THE NERVOUS SYSTEM

Nervous system

A body wide network of nerves with two overarching components (CNS & PNS)

CNS

Brain and spinal cord

PNS

All other nerves in the body

The Brain

receives and makes sense of sensory information, sends instructions to periphery, communications among nerves are carried out by neurotransmitters, complex connections of networks

Three major areas of the brain

Hindbrain, midbrain, forebrain

Hindbrain

Most “basic” area of the brain, involved in essential functions for basic life, includes: medulla oblongata, pons, and cerebellum

Medulla Oblongata

Connects: spinal cord to higher portions of the brain

Regulates: autonomic functions such as heart rate, blood pressure and breathing

Receives: information about oxygen and carbon dioxide levels in the body and alters breathing as necessary to keep these gases balanced

Pons

Part of: the brainstem, helping connect spinal cord to higher portions of the brain

Links: the medulla of the midbrain

Involved in: breathing and the regulation of sleep/wakefulness

Cerebellum

Coordinates voluntary muscle movements and plays role in motor learning

Involved with the maintenance of balance, equilibrium, muscle tone and posture

Midbrain

Involved in motor (especially reflexes) functions and visual and auditory processing

Forebrain

It is: the brains largest and most highly developed region

It supports: complex processes such as thinking memory, language, sensory integration and voluntary movement

Two major areas: cerebrum, diencephalon

Cerebrum

It is: the largest and uppermost part of the brain

Includes: cerebral hemispheres and cortex, hippocampus, amygdala

Support: together these structures support voluntary movement, memory, language, reasoning and other advanced cognitive processes

Hippocampus

important for memory, forming epusodic memory for long-term storage and associating emotions with memories

Amygdala

involved in emotion, threat detection, emotional responses to environment and memories

The four lobes of the cerebral cortex

Frontal, parietal, temporal, occipital

Frontal lobe

voluntary movement and higher-level thinking

Parietal lobe

Touch, pain, temperature, and pressure

Temporal lobe

hearing and smell

Occipital lobe

vision

Diencephalon

Located: beneath the cerebrum

Includes: the thalamus and hypothalamus

Thalamus

Processes and relays sensory information to the cerebral cortex

Hypothalamus

Regulates: hunger, thirst, s3x drive, pleasure, pain

The Limbic System

Involved with: processing and coordination responses to emotions, especially in response to threat

The Peripheral Nervous System

Function: carries information between the central nervous system and the rest of the body

Two major branches: Somatic and Autonomic

Somatic Nervous System (SNS)

Connects the CNS to muscles under conscious control

Directs voluntary movements

Sends feedback about the body’s movement back to the CNS

Autonomic (ANS):

Connects the CNS to internal organs and muscles that generally operate outside conscious control, regulates automatic bodily functions, includes the sympathetic and parasympathetic branches

Autonomic branches

sympathetic & parasympathetic

Sympathetic

the gas pedal

activates body during stress, emergencies, strong emotions and strenuous activity

produces fight or flight response

helps initiate the body’s stress response

chronic activation can contribute to diseases such as heart disease

Parasympathetic

the break pedal

counteracts sympathetic activation

promotes rest, recover, and restoration

helps the body return to its resting state

The endocrine system

Networks of glands regulated by central nervous system

Sends messages throughout body via hormones

Hypothalamus uses the pituitary gland to link nervous system to endocrine system

Hormones

Bind to cells and change how they function

Pituitary gland

located at the base of the brain and consists of two lobes

Posterior pituitary lobe

releases oxytocin, contractions and social bonding

Vasopressin, water absorption and blood pressure

Anterior pituitary lobe

Produces a number of hormones related to growth and development

Adrenal Glands

Located on top of each kidney, each gland consists of two lobes

Adrenal Medulla

part of the sympathetic-adrenal-medullary system

produces epinephrine (adrenaline) & norepinephrine (noadrenaline)

Adrenal Cortex

part of the hypothalamic-pituitary-adrenal axis

produces androgens, mineralocorticoids and glucocorticoids

Type 1 Diabetes

occurs in kids, immune cells attack pancreas = no insulin

Type 2 Diabetes

body is less responsive to insulin