DAT Bootcamp Bio

Neutrophils

• Phagocytes in innate immunity that make up over half of all leukocytes

• One of the first cells to be recruited to a site of inflammation.

Lymphocytes

• B cells, T cells, and natural killer cells

• Natural killer cells are a part of innate immunity and attack virally-infected cells and cancerous cells

  • They use perforin and granzyme to lyse cells

• B and T are the most common type of leukocyte

Eosinophils

• Part of innate immunity

• Have granules that can be released to kill pathogens, especially parasites

Basophils

• Least numerous leukocyte

• Contain granules with histamine and herapin (prevent blood clotting)

Interferons

secreted by virally- or bacterially-infected cells and bind to non-infected cells to prepare them for an attack.

Ductus venous

A duct (tunnel) that connects the umbilical vein to the inferior vena cava. Blood that passes through this bypasses the nonfunctional fetal liver.

Foramen ovale

A hole that allows blood in the right atrium to flow into the left atrium. Recall that the right ventricle pumps to the lungs, which are nonfunctional in the fetus. Blood that passes through this bypasses pulmonary circulation.

Ductus arteriosus

A duct that connects the pulmonary artery to the aorta. Blood pumped by the right ventricle into the pulmonary artery can bypass the lungs by moving through here.

Hydrostatic pressure

pushes fluid out of the capillaries on the arterial end into interstitial space.

Oncotic pressure

brings fluid back into the capillaries at the venule end.

IgM

• Pentameric

• Largest antibody

• First to be produced

• Activates complement system

IgA

• Dimeric form

• Found in bodily secretions

• Newborns receive passive immunity through breastmilk containing this

IgE

• Present on basophil and mast cells as antigen receptors

• Triggers histamine

IgD

• Monomer with very little information known

• Small amounts produced

IgG

• Most abundant antibody in circulation

• Cross placenta to give fetus passive immunity

• Helps the complement system to cause opsonization (tags antigens and subsequent phagocytosis).

telecephalon —> cerebrum and diencephalon —> thalamus, hypothalamus, pineal gland

Forebrain develops into…

Mesencephalon —> midbrain

Midbrain develops into…

Metencephalon —> pons, cerebellum, myelencephalon —> medulla oblongata

Hindbrain develops into…

Frontal lobe

Known for higher function processes such as decision making, problem solving, attention and concentration.

Temporal lobe

Known for speech and hearing

Occipital lobe

Known for visual perception

Parietal lobe

Known for spatial perception and sensation

Cerebellum

located underneath the occipital lobe and is responsible for the coordination of movement.

Midbrain

Relays senses to other parts of brain.

Pons

Relays messages between the forebrain, cerebellum, and medulla.

Medulla Oblongata

Heart and breathing rate, blood pressure, toxin sensing. Connects the cerebrum/cerebellum to the spinal cord.

Reticular formations:

Neurons throughout the brainstem that are involved in cortical arousal, and consciousness.

Thalamus

The “relay center” of the brain and is located between the cerebrum and the midbrain. Relays sensory and motor signals from the body to the brain.

Hypothalamus

Regulates hormone secretion in the body

Hippocampus

Responsible for memory consolidation.

Amygdala

Responsible for the emotional reaction to certain scents.

sympathetic nervous system

Fight or flight

parasympathetic nervous system

rest and digest

Outer ear

takes in sound waves

Tympanic membrane

transfers the sound from outer ear to middle ear

Middle ear

composed of three bony ossicles.

Ossicles

transfer vibrations through the middle ear and amplify the signal. The vibrations get transmitted from the middle to the inner ear.

Cochlea

uses fluid and hairs to convert the mechanical signal into a neuronal signal, known as transduction.

Semicircular canal

fluid and hairs just like the cochlea but gives information about the person’s movement. It is also the reason people get dizzy.

Cornea

Transparent; focuses light and protects the eye.

Iris

Controls the size of the pupil.

Pupil

Controls how much light enters the eye.

Lens

Focuses images on retina.

Retina

Back of the eye that has photoreceptors (rods + cones).

Rods

function at low levels of light and are responsible for low-light perception.

Cones

function at high levels of light and are responsible for color perception.

Fovea

Highest concentration of photoreceptors in the retina. Responsible for high acuity vision.

Optic nerve

Bundle of axons that transmits visual information to the brain.

Optic disk

The blind spot of the eye, where the optic nerve passes through to reach the brain.

Sclera

Protective layer of tissue; the “white part” of the eye.

Smooth muscle

present in organs, airways, blood vessels, not striated

Cardiac muscle

Present in heart, striated

Skeletal muscle

Present around the bone, strated

Z line

are the ends of the sarcomeres. Thin actin filaments branch from here towards the middle of the sarcomere.

M lines

midpoints of the sarcomeres. Thick myosin filaments branch from here towards the ends of the sarcomere.

I band

area in the sarcomere where only actin filaments are present.

A band

the entire length of the myosin filament, including where myosin overlaps actin.

H band

area in the sarcomere where only myosin is present.

Epiphysis

End of a long bone that forms joints with other bones and contains red bone marrow for hematopoiesis (blood cell synthesis).

Diaphysis

Long hollow shaft in center of bone.

Red bone marrow

Contains stem cells that generate red and white blood cells.

Yellow bone marrow

Contains stem cells that generate fat, bone, cartilage, and muscle. Also stores fat.

Metaphysis

Similar to epiphyses. Found between the diaphysis and epiphyseal plates.

Epihyseal plate

“Growth plate” located between epiphysis and metaphysis. Made out of cartilage and works to lengthen the diaphysis through growth and ossification.

Cancellous bone

spongy inner layer of bone that soaks up red bone marrow via a web of

trabeculae (connective tissue that supports cancellous bone).

Cortical bone

dense outer layer of bone that supports the weight of our bodies.

Osteons

Cortical bone functional unit, composed of tiny multi-layered cylinders. Also known as haversian systems because they contain a haversian canal in their center.

Haversian canal

Tubes that contain blood vessels for nutrient supply.

Lamallae

layers of the osteon

Volkmann’s canals

connect Haversian systems to the periostem

Osteoblasts

Build bone by secreting proteins and utilizing blood calcium. They mature into osteocytes after getting trapped inside the bone matrix they create.

Osteocytes

Live in osteons to maintain bone

Osteoclasts

Eat and resorb bone, releasing calcium and phosphate back into the blood. Derived from monocytes.

Parathyroid hormone (PTH)

• Stimulates osteoclasts to increase bone resorption, which releases calcium into the bloodstream.

• Increases reabsorption of calcium in the kidneys, leading to decreased excretion in the urine

Calcitonin

• Inhibits osteoclast activity, reducing bone resorption and leading to decreased blood calcium levels.

• Decreases reabsorption of calcium in the kidneys, leading to increased excretion in the urine

Intramembranous ossification

Bone forms directly in sheets of embryonic connective tissue. Osteoblasts deposit osteoid, which calcifies and forms cortical bone. Occurs primarily for flat bones (e.g., skull, ribs).

Endochondral ossification

An indirect process of bone formation. A cartilage model is initially formed. Cartilage is gradually replaced by bone as osteoid is deposited and calcifies. Occurs for most bones in the body, including long bones (e.g., femur).

Tendons

attach muscles to bones

Ligaments

Attach bones to other bones

Periostem

layer that surrounds cortical bone. provides nutrients and nervous innervation to bone

Endosteum

Layer between cortical and spongy bone

Cartilage

type of fibrous connective tissue that is avascular and is not innervated by nerves. This is distinguished from bone, which is heavily innervated by nerves and vasculature.

Joints

meeting points between two or more bones. Muscles run across joints and pull the bones on either side, producing body movement. Joints are vascularized, innervated by nerves, and contain connective tissues.

Endocrine

hormones secreted through bloodstream

Paracrine

Hormones secreted to neighboring cells

Autocrine

Hormones secreted onto the same cell that is secreting the hormone

Posterior pituitary

direct neuronal extension of hypothalamus, releases ADH and oxytocin

antidiuretic hormone (ADH, vasopressin)

Decreases urination by increasing water retention. Targets nephrons, increasing the number of aquaporins for water reuptake.

Oxytocin

Causes uterine contractions during child labor and the release of milk during breastfeeding (mammary gland). Oxytocin also plays an important role in facilitating maternal behavior (drive to be a good parent).

Anterior pituitary

Produces its own hormones. It is connected to the hypothalamus through a hypophyseal portal system, which allows for quick diffusion of hormones through a portal vein.

GnRH (gonadotropin-releasing hormone)

Causes release of luteinizing hormone (LH) and follicle stimulating hormone (FSH).

TRH (thyrotropin-releasing hormone)

Causes release of thyroid stimulating hormone (TSH).

CRH (corticotropin-releasing hormone)

Causes release of adrenocorticotropic hormone (ACTH).

GHRH (growth hormone-releasing hormone)

Causes release of growth hormone (GH).

Tropic hormones

target other endocrine glands for further hormone release.

Direct hormones

target organs with hormones directly for effects.

FSH (follicle stimulating hormone)

Follicle growth (females) and sperm maturation (males) in the gonads.

LH (luteinizing hormone)

Stimulates ovulation, corpus luteum formation (females), and testosterone production (males) in the gonads.

ACTH (adrenocorticotropic hormone)

Stimulates release of glucocorticoids from the adrenal gland to fight stress. This also leads to an increase in glucose levels in the body.

TSH (thyroid stimulating hormone)

Stimulates T3 and T4 production by the thyroid gland to increase metabolism.