The Abdominal Cavity.

Question 1

Where does the abdominal cavity lie in relation to the diaphragm?

Answer 1

It lies caudally to the diaphragm.

Question 2

What covers all of the organs within the abdominal cavity?

Answer 2

A serous membrane /peritoneum called visceral peritoneum.

Question 3

What is the function of the visceral peritoneum?

Answer 3

It secretes fluid which lubricates the organs and stops them from rubbing together.

Question 4

What is the cranial most boundary of the abdominal cavity?

Answer 4

The diaphragm.

Question 5

What forms the roof of the abdominal cavity?

Answer 5

The axial skeleton.

Question 6

What provides the main support for the abdominal cavity?

Answer 6

The axial skeleton.

Question 7

What forms the walls and floor of the abdominal cavity?

Answer 7

The hypaxial muscles.

Question 8

What name is given to the peritoneum that covers the roof, walls and floor of the abdominal cavity?

Answer 8

The parietal peritoneum.

Question 9

What name is given to the space that lies between the visceral and parietal peritoneum?

Answer 9

The parietal cavity.

Question 10

What are the 2 types of fascia that are found in the abdominal cavity?

Answer 10

The transversalis fascia.

The diaphragmatic fascia.

Question 11

Where do the organs of the thoracic cavity receive their support from?

Answer 11

From folds that are derived from the parietal peritoneum.

Question 12

Where do the folds that provide support to the organs of the thoracic cavity run between?

Answer 12

Between the body wall (parietal mesentery) and the organ (visceral mesentery).

Question 13

What name is given to the folds that provide support to the organs of the thoracic cavity run between?

Answer 13

Connecting peritoneum or mesentery.

Question 14

What contains the blood and nerve supply for the organs of the thoracic cavity?

Answer 14

The mesentery.

Question 15

How does the abdominal cavity help to maintain the pressure in the thoracic cavity?

Answer 15

Via a phenomenon known as the abdominal press.

Question 16

How does the abdominal press work?

Answer 16

The contraction of the abdominal and hypaxial muscles generates pressure in the abdominal cavity.

This pressure can be transferred to the thoracic cavity via the diaphragm and then transferred into a cough.

This same method also allows for the excretion faeces and urine.

Question 17

What are the 4 major muscles in the walls of the abdominal cavity?

Answer 17

The external abdominal oblique muscle.

The internal abdominal oblique muscle.

The transverse abdominalis muscle.

The rectus abdominis muscle.

Question 18

What is the origin, insertion and fibre direction of the external abdominal oblique?

Answer 18

Origin. Rib cage/lumbar region.

Insertion. Linea alba (ventral midline).

The fibres run in a caudo-ventral direction.

Question 19

What is the origin, insertion and fibre direction of the internal abdominal oblique?

Answer 19

Origin. Tubor coxae, aponeurosis of the external abdominal oblique, the transverse processes of the lumbar vertebrae.

Insertion. Linea alba (ventral midline).

The fibres run in a cranio-ventral direction and the muscle fans out.

Question 20

What is the origin, insertion and fibre direction of the transverse abdominalis?

Answer 20

Origin. Transverse processes of the lumbar vertebrae.

Insertion. Linea alba (ventral midline).

The fibres run in a vertical direction.

Question 21

What is the origin and insertion of the rectus abdominis?

Answer 21

Origin. The caudal part of the sternum.

Insertion. The pubic bone.

Question 22

What muscle forms the floor of the abdominal cavity?

Answer 22

The rectus abdominis muscle.

Question 23

What encloses the rectus abdominis muscle?

Answer 23

The aponeuroses of the other 3 muscles.

Question 24

What helps the rectus abdominis to insert onto the pubic bone?

Answer 24

The pre-pubic tendon.

Question 25

How many external oblique muscles are present in the abdominal cavity?

Answer 25

2, one on each side. The aponeuroses of both muscles join up with each other on the linea alba (ventral midline).

Question 26

What is the outermost muscle of the abdominal wall?

Answer 26

The external abdominal oblique.

Question 27

What lies underneath the external abdominal oblique muscle?

Answer 27

The internal abdominal oblique muscle.

Question 28

What lies underneath the internal abdominal oblique muscle?

Answer 28

The rectus abdominis muscle.

Question 29

Where does the transverse abdominalis muscle lie relative to the rectus abdominalis muscle.

Answer 29

Part of it is found outside the rectus abdominalis muscle. Another part is found inside the rectus abdominis muscle.

Question 30

What is the rectus sheath?

Answer 30

The structure that is present along the floor of the abdominal cavity and is associated with the rectus abdominus muscle.

Question 31

What are the 2 sections that the rectus sheath is divided into?

Answer 31

The internal rectus sheath. The external rectus sheath.

Question 32

What is the internal rectus sheath?

Answer 32

Anything that is present inside the rectus abdominal muscle is considered to be part of the internal rectus sheath.

Question 33

What is the external rectus sheath?

Answer 33

Anything that is present outside the rectus abdominal muscle is considered to be part of the external rectus sheath.

Question 34

What are the 3 sections that the rectus sheath is divided into?

Answer 34

The most cranial section is number 1. The middle section is number 2. The caudal most section is number 3.

Question 35

What is section 1 of the rectus sheath known as?

Answer 35

As the xyphoid region.

Question 36

What makes up the innermost layer of section 1 of the rectus sheath?

Answer 36

The transerve abdominalis muscle. This is because the aponeurosis of the transverse abdominalis runs inside the rectus abdominis muscle.

Question 37

What makes up the 2nd layer of section 1 of the rectus sheath?

Answer 37

The internal abdominal oblique muscle.

Question 38

What happens in section 1 of the rectus sheath as the internal abdominal oblique muscle runs towards the rectus abdominis muscle?

Answer 38

The aponeurosis splits and runs on both sides of the rectus abdominis muscle. This means that an inner and outer layer of aponeurosis is formed.

Question 39

What makes up the internal and external rectus sheath in section 1?

Answer 39

Internal rectus sheath. Transversis abdominis muscle + internal abdominal oblique muscle. External rectus sheath. Internal abdominal oblique muscle + external abdominal oblique muscle.

Question 40

What makes up the internal and external rectus sheath in section 2?

Answer 40

Internal rectus sheath. Transversis abdominis muscle. External rectus sheath. Internal abdominal oblique muscle + external abdominal oblique muscle.

Question 41

What makes up the internal and external rectus sheath in section 3?

Answer 41

Internal rectus sheath. None. External rectus sheath. Transversis abdomainis muscle + internal abdominal oblique muscle + external abdominal oblique muscle.

Question 42

Why do we make incisions into the abdomen along the linea alba?

Answer 42

As there is very little blood flow to the aponeurosis and this minimises bleeding.

Question 43

What are the 6 layers that will be cut through when transecting the abdominal wall?

Answer 43

The skin. The external abdominal oblique. The internal abdominal oblique. Rectus abdominis. Transversis abdominalis. Pereitoneum.

Question 44

What are the 2 major blood vessels within the abdominal cavity?

Answer 44

The caudal vena cava. The aorta.

Question 45

What is the superficial inguinal ring?

Answer 45

A hole that lies in the aponeurosis of the external abdominal oblique muscle. The superficial inguinal ring lies above the deep inguinal ring, however, these structures are not aligned with each other.

Question 46

What lies caudally to the superficial inguinal ring?

Answer 46

The vascular lacuna.

Question 47

What is the function of the vascular lacuna?

Answer 47

It is the passage between the medial muscles of the thigh and the aponeurosis of the external abdominal oblique muscle. It allows for the femoral artery, vein and nerve to travel to the hindlimb.

Question 48

What us the tendon of insertion for the external abdominal oblique muscle?

Answer 48

The pre-pubic tendon.

Question 49

The pre-pubic tendon inserts onto what part of the pubis?

Answer 49

The pectin of the pubis.

Question 50

What are the 4 main sites where blood vessels will arrive into the abdominal cavity?

Answer 50

The cranio-dorsal aspect. The caudo-dorsal aspect. The caudo-ventral aspect. The cranio-ventral aspect.

Question 51

The blood vessels that lie in the cranio-dorsal quadrant of the abdomen are supplied by what major blood vessel?

Answer 51

The aorta.

Question 52

What branches of the aorta supply the abdominal walls?

Answer 52

Parietal branches.

Question 53

What is the first arterial branch in the cranio-dorsal quadrant of the abdomen?

Answer 53

The common trunk. It forms the caudal phrenic and cranial abdominal arteries (phrenico-abdominal artery).

Question 54

The caudal phrenic and cranial abdominal arteries are responsible for supplying what areas of the abdomen?

Answer 54

The diaphragm and the cranio-dorsal quadrant of the abdominal wall.

Question 55

What blood vessel supplies the cranial ventral quadrant of the abdomen?

Answer 55

The internal thoracic artery.

Question 56

What blood vessels in the cranial ventral quadrant of the abdomen are formed by the internal thoracic artery?

Answer 56

The musculo-phrenic artery. The cranial epigastric artery.

Question 57

What is the major artery that supplies the cranio-ventral quadrant of the abdomen?

Answer 57

The cranial epigastric artery.

Question 58

What is the major branch of the cranial epigastric artery?

Answer 58

The cranial superficial epigastric artery.

Question 59

What is the main artery for the caudo-dorsal quadrant of the abdomen?

Answer 59

The deepcircumfelx iliac artery.

Question 60

What arteries supply the caudo-ventral quadrant of the abdominal wall?

Answer 60

The caudal epigastric and deep pudendal arteries which both supply the .

Question 61

The caudal epigastric and deep pudendal arteries are both branches of what artery?

Answer 61

The femoral artery.

Question 62

The femoral artery is a branch of what artery?

Answer 62

The external iliac artery.

Question 63

Why does the blood supply to the floor of the abdominal cavity differ depending on whether the animal is a male or female?

Answer 63

Because females have mammary glands which require a good blood supply.

Question 64

What artery supplies the abdominal wall and the mammary glands on both sides

Answer 64

The caudal superficial epigastric artery.

Question 65

How many pairs of mammary glands are found on the dog?

Answer 65

3 pairs of mammary glands.

Question 66

What are the names of the 3 pairs of mammary glands?

Answer 66

The inguinal mammary glands. The caudal abdominal mammary glands. The cranial abdominal mammary glands.

Question 67

What artery supplies the cranial region of the abdominal floor?

Answer 67

The cranial superficial epigastric artery.

Question 68

The cranial superficial epigastric artery anastamoses with what artery?

Answer 68

The caudal superficial epigastric artery.

Question 69

What is the 1st nerve that is present in the abdominal cavity?

Answer 69

The nerve that lies on the caudal side of the 13th rib. It is known as the 13th thoracic costo-abdominal nerve.

Question 70

Any nerves that occur after the 13th thoracic costo-abdominal nerve are what nerves?

Answer 70

Spinal nerves which branch into the dorsal and ventral branches.

Question 71

The dorsal branches of the spinal nerves take care of what muscles?

Answer 71

The epaxial muscles.

Question 72

The ventral branches of the spinal nerves take care of what muscles?

Answer 72

Both abdominal oblique muscles.

Question 73

The nerve that arises from T13 is known by what name?

Answer 73

T13. Costo-abdominal nerve.

Question 74

What direction do the abdominal nerves run in?

Answer 74

They run obliquely along the abdominal wall and are directed caudally and ventrally.

Question 75

What name is given to the nerve that emerges from L1?

Answer 75

L1. Cranial ilio-hypogastric nerve.

Question 76

What name is given to the nerve that emerges from L2?

Answer 76

L2. Caudal ilio-hypogastric nerve.

Question 77

What name is given to the nerve that emerges from L3?

Answer 77

L3. Ilioingual nerve.

Question 78

What name is given to the nerve that emerges from L4?

Answer 78

L4. The lateral cutaneous femoral nerve.

Question 79

The nerves from L5 onwards are part of what plexus?

Answer 79

The lumbo-sacral plexus.

Question 80

The lumbo-sacral plexus supplies what area of the body?

Answer 80

The hindlimb and structures of the pelvic cavity.