nervous system
we take in info from the environment through our spinal cord, then we take the info from the spinal cord and make a decision
Central Nervous System (CNS)
brain and spinal cord
Central Nervous System (CNS) functions
coordinates all voluntary and involuntary responses integrates incoming information
spinal reflex
involuntary responses mediated by spinal cord and spinal nerves (reflexes)
Peripheral Nervous System (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.
Two types of neurons used by PNS to communicate
afferent neurons and efferent neurons
efferent neurons
neurons that take information from the brain to the rest of the body (outward); motor neurons
afferent neurons
neurons that take information from the senses to the brain (inwards); sensory neurons
Parts of PNS
sensory division and motor division
sensory division of PNS
carries info to brain and spinal cord
systems in the motor division of PNS
somatic nervous system and autonomic nervous system
Somatic Nervous System (SNS)
the part of the peripheral nervous system that controls voluntary movement of skeletal muscles
autonomic nervous system (ANS)
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs. Its sympathetic division arouses; its parasympathetic division calms (aka fight or flight).
neuron
The functional unit of the nervous system, a nerve cell
types of neurons
sensory, motor, interneurons
sensory neurons
neurons that carry incoming information from the sensory receptors to the brain and spinal cord (PNS to CNS)
Interneurons
neurons within the brain and spinal cord that communicate internally and are located between the sensory inputs and motor outputs
motor neurons
neurons that carry outgoing information from the central nervous system to the muscles and glands (aka effectors)
neuroglia
supporting cells; physical support, nutrient flow, waste removal, electrical insulation
Synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
Neurotransmitters
chemical messengers that cross the synaptic gaps between neurons
axon
the neuron extension that passes messages through its branches to other neurons or to muscles or glands
Action Potential (AP)
sudden, temporary reversal of voltage across cell membrane that travels through the axon to axon terminal to send messages
presynaptic neuron
neuron that sends the signal towards synapse
postsynaptic neuron
the neuron receiving signal at the end of the synapse
myelin sheath
covers the axon of some neurons and helps speed neural impulses
dendrites
Branchlike parts of a neuron receive information from environment or other dendrites
multiple sclerosis
myelin sheath is inflamed and breaks down, which also damages the nerve fibers leading to plaque in nervous system (aka sclerotic patches of tissue). Creates motor, memory, and vision issues
Divisions of the brain
forebrain, midbrain, hindbrain
hindbrain
coordinated basic, automatic, and vital tasks
parts of hindbrain
medulla oblongata (controls vital automatic functions for internal organs), pons (respiration) , cerebellum (muscles and movement)
midbrain
relays visual and auditory sensory inputs to brain. Also controls circadian rhythm
forebrain
coordinates muscles related to vision and hearing
parts of forebrain
cerebrum, limbic system, hypothalamus, thalamus
cerebrum
receives and integrates information concerning emotions and conscious thought
Cerebrum has 4 lobes
frontal (motor activity, speech, conscious thought), parietal (sensory info from skin), occipital (sensory info from eyes), temporal (auditory info, language, perceptual judgment)
Hypothalamus
secretes hormones, regulates homeostasis thirst, hunger, sex
Thalamus
Relay station for sensory information; processes, receives. and transfers information
limbic system
several structures that regulate emotions and memory (Thalamus, hypothalamus, amygdala, hippocampus)
parts of the ear
outer ear, middle ear, inner ear
outer ear
channels sound waves to tympanic membrane (pinna and auditory canal)
middle ear
amplifies sound from tympanic membrane (malleus, incus, stapes)
inner ear
sorts sounds by tone and converts them (cochlea)
reducing hearing loss in public spaces
ear plugs, be further away from speakers (recommended to have them elevated), and use quiet rooms if provided
parts of eyes
sclera, iris, pupil, lens, retina, optic nerves
Sclera
covers and protects eyeball
iris
regulates the amount of light entering the eye
cornea
bends/focuses incoming light
lens
fine focuses light
retina
contains cones (detail, color—red, blue, green) and rods (provide vision in dim light, shape, movement) that convert light signals into electrical signal
types of abnormal vision
farsighted (close items are blurry but can see far away), nearsighted (far items are blurry, can see close), astigmatism (abnormal curvature of cornea or lens)
blind spot
the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
optic nerve
the nerve that carries neural impulses from the eye to the brain
Pathway of light through the (left) eye
the left visual field is made up of the left half of what both eyes see; processed in right brain
Pathway of light through the (right) eye
the right visual field is made up of the left half of what both eyes see; processed in left brain
cardiovascular/circulatory system
transports essential nutrients, removes waste products, protects the body by transporting immunity cells, regulates temperature, pH, water, and electrolytes
parts of the cardiovascular system
heart, blood vessels, blood
heart
A hollow, muscular organ that pumps blood throughout the body.
blood
Connective tissue made of plasma, erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.
How blood flows through the heart
Right Atrium (deoxygenated blood from body) -> Right Ventricle (pushes deoxygenated blood to lungs) -> Left Atrium (now oxygenated blood from the lungs) -> Left ventricle (pushes oxygenated blood to aortas, then to rest of the body)
types of blood vessels
arteries (thick vessels that carry O2-rich blood away from the heart), veins (carry O2-poor blood to the heart), capillaries (tiny blood vessel that regulates gas, nutrient, and waste exchange)
plasma
liquid portion of blood and does not contain cells; 99% water
stem cells
from bone marrow; can turn into any cell the body needs
Types of white blood cells (leukocytes)
neutrophils, eosinophils, basophils, lymphocytes, monocytes
neutrophil
granular leukocytes; most abundant and first to fight infections and fungi
eosinophil
granular leukocytes; defense against parasites and releases chemicals to reduce allergic reactions
basophil
granular leukocytes; rarest white blood cell and secretes histamine in response to allergies
lymphocyte
agranular; next level after granular cells to protect body
monocyte
agranular; turn into macrophages to destroy pathogens and communicate with other white blood cells to alert them of the issue
how red blood cells transport oxygen and carbon dioxide
hemoglobin- carries O2 in the red blood cells; distributes O2 from high to low concentration
cardiovascular diseases
heart attacks (blood supply to heart reduced/stopped) and strokes (blocked/burst arteries leading to and within the brain)
risks of cardiovascular disease
age, sex, genetics, diet, physical activity, diabetes, stress, smoking
respiratory system
Brings oxygen into the body. Gets rid of carbon dioxide. It filters air, maintains pH, fluid and thermal homeostasis, vocalization
upper respiratory tract
filters, warms, and moistens air; nose, nasal cavity, oral cavity, larynx
lower respiratory tract
exchanges gases; made up of larynx, trachea, bronchi, lungs, and alveoli
larynx
aka voice box; speech, gas exchange, separates food and air
trachea
windpipe that divides into bronchial tree
bronchi
two short branches located at the lower end of the trachea that carry air into the lungs.
bronchioles
smallest branches of the bronchi
Aveoli
sacs of the lungs where oxygen and carbon dioxide are exchanged by diffusion between the air and the blood
conducting zone
brings in air from atmosphere; upper tract + trachea, bronchi, and bronchioles
respiratory zone
gas exchange zone; alveoli/alveolar sacs
obstructive disease
difficulty exhaling air; bronchitis and asthma
restrictive disease
difficulty inhaling air; pneumonia, tuberculosis, lung cancer
chronic obstructive pulmonary disease (COPD)
poor airflow, difficulty breathing; emphysema, chronic bronchitis, asthma (restrictive and obstructive)
urinary system
maintains the fluid regulation of the body (osmoregulation); kidneys, ureters, urinary bladder, urethra
process of how urine is created
kidney filters excess water and solutes from the blood most of the water and solutes will be reabsorbed by the kidneys, the rest will be secreted via urine
ADH (anti diuretic hormone)
helps control the water balance of the body and affects the amount of urine produced by the kidney
aldosterone
retains salt; increases sodium reabsorption, which causes us to retain water
type 1 diabetes
disorder in which the body cannot produce enough insulin, which leads to the rise of blood sugar
type 2 diabetes
insulin is produced, but fatty deposits around cells block the insulin from being absorbed
negative feedback loop
brings your body closer to a set point; homeostasis
positive feedback loop
brings your body past a set point and keeps looping; childbirth stretches until baby is out