Thorax and Abdomen

Abdomen

Abdominal Viscera

Esophagus

Stomach

Small Intestine

Large Intestine

Liver

Function

filters all of the blood in the body and breaks down poisonous substances, such as alcohol and drugs

Anatomy

Diaphragmatic

fits under the vault of the diaphragm which in front separates it on the right from the sixth to the tenth ribs and their cartilages, and on the left from the seventh and eighth costal

Visceral

posteroinferior surface that faces the abdominal organs and other adjacent structures

Lobes

Right

The largest lobe of the liver

Left

Smaller than the right lobe

Quadrate

Located on the inferior surface of the right lobe

Caudate

between the left and right lobes, and in an anterior and superior position

Vessels

Right hepatic vein

Located between the right anterior and right posterior sectors

Middle hepatic vein

Located between the right anterior sector and segment IV

Left hepatic vein

Located between the left medial and left lateral sectors

Hepatic portal vein

a vein conveying blood to the liver from the spleen, stomach, pancreas, and intestines.

Nerves

Sympathetic nerves

Originate in the celiac and superior mesenteric ganglia, which receive pre-ganglionic neurons from the spinal cord.

Parasympathetic nerves:

Originate in the dorsal motor nucleus of the vagus nerve in the brainstem.

Gall Bladder

Spleen

Function

Stores and filters blood

Location

located in the upper left quadrant of the abdomen, behind the stomach and under the left ribs

Vessels

Splenic vein

carries blood from the spleen, pancreas, and part of the stomach to the liver

Splenic artery

supplies oxygenated blood to the spleen, stomach, and pancreas:

Nerves

Sympathetic

The celiac plexus provides sympathetic innervation to the spleen.

Parasympathetic

The vagus nerve (CN X) provides parasympathetic innervation to the spleen.

Pancreas

Function

Exocrine

secretion of digestive enzymes, ions and water into the duodenum

Endocrine

produce and release hormones that regulate blood sugar levels:

Parts

Head

Neck

Body

Tail

Ducts

Main pancreatic

drains pancreatic fluid from the pancreas, which contains digestive enzymes and fluids that help break down food.

Accessory pancreatic

secondary drainage system for the main pancreatic duct, which can help reduce pressure and prevent acute pancreatitis.

Vessels

Greater pancreatic artery

The largest blood vessel that supplies oxygenated blood to the pancreas. It originates from the splenic artery.

Dorsal pancreatic artery

A branch of the splenic artery that supplies the pancreas. It runs along the posterior margin of the pancreas and divides into left and right branches.

Transverse pancreatic artery

Also known as the inferior pancreatic artery, it supplies the pancreatic tail and body. It originates from the proximal splenic artery.

superior mesenteric

A major blood vessel in the digestive system that supplies oxygenated blood to the pancreas and the lower parts of the intestine.

gastroduodenal

A small vessel that supplies blood to the head of the pancreas, the pylorus, and the proximal part of the duodenum.

Nerves

The pancreas receives involuntary innervation via the autonomic nervous system (ANS). Its parasympathetic innervation originates from the vagus nerve (CN X)

sympathetic innervation from the greater and lesser splanchnic nerves (T5-T12).

Kidney

Function

remove waste products from the blood and produce urine. control blood pressure.

Parts

Renal hilum

Renal pelvis

Renal pyramids

Major Calyces

Minor Calyces

Vessels

Renal arteries

supply oxygenated blood to the kidneys, adrenal glands, and ureters

Renal veins

carry filtered blood from the kidneys to the heart:

Nerves

Efferent

regulate renal function, including sodium reabsorption, glomerular filtration, and renin release.

These nerves are sympathetic and originate from the neuraxis.

Afferent

These nerves travel from the kidney to the dorsal root ganglia along the spinal cord. The least splanchnic nerve is the primary afferent signaling nerve from the kidney to the brain.

Glands

Produce hormones that control many important body functions, including blood pressure, blood sugar, metabolism, and the body's response to stress

Posterior Abdominal Wall

Fasica

Psoas

The psoas fascia is a thick layer of connective tissue that covers the psoas major muscle in the posterior abdominal wall:

Thoracolumbar

The TLF has three layers: anterior, middle, and posterior. The posterior layer extends from the neck to the loin, while the anterior and middle layers are limited to the lumbar region.

The TLF spans the length of the back, from the neck to the sacrum. It's most developed in the lumbar region.

Nerves

The nerves of the posterior abdominal wall primarily originate from the lumbar plexus

L1-L4 spinal nerves and sometimes includes T12

Muscles

Psoas major

T12–L5.

Hip flexion and external rotation

Iliacus

flexes and rotates the thigh bone

femoral nerve (L2–L4).

Quadratus lumborum

extensor of the lumbar spine, a stabilizer of the lumbar area, capable of pelvic tilting laterally and capable of acting as an inspiratory accessory muscle.

The quadratus lumborum (QL) muscle is innervated by the subcostal nerve (T12) and the first three nerves of the lumbar plexus (L1-L3):

Vessels

Abdominal aorta

The abdominal aorta is a large blood vessel that runs along the posterior abdominal wall, supplying blood to the abdomen and other parts of the body:

T12

Veins

Inferior vena cava

A large vein that receives venous drainage from all structures below the diaphragm. It's located on the posterior abdominal wall, to the right of the abdominal aorta and in front of the vertebral column.

Lymphatics

super

Follow the superficial circumflex blood vessels in the lumbar and iliac regions

deep

Lumbar

Follows the lumbar arteries and drains into the lateral aortic nodes

Iliac

Follows the deep circumflex iliac artery and drains into the external iliac nodes

Anterio-lateral Abdominal Wall

Fascia

Camper

Protects the abdominal organs, insulates to maintain a constant temperature, and separates the skin from the muscles

Extends from the xiphoid process to the inguinal ligaments, and past the pubic symphysis

Intermediate

Thoracolumbar

Located on either side of the lumbar vertebrae, the TLF is most prominent in the upper lumbar region.

The TLF supports the lower back, helps maintain spinal alignment, and protects the underlying muscles and spinal structures. It also contains nerve endings that help with proprioception, the body's ability to sense its position and movement.

Abdominal

attaches, stabilizes, encloses, and separates muscles and other internal organs.

Scarpa

Scarpa's fascia is a thin membrane of connective tissue located in the lower abdomen and anterior abdominal wall:

allow for smooth movement, protect the underlying organs, provide structural support to the abdominal wall, role in maintaining fluid balance and tissue pressure in the region.

Muscles

External oblique

The external oblique is one of the outermost abdominal muscles, located on the sides of the abdomen, and sits on top of the internal obliques.

The external oblique's primary function is to rotate the trunk from side to side. It also helps stabilize the core, move the spine, and assist with breathing.

Internal oblique

The internal obliques are located on the sides of the trunk, just inside the hip bones, and on top of the external obliques.

The internal obliques work with the external obliques to help the trunk twist and turn. They also help with exhaling and stabilizing the spine.

Transversus abdominus

located between the ribs and pelvis, and wrapping around the trunk from front to back.

postural support and help contain and support the organs inside the trunk. It's also a main core muscle that supports the lumbopelvic region.

Rectus abdominis

move the body between the ribcage and the pelvis.

Flexion of the spine

Pyramidalis

Found at the base of the pubic bone, within the rectus sheath, anterior to the rectus abdominis muscle.

Function: Considered to have a minor role in stabilizing the abdominal wall by tensing the linea alba

Rectus shealth

fibrous compartment in the abdomen that contains the rectus abdominis and pyramidalis muscles

Transverse section

Above umbilicus

Rectus sheath splits around the rectus

Below umbilicus

Rectus sheath anterior to rectus

Internal surface

Peritoneal folds

Median umbilical

Lateral umbilical

Peritoneal fossae

Lateral inguinal

medial inguinal

supravesical

Neruovasculature

Nerves

Thoracoabdominal

T7-T12

Lateral cutaneous

T7-T9

Iliohypogastric

L1

Ilioinguinal

L1

Vessels

Internal Thoracic

musculophrenic

The musculophrenic artery is a branch of the internal thoracic artery that supplies the pericardium and abdominal wall:

superior epigastric

The superior epigastric artery supplies blood to the upper central abdominal wall and skin, and the upper rectus abdominis muscle:

Aorta

posterior epigastric

Supplies blood to the upper part of the rectus abdominis muscle and the linea semilunaris

subcostal

The subcostal arteries supply the muscles and skin beneath the 12th rib of the anterolateral abdominal wall

External iliac

inferior epigastric

The inferior epigastric artery supplies oxygen-rich blood to the abdominal wall, including the skin, muscles, and parts of the male reproductive system

deep circumflex iliac

The deep circumflex iliac artery (DCIA) supplies blood to the muscles, skin, and bone of the lower abdomen and pelvis

femoral artery

superficial epigastric

The superficial epigastric artery's main function is to supply blood to the skin and superficial inguinal lymph nodes of the anterior abdominal wall

superficial circumflex

supplies blood to the skin, subcutaneous tissue, and superficial inguinal lymph nodes of the abdominal wall and groin

Spermatic cord

Layers

Internal spermatic fascia

External spermatic fascia

Parts

Ductus deferens

Carries sperm from the epididymis to the urethra

Runs through the spermatic cord, inguinal canal, and pelvic cavity, looping over the bladder and ending at the ejaculatory duct

Arteries

cremasteric

A branch of the inferior epigastric artery, this artery supplies blood to the skin of the scrotum, including the cremaster muscle, and the layers of the spermatic cord.

testicular

Also known as the internal spermatic artery, this artery branches from the abdominal aorta and supplies blood to the testis, epididymis, and spermatic cord.

Plexus

web-like network of veins in the spermatic cord that surrounds the testicular artery. It begins in the scrotum and extends into the inguinal canal.

Helps regulate temperature

Cremaster muscle

raise and lower the testes in order to regulate scrotal temperature for optimal spermatogenesis and survival of the resultant spermatozoa.

Lymphatic vessels

The lymphatic vessels of the scrotum drain into the superficial inguinal lymph nodes.

Fight infection

Inuinal region

Inguinal ligament

The inguinal ligament is a band of tissue that runs from the pubic tubercle to the anterior superior iliac spine (ASIS) in the lower abdomen.

It's also known as Poupart's ligament or groin ligament

Iliopubic tract

The iliopubic tract is a band of tissue that runs from the iliopectineal arch to the pubic bone

Inguinal canal

Deep ring

It is an opening in the transversalis fascia, forming the deep boundary of the inguinal canal.

serve as the entrance point of the inguinal canal, allowing the passage of the spermatic cord in males and the round ligament of the uterus in females

superficial ring

Location: Located above the pubic tubercle, just superior to the crest of the pubis

The exit point for the inguinal canal, which allows passage for the spermatic cord in males, the round ligament in females, blood vessels, lymphatics, and the ilioinguinal nerve

walls

Floor

Iliopubic tract

Inguinal ligament

lancunar ligament

Anterior

composed of the aponeurosis of the external oblique muscle and reinforced laterally by the internal oblique muscle.

Posterior

formed by the transversalis fascia, conjoint tendon, and deep inguinal ring.

Roof

formed by the medial crus of the aponeurosis of the external oblique, the musculoaponeurotic arches of the internal oblique and transverse abdominal muscles, and the transversalis fascia.

Diaphragm

Vessels

Superior phrenic arteries: Arise from the thoracic aorta

Musculophrenic artery: A branch of the internal thoracic artery

Pericardiacophrenic artery: A branch of the internal thoracic artery

Inferior phrenic arteries: Often arise from the anterior trunk of the aorta above the celiac artery

Lower internal intercostal arteries: Supply blood to the diaphragm

Nerve

Phrenic nerve

C3 through C5

Functions

Motor: The phrenic nerve causes the diaphragm to contract when you inhale

Sensory: The phrenic nerve provides sensation to the central tendon of the diaphragm

Actions

Inhale

When the diaphragm contracts, it moves downwards, creating a vacuum in the chest cavity that pulls air into the lungs.

Exhale

When the diaphragm relaxes, it moves upwards, compressing the chest cavity and pushing air out of the lungs.

dome-shaped muscle that separates the thoracic cavity from the abdominal cavity

Peritoneum & Peritoneal Cavity

Layers

Parietal

The outer layer that attaches to the chest wall.

Visceral

The inner layer that covers the lungs, blood vessels, nerves, and bronchi

Formations

Mesentery

The mesentery is a fold of membrane that attaches the intestine to the wall around the stomach area and holds it in place.

Omentum

Greater

Fat deposition, having varying amounts of adipose tissue. Immune contribution, having milky spots of macrophage collections. Infection and wound isolation

Lesser

Connects liver to stomach

Subdivisions

Omental foramen

allows communication between the greater and lesser sacs of the peritoneal cavity

Omental bursa

Allows stomach to move freely

Quadrants

RUQ

right portion of the liver, gallbladder, right kidney, a small portion of the stomach, portions of the ascending and transverse colon, and parts of the small intestine

LUQ

left portion of the liver, the larger portion of the stomach, the pancreas, left kidney, spleen, portions of the transverse and descending colon, and parts of the small intestine

RLQ

cecum, appendix, right ovary (in females), right fallopian tube (in females), right ureter, the lower pole of the right kidney, portions of the ileum (small intestine), and various blood vessels and lymphatics, including branches of the abdominal aorta and iliac arteries.

LLQ

sigmoid colon, part of the descending colon, the left ovary (in females), the left fallopian tube (in females), the left ureter, portions of the small intestine (especially the ileum), and various blood vessels and lymphatics, including branches of the abdominal aorta and iliac arteries.

Thorax

Boundaries of thorax

Rib cage

Mediastinum

Diaphragm

Cardiovascular system

Anatomy of the heart

Physiology of the heart

Blood

Function

Transport vital substances

remove metabolic waste

pathogen defense

temperature regulation

Flow

Factors effecting blood flow

Pressure

Respiratory system

Anatomy

Trachea

L & R bronchi

Secondary bronchi

Tertiary bronchi

Alveoli

Lobes

physiology

Functions

Ventilation

Respiration (gas exchange)

Gas transport

O2 transport

Hemoglobin

Binds up to 4 O2 molecules

98% of O2 transport

CO2 transport

Bicarbonate

about 70% of CO2

Hemoglobin bound CO2

23%

Plasma CO2

7% dissolved directly

Oxy-hemoglobin binding curve