Epithelial/Connective tissues

Epithelial/Connective tissues US Medical PG Question 1: A 35-year-old woman presents to a pre-operative evaluation clinic prior to an elective cholecystectomy. She has a 5 pack-year smoking history. The anesthesiologist highly recommends to discontinue smoking for at least 8 weeks prior to the procedure for which she is compliant. What is the most likely histology of her upper respiratory tract's epithelial lining at the time of her surgery?

• A. Simple squamous
• B. Simple columnar
• C. Pseudostratified columnar (Correct Answer)
• D. Stratified squamous
• E. Stratified columnar

Epithelial/Connective tissues Explanation: ***Pseudostratified columnar*** - The upper respiratory tract is normally lined by **pseudostratified ciliated columnar epithelium** with goblet cells, which is crucial for mucociliary clearance. - While smoking can initially cause **squamous metaplasia**, discontinuing smoking for 8 weeks allows for significant, if not complete, **reversal of these changes** back to the normal pseudostratified columnar epithelium. *Simple squamous* - This type of epithelium is found in areas designed for efficient **gas exchange** (e.g., alveoli of the lungs) and is not typical for the conductive airways of the upper respiratory tract. - It lacks the **cilia and goblet cells** necessary for clearing inhaled particles and pathogens. *Simple columnar* - **Simple columnar epithelium** is found in regions like the lining of the gastrointestinal tract (e.g., stomach, small and large intestines) and is not characteristic of the upper respiratory tract. - While it can have goblet cells, it typically lacks **cilia** for respiratory clearance. *Stratified squamous* - **Stratified squamous epithelium** is found in areas subject to friction and abrasion, such as the oral cavity, pharynx, and esophagus. - While chronic smoking can induce **squamous metaplasia** in the respiratory tract, an 8-week cessation period would likely result in the reversal of this change back to the normal type. *Stratified columnar* - **Stratified columnar epithelium** is a relatively rare type found in specific locations like parts of the male urethra and some large excretory ducts. - It is not the normal or even a common metaplastic lining for the human upper respiratory tract.

Epithelial/Connective tissues US Medical PG Question 2: A 65-year-old man with a 40-pack-year smoking history presents with hemoptysis and a persistent cough. Chest CT shows a 3.5 cm centrally located mass in the right main bronchus. Positron emission tomography confirms a malignant nodule. Bronchoscopy with transbronchial biopsy is performed and a specimen sample of the nodule is sent for frozen section analysis. The tissue sample is most likely to show which of the following tumor types?

• A. Carcinoid tumor
• B. Metastasis of colorectal cancer
• C. Small cell lung carcinoma
• D. Large cell carcinoma
• E. Squamous cell carcinoma (Correct Answer)

Epithelial/Connective tissues Explanation: ***Squamous cell carcinoma*** - This is the most likely diagnosis given the **central location** in the main bronchus, **heavy smoking history**, and presentation with **hemoptysis**. - **Squamous cell carcinoma** accounts for 25-30% of lung cancers and characteristically arises in **central/proximal airways**, making it readily accessible by **bronchoscopy**. - Histologically, it shows **keratin pearls** and **intercellular bridges** on biopsy. - The **central endobronchial location** and ability to obtain tissue via transbronchial biopsy strongly favor squamous cell over peripheral tumors. *Carcinoid tumor* - **Carcinoid tumors** are **neuroendocrine tumors** that can present as central endobronchial masses and cause hemoptysis. - However, they are typically **slow-growing** with more indolent presentation, and PET scans show **variable uptake** (often less intense than aggressive carcinomas). - They represent only **1-2% of lung tumors** and occur more commonly in **younger, non-smoking patients**. *Metastasis of colorectal cancer* - While lung is a common site for **colorectal metastases**, these typically present as **multiple peripheral nodules** rather than a solitary central endobronchial mass. - The clinical presentation strongly suggests **primary lung cancer** rather than metastatic disease. - Without history of colorectal cancer, this is unlikely. *Small cell lung carcinoma* - **Small cell lung carcinoma** (SCLC) represents 15% of lung cancers and typically presents as a **large central mass** with early mediastinal involvement. - However, SCLC is usually **too extensive at presentation** for transbronchial biopsy alone and often requires mediastinoscopy or CT-guided biopsy. - Histology shows **small cells with scant cytoplasm**, **salt-and-pepper chromatin**, and **oat-cell morphology**. - While possible, the single accessible endobronchial mass is more characteristic of squamous cell. *Large cell carcinoma* - **Large cell carcinoma** is a **diagnosis of exclusion** made when tumors lack features of adenocarcinoma, squamous cell, or small cell differentiation. - It typically presents as **large peripheral masses** rather than central endobronchial lesions. - It represents only **10% of lung cancers** and is less common than squamous cell carcinoma in this clinical scenario.

Epithelial/Connective tissues US Medical PG Question 3: An investigator is studying the interaction between epithelial cells and calcium ion concentration. When the calcium ion concentration available to a sample of epithelial tissue is decreased, an increased gap between adjacent epithelial cells is seen on electron microscopy. This observed decrease in cell adhesion is most likely due to an effect on which of the following proteins?

• A. Actin
• B. Integrin
• C. Cadherin (Correct Answer)
• D. Claudin
• E. Cytokeratin

Epithelial/Connective tissues Explanation: ***Cadherin*** - **Cadherins** are calcium-dependent adhesion proteins that mediate cell-to-cell adhesion, particularly in epithelial tissues. - A decrease in calcium concentration would directly impair cadherin function, leading to reduced cell adhesion and increased intercellular gaps. *Actin* - **Actin** is a component of the cell's cytoskeleton, involved in cell shape, motility, and intracellular transport, but not directly responsible for calcium-dependent cell adhesion between epithelial cells. - While actin filaments interact with adhesion junctions, their primary role is structural and dynamic rather than adhesive. *Integrin* - **Integrins** are primarily involved in cell-to-extracellular matrix adhesion, connecting the cell to the surrounding matrix, not directly mediating calcium-dependent cell-to-cell adhesion between epithelial cells. - They can be affected by intracellular calcium signaling but do not directly bind calcium to mediate their adhesive function in the same way cadherins do. *Claudin* - **Claudins** are key components of **tight junctions**, which regulate paracellular permeability and form a barrier between cells, but they are not directly responsible for calcium-dependent cell-to-cell adhesion, which is characteristic of adherens junctions. - While tight junctions contribute to overall cell-cell contact, the observation of an *increased gap* suggests an issue with adhesive complexes like adherens junctions, where cadherins are prominent. *Cytokeratin* - **Cytokeratins** are intermediate filaments found in epithelial cells, providing structural support and mechanical strength. - They are linked to desmosomes and hemidesmosomes but are not directly involved in calcium-dependent cell-to-cell adhesion.

Epithelial/Connective tissues US Medical PG Question 4: A 37-year-old man presents to the clinic because of painful, severe blistering over his buttocks for the past week. About a year ago, he noticed a similar outbreak on his inner thighs, but it receded within a few days on its own. Physical examination shows the blisters are tense, and rubbing the affected skin does not result in ‘popping’ of the blisters. A biopsy shows the entire epidermis lifting away from the basal lamina with extensive inflammatory infiltrates abundant with eosinophils. Immunofluorescence shows a linear pattern of immune complex deposits. Which of the following cellular structures, if defective, is most likely involved in the formation of these blisters?

• A. Gap junctions
• B. Hemidesmosomes (Correct Answer)
• C. Lamellar bodies
• D. Zonula occludens
• E. Macula adherens

Epithelial/Connective tissues Explanation: ***Hemidesmosomes*** - The clinical picture of **tense blisters** that do not pop with rubbing (**negative Nikolsky sign**), along with the histological finding of the **entire epidermis lifting away from the basal lamina** (subepidermal blistering), strongly suggests **bullous pemphigoid**. - **Immunofluorescence showing linear deposits** along the basement membrane zone is characteristic of bullous pemphigoid, which is caused by autoantibodies targeting proteins within the hemidesmosomes. *Gap junctions* - **Gap junctions** are involved in **intercellular communication** and the passage of small molecules between cells. - Defects in gap junctions do not typically lead to blistering skin disorders. *Lamellar bodies* - **Lamellar bodies** are organelles in **keratinocytes** that release lipids to form the **skin barrier**. - Defects in lamellar bodies are associated with disorders like **ichthyosis**, not blistering as described. *Zonula occludens* - **Zonula occludens**, also known as **tight junctions**, are crucial for forming a **seal between epithelial cells**, regulating paracellular transport. - Dysfunctional tight junctions can lead to increased permeability but are not directly involved in the formation of subepidermal blisters. *Macula adherens* - **Macula adherens**, or **desmosomes**, are cell-to-cell adhesion structures that provide strong mechanical attachments between keratinocytes. - Defects in desmosomes are associated with **pemphigus vulgaris** and **pemphigus foliaceus**, which typically present with **flaccid blisters** that show a **positive Nikolsky sign** and involve intraepidermal cleavage.

Epithelial/Connective tissues US Medical PG Question 5: An 11-year-old girl presents to her primary care physician because she has been having difficulty hearing her teachers at school. She says that the difficulty hearing started about a year ago, and it has slowly been getting worse. Her past medical history is significant for multiple fractures in both her upper and lower extremities. She also recently had a growth spurt and says that her friends say she is tall and lanky. A mutation in which of the following genes is most likely associated with this patient's condition?

• A. Type 4 collagen
• B. Type 3 collagen
• C. Fibrillin
• D. Type 1 collagen (Correct Answer)
• E. Fibroblast growth factor receptor

Epithelial/Connective tissues Explanation: ***Type 1 collagen*** - This patient's symptoms—hearing difficulty, multiple fractures, and tall/lanky stature—are classic signs of **osteogenesis imperfecta (OI)**, a genetic disorder caused by mutations in genes encoding **Type I collagen**. - **Type I collagen** is a major component of bone, so defects lead to fragile bones and susceptibility to fractures, and it also plays a role in the structure of the ear, affecting hearing. *Type 4 collagen* - Mutations in **Type 4 collagen** are primarily associated with **Alport syndrome**, which classically presents with **hematuria**, progressive renal failure, and hearing loss. - While hearing loss is present, the patient's other key symptoms of **multiple fractures** and **tall, lanky stature** are not characteristic of Alport syndrome. *Type 3 collagen* - Defects in **Type 3 collagen** are linked to **Ehlers-Danlos syndrome, vascular type**, which is characterized by fragile blood vessels, organs, and skin, leading to easy bruising, arterial rupture, and bowel perforation. - While Type 3 collagen is found in connective tissues, its primary clinical manifestations do not align with the patient's presentation of recurrent fractures and hearing loss. *Fibrillin* - Mutations in **fibrillin-1** are responsible for **Marfan syndrome**, which presents with tall stature, long limbs (**arachnodactyly**), and cardiovascular issues like aortic dilation. - While tall stature is observed, the patient's primary complaints of **recurrent fractures** and hearing loss are not typical features of Marfan syndrome. *Fibroblast growth factor receptor* - Mutations in **fibroblast growth factor receptor 3 (FGFR3)** are most commonly associated with **achondroplasia**, a form of dwarfism characterized by short stature, short limbs, and a large head. - This is inconsistent with the patient's **tall and lanky stature** and does not account for the recurrent fractures or hearing difficulties.

Epithelial/Connective tissues US Medical PG Question 6: An investigator is studying the structural integrity of collagen. Human fibroblasts are cultured on a medium and different enzymes are applied. One of the cultures is supplemented with an enzyme that inhibits lysyl oxidase, preventing the formation of covalent cross-links between collagen α-chains. Which of the following processes is most likely to be impaired as a result?

• A. Internal elastic lamina formation
• B. Ligament relaxation
• C. Osteoclast activation
• D. Bone matrix synthesis (Correct Answer)
• E. Cartilaginous growth plate mineralization

Epithelial/Connective tissues Explanation: ***Bone matrix synthesis*** * **Collagen** is the primary organic component of the bone matrix (osteoid), and its proper cross-linking through **lysyl oxidase-mediated covalent bonds** is crucial for structural integrity and subsequent mineralization. * **Lysyl oxidase** converts lysine and hydroxylysine residues to aldehydes (allysine and hydroxyallysine), which then form **aldol condensations and Schiff bases** to create stable cross-links between collagen fibrils. * Inhibiting lysyl oxidase directly compromises the formation of stable collagen fibrils, which are essential for **osteoid production** and bone strength, leading to conditions like **lathyrism** (seen with β-aminopropionitrile exposure). *Incorrect Option: Internal elastic lamina formation* * The **internal elastic lamina** is primarily composed of **elastin**, not collagen, and provides arterial elasticity. * While elastin also requires lysyl oxidase for cross-linking (desmosine and isodesmosine formation), the question specifically asks about **collagen α-chains**, making bone matrix synthesis the more direct answer. *Incorrect Option: Ligament relaxation* * **Ligament relaxation** refers to increased laxity, primarily influenced by hormones like relaxin during pregnancy. * Impairing collagen cross-linking would lead to **ligament weakness and fragility** rather than physiologic relaxation, potentially causing joint instability. *Incorrect Option: Osteoclast activation* * **Osteoclast activation** involves bone resorption, regulated by **RANK/RANKL/OPG signaling**, and is independent of newly synthesized collagen cross-linking. * While collagen integrity affects bone quality, lysyl oxidase inhibition impairs **osteoblast-mediated bone formation**, not osteoclast function. *Incorrect Option: Cartilaginous growth plate mineralization* * **Growth plate mineralization** involves calcium phosphate crystal deposition within cartilage matrix, regulated by chondrocytes and factors like alkaline phosphatase. * While collagen integrity is important in cartilage, the defect in collagen cross-linking most critically affects **bone matrix (osteoid)** synthesis, where type I collagen predominates and provides the scaffold for mineralization.

Epithelial/Connective tissues US Medical PG Question 7: A 61-year-old woman comes to the physician for evaluation of numbness and a burning sensation in her feet for the past 5 months. She has type 2 diabetes mellitus and hypercholesterolemia. Her blood pressure is 119/82 mm Hg. Neurologic examination shows decreased sensation to pinprick, light touch, and vibration over the soles of both feet. There is a nontender ulcer on the plantar surface of her left foot. Pedal pulses are strong bilaterally. Her hemoglobin A1c concentration is 8.6%. Which of the following processes is most likely involved in the pathogenesis of this patient's current symptoms?

• A. Demyelination of posterior columns and lateral corticospinal tracts
• B. Increased protein deposition in endoneural vessel walls (Correct Answer)
• C. Accumulation of lipids and foam cells in arteries
• D. Elevated hydrostatic pressure in arteriolar lumen
• E. Osmotic damage to oligodendrocyte nerve sheaths

Epithelial/Connective tissues Explanation: ***Increased protein deposition in endoneural vessel walls*** - The patient exhibits symptoms consistent with **diabetic neuropathy**, including numbness, burning sensation, decreased sensation to pinprick, light touch, and vibration, along with a plantar ulcer and poorly controlled diabetes (HbA1c 8.6%). - **Chronic hyperglycemia** in diabetes leads to the accumulation of advanced glycation end products (AGEs) and activation of the polyol pathway, which cause **thickening and hyalinization of endoneural vessel walls**, impairing blood flow to peripheral nerves. *Demyelination of posterior columns and lateral corticospinal tracts* - **Posterior column demyelination** occurs in conditions like **vitamin B12 deficiency** (subacute combined degeneration) and results in loss of vibratory and proprioceptive sensation. - **Lateral corticospinal tract demyelination** is associated with **motor deficits** (e.g., spasticity, weakness), which are not the primary symptoms described in this patient. *Accumulation of lipids and foam cells in arteries* - This process describes **atherosclerosis**, which can lead to peripheral artery disease (PAD) and contribute to foot ulcers due to **ischemia**. - However, the patient has **strong pedal pulses**, making significant atherosclerosis of the macrovessels less likely to be the primary cause of her neuropathic symptoms. *Elevated hydrostatic pressure in arteriolar lumen* - **Elevated hydrostatic pressure** in arterioles (hypertension) contributes to various microvascular complications, but it is not the direct or most prominent mechanism for the **nerve damage** seen in diabetic neuropathy. - The patient's blood pressure is relatively normotensive, making this cause less likely to be the predominant factor. *Osmotic damage to oligodendrocyte nerve sheaths* - **Oligodendrocytes** are responsible for myelin formation in the **central nervous system**, not the peripheral nervous system. - While osmotic damage can occur in conditions like **rapid correction of hyponatremia** (osmotic demyelination syndrome), it primarily affects the CNS and is not typically associated with chronic diabetic peripheral neuropathy.

Epithelial/Connective tissues US Medical PG Question 8: A 22-year-old Caucasian male is stabbed in his left flank, injuring his left kidney. As the surgeon undertakes operative repair, she reviews relevant renal anatomy. All of the following are correct regarding the left kidney EXCEPT?

• A. The left kidney has a longer renal vein than the right kidney
• B. The left kidney underlies the left 12th rib
• C. The left kidney moves vertically during deep breathing
• D. The left kidney has a longer renal artery than the right kidney (Correct Answer)
• E. The left kidney lies between T12 and L3

Epithelial/Connective tissues Explanation: ***The left kidney has a longer renal artery than the right kidney*** - The **aorta** lies to the left of the midline, so the **right renal artery** must traverse a greater distance to reach the right kidney. - Therefore, the right renal artery is longer than the left renal artery. *The left kidney has a longer renal vein than the right kidney* - The **inferior vena cava (IVC)** is positioned to the right of the midline, requiring the **left renal vein** to cross the aorta to drain. - This anatomical arrangement makes the left renal vein longer than the right renal vein. *The left kidney underlies the left 12th rib* - The kidneys are retroperitoneal organs, and the 12th rib provides significant posterior protection for **both kidneys**. - The superior pole of the left kidney typically extends to the level of the **11th and 12th ribs**. *The left kidney moves vertically during deep breathing* - The kidneys are surrounded by **perirenal fat** and are influenced by the diaphragm's movement. - During **deep inspiration**, the diaphragm descends, causing both kidneys to move vertically by 2-3 cm. *The left kidney lies between T12 and L3* - The kidneys are situated in the retroperitoneum, generally extending from the level of the **T12 vertebra** to the **L3 vertebra**. - The left kidney is typically positioned slightly higher than the right kidney.

Epithelial/Connective tissues US Medical PG Question 9: A 46-year-old man is brought to the emergency department for the onset of severe pain in his right knee that occurred when he tripped while descending a staircase. As he landed, he heard and felt an immediate popping sensation in his right knee. His medical history is positive for obesity, hypertension, type 2 diabetes mellitus, severe asthma, and hyperlipidemia. He currently takes lisinopril, hydrochlorothiazide, metformin, atorvastatin, an albuterol inhaler, and a fluticasone inhaler. He recently completed a hospitalization and week-long regimen of systemic corticosteroids for a severe exacerbation of his asthma. The patient's family history is not significant. In the emergency department, his vital signs are normal. On physical examination, his right knee is warm and swollen and he rates the pain as 9/10. He cannot stand or walk due to pain. He is unable to extend his right knee. A knee X-ray is ordered. Which of the following would best describe the cause of this presenting condition?

• A. Quadriceps tendon tear (Correct Answer)
• B. Meniscal tear
• C. Avascular necrosis of the femur
• D. Traction apophysitis of the tibia
• E. Femoral fracture

Epithelial/Connective tissues Explanation: ***Quadriceps tendon tear*** - The patient's inability to **extend his right knee**, along with the history of a "pop" and severe pain after a fall, is highly indicative of a quadriceps tendon tear. - The quadriceps tendon connects the quadriceps muscle group to the patella, and rupture results in loss of active knee extension—patients cannot perform a straight leg raise. - Recent use of **systemic corticosteroids** can weaken tendons, predisposing individuals to such injuries, especially during a forceful eccentric contraction like catching oneself during a fall. - Classic physical exam findings include a palpable **suprapatellar gap** and inability to extend the knee against gravity. *Meniscal tear* - While a meniscal tear can cause sudden knee pain and a popping sensation, it typically doesn't result in a complete inability to **extend the knee actively**. - Patients with meniscal tears often present with mechanical symptoms like **locking, catching, or clicking**, which are not described here. - Range of motion may be limited by pain or mechanical block, but the extensor mechanism remains intact. *Avascular necrosis of the femur* - This condition involves the death of bone tissue due to disrupted blood supply, often causing **gradual onset pain** that worsens with weight-bearing over weeks to months. - Risk factors include chronic corticosteroid use, but it does not typically present with an acute "pop" and immediate functional loss after a traumatic event like a fall. - Imaging would show collapse of the femoral head, not an acute soft tissue injury. *Traction apophysitis of the tibia* - Traction apophysitis (e.g., Osgood-Schlatter disease) is an **overuse injury** commonly seen in adolescents due to repetitive stress on the tibial tuberosity growth plate. - It presents with gradual onset anterior knee pain and does not explain the acute onset of severe pain and inability to extend the knee in a 46-year-old man after a fall. - This is a pediatric/adolescent condition, not seen in middle-aged adults with closed growth plates. *Femoral fracture* - A femoral fracture would cause severe pain and inability to bear weight, but the primary deficit would be the inability to move the entire leg due to bone instability and severe pain. - The specific, isolated deficit in **active knee extension** with preservation of passive range of motion points to a disruption of the extensor mechanism (tendon injury) rather than a bone fracture. - X-ray would show obvious fracture line in the femoral shaft or neck, which would be a more dramatic presentation.

Epithelial/Connective tissues US Medical PG Question 10: A 45-year-old man comes to the physician for the evaluation of limited mobility of his right hand for 1 year. The patient states he has had difficulty actively extending his right 4th and 5th fingers, and despite stretching exercises, his symptoms have progressed. He has type 2 diabetes mellitus. He has been working as a mason for over 20 years. His father had similar symptoms and was treated surgically. The patient has smoked one pack of cigarettes daily for 25 years and drinks 2–3 beers every day after work. His only medication is metformin. Vital signs are within normal limits. Physical examination shows skin puckering near the proximal flexor crease. There are several painless palmar nodules adjacent to the distal palmar crease. Active and passive extension of the 4th and 5th digits of the right hand is limited. Which of the following is the most likely underlying mechanism of this patient's symptoms?

• A. Ulnar nerve lesion
• B. Ganglion cyst
• C. Palmar fibromatosis (Correct Answer)
• D. Tendon sheath tumor
• E. Tenosynovitis

Epithelial/Connective tissues Explanation: ***Palmar fibromatosis*** - The patient's symptoms, including **painless palmar nodules**, skin puckering near the flexor crease, and inability to actively extend the 4th and 5th fingers (a classic presentation of **Dupuytren's contracture**), are indicative of palmar fibromatosis. - Risk factors like **male sex**, **age > 40**, **smoking**, **alcohol use**, **diabetes mellitus**, and a **family history** of similar symptoms are all present in this patient, strongly supporting the diagnosis. *Ulnar nerve lesion* - An ulnar nerve lesion would primarily cause **sensory deficits** (numbness/tingling in the 4th and 5th digits) and **motor weakness** in intrinsic hand muscles, leading to a **claw hand deformity**, not typically the presence of palmar nodules or skin puckering. - While it can affect the 4th and 5th digits, the mechanism of limitation would be due to muscle weakness rather than fixed contracture. *Ganglion cyst* - A ganglion cyst is a **fluid-filled sac** that typically presents as a smooth, mobile, sometimes painful lump, often on the dorsal aspect of the wrist or fingers. - It does not cause progressive finger contracture, skin puckering, or diffuse palmar nodules. *Tendon sheath tumor* - A tendon sheath tumor (e.g., giant cell tumor of the tendon sheath) is a **benign soft tissue mass** that presents as a firm, localized nodule, usually associated with a tendon. - While it can limit finger movement, it typically does so by mass effect and does not cause the characteristic diffuse fibrotic changes and skin puckering seen in Dupuytren's contracture. *Tenosynovitis* - Tenosynovitis is **inflammation of the tendon sheath**, often causing pain, swelling, and tenderness along the course of the tendon, and sometimes a "triggering" sensation with movement. - It does not typically manifest as painless, firm palmar nodules or progressive contracture with skin puckering.

Epithelial/Connective tissues Flashcard 1 of 10

Question: Which epithelial cell junction connects intermediate filaments of adjacent cells? _____

Answer: Desmosomes (macula adherens, spot desmosome)

Epithelial/Connective tissues Flashcard 2 of 10

Question: Which layer of the epidermis is characterized by keratin in anucleate cells? _____

Answer: Stratum corneum

Epithelial/Connective tissues Flashcard 3 of 10

Question: Where in the cell does the synthesis and formation of tropocollagen and collagen fibrils occur? _____

Answer: Extracellular space

Epithelial/Connective tissues Flashcard 4 of 10

Question: What proteins (2) are tight junctions composed of?_____

Answer: Claudins and occludins

Epithelial/Connective tissues Flashcard 5 of 10

Question: Which epithelial cell junction connects actin cytoskeletons of adjacent cells? _____

Answer: Adherens junctions (zonula adherens, belt desmosome)

Epithelial/Connective tissues Flashcard 6 of 10

Question: epithelial lining of palantine tonsil

Answer: 2nd pouch

Epithelial/Connective tissues Flashcard 7 of 10

Question: epithelial linings of oral cavity

Answer: surface ectoderm

Epithelial/Connective tissues Flashcard 8 of 10

Question: epidermis

Answer: surface ectoderm

Epithelial/Connective tissues Flashcard 9 of 10

Question: parotid, sweat, and mammary glands

Answer: surface ectoderm

Epithelial/Connective tissues Flashcard 10 of 10

Question: connective tissue

Answer: mesoderm