The Nervous & Endocrine System

What is the nervous system divided into

• central nervous system

• peripheral nervous system

How do these systems work

• work together so human nervous system functions

• collect information from inside the body and surrounding environment

• process information then dispatch instructions to body

What is the Central Nervous System comprised of

• brain

• spinal cord

What does the brain do

• complex functions like language and coordination

• essential functions like memory, thinking and problem solving

What does the spinal cord do

• transmits signals from brain to rest of the body

• via peripheral nervous system

What does Peripheral Nervous System do

• transmits messages through the whole body from brain

• relays messages back to brain

• divide into autonomic and somatic nervous system

How is the Peripheral Nervous System divided

• autonomous nervous system

• somatic nervous system

Somatic Nervous System

• transmits and receives senses information

• apart from sight

• controls voluntary movements

• responsible for reflex arc

Autonomous Nervous System

• organ information

• breathing, heart rate

• involuntary

• further subdivides into PNS and SNS

What does the Autonomous System subdivide into

• sympathetic nervous system

• parasympathetic nervous system

Sympathetic Nervous System

• associated with fight or flight

• prepares body for physical activity when hypothalamus detects stimulus requiring attention

• e.g. run away, fight, stand and face

• triggered when body is alert state

• e.g. hearing noise at night

Parasympathetic Nervous System

• known as rest and digest

• body at rest/normal to preserve energy

• regulated bodily functions

• conserves body activity levels by decreasing activity needed later

• e.g. digestion and urination

• slows heart rate and breathing

Nervous System

• central nervous system - brain & spine

• peripheral nervous system - autonomous & somatic nervous system

• autonomous nervous system - sympathetic nervous system & parasympathetic nervous system

What is a hormone

• chemical secreted by endocrine system

• distributed around body by bloodstream

• acts slowly

What is the major gland

• pituitary gland

• base of hypothalamus in brain

Testosterone and Oestrogen

• male & female sec hormones

• control primary and secondary sex characteristics

• regulate key milestones

• e.g. puberty, sperm production, menstrual cycle, menopause

What hormones do the Pituitary Glands secrete

• ACTH

• FSH (follicle stimulating hormone)

• LH (luteinising hormone)

• oxytocin

• TSH (thyroid stimulating hormone)

ACTH

• triggers adrenal gland

• to produce cortisol and androgens (male sex hormones)

FSH (follicle-stimulating hormone)

• sexual development and reproduction

• men and women

LH (luteinising hormone)

• encourage ovulation

• and pregnancy required hormones

Oxytocin

• secreted during childbirth

• attachment between mother and baby

TSH (thyroid-stimulating hormone)

• trigger thyroxine

• regulates bodies metabolism

What hormones are secreted by other glands under Pituitary Gland

• melatonin

• cortisol

• adrenaline

• insulin

Melatonin

• regulated sleep/wake cycle

• sensitive to light levels

Cortisol

• stress hormone

• secreted during anxiety and tension

Adrenaline

• active during fight or flight

• response to danger

Insulin

• helps blood sugar enter body cells

• for sugar to be used for energy

What hormone does the Thyroid Gland secrete

• thyroxin

• regulates metabolism

What hormone does the Pancreas secrete

• insulin

• helps blood sugar enter body cells

• sugar used for energy

What hormone does the Adrenal Gland secrete

• produced adrenaline

• active during fight or flight

• response to danger

What hormone does the Testes secrete

• testosterone

• male sex hormone

• primary & secondary sex characteristics

• puberty and sperm production

What hormone does the Ovaries secrete

• oestrogen

• female sex hormone

• primary & secondary sex characteristics

• puberty, menstruating and menopause

How does the Fight or Flight response start

• situation produces excitement, fear or stress

• sympathetic NS stimulate adrenal medulla to secrete adrenaline

• adrenaline prepares body for stress inducing stimulus

Effects of Adrenaline

• heightened reaction (fight or flight)

• triggers ATP

• adrenaline moves around body through bloodstream

• binds to receptors on target organs (SAN & cardiovascular control centre)

• blood vessels to less important organs constricts

What does ATP do with Adrenaline

• ATP is energy storing molecule

• provides short lived energy surge

What does SAN do with Adrenaline

• leads to increase in frequency of excitations

• increase heart rate to faster supply blood to muscles

• = more oxygen and glucose at muscles

• = increase aerobic respiration

• = more energy provided to deal with situation

What does Cardiovascular Control Centre do with Adrenaline

• increase impulses along sympathetic neurons affecting heart

• speed up heart rate

How does blood flow change due to Adrenaline

• blood vessels to less important organs constricts

• e.g. skin & digestive system

• more blood diverted to organs involved in fight or flight

How does one feel after the Fight or Flight response

• sick, exhausted and ravenously hungry

• due to energy released during response

• if energy is not used via action it can lead to stress and long term health issues