UNIT 11 biology

main parts of nervous system

1. Brain

2. Spinal cord

3. Nerves

nervous system

coordinates the body’s response to stimuli

neuron

transmits electrical and chemical signals

synapse

the gap between neurons

Neurotransmitters

chemical signals of the nervous system that carry messages from one nerve cell to the other

Interneurons

passes messgaes between other neurons ( found in the brain or spinal cord )

Reflex arc

nerve pathway that needs to cross only two synapse before producing a response

Types of neurons

1. Sensory

2. Motor

3. Interneuron

Sensory neuron

detects and transmits signals

Interneuron

passes messages between other neurons

Motor neuron

passes messages from nervous system to body tissues

Endocrine system

Controls growth, development, metabolism, homeostasis, and reproduction through the production and secretion of hormones (Similar to the nervous system, but not physically connected)

Peripheral nervous system ( PNS )

the system that carries messages back and forth between your spinal cord / brain and the rest of your body

( collection of nerves thats a pathway to and from the CNS )

Hormones

chemical signals that influence cell activities

Adrenal glands

produce adrenaline ( epinephrine / norepinephrine ) in response to stress ( fight or flight )

Pancreas

controls blood sugar levels with insulin secretion

Ovaries

produce estrogen

Testes

produce testosterone

Hypothalamus / pituitary / thyroid

glands that produce hormones to regulate growth. Metabolism and homeostasis

Thymus

produces T-cells

Circulatory + endocrine

take hormones to specific location

Immune system

to fight infection, diseases and pathogens

Skin

physical barrier as the “first line of defense”

Nonspecific immune response

Those that happen in the same way to every pathogen ( ex: fever )

Specific immune response

Your body’s targeted defense system that fights a specific germ ( ex: antibodies, B cells, and T cells )

Antigens

make cells go to the site of infection

T cells

seeks out and destroys pathogens

B cells

produces antibodies

Leukemia

abnormal white blood cells

Located in the bone marrow

HIV

attacks and weaken the immune system

Immune + integumentary

protect body from foreign invaders

Lymphatic system

collects fluids that leak out of blood vessels

Interstitial fluid

fluid between cells

Lymph

fluid

Lymph nodes

clean and filter lymph fluid

Reproductive system

produce new life

2 main functions of female system

1. Produce ova, or egg cells

2. Provide a place where zygote develops

Ovaries

produces eggs and estrogen

Uterus

hold the developing fetus

vagina

entrance to the uterus

Ova / egg

female gamete ( sex cell )

Endocrine + reproductive

hormones secreted during puberty

Gametogenesis

production of gametes

2 major parts of male system

1. Testes - produces sperm and testosterone

2. Penis - site of ejection for sperm

Follicle

stimulating hormone FSH ( aids the production of sperm )

Fetus

fertilized egg with total of 46 chromosomes