Anatomy exam Questions

Question 1

List the superior, inferior, medial and lateral borders of the breast, based on relationship with adjacent anatomical landmarks.

Answer 1

Superior Border: The superior border of the breast is formed by the 2nd rib, which is located above the breast tissue.

Inferior Border: The inferior border of the breast is not sharply defined and gradually blends with the chest wall and the abdominal wall below the breast, approx. 6th rib level

Medial Border: The medial border of the breast lies along the lateral margin of the sternum (breastbone).

Lateral Border: The lateral border of the breast extends into the axilla (armpit) and is continuous with the anterior axillary fold or mid axillary line.

Question 2

List the posterior relations of the breast

Answer 2

Posterior Relations of the Breast:
The breast’s posterior relations are primarily with muscles and structures of the chest wall. The deep (posterior) surface of the breast is related to:

Pectoralis Major Muscle: The breast lies directly over the pectoralis major muscle, which is a large muscle of the chest.
Pectoralis Minor Muscle: Deeper to the pectoralis major muscle, the breast is related to the pectoralis minor muscle, a smaller muscle of the chest.
Rib Cage and Intercostal Muscles: The breast also rests on the rib cage and the intercostal muscles located between the ribs.

Question 3

List three anatomical lymph node regions (not surgical levels) that the breast drains into

Answer 3

Anatomical Lymph Node Regions that the Breast Drains Into:
The lymphatic drainage of the breast involves several lymph node regions. Three important anatomical lymph node regions into which the breast drains are:

Axillary Lymph Nodes: The majority of lymph from the breast drains into the axillary lymph nodes, located in the armpit region. These nodes are the first stations for breast lymphatic drainage and are crucial for staging breast cancer.

Internal Mammary Lymph Nodes: Some lymphatic drainage from the breast can also pass to the internal mammary lymph nodes, which are located along the internal mammary vessels on either side of the sternum.

Supraclavicular Lymph Nodes: A small portion of lymphatic drainage from the upper outer quadrant of the breast can drain into the supraclavicular lymph nodes, located just above the clavicle (collarbone).

Question 4

Define the anatomical boundaries of the axilla

Answer 4

The axilla is a pyramidal-shaped region.

Anterior Wall: Formed by the pectoralis major and pectoralis minor muscles, which cover the front of the axilla.

Posterior Wall: Comprised of the subscapularis muscle and the teres major muscle, located at the back of the axilla.

Medial Wall: Consists of the serratus anterior muscle and the thoracic wall, which is covered by the ribs.

Lateral Wall: the humerus bone

Base: The base of the axilla is an imaginary line connecting the anterior and posterior walls near the upper limb’s attachment to the trunk.

Apex: The apex of the axilla is the region superior to the axillary inlet or the cervico-axillary canal. It is a narrow passageway leading to the neck.

Question 5

Define the anatomical boundaries of the axilla

Answer 5

The axilla is a pyramidal-shaped region.

Anterior Wall: Formed by the pectoralis major and pectoralis minor muscles, which cover the front of the axilla.

Posterior Wall: Comprised of the subscapularis muscle and the teres major muscle, located at the back of the axilla.

Medial Wall: Consists of the serratus anterior muscle and the thoracic wall, which is covered by the ribs.

Lateral Wall: the humerus bone

Base: The base of the axilla is an imaginary line connecting the anterior and posterior walls near the upper limb’s attachment to the trunk.

Apex: The apex of the axilla is the region superior to the axillary inlet or the cervico-axillary canal. It is a narrow passageway leading to the neck.

Question 6

Define levels I-III of the axilla from a surgical perspective.

Answer 6

Level I Axillary Lymph Nodes:
Location: Level I nodes are located along the lower border of the pectoralis minor muscle.
Contents: Level I nodes primarily receive lymphatic drainage from the lateral quadrants of the breast. They are also known as the lateral or lateral pectoral nodes.

Level II Axillary Lymph Nodes:
Location: Level II nodes lie posterior to the pectoralis minor muscle.
Contents: Level II nodes receive lymphatic drainage from both the lateral quadrants and the central part of the breast. They are also known as the intermediate nodes.

Level III Axillary Lymph Nodes:
Location: Level III nodes are situated medial to the pectoralis minor muscle.
Contents: Level III nodes primarily receive lymphatic drainage from the medial quadrants of the breast. They are also known as the medial or subclavicular nodes.

Question 7

Answer 7

A = sternum
B= L pec major
C= L pec minor
D= L scapula
E= Spinal cord
F= oesophagus
G= R lung
H= Trachea

I= Pulmonary trunk
J= L pulmonary artery
K= Descending aorta
L= R main bronchus
M= SVC
N= Ascending aorta
0= internal thoracic vessels

Question 8

List the relations of the femoral canal

Answer 8

The femoral canal is located in the anterior thigh within the femoral triangle.

It can be thought of as a rectangular shaped compartment with four borders and an opening:

Medial border – lacunar ligament.
Lateral border – femoral vein.
Anterior border – inguinal ligament.
Posterior border – pectineal ligament, superior ramus of the pubic bone, and the pectineus muscle

The opening to the femoral canal is located at its superior border, known as the femoral ring. The femoral ring is closed by a connective tissue layer – the femoral septum. This septum is pierced by the lymphatic vessels exiting the canal.

Question 9

List the relations of the femoral triangle

Answer 9

The femoral triangle consists of three borders, a floor and a roof:

Roof – fascia lata.
Floor – pectineus, iliopsoas, and adductor longus muscles.
Superior border – inguinal ligament (a ligament that runs from the anterior superior iliac spine to the pubic tubercle).
Lateral border – medial border of the sartorius muscle.
Medial border – medial border of the adductor longus muscle. The rest of this muscle forms part of the floor of the triangle.
The inguinal ligament acts as a flexor retinaculum, supporting the contents of the femoral triangle during flexion at the hip.

Question 10

List the contents of the femoral triangle

Answer 10

The femoral triangle contains some of the major neurovascular structures of the lower limb. Its contents (lateral to medial) are:

Femoral nerve – innervates the anterior compartment of the thigh, and provides sensory branches for the leg and foot.
Femoral artery – responsible for the majority of the arterial supply to the lower limb.
Femoral vein – the great saphenous vein drains into the femoral vein within the triangle.
Femoral canal – contains deep lymph nodes and vessels.
The femoral artery, vein and canal are contained within a fascial compartment – known as the femoral sheath.

Acronym for the contents of the femoral triangle (lateral to medial) – NAVEL: Nerve, Artery, Vein, Empty space (allows the veins and lymph vessels to distend to accommodate different levels of flow), Lymph nodes.

Question 11

List the boundaries of the inguinal canal

Answer 11

Anterior wall – aponeurosis of the external oblique, reinforced by the internal oblique muscle laterally.
Posterior wall – transversalis fascia.
Roof – transversalis fascia, internal oblique, and transversus abdominis.
Floor – inguinal ligament (a ‘rolled up’ portion of the external oblique aponeurosis), thickened medially by the lacunar ligament.

Question 12

Contents of the inguinal canal

Answer 12

Contents
The contents of the inguinal canal include: ====3====

1. Spermatic cord (biological males only) – contains neurovascular and reproductive structures that supply and drain the testes. See here for more information.
2. Round ligament (biological females only) – originates from the uterine horn and travels through the inguinal canal to attach at the labia majora.
3. Ilioinguinal nerve – contributes towards the sensory innervation of the genitalia
   Note: only travels through part of the inguinal canal, exiting via the superficial inguinal ring (it does not pass through the deep inguinal ring)
   This is the nerve most at risk of damage during an inguinal hernia repair.
4. Genital branch of the genitofemoral nerve – supplies the cremaster muscle and anterior scrotal skin in males, and the skin of the mons pubis and labia majora in females.

The walls of the inguinal canal are usually collapsed around their contents, preventing other structures from potentially entering the canal and becoming stuck.

Question 13

• Anatomical course of spermatic cord
• layers of spermatic cord
• Contents of the spermatic cord

Answer 13

Anatomical Course
Formed at the deep inguinal ring. (located laterally to the inferior epigastric vessels)
Through the inguinal canal, entering the scrotum via the superficial inguinal ring.
Into the scrotum, ending at the posterior border of the testes.

Layers:
1. External spermatic fascia – derived from the aponeurosis of the external oblique muscle.
2. Cremaster muscle and fascia – derived from the internal oblique muscle.
3.Internal spermatic fascia – derived from the transversalis fascia.
The three fascial layers themselves are covered by a layer of superficial fascia, which lies directly below the scrotal skin.

Contents: ===9===
===Blood vessels===
1. Testicular artery – branch of the aorta that arises just inferiorly to the renal arteries.
2. Cremasteric artery and vein – supplies the cremasteric fascia and muscle.
3. Artery to the vas deferens – branch of the inferior vesicle artery, which arises from the internal iliac.
4. Pampiniform plexus of testicular veins – drains venous blood from the testes into the testicular vein.
===Nerves===
5. Genital branch of the genitofemoral nerve – supplies the cremaster muscle.
6. Autonomic nerves
===Other structures===
7. Vas deferens – the duct that transports sperm from the epididymis to the ampulla.
8. Processus vaginalis – projection of peritoneum that forms the pathway of descent for the testes during embryonic development. In the adult, it is fused shut.
9. Lymph vessels – these drain into the para-aortic nodes, located in the lumbar region.

Question 14

Anatomical course of the vas deferens

Answer 14

• It is continuous with the tail of the epididymis.
• Travels through the inguinal canal, as part of the spermatic cord.
• Moves down the lateral pelvic wall close to the ischial spine.
• Turns medially to pass between the bladder and the ureter and then travels downward on the posterior surface of the bladder.
• The inferior narrow part of the ampulla joins the duct from the seminal vesicle to form the ejaculatory duct.

Question 15

Answer 15

Sacral plexus L4-S4
‘Some Irish Sailor Pesters Polly’.
Superior Gluteal,
Inferior Gluteal,
Sciatic,
Posterior cutaneous nerve of thigh, Pudendal.

A= L4 nerve root
B= S2 nerve root
C= S4 nerve root
D= pudendal nerve
E= Posterior cutaneous nerve of thigh
F= Tibia nerve (bigger bone, more nerve roots)
G= Common fibular
H= sciatic nerve
I= Inferior gluteal
J= Superior gluteal

Question 16

Answer 16

A= L1
B= S5
C= S4
D= S3
E= L2
F= S2
G= L3
H= L5
I= L4
J= S1

Question 17

Name one major muscle and one spinal nerve root responsible for hip flexion and plantar flexion

Answer 17

Hip Flexion - illopsoas
L1,L2, L3
Spinal Nerve Root for Hip Flexion: The femoral nerve (specifically the branches arising from the lumbar spinal nerve roots L2-L4) is primarily responsible for innervating the muscles involved in hip flexion, including the iliopsoas.

Plantar flexion - Gastrocnemius
S1
Spinal Nerve Root for Plantar Flexion: The tibial nerve (which arises from the lumbar and sacral spinal nerve roots, particularly L4-S3) is responsible for innervating the muscles involved in plantar flexion, including the gastrocnemius and soleus.

Question 18

Using a table, compare and contrast the appearance of the thoracic and lumbar vertebrae.
In your answer, address the differences in the body, spinous process, transverse process and articulations.

Answer 18

Question 19

Describe the course of the internal carotid artery.

Answer 19

1. Origin: The common carotid artery bifurcation, at the level of the upper border of the thyroid cartilage (Adam’s apple) in the neck.
2. Course within the Neck: ascends vertically within the carotid sheath. No branches in neck.
3. Passage through Carotid Canal: The internal carotid artery continues its upward course through the base of the skull, through an opening in the temporal bone , the carotid canal.
4. Cerebral Circulation: Within the cranial cavity, gives off branches:
   - ophthalmic artery
   - Posterior communicating artery
   - Superior hypophyseal artery
   - anterior cerebral artery
   - middle cerebral artery
5. Termination: The internal carotid artery terminates by dividing into two major branches known as the anterior cerebral artery and the middle cerebral artery.

Question 20

Label the branches of the external carotid artery

Answer 20

8 branches

Question 21

Describe the structure and boundaries of the bony orbit

Answer 21

Bony orbits are four-sided pyramidal cavities on either side of the nose.

Roof: Formed by the frontal bone and lesser wing of sphenoid, this boundary separates the orbit from the frontal sinus of the skull.
Floor: Primarily formed by the maxillary bone, the floor of the orbit separates it from the maxillary sinus.
Medial Wall: Composed of the ethmoid bone and the lacrimal bone, the medial wall separates the orbit from the nasal cavity.
Lateral Wall: Formed by the zygomatic bone and greater wing of sphenoid, the lateral wall provides protection to the side of the eye.
Anterior Opening: The anterior boundary of the orbit is open and allows for the passage of the optic nerve, blood vessels, and other structures. This opening is covered by the orbital septum and the periorbita, connective tissues that help hold the structures within the orbit in place.

Question 22

List the nerves and muscles within the bony orbit.

Answer 22

Nerves: 6

1. Optic Nerve (Cranial Nerve II)
2. Oculomotor Nerve (Cranial Nerve III)
3. Trochlear Nerve (Cranial Nerve IV)
4. Abducens Nerve (Cranial Nerve VI)
5. Ophthalmic Nerve (Branch of Trigeminal Nerve - Cranial Nerve V)
6. Maxillary Nerve (Branch of Trigeminal Nerve - Cranial Nerve V)

Muscles:

1. Extraocular Muscles: These are a group of six muscles that attach to the eyeball and are responsible for moving the eye in different directions. They include:
   - Superior Rectus Muscle: Elevates the eye and turns it medially.
   - Inferior Rectus Muscle: Depresses the eye and turns it medially.
   - Medial Rectus Muscle: Moves the eye medially.
   - Lateral Rectus Muscle: Moves the eye laterally.
   - Superior Oblique Muscle: Moves the eye downward and outward.
   - Inferior Oblique Muscle: Moves the eye upward and outward.
2. Levator Palpebrae Superioris Muscle: This muscle lifts the upper eyelid, allowing the eye to open.
3. Orbicularis Oculi Muscle: This muscle encircles the eye and allows for blinking and closing of the eyelids.
4. Ciliary Muscle: Located within the eye, this muscle controls the shape of the lens for focusing on near and distant objects (accommodation).
5. Iris Sphincter Muscle (Pupillary Constrictor): This muscle controls the size of the pupil, regulating the amount of light entering the eye.

Question 23

Answer 23

A= nasal septum
B= R paranasal sinus
C = R Masseter
D = R parotid
E = R external ear
F= Dens of avis
G = spinal cord
H = hard palate
I= mandible
K = L Internal carotid artery
L = L Internal jugular vein
M= L vertebral artery

Question 24

Answer 24

N= Mandible
O= R Submandibular gland
P= R SCM
Q =R IJV
R = R Trapezius
S = L Platysma
T = hyoid bone
U = epiglottis
V= L Internal carotid artery
W= Spinous process of cervical vertebra

Question 25

The initial presentation of pancreatic cancer varies according to tumour location and type of cells involved. i. Describe the microscopic features of the pancreas. In your answers include the names of the cell types and their secretory product.

Answer 25

I The pancreas is an abdominal glandular organ with both digestive (exocrine) and hormonal (endocrine) functions. Exocrine Tissue: 1. Acinar Cells: These are the primary exocrine cells in the pancreas. They form small clusters called acini and secrete digestive enzymes into the pancreatic ducts. These enzymes include amylase (for carbohydrate digestion), lipase (for fat digestion), and proteases (for protein digestion). 2. Centroacinar Cells: These cells are located at the center of the acini and are involved in the production of bicarbonate-rich fluid, which helps neutralize stomach acid and provides an optimal environment for enzyme activity. 3. Duct Cells: These cells line the pancreatic ducts and secrete bicarbonate ions, which help further neutralize the acidic chyme from the stomach before it enters the small intestine. Endocrine Tissue (Islets of Langerhans): 1. Alpha Cells: These cells secrete glucagon, a hormone that raises blood sugar levels by promoting the release of glucose from the liver. 2. Beta Cells: These cells secrete insulin, a hormone that lowers blood sugar levels by facilitating the uptake of glucose by cells. 3. Delta Cells: These cells secrete somatostatin, a hormone that inhibits the release of both insulin and glucagon, thus helping regulate the overall hormonal balance. 4. Gamma Cells: These cells secrete pancreatic polypeptide, which plays a role in regulating the release of pancreatic enzymes and gallbladder contractions.

Question 26

ii. List the relationships of the head of the pancreas.

Question 27

ii. List the relationships of the head of the pancreas.

Answer 27

Ant= 1st part duodenum, Transverse colon, stomach Post = IVC, Aorta Lateral = R kidney, duodenum 2nd part Inferior = 3rd part duodenum Medial = SMA vessels

Question 28

List the microscopic layers of the oesophagus from innermost to outermost.

Answer 28

Innermost -> outermost 1. Mucosa 2. Submucosa 3. Muscle - inner circular, outer longitudinal 4. Adventitia

Question 29

Describe the lymphatic drainage of the oesophagus. In your answer include the following: - Lymphatic system within the organ - Regional lymph nodes for the upper, middle and lower third of the oesophagus

Answer 29

The esophagus contains its own lymphatic system, which includes lymphatic vessels and nodes within its walls. 1. Upper Third of the Esophagus: Deep cervical nodes The lymphatic vessels within the upper third of the esophagus drain into the cervical lymph nodes, which are located in the neck. These lymph nodes include: Superior Deep Cervical Nodes: These nodes are located along the internal jugular vein and drain the upper part of the esophagus. 2. Middle Third of the Esophagus: Superior and posterior mediastinal nodes The lymphatic vessels within the middle third of the esophagus drain into the mediastinal lymph nodes, which are located in the mediastinum (the space between the lungs). These lymph nodes include: Inferior Deep Cervical Nodes: Some drainage from the middle esophagus may also reach these nodes. Tracheobronchial Nodes: These nodes are located near the trachea and bronchi and receive lymphatic drainage from the middle esophagus. 3. Lower Third of the Esophagus: Left gastric and celiac nodes The lymphatic vessels within the lower third of the esophagus drain into the abdominal lymph nodes, which are located in the abdomen. These lymph nodes include: Gastric Nodes: These nodes are located along the left gastric artery and receive lymphatic drainage from the lower esophagus. Celiac Nodes: These nodes are part of the celiac lymph node group and receive lymphatic drainage from the lower esophagus.

Question 30

Answer 30

A = R lobe liver B = R kidney C = IVC D= L lobe liver E = abdominal aorta F = L common iliac artery G = bladder

Question 31

Answer 31

H = Celiac trunk I = pancreas J= Spleen

Question 32

Liver segmentation can be described using Couinaud System. Briefly describe the Couinaud System. Draw a labelled diagram (from the anterior view of the liver) demonstrating the layout of the segments Outline how these segments are grouped into the anatomical lobes of the liver.

Answer 32

The liver is divided into eight segments based on the distribution of the hepatic vessels and bile ducts. Each segment has its own vascular inflow and outflow, which is important for surgical procedures, including liver resections and transplants. The segments are numbered using Roman numerals, and they are further categorized into four major sectors: Left lateral, left medial, R medial, R lateral Left lobe - II+III Accessory lobes caudate + quadrate R lobe V- VIII

Question 33

Anatomical boundaries of the axilla

Answer 33

1. Anteriorly: Pectoralis major and minor muscle 2. Posteriorly: Teres major and Subscapularis muscle and the scapula's posterior surface. 3. Medially: The upper ribcage and serratus anterior muscle. 4. Laterally: Intertubercular groove of the humerus.

Question 34

List the contents of the axilla

Answer 34

1. Axillary artery 2. Axillary vein 3. Brachial plexus 4. Lymph nodes. 5. Lymphatic vessels 6. Fat and connective tissue 7. Axillary fascia 8. Small blood vessels, nerves, and muscles

Question 35

Describe the lymphatic drainage of the upper limb.

Answer 35

Superficial drainage: Arise from lymphatic plexuses in the skin of the hand. These vessels then travel up the arm in close proximity to the major superficial veins: - Basilic vein go on to enter the cubital lymph nodes. These are found medially to the vein, and proximally to the medial epicondyle of the humerus. Vessels carrying on from these nodes then continue up the arm, terminating in the lateral axillary lymph nodes. - Cephalic vein generally cross the proximal part of the arm and shoulder to enter the apical axillary lymph nodes, though some exceptions instead enter the more superficial deltopectoral lymph nodes. Deep drainage: The deep lymphatic vessels of the upper limb follow the major deep veins (i.e. radial, ulnar and brachial veins), terminating in the humeral axillary lymph nodes.

Question 36

Describe the axillary lymph nodes

Answer 36

The majority of the upper extremity lymph nodes are in the axilla. They can be divided anatomically into 5 groups: 1- Pectoral (anterior) – 3-5 nodes, located in the medial wall of the axilla. They receive lymph primarily from the anterior thoracic wall, including most of the breast. 2- Subscapular (posterior) – 6-7 nodes, located along the posterior axillary fold and subscapular blood vessels. They receive lymph from the posterior thoracic wall and scapular region. 3- Humeral (lateral) – 4-6 nodes, located in the lateral wall of the axilla, posterior to the axillary vein. They receive most of the lymph drained from the upper limb. 4- Central – 3-4 large nodes, located near the base of the axilla (deep to pectoralis minor, close to the 2nd part of the axillary artery). They receive lymph via efferent vessels from the pectoral, subscapular and humeral axillary lymph node groups. 5-Apical – Located in the apex of the axilla, close to the axillary vein and 1st part of the axillary artery. They receive lymph from efferent vessels of the central axillary lymph nodes, therefore from all axillary lymph node groups. The apical axillary nodes also receive lymph from those lymphatic vessels accompanying the cephalic vein. Efferent vessels from the apical axillary nodes travel through the cervico-axillary canal, before converging to form the subclavian lymphatic trunk. The right subclavian trunk continues to form the right lymphatic duct and enters the right venous angle (junction of the internal jugular and subclavian veins) directly. The left subclavian trunk drains directly into the thoracic duct.

Question 37

Using a well-labelled diagram, illustrate the lobar structure of the lungs and fissures.

Answer 37

Question 38

List the structures that can be found along the medial surface of the left lung.

Answer 38

- Arch of aorta and thoracic aorta - Oesophagus - Heart

Question 39

Briefly describe the blood supply to the lung.

Answer 39

Paired pulmonary arteries supply deoxygenated blood to the lungs. The bronchi, lung roots, visceral pleura and supporting lung tissues require an extra nutritive blood supply. This is delivered by the bronchial arteries, which arise from the descending aorta.

Question 40

Label the CT

Answer 40

A= latissimus dorsi B= Subscapularis C= Spine of scapula D= Erector spine muscle E= spinal cord F= transverse process of thoracic vertebra G = Left lung H = Left pectorals minor muscle I = L subclavian artery J= L common carotid artery K= Sternum L = Oesophagus M = Trachea N = R brachiocephalic vein

Answer 41

A= R rib B = R main bronchus C = R infraspinatus muscle D = Trapezius E = Descending aorta F = Intercostal muscle G= Pectoralis major muscle H = Pulmonary trunk I = Ascending aorta J = R pulmonary artery

Question 42

What structure produces cerebrospinal fluid (CSF) and where is it located?

Answer 42

Cerebrospinal fluid (CSF) is produced by specialized structures within the brain known as the choroid plexuses. The choroid plexuses are located in the ventricles of the brain, which are fluid-filled cavities within the brain's cerebral hemispheres.

Question 43

Name the ventricles of the brain and their connecting foramina.

Answer 43

Lateral Ventricles (First and Second Ventricles): located within each cerebral hemisphere. They consist of a body, an anterior horn, and a posterior horn. The lateral ventricles are connected to each other and to the third ventricle through the following foramen: Interventricular Foramen: This foramen connects each lateral ventricle with the third ventricle. Third Ventricle: This ventricle is located in the midline of the brain, between the right and left thalami. The third ventricle is connected to the fourth ventricle through the following foramina: Cerebral Aqueduct: This narrow channel connects the third ventricle to the fourth ventricle. It allows CSF to flow from the third ventricle to the fourth ventricle. Fourth Ventricle: This ventricle is situated between the brainstem and the cerebellum. It is connected to the subarachnoid space around the brain and spinal cord through the following foramina: Lateral Apertures (Foramina of Luschka): These two openings are located on the lateral sides of the fourth ventricle. They allow CSF to flow from the fourth ventricle into the subarachnoid space. Median Aperture (Foramen of Magendie): This single opening is located at the midline on the roof of the fourth ventricle. It also allows CSF to flow from the fourth ventricle into the subarachnoid space.

Question 44

Name the components of the brainstem.

Answer 44

Midbrain, pons, medulla oblongata

Question 45

Where does the vagus nerve (CN X) originate from?

Answer 45

Medulla

Question 46

Name the major branches of the vagus nerve.

Answer 46

1. Pharyngeal Branches: These branches innervate the muscles of the pharynx (throat), including the muscles involved in swallowing and speaking. 2. Superior Laryngeal Nerve: This nerve has two branches: - External Branch: Supplies motor innervation to the cricothyroid muscle, which is important for controlling pitch during speech. - Internal Branch: Provides sensory innervation to the mucous membranes of the larynx above the vocal cords. 3. Recurrent Laryngeal Nerves: These nerves are critical for vocal cord function and have slightly different paths on each side: - Left Recurrent Laryngeal Nerve: Loops around the aortic arch before ascending to innervate the muscles of the larynx. - Right Recurrent Laryngeal Nerve: Loops around the right subclavian artery before ascending to innervate the muscles of the larynx. 4. Cardiac Branches: These branches innervate the heart and are involved in regulating heart rate and cardiac output. 5. Pulmonary Branches: These branches supply the bronchi, bronchioles, and lungs, contributing to the control of respiratory functions. 6. Esophageal Branches: These branches innervate the esophagus and are involved in controlling peristalsis during swallowing. 7. Gastric Branches: These branches innervate the stomach and contribute to the regulation of digestive processes. 8. Hepatic Branches: These branches innervate the liver and are involved in controlling various liver functions. 9. Splenic Branches: These branches innervate the spleen and are part of the vagus nerve's extensive influence on the autonomic nervous system. 10. Renal Branches: These branches innervate the kidneys and contribute to the regulation of kidney functions. 11. Intestinal Branches: These branches innervate the intestines and play a role in controlling gastrointestinal motility and secretion. 12. Auricular Branches: These branches provide sensory innervation to the external ear.

Question 47

Name the structures

Answer 47

A = Sphenoid sinus B = Pons C = Frontal sinus D= ?Septum pallucidum E = Corpus callous F = Mid brain G = 4th ventricle H= cerebellum I = Medulla oblongata J= tonsil of cerebellum

Question 48

List the foramina from which each cranial nerve exits the skull (and its corresponding cranial nerve/s).

Answer 48

Occipital nerve = Ethmoid cribriform plate Optic nerve = Optic canal Oculomotor = SOF Trochlear = SOF Trigeminal = V1 (SOF), V2 (Foramen Rotundum), V3 (Foramen ovale) Abducens = SOF Facial = Internal acoustic meatus and facial canal Vestibulocochlear = Internal acoustic meatus Glossopharyngeal = Jugular foramen Vagus = Jugular foramen Accessory = Jugular foramen Hypoglossal = hypoglossal canal

Question 49

Describe the course of the oculomotor nerve.

Answer 49

The oculomotor nerve originates from the oculomotor nucleus – located within the midbrain of the brainstem. It emerges from the anterior aspect of the midbrain, passing inferiorly to the posterior cerebral artery and superiorly to the superior cerebellar artery. The nerve then pierces the dura mater and enters the lateral aspect of the cavernous sinus. The nerve leaves the cranial cavity via the superior orbital fissure. At this point, it divides into superior and inferior branches:

Question 50

List the structures that are innervated by the oculomotor nerve.

Answer 50

The oculomotor nerve innervates many of the extraocular muscles. These muscles move the eyeball and upper eyelid. Superior Branch 1. Superior rectus – elevates the eyeball 2. Levator palpabrae superioris – raises the upper eyelid. Inferior Branch: 3. inferior rectus – depresses the eyeball 4. Medial rectus – adducts the eyeball 5. Inferior oblique – elevates, abducts and laterally rotates the eyeball

Question 51

Label diagram

Answer 51

A = Mandible B = Platysma C = R parotid D = R common carotid artery E = R internal jugular vein F = Trapezius muscle G = Digastric muscle H = Epiglottis I = L External jugular vein J = L greater horn of thyroid bone

Question 52

Label diagram

Answer 52

A = Tongue B = R masseter C = Mandible D = Parotid gland E = R internal carotid artery F = Spinal cord G = Molar tooth H = Uvula I = L Medial pterygoid muscle J = L vertebral artery

Question 53

List the microscopic layers of the rectum from innermost to outermost.

Answer 53

1. Mucosa: The innermost layer, the mucosa, is in direct contact with the contents of the rectum. It consists of several sublayers: - Epithelium: The innermost lining of the mucosa is composed of a simple columnar epithelium, which helps in the absorption of water and electrolytes. - Lamina Propria: This layer contains blood vessels, lymphatic vessels, and connective tissue that support the epithelium. - Muscularis Mucosae: A thin layer of smooth muscle that aids in the movement of the mucosal folds. 2. Submucosa: This layer contains larger blood vessels, lymphatics, and nerve fibers. It also contains connective tissue that supports the mucosa and helps maintain its structural integrity. 3. Muscularis Externa: The muscularis externa consists of two layers of smooth muscle: - Inner Circular Layer: This layer of muscle fibers encircles the rectum and is responsible for constricting the rectal lumen. - Outer Longitudinal Layer: This layer runs along the length of the rectum and aids in shortening and lengthening the rectal tube during defecation. 4. Mesorectum 5. Mesorectal fascia

Question 54

Describe the arterial supply of the rectum.

Answer 54

Arterial Supply: The arterial supply to the rectum primarily comes from the following arteries: Superior Rectal Artery: This is a branch of the inferior mesenteric artery, which arises from the abdominal aorta. The superior rectal artery supplies the upper part of the rectum. Middle Rectal Artery: These arteries usually arise from the internal iliac artery. They supply the middle part of the rectum. Inferior Rectal Artery: These arteries originate from the internal pudendal artery, which is a branch of the internal iliac artery. The inferior rectal arteries supply the lower part of the rectum, including the anal canal. \

Question 55

Describe the Venous drainage of the rectum

Answer 55

Venous Drainage: submucosal rectal venous plexus -> drains into the superior, middle and inferior rectal veins that follow the course the same named arteries. * superior rectal vein - drains into the portal venous system, * middle and inferior rectal veins - drains into systemic veins. * Anastomoses occurs between the three, this forms an important area of portocaval anastomosis. - this occurs mainly in the anal canal

Question 55

Describe the lympatic drainage of the rectum

Answer 55

Rectum- lymphatic drainage * Lymph vessels from the rectum drain into pararectal nodes - embedded in the perirectal connective tissue, just outside the muscular coat. (mesorectum) * The superior group of these nodes drain through lymph vessels ascend with the superior rectal vessels to drain into the lymph nodes in the inferior part of the mesentery of the sigmoid colon, and then to the inferior mesenteric lymph nodes. * The inferior group of these nodes drain through vessels that accompany the middle rectal vessels to drain into the internal iliac lymph nodes.

Question 56

Describe the nerves of the rectum

Answer 56

Sympathetic * From lumbar spinal cord (T12-L2) * Lumbar splanchnic n -> hypogastric/pelvic plexus ->plexi around inf mesenteric and sup rectal art Parasympathetic * S2-4 * Pelvic sphlanchnic n * L & R inf hypogastric plexus ->pelvic plexus * Visceral afferents to S2-4 * The rectum is only sensitive to stretch

Question 57

Describe the neurovasculature of the anal canal above and below the dentate line

Answer 57

Question 58

Describe the lymphatic drainage of the uterus and the nerves

Answer 58

Uterus lymphatics and nerves Lymphatics * Fundus – lymph vessels accompany the ovarian artery and drain to the para-aortic nodes at L1. * Body and Cervix – drain to the internal and external iliac nodes * Some lymph vessels follow the round ligament and drain into the superficial inguinal nodes. Nerves * Sympathetic and parasympathetic nerves from the inferior hypogastric plexus.

Question 59

Describe the artrerial and venous supply of the uterus

Answer 59

Uterus blood supply Arterial * Uterine artery (branch of internal iliac) * Runs medially in the base of the broad ligament, and crosses above the ureter at right angles, just above the lateral fornix of the vagina. * The artery then ascends along the lateral margin of the uterus within the broad ligament. Venous * Uterine vein follows the artery and drains into the internal iliac vein. Pampiniform plexus

Question 60

Ovarian bood supply

Answer 60

Arterial * Ovarian artery - arises from the aorta at L1. - Descends along posterior abdominal wall - Crosses over external iliac vessels at pelvic brim - Enters the suspensory ligaments - Terminates by bifurcating into ovarian and tubal branches, which pass though the mesovarium to the ovary - Both branches anastomose with the corresponding branches of uterine artery Venous * Veins form pampiniform plexus in broad ligament. * plexus usually merges to form one ovarian vein * Leaves the pelvis with the ovarian artery * right drains to - IVC * Left drains to - left renal vein

Question 61

Vagina blood supply and lymphatics

Answer 61

Arterial * Upper part; vaginal branches of the uterine artery * Lower part; vaginal arteries, branches of the middle rectal and internal pudendal arteries. Venous * Vaginal veins form a venous plexus around the sides of the vagina within mucosa * Continuous with uterovaginal venous plexus * drain into the internal iliac veins through the uterine vein. * Lymphatic Drainage * Upper 1/3 - to internal and external iliac nodes * Middle 1/3 - to internal iliac nodes * Lower 1/3 - to sacral and common iliac, as well as superficial inguinal nodes

Question 62

Use well-labelled diagrams in the sagittal plane to describe the two version and two flexion positions of the uterus.

Answer 62

The uterus is normally anteverted and anteflexed so that its weight is borne largely by the urinary bladder, although it also receives significant passive support from the cardinal ligaments and active support from the muscles of the pelvic floor.

Question 63

List the relations of the left and right adrenal glands

Answer 63

Question 64

Describe the macroscopic structure of the left and right adrenal glands.

Answer 64

The adrenal (or suprarenal) glands are paired endocrine glands situated over the medial aspect of the upper poles of each kidney. They secrete steroid and catecholamine hormones directly into the blood. The adrenal glands are located in the posterior abdomen, between the superomedial kidney and the diaphragm. They are retroperitoneal, with parietal peritoneum covering their anterior surface only. The right gland is pyramidal in shape, contrasting with the semi-lunar shape of the left gland. Perinephric (or renal) fascia encloses the adrenal glands and the kidneys. This fascia attaches the glands to the crura of the diaphragm. They are separated from the kidneys by the perirenal fat.

Question 65

label the structures

Answer 65

A = R lobe liver B = IVC C = ?R kidney D = Ascending colon E = R common iliac vein F = R head of femur G = R obturator internus H = stomach I = spleen J = abdominal aorta K = L psoas major muscle L = L lilacus M = Sigmoid N = bladder O = prostate

Question 66

1. Describe the anatomical boundaries of the left breast. (2 marks)

Answer 66

* Posterior – Pectoralis major and serratus anterior * Anterior – Skin * Medial – Sternunm * Lateral -mid-axillary line * Superior – inferior edge of the sternoclaviular joint (approx. 2nd rib) * Inferior – Inframammary fold (approx. 6th rib)

Question 67

2. Describe the lymphatic drainage of the left breast. (2 marks)

Answer 67

* There are three groups of lymph nodes that receive lymph from breast tissue – the axillary nodes (75%), parasternal nodes (20%) and posterior intercostal nodes (5%). Lymphatic drainage of breast originates from breast lobules and flows through intramammary nodes and channels into a subareolar plexus, called Sappey’s plexus. From this plexus, lymphatic drainage takes place through three main routes that parallel venous tributaries. * Lateral drainage is into 5 groups of axillary nodes (pectoral, subscapular, humeral, central, apical) * Superior drainage is into interpectoral nodes. * Medial drainage is into parasternal nodes. Lymphatics from the left breast all ultimately drain via the thoracic duct into the angle of the left subclavian and internal jugular vein.

Question 68

3. Describe the anatomical boundaries and list the contents of the left supraclavicular fossa. (3 marks)

Answer 68

1. Superior Boundary: lower edge of the sternocleidomastoid muscle. 2. Inferior Boundary: The inferior boundary is formed by the upper border of the left clavicle. 3. Medial Boundary: The medial boundary is defined by the medial edge of the sternocleidomastoid muscle. 4. Lateral Boundary: The lateral boundary is typically open and does not have a specific anatomical structure defining it. Could be the trapezius Contents: - SCF nodes - Fat - Subclavian artery and vein - Transverse cervical artery - Nerves: Brachial plexus, vagus nerve - External and internal jugukar vein - Muscle: platysma

Question 69

4. Describe the structure and course of the right brachial plexus from roots to the five terminal branches.

Answer 69

1. Roots (C5-T1): The brachial plexus begins with five spinal nerve roots: C5, C6, C7, C8, and T1. These roots exit the spinal cord and travel between the anterior and middle scalene and converge to form three trunks: 2. Trunks (Superior, Middle, and Inferior): In the base of neck the roots combine to form three trunks, which are named based on their relative positions: * Superior Trunk: Formed by the union of C5 and C6 roots. * Middle Trunk: Formed by the continuation of the C7 root. * Inferior Trunk: Formed by the union of C8 and T1 roots. 3. Divisions (Anterior and Posterior): Each trunk divides into two divisions as they pass behind the clavicle: * Anterior Divisions * Posterior Divisions. 4. Cords (Lateral, Medial, and Posterior): The divisions recombine to form three cords in the axilla, named according to their relative positions to the axillary artery: * Lateral Cord: Formed by the anterior divisions of the superior and middle trunks. * Medial Cord: Formed by the anterior division of the inferior trunk. * Posterior Cord: Formed by the posterior divisions of all three trunks. 5. Terminal Branches (Five Major Nerves): From the cords, the brachial plexus gives rise to five major terminal branches that provide motor and sensory innervation to the upper limb: * Musculocutaneous Nerve C5-C7: Arises primarily from the lateral cord and innervates muscles in the anterior compartment of the arm. * Median Nerve C6-T1: Formed by contributions from both the lateral and medial cords. It innervates muscles in the anterior forearm and most of the muscles in the hand. * Ulnar Nerve C7-T1: Arises primarily from the medial cord and innervates muscles in the anterior forearm and hand. * Axillary Nerve C5-C6: Comes from the posterior cord and innervates the deltoid muscle and teres minor in the shoulder. * Radial Nerve C5-T1: Also from the posterior cord, it innervates muscles in the posterior compartment of the arm and forearm, as well as the extensors of the wrist and hand.

Question 70

5. Name the structures labelled A to J on the axial CT slice below through the upper thorax. Indicate laterality where applicable. (2 marks)

Answer 70

A = R body of clavicle B = R common carotid artery C = R head of clavicle D = Trachea E = L lobe of thyroid F = L humerus head G = L coracoid process of scapula H = Trapezius I = spinal cord J = body of thoracic vertebra

Question 71

Answer 71

a. SVC b. R pec major muscle c. R Internal thoracic artery and vein d. L pec minor e. L breast f. L pulmonary artery g. Descendig aorta h. R erector spinae muscle i. Oesophagus j. R scapula

Question 72

i. Describe the gross anatomy of the duodenum. In your answer, include the duodenal segments and their corresponding vertebral levels. (2 marks)

Answer 72

The duodenum can be divided into four parts: superior, descending, inferior and ascending. Together these parts form a ‘C’ shape, that is around 25cm long, and which wraps around the head of the pancreas. D1 – Superior (Spinal level L1) The first section of the duodenum is known as ‘the cap’. It ascends upwards from the pylorus of the stomach, and is connected to the liver by the hepatoduodenalligament. This area is most common site of duodenal ulceration. The initial 3cm of the superior duodenum is covered anteriorly and posteriorly by visceral peritoneum, with the remainder retroperitoneal (only covered anteriorly). D2 – Descending (L1-L3) The descending portion curves inferiorly around the head of the pancreas. It lies posteriorly to the transverse colon, and anterior to the right kidney. Internally, the descending duodenum is marked by the major duodenal papilla – the opening at which bile and pancreatic secretions to enter from the ampulla of Vater (hepatopancreatic ampulla). D3 – Inferior (L3) The inferior duodenum travels laterally to the left, crossing over the inferior vena cava and aorta. It is located inferiorly to the pancreas, and posteriorly to the superior mesenteric artery and vein. D4 – Ascending (L3-L2) After the duodenum crosses the aorta, it ascends and curves anteriorly to join the jejunum at a sharp turn known as the duodenojejunal flexure. Located at the duodenojejunal junction is a slip of muscle called the suspensory muscle of the duodenum. Contraction of this muscle widens the angle of the flexure, and aids movement of the intestinal contents into the jejunum.

Question 73

ii. Describe the arterial supply of each segment of the duodenum. (2 marks)

Answer 73

The arterial supply of the duodenum is derived from two sources: * Proximal to the major duodenal papilla (D1 + D2)– supplied by the gastroduodenal artery (branch of the common hepatic artery from the coeliac trunk). * Distal to the major duodenal papilla (D3+D4) – supplied by the inferior pancreaticoduodenal artery (branch of superior mesenteric artery). This transition is important – it marks the change from the embryological foregut to midgut. The veins of the duodenum follow the major arteries and drain into the hepatic portal vein.

Question 74

Answer 74

a. Cortex b. Minor calyx c. Major calyx d. Medullary Pyramid e. Renal capsule f. Renal column g. Renal papilla h. Renal artery + vein i. Renal pelvis

Question 75

iii. List the four layers of fascia and fat encasing the kidney. (1 mark)

Answer 75

i. From outer -> inner 1. Pararenal fat 2. Renal fascia 3. Perirenal fat 4. Renal capsule

Question 76

c. Describe the efferent nerve supply of the bladder, including function and the nerve roots from which they arise. (3 marks)

Answer 76

1. Sympathetic Nerve Supply: * Origin (Nerve Roots): Hypogastric nerve (T12-L2) holds onto urine * They do this by: * Causes relaxation of the detrusor muscle 2. Parasympathetic Nerve Supply (Pelvic Splanchnic Nerves): * Origin (Nerve Roots): Pelvic nerve (S2-S4) * Function: Parasympathetic nerves play a crucial role in bladder emptying (micturition). Their functions include: * Contracting the detrusor muscle to promote bladder emptying. * Relaxing the internal urethral sphincter to facilitate the flow of urine from the bladder into the urethra. 3. Somatic Nerve Supply (Pudendal Nerve): * Origin (Nerve Roots): The pudendal nerve (S2-S4.) * Function: voluntary control of the external urethral sphincter

Question 77

Answer 77

a. Gallbladder b. Small bowel /duodenum c. IVC d. R kidney e. Spinal cord f. L erector spinae g. L adrenal gland h. SMA i. Pancreas j. Stomach

Question 78

Answer 78

a. Pubic symphis b. R Sartorius c. R Femoral vein d. R acetabulum /ligament of head of femur e. R obturator internus muscle f. R superior gemellus /R quadratus femoris muscle g. Ischiorectal fat h. Coccyx i. L gluteus maximus j. Rectum k. L head of femur l. Prostate m. L femoral artery n. L superior pubic rami o. L Spermatic cord

Question 79

i. Name the arterial supply and sensory innervation of the anterior (oral) tongue. (1 mark)

Answer 79

i. Lingual artery ii. Anterior 2/3 supplied by trigeminal nerve (lingual nerve) for general sensation and for taste is a branch of the facial nerve (chorda tympani

Question 80

ii. Name the major draining nodal station(s) and sensory innervation of the posterior tongue (base of tongue). (1 mark)

Answer 80

i. Nodes: Deep cervical lymph nodes ( Treat bilateral levels 2a, 2b, 3, and 4)

Question 81

iii. List four extrinsic muscles of the tongue. (1mark)

Answer 81

i. Hyoglossus ii. Styloglossus iii. Palatoglossus iv. Genioglossus

Question 82

b. Describe the boundaries of the anterior triangle of the neck. (2 marks)

Answer 82

Lateral – Anterior edge of SCM Medial border – sagittal line down midline of neck Posterior border – platysma Superior border – Inferior border of the mandible Inferior border – clavicle

Question 83

List the hormone output(s) of the pituitary gland, indicating whether they are of the anterior or posterior pituitary. (1 mark)

Answer 83

Anterior – GH, FSH, LH, TSH, ACTH, Prolactin Posterior – ADH, Oxytocin

Question 84

Describe the venous drainage of the pituitary gland. (1.5 marks

Answer 84

Anterior -> superior hypophyseal vein posterior lobe -> inferior hypophyseal vein drain into hypophyseal portal veous plexus and then into cavernous sinus into systemic circulation

Question 85

Name the anatomical relations of the pituitary gland. (1.5 marks)

Answer 85

Laterally – cavernous sinus Anterior – sphenoid sinus, optic chiasm Posterior – basillar artery, pons Superior – optic chiasm, diaphragma sellae, cerebellum Inferior – sphenoid sinus

Question 86

List the six contents of the cavernous sinus. (1.5 marks)

Answer 86

1. Internal carotid artery 2. CN III 3. CN IV 4. CN V2 5. CN V3 6. CN VI

Question 87

Answer 87

a. L Superior rectus muscle b. L superficial temporal artery c. L temporalis muscle d. L Lateral rectus muscle e. L inferior rectus muscle f. L masseter muscle g. Intranasal septum h. Hard palate i. Tongue j. R inferior nasal concha k. R maxillary sinus l. Ethmoid sinus / olfactory bulb m. R medial rectus muscle n. R optic nerve o. R superior oblique rectus

Question 88

Answer 88

a. L superior rectus muscle b. L middle cerebellar artery c. L posterior cerellar artery / L optic tract d. L hippocampus e. L Midbrain f. Cingulate gyrus g. Sagittal sinus h. Quadrigeminal cistern i. R mamillary body j. R uncus

Question 89

List the microscopic layers and sublayers of the skin, from superficial to deep. (1.5 marks)

Answer 89

1. Epidermis: * Stratum Corneum: The outermost layer of the epidermis consists of dead, flattened keratinocytes (skin cells) that provide a protective barrier against environmental factors. * Stratum Lucidum: Present only in thick skin (e.g., palms and soles), this translucent layer consists of clear, dead keratinocytes. * Stratum Granulosum: This layer contains granular cells that produce lipids, which contribute to the skin's barrier function. * Stratum Spinosum: Composed of living keratinocytes that appear spiny under a microscope, this layer provides strength and support to the epidermis. * Stratum Basale (Stratum Germinativum): The deepest layer of the epidermis contains actively dividing keratinocytes and melanocytes (pigment-producing cells). 2. Dermis: * Papillary Layer: The superficial layer of the dermis contains papillae that project into the epidermis. It houses blood vessels, nerves, and touch receptors. * Reticular Layer: This deeper layer consists of dense irregular connective tissue, providing strength and support to the skin. It contains blood vessels, sweat glands, sebaceous glands, and hair follicles. 3. Hypodermis (Subcutaneous Tissue): * The hypodermis is not technically part of the skin but is an underlying layer of subcutaneous tissue composed of adipose (fat) and connective tissue. It serves as an insulating layer, energy storage, and provides cushioning and support to the skin.

Question 90

Answer 90

a. Skin b. Superficial fascia c. Areolar tissue d. Deep fascia e. Tunica albuginea f. Corpus cavernosum g. Corpus spongiosum h. Superficial dorsal vein i. Deep dorsal vein j. Dorsal artery k. Dorsal nerve l. Deep artery m. Spongy urethra

Question 91

Describe the lymphatic drainage of the penis. (2 marks)

Answer 91

1. Superficial Lymphatic Drainage: * Penile and perineal skin drain to the superficial inguinal lymph nodes. 2. Deep Lymphatic Drainage: * Glans drains to the external illac nodes * Deeper penile structures drain to internal iliac nodes * Deeper lymphatic vessels follow the course of the deep arteries and drain into the internal iliac lymph nodes (also known as the hypogastric lymph nodes). * The internal iliac lymph nodes are located within the pelvis, near the internal iliac arteries. They receive lymphatic drainage from the deep structures of the penis. 3. Pelvic Lymph Nodes: * Some lymphatic vessels from the penis may further drain into pelvic lymph nodes located in the pelvis. These nodes include the external iliac, common iliac, and para-aortic lymph nodes. * The pelvic lymph nodes play a role in filtering and monitoring lymphatic fluid from the lower pelvic region.

Question 92

Describe the boundaries and the contents of the left femoral triangle. 2 marks)

Answer 92

The femoral triangle consists of three borders, a floor and a roof: Roof – fascia lata. Floor – pectineus, iliopsoas, and adductor longus muscles. Superior border – inguinal ligament (a ligament that runs from the anterior superior iliac spine to the pubic tubercle). Lateral border – medial border of the sartorius muscle. Medial border – medial border of the adductor longus muscle. The rest of this muscle forms part of the floor of the triangle Contents Femoral nerve – innervates the anterior compartment of the thigh, and provides sensory branches for the leg and foot. Femoral artery – responsible for the majority of the arterial supply to the lower limb. Femoral vein – the great saphenous vein drains into the femoral vein within the triangle. Femoral canal – contains deep lymph nodes and vessels.

Question 93

Describe the origin nerve roots, course and terminal branches of the sciatic nerve. (2 marks)

Answer 93

Nerve roots: L4-S3. Motor functions: Innervates the muscles of the posterior thigh (biceps femoris, semimembranosus and semitendinosus) and the hamstring portion of the adductor magnus (remaining portion of which is supplied by the obturator nerve). Indirectly innervates (via its terminal branches) all the muscles of the leg and foot. Sensory functions: No direct sensory functions. Indirectly innervates (via its terminal branches) the skin of the lateral leg, heel, and both the dorsal and plantar surfaces of the foot. Course: The sciatic nerve is derived from the lumbosacral plexus. After its formation, it leaves the pelvis and enters the gluteal region via greater sciatic foramen. It emerges inferiorly to the piriformis muscle and descends in an inferolateral direction. As the nerve moves through the gluteal region, it crosses the posterior surface of the superior gemellus, obturator internus, inferior gemellus and quadratus femoris muscles. It then enters the posterior thigh by passing deep to the long head of the biceps femoris. Within the posterior thigh, the nerve gives rise to branches to the hamstring muscles and adductor magnus. When the sciatic nerve reaches the apex of the popliteal fossa, it terminates by bifurcating into the tibial and common fibular nerves.

Question 94

Name the nerves of the sacral plexus, include nerve roots and functions

Answer 94

Silly Irish Sailors Pester Polly 1. Superior gluteal Roots: L4, L5, S1. Motor Functions: Innervates the gluteus minimus, gluteus medius and tensor fascia lata. Sensory Functions: None. 2. Inferior gluteal Roots: L5, S1, S2. Motor Functions: Innervates gluteus maximus. Sensory Functions: None. 3. Sciatic Roots: L4, L5, S1, S2, S3 Motor Functions: Tibial portion – Innervates the muscles in the posterior compartment of the thigh (apart from the short head of the biceps femoris), and the hamstring component of adductor magnus. Innervates all the muscles in the posterior compartment of the leg and sole of the foot. Common fibular portion – Short head of biceps femoris, all muscles in the anterior and lateral compartments of the leg and extensor digitorum brevis. Sensory Functions: Tibial portion: supplies the skin of the posterolateral leg, lateral foot and the sole of the foot. Common fibular portion: supplies the skin of the lateral leg and the dorsum of the foot. 4. Posterior femoral Roots: S1, S2, S3 Motor Functions: None Sensory Functions: Innervates the skin on the posterior surface of the thigh and leg. Also innervates the skin of the perineum. 5. Pudendal Roots: S2, S3, S4 Motor Functions: Innervates the skeletal muscles in the perineum, the external urethral sphincter, the external anal sphincter, levator ani. Sensory Functions: Innervates the penis and the clitoris and most of the skin of the perineum.