Bio/Biochem Deck 9: High-Yield Miscellaneous

For embryology: The three germ layers

Ectoderm

• Nervous system

• Epidermis

• Hair

• Nails

Mesoderm

• Muscle

• Bone

• Blood

• Kidneys

• Heart

• Gonads

Endoderm

• GI tract

• Liver

• Pancreas

• Lungs

• Thyroid/parathyroid epithelium

Ectoderm

"Attracto" (outside)

Skin

Brain

Nerves

Mesoderm

"Means movement."

Muscle

Bone

Blood

Heart

Kidneys

Endoderm

"Inside."

Digestive tract

Respiratory tract

Liver

Pancreas

What is neurulation?

Formation of the neural tube, which develops into the brain and spinal cord.

Neural crest cells give rise to...

• Peripheral nervous system

• Schwann cells

• Melanocytes

• Adrenal medulla

• Facial cartilage

Which hormone triggers ovulation?

LH surge

Which hormone stimulates follicle development?

FSH

Which hormone is highest during the follicular phase?

Estrogen.

Which hormone dominates the luteal phase?

Progesterone.

Function of progesterone

Maintains the endometrium for implantation.

What happens if fertilization does NOT occur?

Corpus luteum degenerates.

↓

Progesterone falls.

↓

Menstruation occurs.

What hormone maintains the corpus luteum during pregnancy?

hCG.

Where does fertilization usually occur?

Ampulla of the fallopian tube.

Where does implantation occur?

Endometrium of the uterus.

Where are sperm produced?

Seminiferous tubules.

Where do sperm mature?

Epididymis.

Which cells produce testosterone?

Leydig cells.

Which cells support spermatogenesis?

Sertoli cells.

Function of red blood cells

Transport oxygen and carbon dioxide.

Function of platelets

Blood clotting.

Function of plasma

Carries proteins, nutrients, hormones, and clotting factors.

Which protein carries oxygen?

Hemoglobin.

Where is hemoglobin found?

Inside red blood cells.

Which blood type is the universal donor?

O negative.

Which blood type is the universal recipient?

AB positive.

Blood type A has...

A antigens.

Anti-B antibodies.

Blood type B has...

B antigens.

Anti-A antibodies.

Blood type AB has...

A and B antigens.

No anti-A or anti-B antibodies.

Blood type O has...

No A or B antigens.

Both anti-A and anti-B antibodies.

Can Rh-negative patients receive Rh-positive blood?

Generally no, because they may develop anti-Rh antibodies after exposure.

Order of hemostasis

• Vasoconstriction

• Platelet plug formation

• Coagulation cascade

• Fibrin clot

Function of fibrin

Stabilizes the blood clot.

Prokaryotes vs Eukaryotes

Prokaryotes

• No nucleus

• No membrane-bound organelles

• Circular DNA

• 70S ribosomes

Eukaryotes

• Nucleus

• Organelles

• Linear DNA

• 80S ribosomes

Gram-positive bacteria

Thick peptidoglycan.

Purple stain.

Gram-negative bacteria

Thin peptidoglycan.

Outer membrane.

Pink stain.

Viruses are...

Obligate intracellular parasites.

Do viruses reproduce independently?

No.

They require host cells.

Retroviruses use which enzyme?

Reverse transcriptase.

DNA viruses usually replicate where?

nucleus

RNA viruses usually replicate where?

Cytoplasm

Fungi are...

Eukaryotic organisms with chitin cell walls.

Antibiotics work against...

Bacteria.

Not viruses.

Innate immunity

Fast.

Nonspecific.

Adaptive immunity

Specific.

Memory.

B cells become...

Plasma cells that produce antibodies.

CD4 T cells

Helper T cells.

Coordinate immune responses.

CD8 T cells

Cytotoxic T cells.

Kill infected cells.

What does MHC I present?

Intracellular antigens.

Recognized by CD8 T cells.

What does MHC II present?

Extracellular antigens.

Recognized by CD4 T cells.

Primary immune response

Slower.

First exposure.

Secondary immune response

Faster.

Memory cells respond rapidly.

Function of vaccines

Stimulate adaptive immunity and generate memory cells without causing disease.

IgM

First antibody produced during infection.

IgG

Most abundant antibody in blood.

Provides long-term immunity.

Crosses the placenta.

IgA

Found in mucosal secretions (saliva, tears, breast milk).

IgE

Allergic reactions and defense against parasites.

IgD

B-cell receptor involved in B-cell activation.