Biology Test revision KEY TERMS

Nervous system

The nervous system is the that sends and receives signals from the different parts of the body to control movement and sensory information.

Nerve

A cell that carries information in the body.

Brain

Is responsible for receiving and sending commands to the body through neurons.

Afferent

Information sent TO the brain

Efferent

Commands sent FROM the Brain to the organs, muscles and glands.

Neuron

A nerve cell

Cell membrane

Thin layer that separates cell from it’s surroundings.

Nucleus

The organelle that contains the genetic information for a cell.

Myelin sheath

The insulating layer that covers a neuron.

Dendrite

A branch from a cell body that receives messages from other neurons.

Axon

A long thin projection of a nerve cell.

Axon Terminals

A axon ending that makes synaptic connections with another nerve cell.

Synapse

A synapse is the gap between two neurons and transfers the information from one cell to another transforming neuron transmitters from a chemical signal to electrical signal.

White matter

Myelinated neurons

Grey matter

Unmyelinated neuron

CNS

Central Nervous system connects the brain to the spinal cord.

PNS

Peripheral nervous system the nerves that carries messages to and from the CNS and other parts of the body.

Prokaryotic

Doesn’t have a nucleus because the lack of a membrane distinguishes it from Eukayote

Eukayote

An organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus.

example of efferent pathway

Smelling perfume.

example of afferent pathway

What are a bunch of neurons?

A nerve

CNS

Central nervous system

PNS

Peripheral nervous system

how many neurons does the brain contain?

7 trillion

what’s the cerebrum?

80% of the brain folding creases

what’s cerebellum?

Balance and coordination

What does the brain stem do?

Controls breathing, heartrate, blood pressure and sleep.

What are the lobes of the brain?

Frontal lobe (motor control, problem solving), Parietal lobe (touch, sensory integration), Temporal lobe (hearing, language and memory) and Occipital lobe (vision).

what does the left side of the brain control?

Right side

what does the right side of the brain control?

Left side

What does the spinal cord carry?

commands FROM the brain and senses TO the brain

what does the PNS do?

sends Voluntary and Automatic commands

what are one example of each command

automatic - heartbeat voluntary - putting hand up

what is the feedback in the body ?

Detect PNS

Process PNS

Respond PNS

What is the chemical released from a Synapse ?

Neurotransmitter

what are the steps for your body to take to respond?

Detect stimuli, delivering the information, processing the situation, delivering the orders and carrying out the orders.

what’s is a stimulus?

The response/reaction

what’s the difference between a stimulus and response?

The stimulus is something that causes a response, and a response is how the body reacts to the stimulus.

what are stimulus detected by?

Receptors.

where are receptors found?

In the sensory nerve ending.

what pathway does the sensory neurons take?

Afferent pathway.

what’s the occipital lobe for?

Vision.

what’s the temporal lobe for?

Hearing.

what’s the parietal lobe for?

Touch.

what does the brain do before responding?

The brain interprets and decides a response and weighs a consequence.

what are commands sent through, and what pathway is it?

Nerve neurons and the efferent pathway.

what is an example of the efferent pathway?

catch ball - muscle - response

what is the stimulus response model

Stimulus - receptor - sensory neuron - spinal cord - motor neuron - effector

Example:

Heat (stimulus) - temp receptors (skin temp changes) - sensory nerve (hypothalamus acts as control center detecting temp change) - effector (muscle of arm) - response (getting hot so you take jumper off)

What is an effector?

A muscle or gland that puts the messages into effect.

what is a reflex?

A involuntary response.

is a involuntary response controlled by the brain?

No.

what is the reflex arc?

Receptor

sensory

spinal cord

motor

effector

what are 2 examples of reflexes?

knee jerk, grasp reflex.

what does feedback help?

Homeostasis.

what is the feedback?

detect - process - response

what is the Endocrine system a system of?

Organs and glands.

how does it send messages?

By using hormones.

How much are they released at a time?

In small amounts.

Where are they released?

Into the bloodstream.

what do hormones act on ?

target cells.

what does the Thyroid gland control?

Metabolism.

what does the pancreas gland control?

insulin with both blood and glucose levels.

what does the adrenal gland control?

Produce stress hormone.

what does the pituitary gland control?

Growth, cell growth, development.

what does the ovaries gland control?

Sexual development.

what does the thymus gland control?

Stimulate the production and maturation of immune cells.

why does the hormones only affect certain cells?

Because they go to certain cell when somethings wrong, depending on the situation.

what does homeostasis do?

Maintains the internal conditions eg temperature, PH, glucose and water.

what does the hypothalamus do?

It sends info to the master gland (pituitary gland) detects change.

how does the endocrine system help keep your internal levels in check?

It goes through hypothalamus - pituitary and kidneys to maintain homeostasis.

why are hormones effective for long-term regulation?

Because we keep making them and producing them.

Comparing both nervous system and endocrine system what are the similarities?

sends messages, responds to stimuli and maintains homeostasis

what are endocrine messages chemical or electrical?

chemical messages.

what are the messages in the nervous system?

Electrical impulses.

why is the nervous system faster?

Because it skips the brain so it doesn’t process

what is the normal or average temperature for people?

37 degrees.

what are enzymes?

enzymes are the protein to help the body function properly.

what happens when your temperature increases?

Your chemical reactions increase and enzymes change shape.

what are the symptoms of heatstroke?

temperature gets higher

nausea

increased heartrate

headaches

feeling faint

what happens with frost bite?

Reduced blood supply in cold conditions the body redirects the blood to the vital organs to try keep you alive.

why do we sweat when we’re hot?

Because our bodies react to the stimuli which causes a reaction like to our sweat glands.

what happens when sweat glands are activated?

we sweat and our blood vessels widen and it’s called vasodilation.

what are pathogens?

A microorganism that causes diseases.

what are the types of pathogens?

Bacteria, viruses, fungi, protists and parasites.

Explain how the body reacts when temperature gets too high?

how does the body respond when it gets too cold?

how does the white blood cells protect body from diseases?

They attack the virus or disease or engulf (eat the virus)

Describe type 1 and type 2 diabetes?