGraw-Hill Education.

Embryology Problem Based Question (Q3 - Langman)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

What is the most common cause of abnormal chromosome number? Give an example of a clinical syndrome involving abnormal numbers of chromosomes.

Answer:

The most common cause of abnormal chromosome number is non-disjunction during cell division, which results in the unequal distribution of chromosomes between daughter cells. Non-disjunction can occur during both meiosis and mitosis, leading to an abnormal number of chromosomes in the resulting cells.

During meiosis, non-disjunction can lead to aneuploidy, which is an abnormal number of chromosomes in the resulting gamete. Aneuploidy can result in various clinical syndromes, such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13).

Down syndrome is the most common example of a clinical syndrome involving abnormal numbers of chromosomes. It occurs due to the presence of an extra copy of chromosome 21. Down syndrome is characterized by distinct facial features, intellectual disability, and an increased risk of certain health conditions such as heart defects and Alzheimer's disease.

Reference:

Sadler, T. W. (2019). Langman's medical embryology (14th ed.). Wolters Kluwer.

Embryology Problem Based Question (Q2 - Langman)

ANATOMY AIIMS, GROSS ANATOMY, EMBRYOLOGY, NEUROANATOMY, MICROANATOMY, APPLIED/ CLINICAL ANATOMY

Under normal conditions, FGFs and their receptors (FGFRs) are responsible for growth of the skull and development of the cranial sutures. How might these signaling pathways be disrupted? Do these pathways involve paracrine or juxtacrine signaling? Can you think of a way that loss of expression of one FGF might be circumvented?

Answer:

Fibroblast Growth Factors (FGFs) are important signaling molecules that play a critical role in the development of the cranial sutures and the growth of the skull. These signaling pathways can be disrupted in various ways, such as mutations in the FGF genes, mutations in the FGFR genes, or alterations in the downstream signaling pathways that are involved in the regulation of FGF signaling.

The FGF signaling pathways involve both paracrine and juxtacrine signaling. In paracrine signaling, FGFs are secreted by one cell and act on neighboring cells that express FGFRs. In juxtacrine signaling, FGFs and FGFRs are expressed on adjacent cells and interact directly with each other. Both types of signaling are important for the proper development of the skull and cranial sutures.

Loss of expression of one FGF might be circumvented by compensatory upregulation of other FGFs. For example, in a study on Fgf9 knockout mice, compensatory upregulation of other FGFs was observed, leading to partial rescue of the phenotype. Additionally, exogenous application of FGFs might also be a way to circumvent the loss of expression of one FGF, although this would depend on the specific circumstances and would need to be tested experimentally.

References:

Rice DP, Aberg T, Chan YS, et al. Integration of FGF and TWIST in calvarial bone and suture development. Development. 2000;127(9):1845-1855. doi:10.1242/dev.127.9.1845

Wilkie AO. Craniosynostosis: genes and mechanisms. Hum Mol Genet. 1997;6(10):1647-1656. doi:10.1093/hmg/6.10.1647 Ohbayashi N, Shibayama M, Kurotaki Y, et al. FGF18 is required for normal cell proliferation and differentiation during osteogenesis and chondrogenesis. Genes Dev. 2002;16(7):870-879. doi:10.1101/gad.976102