Monday, July 7, 2025

 Which of the following blood vessels carries oxygenated blood?

A. Pulmonary artery
B. Pulmonary vein
C. Superior vena cava
D. Right atrium




  1. The pulmonary vein carries oxygenated blood from the lungs to the left atrium of the heart.
  2. The pulmonary artery actually carries deoxygenated blood from the heart to the lungs, which is the opposite of most arteries.

  3. The superior vena cava carries deoxygenated blood from the upper body to the right atrium.




What is the primary function of white blood cells (leukocytes)?
A. Carry oxygen
B. Fight infections
C. Clot blood
D. Produce hormones

✔️ Answer: B. Fight infections

Explanation:
White blood cells (leukocytes) are a key part of the immune system. Their main job is to:

  • Detect and destroy pathogens (like bacteria, viruses, and parasites)

  • Support the body’s immune defense

Which process describes water moving across a semipermeable membrane?
A. Active transport
B. Diffusion
C. Osmosis
D. Filtration


Explanation:

  • Osmosis is the movement of water molecules through a semipermeable membrane from an area of low solute concentration to an area of high solute concentration, aiming to balance the solute levels.

  • It’s a passive transport process (doesn’t require energy).

What type of joint is found in the shoulder and hip?
A. Hinge
B. Pivot
C. Saddle
D. Ball and socket

✔️ Answer: D. Ball and socket

Explanation:

  • The shoulder and hip joints are both ball-and-socket joints, which allow for a wide range of motion in almost all directions.

  • These joints enable movements like rotation, abduction, adduction, and circumduction.


Which structure connects muscle to bone?
A. Ligament
B. Cartilage
C. Tendon
D. Fascia

  • Tendons connect muscle to bone and help transfer the force of muscle contraction to move the bones.

  • Ligaments, in contrast, connect bone to bone at joints.

  • Cartilage cushions joints, and fascia is connective tissue surrounding muscles and organs.

  • Which organ is responsible for detoxifying the blood and producing bile?
    A. Kidney
    B. Liver
    C. Pancreas
    D. Gallbladder

    What’s your answer?


  • Question 7:

    DNA is made up of:
    A. Amino acids
    B. Fatty acids
    C. Nucleotides

    D. Monosaccharides


    • A sugar (deoxyribose)

    • A phosphate group

    • A nitrogenous base (A, T, C, or G)

  • DNA (deoxyribonucleic acid) is made up of repeating units called nucleotides, each consisting of:

  • Amino acids build proteins, fatty acids build lipids, and monosaccharides are simple sugars.


  • At extremely high temperatures, enzymes denature, meaning:

    • Their shape changes

    • They lose function

  • Enzymes only work within an optimal temperature range. Too hot = structure breaks down.


  • What is the atomic number of an element?
    A. Number of protons
    B. Number of neutrons
    C. Number of electrons + neutrons
    D. Number of isotopes


    • Golgi apparatus

      Explanation:


      The Golgi apparatus is the organelle that modifies, sorts, and packages proteins for transport inside or outside the cell.


      Ribosomes (your answer) are where proteins are made, but they don’t package or transport them.


  •  

    [Brain Ventricles] ← Catheter → Tube → [External Drain Bag + ICP Monitor]

    astrocytoma

     An astrocytoma is a type of glioma, a tumor that develops from star-shaped brain cells called astrocytesThese tumors can be benign (non-cancerous) or malignant (cancerous) and can occur in both children and adults. Astrocytomas can vary in their growth rate and aggressiveness, ranging from slow-growing to rapidly growing, and are classified into grades 1 through 4, with grade 4 being the most aggressive. 



    🧑‍⚕️ Nursing & Monitoring

    • Head must stay aligned and at the correct level (usually 0°–30° angle)

    • The drainage system must stay level with the child’s head to prevent over- or underdrainage

    • Regular monitoring for CSF output, ICP values, and signs of infection

    📤 When is it removed?

    • When the underlying issue is resolved (e.g., tumor removed, swelling gone)

    • Or when a permanent solution like a VP shunt is placed


    1. EVD Placement (External Ventricular Drain)

    What is it?

    An External Ventricular Drain (EVD) is a temporary catheter (tube) surgically inserted into the ventricles of the brain to:

    • Drain cerebrospinal fluid (CSF)

    • Relieve intracranial pressure (ICP)

    • Monitor pressure within the brain 

      Normal ICP:

      • 3 to 7 mmHg (millimeters of mercury)

      • 📈 Elevated ICP in children:

        • > 15 mmHg is concerning

        • > 20 mmHg is generally considered pathologic and may require intervention

        • > 40 mmHg is severe and life-threatening

        • 🎯 ICP Management Goals (in critical care):

          For children with brain injury, hydrocephalus, or post-op care:

          • Keep ICP < 20 mmHg

          • Maintain cerebral perfusion pressure (CPP) to avoid brain ischemia

        • 📈 How is ICP monitored?

          • The EVD system is connected to a pressure transducer

          • Normal ICP in a 6-year-old = 3–7 mmHg

          • Readings are continuously monitored in the ICU

          • If ICP rises (e.g., > 15–20 mmHg), doctors may adjust drainage or give medications

    • Remove blood or infection (in some cases)

    Why is it placed?

    EVD is placed when there's:

    • Hydrocephalus (too much CSF in the brain)

    • Increased ICP from trauma, tumor, hemorrhage, or infection

    • Need for CSF diversion while waiting for a permanent solution (e.g., VP shunt)

    How is it placed?

    1. Preparation:

      • The patient is sedated or under general anesthesia.

      • Head is shaved and sterilized.

    2. Burr Hole:

      • A small hole is drilled in the skull (usually in the frontal bone).

    3. Catheter Insertion:

      • A soft catheter is inserted through the brain tissue into a lateral ventricle.

      • CSF flows through the catheter and is collected in an external drainage system.

    4. System Setup:

      • The drainage system is calibrated to drain at a specific pressure level.

      • The EVD height relative to the patient’s head determines the drainage rate.

  • Risks

    1. Infection (especially after 5–7 days)

    2. Hemorrhage

    3. Overdrainage → collapsed ventricles

    4. Misplacement or clogging of the catheter

    What is SEGA?

    SEGA stands for Subependymal Giant Cell Astrocytoma:

    • A benign brain tumor

    • Often associated with Tuberous Sclerosis Complex (TSC)

    • Usually located near the foramen of Monro (the passage between ventricles)

    Why is resection needed?

    • Tumor blocks CSF flow → causes obstructive hydrocephalus

    • Can lead to increased ICP, headaches, nausea, vision changes, seizures

    • Though slow-growing, it can become life-threatening due to location

    Surgical Resection Procedure:

    1. Pre-op Imaging:

      • MRI/CT to visualize the tumor and plan surgery

    2. Craniotomy:

      • The skull is opened to access the tumor.

      • Usually done via interhemispheric transcallosal or transcortical approach.

    3. Tumor Removal:

      • The surgeon carefully dissects the tumor from surrounding brain tissue.

      • Aim: Total resection, while preserving surrounding structures

    4. Post-op Monitoring:

      • Watch for CSF leaks, infections, hydrocephalus, seizures, or neurologic deficits

    5. \

    Alternative Treatment (if surgery is risky):

    • mTOR inhibitors like everolimus (Afinitor) may shrink the tumor in patients with TSC.

      • Especially helpful when surgery is not safe or tumor is small.


    Recovery & Follow-up:

    • ICU monitoring post-surgery

    • Neurologic assessments

    • MRI follow-ups to check for residual tumor or recurrence

    • Consideration of VP shunt if hydrocephalus persists


    Summary Table:

    TopicDescription
    EVDCatheter to drain CSF and reduce ICP
    Reason for EVDHydrocephalus, increased pressure from SEGA tumor
    SEGA TumorBenign brain tumor near foramen of Monro, common in TSC
    Why Remove SEGABlocks CSF flow → hydrocephalus, symptoms, pressure
    Surgical RiskBleeding, infection, damage to brain tissue
    Post-op CareICU monitoring, imaging, neurologic checks