Anatomy π« Flashcards
what are the muscles of the tongue?
The tongue has 2 groups of muscles: intrinsic and extrinsic muscle.
A) Intrinsic muscle: 4 muscles
1. Superior longitudinal muscle
2. Inferior longitudinal muscle
3. Vertical muscle
4. Transverse muscle
B) Extrinsic muscles
These are muscles which arise from structures outside the tongue and inserted into the substance of the tongue.
1. Genioglossus.
2. Hyoglossus.
3. Styloglossus.
4. Palatsglossus.
what is the origin of Genioglossus muscle?
(Fan shaped muscle)
Superior genial tubercle of the mandible.
what is the insertion of Genioglossus muscle?
β the whole length of the tongue.
β the body of the hyoid bone.
what is the nerve supply of Genioglossus muscle?
Hypoglossal nerve
what is the action of Genioglossus muscle?
- Both sides: protrude the tongue
- One side: protrude the tongue and push it to the opposite side.
what is the origin of Hyoglossus muscle?
Body & greater horn of hyoid bone.
what is the insertion of Hyoglossus muscle?
The side of the tongue.
what is the nerve supply of Hyoglossus muscle?
Hypoglossal nerve
what is the action of Hyoglossus muscle?
Depression of the tongue
what is the origin of styloglossus muscle?
β styloid process.
β stylomandibular ligament.
what is the insertion of styloglossus muscle?
The side of the tongue.
what is the nerve supply of styloglossus muscle?
Hypoglossal nerve
what is the action of styloglossus muscle?
Retracts the tongue.
what is the origin of Palatoglossus muscle?
(runs in the palatoglossal fold)
Lower surface of palatine aponeurosis.
what is the insertion of Palatoglossus muscle?
The side of the tongue.
what is the nerve supply of Palatoglossus muscle?
From the pharyngeal plexus (vagoaccessory complex)
what is the action of Palatoglossus muscle?
- Elevates the tongue.
- Depresses the palate.
- approximate the two palatoglossal folds.
what is the function of longitudinal muscles of the tongue?
The superior longitudinal muscle:
- Curls the tip upwards and rolls it posteriorly.
The inferior longitudinal muscles:
- They curl the tip of the tongue inferiorly, and act with the superior muscle to retract and widen the tongue.
origin and insertion of transverse muscles of the tongue
Run from the septum (at the midline) to the margins.
what is the function of transverse muscle of the tongue?
They narrow the tongue and increase its height.
what is the function of vertical muscle of the tongue?
β They flatten the dorsum, increase the transverse diameter, and tend to roll up the margins.
β Acting with the transverse muscles, they increase the length of the tongue and assist with protrusion.
what are the articular surfaces of TMJ?
head of the mandible - Mandibular fossa and articular tubercles (parts of the temporal bone)
what is the type of TMJ?
synovial condylar
what does TMJ consist of?
β It has two (superior and inferior) synovial cavities divided by a fibrous articular disc.
β It Consists of:
β’an upper gliding joint between the articular tubercle and mandibular fossa above and the articular disk below where forward gliding or protrusion and backward gliding or retraction (translation by dentists) takes place.
β’ a lower hinge joint between the disk and the mandibular head (condyle) where elevation or closing and depression or opening of the jaw takes place.
what are the accessory ligaments of TMJ?
Lateral temporomandibular ligament
- Thickening of the lateral part of the fibrous capsule
- Function: prevents dislocation of the jaw.
Sphenomandibular ligament
Stylomandibular ligament
what are the movements done by TMJ?
elevation, depression, protrusion, retraction and side to side movement.
Dislocation of the temporomandibular joint
occurs anteriorly as the mandible head glides across the articular tubercle during yawning and laughing.
what is the origin of Temporalis muscle?
- Temporal fossa.
- Temporal fascia.
what is the insertion of Temporalis muscle?
Coronoid process of the mandible.
what is the nerve supply of Temporalis muscle?
anterior division of mandibular nerve.
what is the action of Temporalis muscle?
Elevation and retraction of the mandible
what is the origin of Masseter muscle?
from the zygomatic arch.
what is the insertion of Masseter muscle?
Outer surface of the ramus of the mandible
what is the nerve supply of Masseter muscle?
anterior division of mandibular nerve.
what is the action of Masseter muscle?
Elevation and protraction of the mandible
what is the origin of Lateral pterygoid muscle?
- Upper head: greater wing of sphenoid.
- Lower head: lateral surface of lateral pterygoid plate.
what is the insertion of Lateral pterygoid muscle?
- capsule and intra articular disk of TMJ.
- pterygoid fovea on the neck of mandible.
what is the nerve supply of Lateral pterygoid muscle?
anterior division of mandibular nerve.
what is the action of Lateral pterygoid muscle?
- depression and protraction of the mandible (opening of the mouth).
- grinding (side to side) movements.
what is the origin of Medial pterygoid muscle?
1. Superficial head: from tuberosity of maxilla.
2. deep head: from medial surface of lateral pterygoid plate
what is the insertion of Medial pterygoid muscle?
Inner surface of the angle of the mandible.
what is the nerve supply of Medial pterygoid muscle?
trunk of mandibular nerve.
what is the action of Medial pterygoid muscle?
- Elevation and protraction of the mandible
- grinding (side to side) movements.
what is the definition of the esophagus?
Narrow muscular tube for food passage between the pharynx and the stomach.
what is the length of the esophagus?
10 inches.
what is the beginning, course & termination of the esophagus?
Beginning: Continuation of the pharynx at the lower border of C6.
Course:It descends downward in the neck, through superior and posterior mediastinum.
Termination: It traverses the esophageal orifice in the right crus of the diaphragm at the level of the T10, Enters the stomach at the cardiac orifice opposite T11, one inch to the left of median plane.
what are the constrictions of the esophagus?
Sites:
1. At the beginning of the esophagus.
2. Opposite the arch of the aorta.
3. Opposite the point of crossing of the left principle bronchus.
4. At the esophageal opening of the diaphragm.
Importance: These constrictions are of clinical importance during the passage of the instruments (gastroscope) along the esophagus.
what are the parts of the esophagus?
- Cervical portion: in the lower part of the neck.
- Thoracic portion: in the superior and posterior mediastinum.
- Abdominal portion: in the upper part of the abdominal cavity.
what are the relations in the thoracic part of the esophagus?
β’ In the superior mediastinum:
- It descends anterior to vertebral column behind the trachea.
- The thoracic duct ascends on its left side
β’ In the posterior mediastinum:
- At T7: the esophagus crosses anterior to aorta from right to left side.
- At T5: The thoracic duct crosses behind esophagus from right to left.
- Related anteriorly to oblique sinus of the pericardium separating it from the left atrium.
what is the blood supply of the esophagus?
Arterial supply:
* Cervical portion: inferior thyroid artery.
* Thoracic portion: descending thoracic aorta.
* Abdominal portion: left gastric artery - inferior phrenic artery.
Venous drainage:
* Cervical portion: brachiocephalic vein.
* Thoracic portion: azygos and hemiazygos.
* Abdominal portion: left gastric vein.
what is the site of the stomach?
Left hypochondriurn, epigastrium and umbilical regions.
what are the divisions of the stomach?
- Cardiac portion
- pyloric portion
cardiac portion of the stomach
1. Fundus: Full rounded upper most part stomach.
2. Body: Extends from cardiac end to angular notch at the lesser curvature of the stomach, including the corresponding area on the greater curvature.
pyloric portion of the stomach
1. Pyloric antrum: dilatation on the greater curvature opposite the angular notch of the lesser curvature.
2. Pyloric canal: cylindrical canal 1 inch long to the right of pyloric antrum.
3. Pyloric sphincter.
compare between cardiac orrifice & pyloric orifice according to site and sphincter
compare between Lesser curvature & Greater curvature Acc to shape, peritoneal folds and related vessels
what is the peritoneal covering of the Antero-superior surface?
Completely covered by the peritoneum of the greater sac
what are the structures related to the Antero-superior surface?
1) Anterior abdominal wall
2) Left lobe of the liver
3) Diaphragm
what is the peritoneal covering of the Postero-inferior surface?
Completely covered by the peritoneum of the lesser sac except the bare area of the stomach
what are the structures related to the Postero-inferior surface?
(stomach bed)
- 4 transverse structures
1. pancreas.
2. Splenic artery
3. Transverse mesocolon
4. Transverse colon.
- 4 left sided structures
1. Left crus of diaphragm.
2. Left kidney.
3. Left suprarenal gland.
4. Spleen
what are the parts of the small intestine?
divided into three parts:
β Duodenum: it is the proximal part.
β Jejunum: follows the duodenum.
β Ileum: it is the distal part.
what is the definition of the Duodenum?
The widest, shortest and most fixed part of small intestine
what is the shape and length of the Duodenum?
Shape: is a C-shaped tube
Length: ten inches (25 cm) long.
mobility and peritoneal coverings of the Duodenum
- The proximal one-inch: is free and mobile because of its attachment to the lesser and greater omenta (completely covered)
- The rest: is fixed to the posterior abdominal wall (retroperitoneal)
what is the beginning of the Duodenum?
Begins at At the junction of pylorus & duodenum One inch to the right of the median plane at level of L1 (transpyloric plane).
what is the termination of the Duodenum?
It ends at the duodenojejunal flexure one inch to the left of median plane at the level of the 2nd lumbar vertebra. This duodenojejunal flexure is attached to the diaphragm by the suspensory muscle (ligament) of duodenum (ligament of Treitz).
what are the parts of the Duodenum?
is divided into four parts :
A. Superior (first part): 2 inches long.
B. Descending (second part): 3 inches long.
C. Horizontal (third part): 4 inches long.
D. Ascending (fourth part): 1 inch long.
what does the Duodenum surround?
the head of the pancreas.
Relations of the first part of the Duodenum
A. Posterior relations: common bile duct, gastroduodenal artery, portal vein, and inferior vena cava.
B. clinically, the beginning of this part of the duodenum is referred to as the ampulla or duodenal cap, and most duodenal ulcers occur in this part of the duodenum
Relations of the second part of the Duodenum
A. crossed anteriorly by the transverse colon
B. contains the major duodenal papilla, which is the common entrance for the common bile and main pancreatic ducts, and the minor duodenal papilla, which is the entrance for the accessory pancreatic duct
C. the junction of the foregut and the midgut just below the major duodenal papilla.
Relations of the third part of the Duodenum
A. Posterior relations: the inferior vena cava and the aorta.
B. Anterior relations: the superior mesenteric artery and vein.