Intro to Human Biology (Test 2 study guide)

2, 5, 3, 1, 4, 6

When light hits the photoreceptors, it sets off a cascade of biochemical events that is eventually sent to the brain to be processed, giving us the sensation of sight. Put the structure through which the nerve impulses passes in the correct order. (1) optic disk (2) rods and cones (3) ganglion cells (4) thalamus (via the optic nerve) (5) bipolar cells (6) visual cortex

mineral salts

about 2/3 of the weight of the body is

dopamine

affects movement, and can also can psychosis at high levels

cell body

area where input from other neurons is integrated

synaptic knob

area where neurotransmitters are stored

myofiber, myofibril, myofilament

arrange the following in order from largest to smallest. myofibril, myofiber, myofilament

collagen

1/3 of the weight of bone is a protein called

motor

what type of neuron carries information away from the brain and spinal cord to an effector - e.g., muscle or gland

interneuron

what type of neuron is the most abundant (99% of all neurons), is located in the brain and spinal cord, and interprets sensory signals and decides on an appropriate response

sensory

what type of neuron sends information toward the brain and spinal cord from sensory receptors

retina

which layer of the eye contains the photoreceptors

pectoral girdle

which of the following is a part of the appendicular skeleton

acetylcholine

involved in muscular contractions; present in all neuromuscular synapses

as early as age 35

loss of bone density occurs

osteocytes

mature bone cells are called

3, 1, 5, 2, 4

place the following events that occur at a synapse in the correct order (1) neurotransmitter release / diffusion (2) generation of action potential in the postsynaptic cell axon (3) arrival of nerve impulse at synaptic knob in presynaptic cell (4) removal of neurotransmitter molecules from receptors (5) binding of neurotransmitter to receptors

3, 2, 4, 1

place the following events that occur during a muscle contraction in order. (1) myosin heads separate from actin filaments, cross-bridge detachment. (2) myosin heads attach to actin filaments, an action called cross-bridging. (3) myosin heads 'cock'. (4) myosin heads bend backwards, pulling the actin filaments toward the midline of the sarcomere.

2, 1, 3, 4, 5, 6

place the steps of hearing in correct order (1) sound waves cause tympanic membrane to vibrate, converting sound energy into mechanical energy (2) sound waves are collected by the pinna /auricle (3) ossicle vibration transmits sound to oval window (4) vibrations cause waves in the fluid in the cochlear duct (5) vibrations of basilar membrane cause hair cells to rub against tectorial membrane (6) action potentials transmitted to the auditory cortex by the auditory nerve

limbic system

plays an important role in forming emotions and memories

thalamus

relays messages to the cerebral cortex; all messages going to the cerebral cortex pass through this region

endorphins

relieves pain

cerebral cortex

responsible for higher thought processes and intellect

hypothalamus

responsible for maintaining homeostasis: heat rate, blood pressure, body temperature, is the center for emotions

cerebellum

responsible for smooth, well-timed voluntary movements

axon

structure that conducts the nerve impulse away from the cell body

myelin sheath

structures that increase the rate of conduction of a nerve impulse

dendrites

structures that receive information from other neurons or from the environment

collagens

this substance make(s) bones flexible

mineral salt

this substance make(s) bones very hard

osteoclasts

cells that break down bone are called

osteoblasts

cells that form bone by secreting collagen, as well as other organic materials are called

serotonin

elevates mood, contributing to feeling of happiness