biology test 2

epithelial

epithelial

tissue that covers surface, all 3 germ layers

connective

cells in an extracellular matrix (ground substance and protein fibers), mesoderm

muscle

tissue for contraction, mesoderm

nervous

tissue with electrochemical impulses, ectoderm

ectoderm

outer layer: epidermis of skin, lining of oral cavity, nervous system

mesoderm

middle layer: skeleton, muscles, circulatory system, dermis of skin, reproductive organs

endoderm

inner layer- inner layer of digestive and respiratory system, major glands (pancreas and liver)

homeostasis

maintained by negative feedback

negative feedback

reverses the original change (temp regulation)

positive feedback

intensifies the original change (childbirth)

radiation

heat moves in the form of electromagnetic waves (standing near a campfire and you get hot)

evaporation

liquid to gas, taking heat with it (sweating)

conduction

transfer of heat through liquids or gasses (boiling water)

endotherms

internal heat generation, metabolic heat (insulation, shivering)

ectotherms

external sources of heat (behavioral mechanisms: basking in the sun or seeking shade)

larger

____ bodies have a higher metabolic rate

neuroglia

supporting cells of neurons

cell body

where impulses are recieved

dendrites

allow cell to receive impulse and pass to cell body

axon

where outgoing electrical impulses are generated, branches to interact with other cells

neuron

produce and conduct electrochemical impulses

Schwann cells

type of neuroglial cell that forms myelin sheath

Myelin sheath

insulation, formed by cell membrane of the Schwann cells in PNS and oligodendrocytes in the CNS

myelinated

type of axons/dendrites that make white matter

nodes of Ranvier

interrupt myelin sheath

oligodendrocyte

produce myelin in the CNS

sensory neuron

• carry information from your senses to your brain

  • motor neurons: carry instructions from your brain to your muscles (help you move by transmitting signals that tell your muscles when/how to contract or relax)

somatic motor neurons

• motor neurons that control skeletal muscles (voluntary muscles)

autonomic motor neurons

• motor neurons that control involuntary functions in your body (heart rate, digestion, breathing)

sympathetic

• ‘fight or flight’, prepare body to respond, increases heart rate, dilate pupils, slow digestion

parasympathetic

‘rest and digest’, relax and recover, constrict pupils, promote digestion, slow HR

resting phase

The interior of the nerve cell is more negatively charged than the exterior of the cell.

rising phase

depolarization by influx of sodium ions

top of curve

• maximum voltage of the action potential. At this point, the sodium inactivation gate closes and the voltage-gated potassium gate opens .

falling phase

hyperpolarization due to outflux of potassium ions

gated channels

• open in response to a nerve impulse

ligand gated channels

• signaling molecules (neurotransmitters) bond to the receptor protein and the ion channels open

voltage gated channels

• open in response to a nerve impulse

mechanoreceptors

1. touch, hearing, balance

chemoreceptors

taste, smell, pH

electromagnetic receptors

vision

stimulation

first step, A physical stimulus acts on a receptor.

transduction

second step, The energy from the stimulus is converted into graded potentials (electrical energy).

transmission

third step, Graded potentials are converted into action potentials, which are conducted to the central nervous system.

interpretation

fourth step, the brain creates a perception of the electrochemical events

semicircular canals

• balance

• hair cells in here are responsible for detecting rotational movement of the head in different planes

• bending of these hair cells generates electrical signals that are sent to the brain via the vestibular nerve, helping you maintain balance and a sense of spatial orientation.

Cochlea

• hearing

• hair cells are responsible for converting sound vibrations into electrical signals that can be interpreted by the brain

• vibrations from sound waves bends hairs

ganglion cell

• light passes through first

• make up the layer that is closest to the cavity of the eye

bipolar cells

• second place light passes through in the eye

cones

responsible for color vision and sharpness in bright light

rods

black and white vision in dim light

scotoma

blind spot in the eye

paracrine regulator

• hormones released that act only on nearby cells

autocrine signalling

• cell releases hormones that act on itself

hormones

• released by glands that go through the bloodstream (long distance messengers)

neurotransmitters

deliver messages in the brain and nervous system (cars that drive between nerve cells)

pheromones

• animals use these to communicate with other animals of the same species 

endocrine

• glands that release hormones into the bloodstream and travel to specific organs or tissues

exocrine

glands release substances through ducts (salivary, tear ducts)

lipophilic

• steroid and thyroid hormones

hydrophilic

• peptide, protein, most amino acid derivatives

hypothalamus

controls anterior pituitary by secreting releasing and inhibiting hormones

hypophyseal portal vein

• allows hormones produced in the hypothalamus to be quickly transported to the anterior pituitary gland, where they stimulate or inhibit the release of other hormones.

posterior pituitary

oxytocin and ADH are stored and released here

anterior pituitary

• produces 7 hormones whose release is controlled by the hypothalamus

• TSH, ACTH, GH

thyroid

• produces hormones that regulate your metabolism, which is how your body uses energy. These hormones help control things like your heart rate, body temperature, and how fast you burn calories.

parathyroid

• small glands located near the thyroid gland. They produce a hormone that helps regulate the levels of calcium and phosphorus in your body. This hormone helps keep your bones strong and your muscles working properly.

adrenal gland

• the body's stress response system. They produce hormones like adrenaline that help you react to stress and danger. They also produce other hormones that help regulate your metabolism, immune system, and blood pressure.

pancreas

• It produces enzymes that help digest food in your stomach. It also produces hormones like insulin that help regulate your blood sugar levels. Insulin helps move sugar from your blood into your cells, where it can be used for energy.

insulin

key that helps unlock your cells so they can take in sugar (glucose) from the blood.

glucagon

a messenger that tells your liver to release stored sugar into the blood when your blood sugar levels are low

bone remodeling

Mechanical stresses and hormones regulate how osteoblasts produce new bone and osteoclasts dissolve bone continuously.

slow twitch

• More capillaries

• Numerous mitochondria

• High myoglobin

• Sustained action, endurance

• Red fibers

fast twitch

• Fewer capillaries

• Fewer mitochondria

• Less myoglobin

• Rapid generation of power

• White fibers