Anatomy exam 2

Somatic motor system

One neuron pathway targeting skeletal muscle. Cell bodies in ventral horn of grey matter. Purely stimulatory effects.

Autonomic motor system

Two-neuron pathway targeting smooth muscle, cardiac muscle, glands. Consists of preganglionic neuron and postganglionic neuron with stimulatory or inhibitory effects

Preganglionic axon length in symp vs para divisions

Symp: Short (myelinated), para: long (myelinated)

Postganglionic axon length in symp vs para divisions

Symp: Long (unmyelinated), para: short (unmyelinated)

Ganglia location in symp vs para divisons

Symp: close to spinal cord; para: close to or within target organ wall

Neurotransmitters in symp vs para divisions

Symp: Ach at ganglion, norepinephrine at target organ; para: Ach at both ganglion and target organ

Response type in symp vs para divisions

Symp: widespread; para: localized

CNS origin in symp vs para divisions

Symp: T1-L2 lateral horn of grey matter; para: Brainstem and sacral spinal cord

White rami communicantes

Contain myelinated preganglionic sympathetic axons (T1-L2)

Gray rami communicantes

Contain myelinated postganglionic sympathetic axons exiting back to spinal nerves

Foregut artery, ganglion, and plexus

Celiac trunk, celiac ganglion, celiac plexus

Midgut artery, ganglion, plexus

Superior mesenteric artery, superior mesenteric ganglion, superior mesenteric plexus

Hindgut artery, ganglion, and plexus

Inferior mesenteric artery, inferior mesenteric ganglion, inferior mesenteric plexus

Vagus nerve (CN X)

Primary cranial nerve providing parasympathetic innervation to thoracic and abdominal viscera up through midgut

Adrenal medulla innervation

Directly innervated by preganglionic sympathetic axons with no postganglionic neuron

Adrenal medulla pathway function

Activation causes secretion of epinephrine and norepinephrine directly to capillaries for systemic stress response

Autonomic plexus

Composed of sympathetic postganglionic axons, parasympathetic preganglionic axons, and visceral sensory axons that branch with arteries to target organs

Referred pain

Occurs when visceral sensory pain signals are perceived as originating from a skin dermatome rather than organ itself due to convergence in shared spinal cord segments

What organs are in foregut

Esophagus, stomach, liver, gallbladder, spleen, 1st and 2nd parts of duodenum

What supplies the foregut

Celiac trunk

What organs are found in the midgut

3rd and 4th part of duodenum, jejunum, ileum, cecum, appendix, ascending colon, 2/3 of transverse colon

What supplies the midgut

Superior mesenteric artery

What organs are found in the hindgut

Distal 1/3 of transverse colon, descending colon, sigmoid colon, rectum

What supplies the hindgut

Inferior mesenteric artery

What is superior 1/3 of esophagus made of

Skeletal muscle (voluntary control)

What is middle 1/3 of esophagus made of

Mix of skeletal and smooth muscle

What is inferior 1/3 of esophagus made of

Smooth muscle (involuntary control)

What is the superior esophageal sphincter

Sits at junction with pharynx (throat)

What is the inferior esophageal sphincter (cardiac sphincter)

Sits at esophageal hiatus of diaphragm to prevent stomach acid reflux

Stomach muscularis externa: 3 layers

All smooth muscle: innermost oblique layer, middle circular layer, outermost longitudinal layer

Parietal cell

Gastric cell that secretes HCl and intrinsic factor (vitamin B12 absorption)

Chief cell

Gastric cell that secrete pepsinogen and gastric lipase

Surface mucous cells

Gastric cell that secrete an alkaline fluid with mucin to protect lining from acid

Mucous neck cells

Gastric cell that secrete an acidic fluid with mucin

Enteroendocrine cell

Gastric cell that secrete the hormone gastrin into bloodstream

What is stomach innervated by

Autonomic innervation from celiac plexus

What is stomach supplied by

Celiac trunk

What are the regions of small intestine

Duodenum, jejunum, ileum

Which part of small intestine is primary site of chemical digestion/nutrient absorption

Jejunum

What parts of small intestine contribute to surface area adaptations

Circular folds, villi, microvilli

What crypt cells are in small intestine

Paneth cells, stem cells

What are paneth cells

They secrete antimicrobial peptides in small intestine

What ducts form the hepatopancreatic ampulla

Common bile duct and main pancreatic duct

What does the conducting portion of respiratory system consist of

Nose, nasal cavities, paranasal sinuses, pharynx, larynx, trachea, bronchi, and bronchioles

What is the function of the conducting portion of respiratory system

Conditions the air by filtering, warming, and humidifying it before it reaches the lungs

What does the respiratory portion of the respiratory system consist of

Respiratory bronchioles, alveolar ducts, alveoli

What is respiratory portion of respiratory system function

Serves as site of gas exchange between air and blood

What are the functions of respiratory system?

Breathing, gas exchange, gas conditioning, sound production and communication, olfaction, defense

What is the function of trachea

Acts as primary airway connecting larynx to bronchial tree while trapping and clearing debris

Primary bronchi

Bifurcate at carina, right main bronchus is wider, shorter, and more vertical than left

Secondary bronchi

3 in right lung, 2 in left lung

Tertiary bronchi

Supply distinct bronchopulmonary segments (10 in right, 8-10 in left)

Bronchioles

Small airways leading to terminal bronchioles

Pulmonary circuit (blood supply)

Pulmonary arteries carry deoxygenated blood from right ventricle to lungs, branching alongside bronchial tree to form capillary beds around alveoli for gas exchange. Oxygenated blood drains through pulmonary veins to left atrium.

Bronchial circulation (blood supply)

Bronchial arteries carry oxygenated blood directly to structural tissues of bronchial tree and visceral pleura. Venous blood drains into pulmonary veins.

Components of superior mediastinum

Thymus, great vessels, trachea, esophagus, vagus nerves, phrenic nerves

Components of anterior mediastinum

Space between sternum and pericardium containing loose CT, fat, lymphatic vessels, and internal thoracic vessel branches

Components of middle mediastinum

Heart, pericardium, roots of great vessels

Components of posterior mediastinum

Thoracic aorta, esophagus, thoracic duct, azygos venous system, vagus nerves, phrenic nerves, thoracic sympathetic trunk