bio exam 3

Innate immunity

• Non-specific defenses

• Barriers like skin, hair, mucus, stomach acid

Adaptive immunity

• Specific defenses to specific invaders

• Cellular based

• Takes time to build

• Diverse- can defend against most threats

• Long term immunity

Phagocytes

Cells whose job it is to ingest and destroy pathogens

Antigen

Only particle recognized as foreign by your immune system, generate anti-bodies

B cells

• Leading role in adaptive immunity

• Form in bone marrow

• Divide repeatedly to form plasma cells when activated

• Secrete antibodies

T cells

• Form in thymus

• Activates B cells to become plasma cells

Humoral immunity

Blood and lymph based invaders

Cell meditated immunity

Targets body cells and tissues

Cytoxic/Killer T cells

Kills infected cells and patrols body

Primary immune response

• Initial exposure to pathogen

• T and B cells are activated

Secondary immune response

• Occurs upon second exposure to a particular pathogen

• Stronger and longer response

Vaccines

Primary reason for massive reduction in viral illnesses since 1900s

Antigen drift

• Gradual accumulation of mutations

• Causes small changes in antigens on a virus surface

• Why we update vaccines

Antigenic shift

• Different strains of viruses exchange genetic material

• Changes in the antigens on the virus surface

Mouth

Teeth and tongue mechanically process food

Salivary glands

Produce amylase to digest carbohydrates

Esophagus

Transports food from mouth to stomach

Stomach

Secretes avid and pepsin to digest proteins

Small intestine

Food molecules are absorbed by epithelial cells linings

Liver and gall bladder

Makes bile and salts and secretes them

Pancreas

Secretes juice into small intestine when food enters

Large intestine

Absorbs remaining water, salts, and vitamins

Glycosis

Occurs in the cytoplasm

Citric acid cycle and electron transport chain

Occurs inside the mitochondria

Alveoli

Sites of gas exchange

Pharynx-larynx-trachea-bronchi-bronchioles-alveoli

Flow of air

Lungs-heart-arteries-body tissues-veins-back to heart

Flow of blood

Vena cava-right atrium-right ventricle-pulmonary artery-pulmonary veins-left atrium-left ventricle-aorta-body tissues

Flow of blood to heart

Estrogen and progesterone

Drives female reproductive cycle

Menopause

Ovaries stop responding to FSH and LH, ovulation and menstruation stop

Contraception

Interfere with normal female hormone cycle and prevent sperm from accessing eggs

Protooncogene

• Precursor to cancer gene

• Mutations turn to oncogenes and tells cells to divide

Tumor suppressor gene

• Tells cells to stop at checkpoints and stop dividing

• Mutations but the break line

Mitosis

Single cells condense and replicate its chromosomes and divides to produce two genetically identical daughter cells

Cytokinesis

Splits the cytoplasm of a parent cell into two daughter cells, no active changes happen to chromosomes

G1 phase

First growth phase, protein and RNA synthesis

S phase

DNA synthesis for sister chromatids

G2 phase

Second growth phase, protein synthesis, replication, damage screening

Interphase

Growth and preparation, G1, S, G2 phases, chromosomes exist as chromatin

Cancer

• A group of diseases of unregulated cell division

• Uncontrolled growth and spread of abnormal cells

• Can invade and damage healthy tissues and organs

BRCA mutations

Indicate increased risk of cancer, produce proteins responsible for repairing damaged DNA

Cell division

Necessary for our bodies to grow and function

Tumor

Abnormal mass of tissue formed by uncontrolled cell division

Benign

Noncancerous

Malignant

Cancerous with cells that can spread over the body

Metastasis

Spread of cancer cells

Surgery

Removes cancerous tissue, most effective for early solid tumors

Chemotherapy

Toxic chemicals to kill rapidly dividing cells, severe side effects

Radiation therapy

High energy ionizing radiation to kill cells

Targeted therapy

Kill cancer cells by exploiting weaknesses caused by oncogenes

Immunotherapy

Cancer cells prevent immune system from killing them, helps immune cells

Mutations

Permanent change in the DNA sequence of an organism’s genome

Mutagens

Environmental factors that damage

Point mutations

A single nucleotide base is replaced by another

Insertions/deletions

The addition or removal of one or more nucleotides

Germline Mutations

Occur in egg or sperm cells, can be inherited by offspring and passed down through generations

Somatic mutations

Occur in non-reproductive body cells, affect only the individual organism and are not inherited 

Growth factors

Naturally occurring proteins or polypeptides, external messengers to stimulate cell growth, division, survival, and differentiation