Biology Exam

The brain contains over ____________ neurons

100 billion

Normal Blood Glucose Level

100 mg glucose/mL blood

Normal Blood Pressure

120/80 mmHg

Normal Internal Temperature

37 degrees Celsius

Normal Blood pH

7.4

Sensor

A body structure that monitors and detects changes in the internal environment, sending signals to the control centre

Effector

A body structure that responds to signals from a control centre, resulting in a change to an internal variable

Control Centre

A body structure that sets the range of values within which a variable should be maintained, receives information from the sensor, and sends signals to effectors when needed

The spinal cord

A column of nerve tissue, links the brain with the PNS, is the reflex center that coordinates rapidly incoming and outgoing neural information

Common Function of Digestive, Respiratory and Excretory Systems

Add/remove substances from the blood

98% of neural tissue is contained in the

Brain and spinal cord

The Central Nervous System (CNS) consists of the

Brain and spinal cord

The control center is the

Brain and spinal cord

Examples of activities the autonomic nervous system regulates

Breathing, heartbeat, peristaltic motion

Afferent Division

Brings sensory information to the CNS

Efferent Division

Carries signals to effectors

Neurons contain a

Cell membrane, cytoplasm, mitochondria and a nucleus

Example of Negative Feedback System

Change: Rise in body temperature -> Signal sent to brain -> Effector: Blood vessels and sweat glands -> Blood vessels, sweat glands open -> Temperature returns back to normal

Example of Positive Feedback System

Childbirth: Signal sent to brain -> Brain sends signal to pituitary gland -> Pituitary gland releases oxytocin -> Uterus contracts longer and more frequently -> Uterus contracts

The human body is composed of the following organ systems

Circulatory, lymphatic, digestive, respiratory, excretory, integumentary, muscular, skeletal, nervous, endocrine, reproductive

Functions of Neurons

Conduct electrical signals, respond to physical and chemical stimuli, release chemicals

Axon

Conduct outgoing messages

Cell Body

Contains the nucleus and processes the signal from the dendrites and, if a threshold is reached, sends the signal to the axon

Common Function ofNervous and Endocrine Systems

Coordinate and regulate functions of the body's systems

The hindbrain is responsible for regulating

Coordination and homeostasis

The right and left hemispheres of the brain are connected by the

Corpus callosum

Chronic Traumatic Encephalopathy (CTE)

Degenerative brain disease that can result from sustaining repeated blows to the head

Receptors in the Nervous System

Dendrite, eye, ear, specialized cells

Specialized Structures of Neurons

Dendrites, cell body, axon, branching ends, myelin sheath

The human brain alone contains 100 billion nerve cells

Each nerve cell can make up to 10 000 connections to other nerve cells

The inner tissue of the spinal cord, that resembles a butterfly or H, is composed of

Grey matter

Organ System

Groups of organs that act to perform a common function

Bipolar Neurons Description

Has a single dendrite; found in inner ear, retina, brain

Multipolar Neurons Description

Have several dendrites, found in brain and spinal cord

3 general regions of the brain

Hindbrain, midbrain, and forebrain

The brain maintains

Homeostasis

The sympathetic and parasympathetic divisions often work

In opposition to each other to regulate the involuntary processes of the body

The brain is the center of

Intelligence, consciousness, and emotion

Tau Protein

Interferes with the normal functioning of the brain, eventually kills brain cells and disrupts homeostasis

The autonomic nervous system is under ____________ control

Involuntary (unconscious thought)

Interneurons

Link sensory neurons to motor neurons, process sensory information and relay outgoing messages to the motor neurons

Negative Feedback System

Mechanism of homeostatic response by which the output of a system reverses a change in a variable, bringing the variable back to within normal range

Symptoms of CTE

Memory loss, disorientation and confusion, erratic behaviour, tremors, slowed muscular movements, impaired speech

Feedback System

Monitors and regulates homeostasis within the body

The peripheral nervous system contains two types of pathways:

Motor and sensory

Effectors in the Nervous System

Muscles, glands, specialized cells

White matter

Myelinated axons

Brain tissue can be _________ or __________

Myelinated, unmyelinated

Several neurons make a

Nerve

The Peripheral Nervous System (PNS) consists of the

Nerves branching out from the spinal cord

The nervous system is made up of

Neural tissue

The longest cells in the body (some 1 m. in length)

Neurons

Dendrites

Numerous highly branched terminals that receive signals from other nerves and relay the signal to the cell body

Organs form

Organ systems

Tissues form

Organs

2 Types of Feedback Systems

Positive and negative

The Central Nervous System (CNS) contains the control centers responsible for

Processing and integrating sensory information, planning and coordinating responses to stimuli, and providing short-term control over the activities of other systems

The midbrain is responsible for

Processing sensory input

Common Functions of Integumentary, Muscular and Skeletal Systems

Protection and support, locomotion, sensory

Function of Heart and Blood Vessels

Pump and carry blood through the body

Sensory Neurons

Receive stimuli and send signals to the CNS

Functions of the Control Center

Receives impulses/signals, interprets/processes impulses, sends signals to effectors

Neurons have a limited ability to. .

Repair themselves; most are incapable of mitosis

The nervous system receives signals from receptors and

Sends signals out to effectors

Negative Feedback System Process

Sensor detects a change and sends a signal to a control center -> control center activates an effector -> effector restores normal levels

The 3 Components of a Feedback System

Sensor, control center, effector

Reflex Arc

Simple connection of neurons that results in a reflex action in response to a stimulus

Unipolar Neurons Description

Single process that extends from the cell body, found in PNS

The somatic nervous system controls

Skeletal muscle contractions

Examples of Sensory Neurons

Skin, ears, eyes

The autonomic nervous system regulates

Smooth muscle, cardiac muscle and glandular activity

Stem cells form

Specialized cells

Surrounding and protecting the delicate tissue of the spinal cord are the

Spinal column, meninges and cerebral spinal fluid

Events that Occur When An Action Potential is Transferred to a Neuron

Stimulus -> Na+ rushes into the cell -> -70 mV to -50 mV -> More Na+ channels open -> 40 mV -> Na+ channels close and K+ channels open so K+ rushes into the cell -> Repolarization -> -90 mV hyperpolarization -> Na+/K+ pump restores the resting membrane potential (Na+ channels open and Na+ flows in) -> back to -70 mV

Neurons are the basic

Structural and functional units of the nervous system

Neurons can be classified by their

Structure--specifically the number of processes that extend from the cell body (multipolar, bipolar, unipolar neurons)--or their function (sensory neurons, interneurons, motor neurons)

Glial Cells

Supporting cells

The autonomic nervous system is divided into two nervous systems:

Sympathetic and Parasympathetic

The nervous system is divided into

The Central Nervous System (CNS) and Peripheral Nervous System (PNS)

The PNS is divided into 2 types

The Somatic Nervous System and the Autonomic Nervous System

Locomotion

The ability to move from place to place

One of the key markers of CTE

The build-up of an abnormal version of a protein called "tau", throughout the brain (same protein that appears in the brains of Alzheimer's disease patients)

Neural tissue is specialized for

The conduction of electrical signals

Branching Ends

The end of an axon branches into many fibres that can communicate with neurons, glands or muscles

The Peripheral Nervous System (PNS)

The neural tissue outside of the CNS, which provides sensory information to the CNS and carries motor commands from the CNS to tissues and systems

What protects the brain?

The skull, 3 layers of meninges, and cerebral spinal fluid

Homeostasis

The tendency of the body to maintain a relatively constant internal environment

The forebrain is responsible for

Thought, learning and emotion

Reflex arcs usually involve only _________ neurons to __________

Three; transmit messages

Specialized cells form

Tissues

Motor Neurons

Transmit signal from the CNS to the effector

Common Functions of Circulatory and Lymphatic Systems

Transport materials throughout the body, involved in the immune response

Function of Blood

Transports nutrients and oxygen to cells and removes waste molecules excreted by cells

Grey matter

Unmyelinated axons

The somatic nervous system is under ________ control

Voluntary (conscious thought)

The outer tissue of the spinal cord is made of

White matter

Positive Feedback System

mechanism of homeostatic response by which the output of a system strengthens or increases a change in a variable