Foundations 2 Week 3

Question 1

Where would you expect to see this type of epithelium?

A. Skin

B. Blood vessel

C. Lining of respiratory tract

D. Bladder

Answer 1

D. Bladder

This is an example of transitional epithelium which is mainly found in the urinary tract. The most apical layer of cells in this image are dome-shaped which is a hallmark of this type of epithelium.

Lecture: Epithelium Histology

Objective 3: Identify/name the different types of epithelia at the light microscopic (LM) level

Question 2

You are inspecting a nerve which innervates a body wall muscle. From which nerve primordia was it derived?

Answer 2

This is a somatomotor neuron which has its cell body in the spinal cord, a part of the Central Nervous System (CNS).

All such cells are derived from neural tube whereas neurons with cell bodies in the Peripheral Nervous System (PNS) are derived from neural crest.

Lecture: Somatic Nervous System

Objective 4: Describe how the nervous system develops from the neural plate, neural tube, and neural crest

Question 3

The crosslinking of lysine and hydroxylysine residues is a key step in the assembly of collagen molecules into what structures? Is this step completed intra- or extracellularly?

Answer 3

The extracellular crosslinking of lysine and hydroxylysine residues results in the formation of collagen fibrils.

Lecture: Connective Tissue Proper

Objective 5: Describe how fibroblasts assemble collagen molecules and fibrils. Indicate which steps are intracellular and which steps are extracellular. Describe the role of vitamin C.

Question 4

4. Necrosis due to ischemia in the brain occurs in a different fashion than ischemic injury in other tissues. While ischemic injury in the heart can result in ___(A)____ necrosis, ischemia in the brain results in ___(B)____ necrosis.

Answer 4

(A) Coagulative necrosis

(B) Liquefactive necrosis

Ischemia in most tissues leads to coagulative necrosis if the cells die, but in the brain, tissue is lysed and liquified. To clarify, liquefactive necrosis is a type of coagulative necrosis.

Lecture: Cellular Adaptation

Objective 4: List the different subtypes of necrosis.

Question 5

Which of the following is not a feature of irreversible cell injury?

A. Nuclear fragmentation

B. Increased eosinophilic staining

C. Mitochondrial swelling

D. Nuclear shrinkage

Answer 5

D. Nuclear shrinkage (also known as pyknosis), not swelling is a feature of irreversible cell injury.

Pyknosis also includes increased basophilia of the nuclei.

Note on Choice A: Nucleic fragmentation is known as karyorrhexis

Lecture: Cell Injury and Death

Objective 3: Explain the changes that occur as reversible injury becomes irreversible.

Question 6

Sympathetics are known as ___(A)_____ outflow while parasympathetic are known as ____(B)____ outflow. Which ventral roots do sympathetics exit the CNS at?

Answer 6

A) Thoracolumbar outflow. Sympathetics exit from the T1-L2 ventral roots.

(B) Craniosacral outflow. Parasympathetics exit from the brain and pelvic splanchnics.

Lecture: Autonomic Nervous System

Objective 9: For autonomic nerves, describe the concept of pre-synaptic and post-synaptic in the two neuron sequence from the CNS to target tissues.

Question 7

Match the following.

1. Does not shorten during contraction
2. Marks boundaries of sarcomere
3. Composed of thin filaments
4. Where thick filaments are connected to each other
5. Has no overlap with actin
   a. A-band b. I-band c. H-band d. Z-line e. M-line

Answer 7

1. (A) The A-band does not shorten during contraction
2. (D) The Z-line marks the boundaries of a sarcomere
3. (B) The I-band consists of thin filaments
4. (E) The M-line is where thick filaments are connected to each other
5. (C) The H-band has no overlap with actin

Lecture: Muscle Histology

Objective 3: Explain how the organization of myofilaments, myofibrils, and sarcomeres relates to the microscopic appearance of striations. Define A-band, I-band, H-band, Z-line, and M-line.

Question 8

The sciatic nerve is the longest spinal nerve in the human body. In order to get signals to leg muscles quickly, would you expect this nerve to be large or small in diameter?

Answer 8

The sciatic nerve is large in diameter! Conduction speed is positively correlated with diameter.

Lecture: Histology of the Nervous System

Objective 3: Describe the process of nerve conduction and indicate factors that relate to its speed. Describe how a nerve impulse is transferred from one neuron to another.

Question 9

Beta-2 receptors induce smooth muscle relaxation by stimulating adenylyl cyclase to increase cAMP levels which then activates what enzyme?

Answer 9

Protein Kinase A (PKA)

Lecture: Signal Transduction and Receptor Pharmacology in the Peripheral Nervous System

Objective 4: List pharmacological agents in clinical use that are agonists at alpha-1, alpha-2, and beta-2 adrenoreceptors and those that block muscarinic acetylcholine (ACh) receptors and beta-1 adrenoreceptors. Review the signaling mechanisms involved in the actions of these agonists and antagonists.

Question 10

Contraction of the R external oblique rotates the trunk to which side?

Answer 10

To the Left. External oblique muscle fibers are oriented “hands in pockets” and rotate the trunk to the opposite side.

Lecture: Body Wall

Objective 2: Describe the arrangement and function, and innervation of the thoracic body wall muscles.