Health Midterm 2023

The nervous system is responsible for regulating your body temperature, sending signals to the brain through nerves, and controls movement. It is the master control and communication system of our body.

Brain, Spinal Cord, Nerves, Sensory Organs(5 senses)

Sensory Input, Integration, Motor Output

Stimuli; noticing things

Process of carrying out information by your CNS; translating what you notice

Muscle/Gland; Using bodily movements to control movement

-Made up of the brain and spinal cord

-Acts as the body’s control center and coordinates bodily activities

-Acts as the integration and command center

Impulses travel through the neurons in your body to reach the brain

• Takes in conscious and unconscious thoughts

• Makes decision for controlling and maintaining homeostasis

• Asks as integration as a command center

• Made up of everything else (nerves/nerve endings) that carry messages to and from the CNS

• Carries Impulses to and from CNS to glands and muscles

• Links all parts of the body by carrying impulses from the sensory receptors to the CNS and from the CNS to glands or muscles

Somatic Nervous System & Autonomic Nervous System

• Relay info between the skin, skeletal muscles and CNS

• You consciously control this pathway by deciding whether or not to move muscles (except reflexes)

-Relay info from CNS to organs

automatic response to stimuli

You do not consciously control these

control in times of stress such as flight or fight

• controls body in times of rest

look at pic

The division of the PNS composed of nerves that carry information TO the CNS

The division of the PNS composed of nerves that carry information FROM the CNS

Nerve cells

Fibers that receive and convey messages to the cell body of a neuron

Metabolic center of the cell; contains the nucleus

Support Cells aka neuroglia and neurons

To insulate, support, and protect delicate neurons

• At their terminal end axons branch into hundreds or thousands of axon terminals

• Each contains vesicles or sacs of neurotransmitters

• When a nerve impulse reaches an axon terminal it stimulates the release of neurotransmitters

The junction between neurons

• Neurotransmitters diffuse across the synapse to continue cell to cell communication

Bundles of nerve fibers in CNS

White Matter: Myelinated Axons

Grey Matter: Unmyelinated Cell Bodies

• Sensory Neurons, Interneurons, Motor neurons

• carry impulses from receptors such as the skin to the CNS

connect sensory and motor neurons in the CNS

carry impulses from the CNS to a muscle or gland

• Sensory receptors in the muscles and tendons

• Detect stretch or tension in skeletal muscles, tendons and joints

• Maintain balance and posture

Unipolar, Bipolar, Multipolar(most common), Pseudounipolar

Irritability & Conductivity

Ability to respond to a stimulus and convert it into a nerve impulse

Ability to transmit the impulse to other neurons, muscles, or glands

Lights, sound waves, pressure, chemicals, neurotransmitters

1. Neuron at rest is polarized

2. Stimulus changes membrane permeability

3. Depolarization & generation of action potential

4. Action potential propagates along entire length of neuron

5. Repolarization-membrane returns to resting state

6. Sodium-potassium pump restores ion balance

• Chemicals released at the end of an axon terminal that diffuse across the synapse and transfer the nerve impulse to another nerve, muscle, or gland

Via electrical and chemical synapses

Cerebrum, Diencephalon, Brain Stem, Cerebellum

• The largest and most superior part of the brain

• Composed of 2 cerebral hemispheres divided by longitudinal fissure

• Surface shows elevated ridges of tissues called gyri and shallow grooves called sulci

• Outermost layer of the cerebrum

• Composed of gray matter

• Responsible for thinking and processing information from the five senses

• Grooves or fissures divide into sections or lobes

• Motor function, problem solving, memory, language, judgment, socially acceptable behavior

• Processes sensory information such as touch, temperature, and taste

• Auditory perception, Olfactory area is deep inside

Visual processing center

• Superior to the brainstem

• 3 major structures: Thalamus, Hypothalamus, Epithalamus

• Relay station for sensory impulses traveling to the sensory cortex

• Contains the pineal gland and choroid plexus which forms the cerebrospinal fluid

Keeps your body in homeostasis

Made up of the midbrain, pons, and medulla oblongata

• Reflex center for vision and hearing, eye movements

Coordinates information between brain areas, involved in breathing

• Blood pressure, breathing, heart rate

• Precise timing of skeletal muscle activity

• Balance and equilibrium

• Makes body movement smooth and coordinated

Skull and vertebrae

Connective tissue matter

Tough outer double layer membrane

Web-like layer spans the subarachnoid space

Innermost membrane that clings tightly to the surface of the brain and spinal cord

• Continually formed plasma by clusters of capillaries in cavities called ventricles

• Provides a watery cushion for the brain & spinal cord

• Significant changes in CSF composition may indicate problems

It’s obtained through a procedure called a spinal or lumbar tap

• The brain depends on a very stable internal environment

• Neurons are protected from blood-borne substances by the least permeable capillaries in the body

• Continuous with the brain stem; connects the brain to nerves

• Enclosed within vertebrae; provides a 2-way path to and from the brain

• Major reflex center

Endoneurium, Perineurium, Epineurium

Surrounds each neutron

Surrounds a group of neurons or fascicle

Surrounds a nerve

• 31 pairs of spinal nerves exit from the vertebral column

• All other spinal nerves form complex networks each called a plexus, which serve the motor and sensory needs of limbs

Nerves that originate in the brain

12 pairs that serve the head and neck

• Motor subdivision of the PNS that automatically controls bodily activities

• Maintains homeostasis

• Includes neurons that control cardiac muscle, smooth muscle, glands

• The sympathetic nervous system prepares the body to either fight or run from a threat

• Enables the body to cope rapidly and vigorously with situations that may disrupt homeostasis

• A motor system disorder that leads to trembling of the hands, arms, legs, jaws, or face and impaired balance and coordination

• Results from a loss of brain cells in area of the midbrain called the substantia nigra

Occurs when the Myelin Sheath around neurons is gradually destroyed and hardens into “scleroses”

Nerve impulse are interrupted

Autoimmune disease with no cure

A type of mental illness caused by progressive brain cell death

Leads to problems with memory, thinking, and behavior

Symptoms worsen over time and there was no cure

A mild traumatic brain injury

Caused by a jolt, bump, or blow to the head that causes the brain to move rapidly inside the skull

Symptoms: Dizziness, confusion, headache & nausea

Acute inflammation of the meninges

Usually caused by vital or bacterial infection

Can lead to deafness, epilepsy, brain damage, or death

Symptoms: sever headaches & neck stiffness

Brain disorder that causes seizures

Occurs when something blocks oxygen supply to the brain and a blood vessel bursts