Body Systems Chapters 35-40

35.1 Organization of the Body Nervous System –Structures: Brain Spinal cord Peripheral nerves –Function: Recognizes & responds to Δs in external & internal env.

35.1 Organization of the Body Integumentary System –Structures: Skin Hair Nails Sweat & oil glands –Function : Barrier against infection Protect against radiation Regulate temp.

35.1 Organization of the Body Respiratory System –Structures: Nose Pharynx Larynx Trachea Bronchi Bronchiols Lungs –Function: Oxygen for respiration Remove CO 2

35.1 Organization of the Body Digestive System –Structures: Mouth Pharynx Esophagus Stomach Small & large intestines rectum –Function: Break down food Absorb nutrients Eliminate waste

35.1 Organization of the Body Excretory System –Structures: Skin Lungs Kidneys Ureters Urinary bladder Urethra –Function: Eliminate waste

35.1 Organization of the Body Skeletal System –Structures: Bones Cartilage Ligaments Tendons –Function: Support body Protect organs Allow movement Store minerals Site of blood cell formation

35.1 Organization of the Body Muscular System –Structures: Skeletal muscle Smooth muscle Cardiac muscle –Function: Voluntary movement Circulate blood Move food through digestive system

35.1 Organization of the Body Circulatory System –Structures: Heart Blood vessels Blood –Function: Bring oxygen, nutrients, & information to cells Remove wastes Regulate body temp.

35.1 Organization of the Body Endocrine System –Structures: Hypothalamus Pituitary Thyroid Parathyroids Adrenals Pancreas Ovaries/testes –Function: Control growth Development Metabolism Maintain homeostasis

35.1 Organization of the Body Reproductive System –Structures: Testes Epididymis Vas deferens Urethra Penis Ovaries Fallopian tubes Uterus Vagina –Function: Reproductive cells Nurtures/protects embryo

35.1 Organization of the Body Lymphatic/Immune System –Structures: White blood cells Thymus Spleen Lymph nodes Lymph vessels –Function: Protect from disease Return fluid to circulatory system

Organization of the Body Multicellular organisms –Organ system: group of organs that perform closely related functions –Organs: group of tissues that work together to perform a complex function –Tissues: group of similar cells that perform a single function –Cells: basic unit of life

Goal of all body systems HOMEOSTASIS! –Balance w/in the body –Maintain a stable environment –Feedback inhibition Negative feedback Shuts off original signal Thermostat/hypothalamus example

Homeostasis & feedback inhibition Room temp. increasesRoom temp. decreases Senses temp change & turns on heating system Senses temp change & turns off heating system

35.3 Central Nervous System Brain & spinal cord –Protected by skull & vertebrae –Meninges wrapped around 3x Note: meningitis –Cerebrospinal fluid Protects (shock absorber) Nutrients & waste exchange

Parts of the Brain Cerebrum –Voluntary & conscious thought –Intelligence, learning, judgment Cerebellum –Coordinates movement –Balance Brain Stem –Connects brain to spinal cord Thalamus & Hypothalamus –Thalamus: gets sensory info & directs it –Hypothalamus: hunger, thirst, fatigue, anger, temp

Reflexes Automatic response to stimuli Allow body to respond w/o thought –Esp important in danger situations Ex: blinking & sneezing

35.2 Nerves Communication network –Send & receive signals throughout body –Monitors & controls internal conditions –Respond to stimuli 3 types –Sensory organ  spinal cord –Motor Brain  muscles –Interneurons Sensory motor

Nerves nucleus cell body dendrites axon myelin sheath nodes axon terminals At rest –Na + ions pumped out, K + ions pumped in but leak out –Outside cell has a + charge –Inside cell has a – charge Moving impulse –Stimuli –Reverses charge (+ inside, - outside)

The Impulse All or nothing –Threshold Below = no response Above = response The Synapse –Where message transferred –neurotransmitters