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Question 1

Infundibulum vs isthmus of fallopian tube

Answer 1

Infundibulum: The funnel-shaped opening near the ovary, with finger-like projections called fimbriae

Isthmus goes into uterus

Question 2

Coronary sinus

Answer 2

: in heart. Get deoxygenated blood from myocardium and give to right atrium

Question 3

osteocytes location

Answer 3

Osteocytes (from osteoblasts) are found in: lacunae of haversarian system

Question 4

otitis media vs externa from which bacteria?

Answer 4

Otitis externa and otitis media, both ear infections, are caused by different types of bacteria. Otitis externa (swimmer’s ear) is typically caused by Pseudomonas aeruginosa and Staphylococcus aureus,

while otitis media (middle ear infection) is commonly caused by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis

Question 5

liver blood supply; 2 sources

Answer 5

The liver receives blood from two main sources: the hepatic artery and the hepatic portal vein. The hepatic artery carries oxygenated blood from the heart, while the hepatic portal vein carries nutrient-rich, deoxygenated blood from the intestines and spleen

The blood then flows through the liver and exits via the hepatic veins, which lead to the inferior vena cava.

Question 6

mnemonic for transamination reactions

Answer 6

-always have alpha ketoglutarate and glutamate

• al like pie. Alanine + AK <—> pyruvate + glutamate
• Ox ass. Aspartame +AK <—> oxaloacetate + glutamate

Question 7

polycythemia vera affects which blood cell lines and who is most common in?

Answer 7

All blood lines esp RBC and older adults

Polycythemia Vera (PV) primarily affects the red blood cell line, causing an overproduction of these cells. However, it also impacts the white blood cell and platelet lines, leading to an increase in their production as well

Question 8

ascending aorta vs aortic arch vs descending aorta

Answer 8

Ascending aorta: supplies oxygenated blood to the heart muscle via the coronary arteries

Aortic arch: supplies blood to the head, neck, and upper extremities. It gives rise to three major branches: the brachiocephalic trunk (which further divides into the right subclavian and right common carotid arteries), the left common carotid artery, and the left subclavian artery

Descending aorta: supplies oxygenated blood to the chest wall, digestive system, kidneys, legs, reproductive organs, respiratory tract, and spinal cord. It also provides blood to the pelvic limbs and other abdominal organs.

Question 9

what are the three branches of CN V (trigeminal nerve)

Answer 9

V1= ophthalmic
V2= maxillary
V3= mandibular

Question 10

LR6 SO4

Answer 10

LR6 = Lateral Rectus is innervated by Cranial Nerve VI (Abducens)
Function: Abducts the eye (moves it laterally)

SO4 = Superior Oblique is innervated by Cranial Nerve IV (Trochlear)
Function: Intorts and depresses the eye (especially when adducted)

All else CN III = The remaining extraocular muscles are innervated by Cranial Nerve III (Oculomotor):
Medial rectus (adducts)
Superior rectus (elevates)
Inferior rectus (depresses)
Inferior oblique (elevates when adducted)
Also innervates levator palpebrae superioris (eyelid elevation)
Parasympathetics to pupil constriction (via sphincter pupillae)

Question 11

periosteum vs endosteum of bone

Answer 11

Periosteum = outer protective and nourishing layer

Endosteum = inner bone-lining membrane involved in turnover and remodeling

Question 12

nerve roots for thoracic outlet syndrome and sciatica

Answer 12

Thoracic outlet syndrome: compress brachial plexus via scalenes (C5-T1)

Sciatica nerve roots: L4-S3

Question 13

PTH and calcitonin and impact on blood calcium

Answer 13

🦴 Parathyroid Hormone (PTH)
Goal: Increase blood calcium
Acts on osteoblasts → stimulates them to release RANKL
RANKL activates osteoclasts (indirect activation)
Osteoclasts break down bone (resorption) → Ca²⁺ released into blood
Net effect: ↑ Blood calcium
➡️ PTH: Indirectly stimulates osteoclasts via osteoblast signaling

🦴 Calcitonin
Goal: Decrease blood calcium
Directly inhibits osteoclasts → reduces bone resorption
May mildly stimulate osteoblast activity
Net effect: ↓ Blood calcium
➡️ Calcitonin: Directly inhibits osteoclasts

Question 14

PTH and calcitonin impact on osteoblasts and osteoclasts and net effect of blood calcium

Answer 14

PTH:
-osteoblast: stimulate RANKL which increase osteoclasts
-osteoclast- indirectly stimulated via RANKL
-increase blood calcium

Calcitonin:
-osteoblast: mild stimulation or neutral
-osteoclasts: direct inhibition
- decrease blood calcium.

Question 15

vitamin D impact on blood calcium

Answer 15

☀️ Vitamin D (Calcitriol = 1,25-dihydroxyvitamin D₃)
Goal: Increase blood calcium and phosphate

📌 Mechanism:

Increases intestinal absorption of Ca²⁺ and PO₄³⁻ (major effect)
Increases renal reabsorption of calcium and phosphate
Synergizes with PTH to stimulate osteoclast activity indirectly via RANKL
🦴 Bone Effects:

Stimulates osteoblasts to produce RANKL
RANKL activates osteoclasts → increased bone resorption
BUT also promotes mineralization if Ca/PO₄ supply is adequate
→ It’s dual-acting: resorptive if calcium is low, mineralizing if it’s high

Question 16

vitmain D and PTH

Answer 16

PTH and vitamin D work together to raise blood calcium

Calcitonin counters them by lowering calcium, mainly via osteoclast inhibition

Question 17

what increases RANKL which increases osteoclasts activity

Answer 17

PTH and vitamin D (to increase blood calcium)

Question 18

what does vitamin D help to increase

Answer 18

calcium and PO4

Question 19

asthma criteria (and also give; obstructive lung disease; what is FEV1/FVC)

Answer 19

1. Reversible airflow obstruction
   ↑ FEV1 ≥12% & ≥200 mL after bronchodilator
2. Episodic symptoms
   Wheezing, cough, dyspnea (often at night or with triggers)
3. Airway hyperresponsiveness
   Positive methacholine challenge (↓ FEV1 ≥20%)
4. Inflammation (supportive)
   Eosinophils, ↑ exhaled NO
   Often linked to atopy

——-1
FEV1/FVC is deceased

Question 20

1st step of gluconeogenesis

Answer 20

The first step in gluconeogenesis is the conversion of pyruvate to phosphoenolpyruvate (PEP). This process involves two key enzymatic reactions, both of which are needed to bypass the irreversible step in glycolysis catalyzed by pyruvate kinase.

Here’s a breakdown of the first step:
1. Pyruvate to Oxaloacetate:
Pyruvate is first carboxylated to oxaloacetate by the enzyme pyruvate carboxylase. This reaction occurs in the mitochondrial matrix and requires one molecule of ATP and the cofactor biotin.






2. Oxaloacetate to Phosphoenolpyruvate (PEP):
Oxaloacetate is then converted to PEP by phosphoenolpyruvate carboxykinase (PEPCK). This step utilizes GTP and can occur in both the mitochondria and the cytosol, depending on the organism.






In essence, these two reactions effectively bypass the pyruvate kinase reaction of glycolysis, allowing for the synthesis of glucose from pyruvate in the gluconeogenic pathway

Question 21

gluconeogenesis

is the reverse of?
purpose?
location?
substrates? irreversible steps

Answer 21

REVERSE OF GLYCOLYSIS

• Purpose:
To produce glucose when dietary intake is insufficient or during periods of energy demand.




• Location:
Primarily occurs in the liver and kidneys.




• Substrates:
Lactate (from muscle and red blood cells), glycerol (from fat breakdown), and glucogenic amino acids (from protein breakdown) are the main precursors.




• Irreversible steps:
Gluconeogenesis bypasses three irreversible steps in glycolysis (catalyzed by hexokinase, phosphofructokinase, and pyruvate kinase) by using alternative enzymes.


Question 22

Sodium or calcium for heart action potential?

Answer 22

Heart action potentials involve both sodium and calcium, but in distinct phases. The initial rapid depolarization is primarily driven by sodium ions, while a subsequent plateau phase and the overall duration of the action potential are influenced by calcium ions. Potassium ions also play a crucial role in repolarization, returning the cell to its resting state.

Elaboration:
1. Sodium (Na+):
* Depolarization: The action potential begins with a rapid influx of sodium ions through voltage-gated sodium channels. This influx makes the inside of the cell more positive, leading to depolarization.

* Fast Channels: These sodium channels are fast-acting, causing the initial rapid rise in the action potential.



2. Calcium (Ca2+):
   
   • Plateau Phase: Following depolarization, calcium ions enter the cell through slow calcium channels, creating a plateau phase in the action potential. This phase is crucial for the prolonged contraction of heart muscle.

   • Contraction: Calcium influx triggers the release of more calcium from internal stores within the cell, leading to muscle contraction.

   • Duration: Calcium channels also contribute to the overall duration of the action potential.

Question 23

lub dub

Answer 23

The first heart sound, S1 (“lub”), is primarily caused by the closure of the mitral and tricuspid valves at the beginning of ventricular systole (contraction). The second heart sound, S2 (“dub”), is produced by the closure of the aortic and pulmonic valves at the beginning of diastole (relaxation).

Question 24

Sperm made where and stored where?

Answer 24

Sperm is produced in the testes (or testicles) within coiled structures called seminiferous tubules. After production, sperm are stored and mature in the epididymis, a tube located on the back of each testicle