Exam #3 W 4/7 in class

Review T 4/6 at 6-8pm in SZB 104

Fig 48.3

Nerves allow us to perceive the environment while the brain integrates the incoming signals to determine an appropriate response.

Response

Responses can be release of hormones, change in cell activity, or muscle contraction

Fig 50.32

Muscles can only contract. Therefore, two muscles are needed for each range of motion.

2 nerve signals for every movement:excitatory and inhibitory

Fig 50.32

How do muscles contract?

Fig 50.29Excitatory neuro-transmitters released by motor neurons cause muscle cells to contract

Muscle cells are comprised of series of sarcomeres.

Fig 50.25

Each sarcomere is a repeating unit of actin and myosin proteins

Fig 50.25

As each sarcomere contracts, the muscle cell contracts

Fig 50.25

Fig 50.29Neuro-transmitters released at nerve/muscle junction cause calcium to be released in muscle

Fig 50.28

A third protein, tropomyosin controls when the muscle contracts

Fig 50.27

ATP provides the energy for myosin movement along the actin

The contraction of muscle cells causes the muscle to contract

esophagus

stomach

Taking in food and oxygen exposes us to pathogens

Pathogen: a disease causing agent

Ebola

E. coli

Fungus from soil

Phage virus

various pathogens

The Immune System

• Non-specific:–barriers

• Specific:–B-cells -> antibodies

–T-cells

Fig 43.2

Non-Specific Immune SystemBarriers: Skin-

DryInhospitableCompetitionSecretions (lysozyme)

Hairs and Mucus (protect openings)Traps particles, swallowed

Stomach acidkills pathogens

Fig 43.2

Skin protects us from most pathogens

Fig 43.2

esophagus

stomach

Stomach acidkills pathogens

Hairs and Mucus (protect openings)Traps particles

Non-Specific Immune SystemBarriers: Skin-

DryInhospitableCompetitionSecretions (lysozyme)

Hairs and Mucus (protect openings)Traps particles, swallowed

Stomach acidkills pathogens

Fig 43.2

The Immune System

• Non-specific:–barriers

• Specific:–B-cells -> antibodies

–T-cells

Fig 43.2

The Specific Immune System

B-cells and T-cells move through the circulatory system scanning for pathogens

B-cells develop in bone marrowT-cells in the thymus

B-cells make and secrete antibodies

Fig 43.14

Constant region

Variable region

An Antibody

Fig 43.10

Antibodies recognize and bind to antigens

Fig 43.10

Marked fordestructionby WBC

B-cells male antibodies that bind to antigens marking them for destruction

Fig 43.19

Fig43.14

Each B-cell/antibody recognizes a specific antigen

Fig43.13

B-cell DNA rearranges to

make a unique and random gene

SpecificImmuneSystemOverview

Fig43.16

Exam #3 W 4/7 in class

Review T 4/6 at 6-8pm in SZB 104