Cranial Foramina and Associated Structures

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Questions and Answers

Which structure passes through the Foramen Rotundum?

Maxillary Nerve (correct)

Ophthalmic Artery

Mandibular Nerve

Greater Petrosal Nerve

Which cranial nerves pass through the Internal Acoustic Meatus?

III, IV, VI

IX, X, XI

VII, VIII, X

VII, VIII (correct)

Which structure is incorrectly paired with its corresponding foramen?

Hypoglossal Canal - Foramen Lacerum (correct)

Middle meningeal Artery - Foramen Spinosum

Cribriform Plate - Olfactory Nerve

Optic Canal - Ophthalmic Artery

Which structure does the Jugular Foramen NOT transmit?

Middle Meningeal Artery Signup and view all the answers

Which structure does not pass through the Foramen Ovale?

Greater Petrosal Nerve Signup and view all the answers

Which mechanism is involved in atrophy?

Ubiquitin mediated proteolysis Signup and view all the answers

Which type of atrophy is characterized by the accumulation of lipofuscin?

Brown atrophy Signup and view all the answers

Hypertrophy in cardiac muscle is commonly caused by which condition?

Hypertension and valvular disease Signup and view all the answers

Which type of cellular adaptation involves an increase in cell number?

Hyperplasia Signup and view all the answers

Endometrial hyperplasia is primarily caused by an increase in which hormone?

Estrogen Signup and view all the answers

Which of the following is a premalignant condition?

Metaplasia Signup and view all the answers

Which proteins are involved in the intrinsic pathway of apoptosis?

BAK and Bcl-2 Signup and view all the answers

What event directly follows the increase in mitochondrial membrane permeability in the intrinsic pathway of apoptosis?

Leakage of Cytochrome C into the cytosol Signup and view all the answers

Which caspase is directly involved in the executioner phase of apoptosis?

Caspase 3 Signup and view all the answers

What is the role of the necrosome in necroptosis?

Increase in free radicals (FR) and decrease in ATP Signup and view all the answers

Which factor is common between necroptosis and pyroptosis?

TNFα Signup and view all the answers

Which protein is responsible for activating IL-1 in pyroptosis?

Caspase 1 Signup and view all the answers

Study Notes

Cranial Foramina

Foramen Spinosum: Middle meningeal artery, emissary vein, and nervous spinosum
Foramen Lacerum: Hypoglossal canal (XII)
Foramen Magnum:
Cribriform plate: (I, COVID)
Optic Canal: (II, opthalmic A)
Sup.orbital fissure: (III, IV, V1, VI)
Foramen Rotundum: (V2)
Foramen ovale: (V3)
Mandibular Nerve:
Accessory Meningeal Artery:
Lesser petrosal nerve:
Emissary vein:
Internal acoustic meatus: (VII, VIII, Labyrinthine Artery)
Jugular foramen:
- Ant.: Inf.Petrosal Sinus
- Middle: IX, X, XI
- Post.: Sigmoid Sinus

Cell Death

I. Apoptosis

Mechanism:
- Initiator Phase:
  - Extrinsic Pathway: Stimulus to Death Receptor (e.g., FAS, TNFα, R, IL-1 R)
  - Intrinsic Pathway (Mitochondrial): Imbalance between pro-apoptotic and anti-apoptotic proteins (e.g., BAK, BAX, Bcl-2, Mcl-1, Bcl-XL)
- Executioner Phase:
  - Caspase 8, 10 → Caspase 9
  - Caspase 3 (Executioner Caspase) → DNA fragmentation, cytoskeletal protein breakdown, cell shrinkage, cytoplasmic condensation, membrane blebs, and apoptotic bodies

II. Necroptosis

Mechanism of Death: Necrosis
Trigger (Genetically Programmed): TNFα → TNFα, R (Death Receptor) → Necrosome (RIP1, III) → Necrosis

III. Pyroptosis

Trigger: Bacterial infection → ↓ Inflammasome → Caspase 1 → ↓ Caspase 11 → IL-1 (inactive) → ↓ Active IL-1 → ↓ Inflammation → ↑ Cell death

Cellular Adaptations

Atrophy: Decrease in organ size due to decreased cell size or decreased cell count
- Mechanism: Ubiquitin-mediated proteolysis, autophagic vacuole → lysosomal hydrolysis
Examples of Atrophy:
- Disuse Atrophy: Immobilized limbs
- Ischemic Atrophy: Thromboangitis obliterans
- Pressure Atrophy: Tumors
- Denervation Atrophy: Hemiplegia
- Nutritional Atrophy: PEM, brown color
- Brown Atrophy: Lipofuscin, uncleared autophagic vacuoles in the cell, Myocardium, old age, wear and tear pigment, Aging pigment
- Endocrine Atrophy: Past menopausal, breast, uterus, ovary
Hypertrophy: Increase in organ size due to increased cell size
- Mechanism: Increase in stimulus/ workload
- Examples:
  - Cardiac muscle: HTN, valvular disease (stenosis and regurgitation)
  - Skeletal muscle: Exercise
  - Smooth Muscle: Pregnant uterus
  - Glandular Hypertrophy: Breast (lactation, pregnancy)
Hyperplasia: Increase in the number of cells leading to increased organ size

Examples of Hyperplasia

- Smooth muscle: Pregnant uterus
- Glands of breast: Pregnancy and puberty
- Endometrial hyperplasia: ↑ Estrogen
- Bronchial Gland: Chronic bronchiolitis
- Benign Prostatic hyperplasia
- Enthyroid Hyperplasia: High altitude

Metaplasia: One mature cell is replaced by another cell
- Pre-malignant

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Description

This quiz covers the different foramina in the cranium, including the foramen spinosum, foramen lacerum, and others, as well as the nerves and blood vessels that pass through them. Test your knowledge of these important anatomical structures.