Brain Spinal cord

Spinal Cord

Sensory Nerves: Afferent Motor Nerves: Efferent

Afferent: stimuli both internal and external

Internal: ◦ Stretch Receptors

External: ◦ Integumentary receptors

Messiner corpusle: touchPacinian corpusle: pressureNociceptor: painThermoreceptor: heat

Efferent: Response to effectors

Two functional divisions

Somatic:◦ Skeletal muscle

Autonomic:◦ Cardiac & Smooth

muscles◦ Glands

Sympathetic Parasympathetic:

Fight or FlightIncrease

◦ HR, RR, BP, BSDecrease blood flow

digestiveAdrenaline (Stress Hormone)

◦ released for the Adrenal glandsPupils DilateIncrease Blood Flow to MusclesSenses HeightenRelease of glucagon

◦ stimulates liver to release glucose increase BS

Homeostasis: CalmingSelf-Maintenance Activities

◦ Balance the Sympathetic response

◦ Decrease HR, RR, BPIncrease blood flow

◦ Digestive system

Adrenals stop releasing Adrenaline

Release of glycogen ◦ Stimulates liver to store BS

Fight or Flight: Sympathetic

Homeostasis: Parasympathetic

Cerebrum Cerebellum Meningies Ventricles Medulla Oblongata Corpus Callosum Pons Midbrain Spinal cord

Largest part of the brain Divided into hemispheres Each hemisphere has four lobes (F,T,P,O) Connected by the CORPUS CALLOSUM

Thick band of nerve fibres◦ connect the brain cells in one

hemisphere to those in the other hemisphere

◦ allows for constant communication

Aids motor coordination of left and right side

Left : Logical words logic numbers analysis lists linearity and

sequence

Right: Creative creative brain rhythm spatial awareness colour imagination daydreaming holistic awareness

and dimension

◦ planning ◦ organizing◦ problem solving◦ personality ◦ reasoning◦ Intuition or

perception ◦ behavior and

emotions

Frontal lobe

visual processing color recognition vision recognition

Occipital Lobe

◦ cognition (acquiring knowledge by the use of reasoning, intuition, or perception)

◦ information processing

◦ pain and touch sensation

◦ spatial orientation ◦ speech and visual perception.

Parietal Lobe

◦ emotional responses◦ hearing◦ speech. ◦ differentiate smells and

sounds

Memory (Hippocampus & Amygdala)◦ information sorting short and

long term memory. right lobe visual memory left verbal memory

Temporal lobe

Hippocampus

Motor Sensory

3 Layers◦ Dura Mater-toughest and outermost layer◦ Arachnoid Mater (resembles a spider web) middle

layer◦ Pia Mater-inner layer and most delicate sits

directly on top of the brain and spinal cord

Space between Arachnoid and Pia Mater has cerebrospinal fluid (CSF)

What is inflammation of the Meningies called?

Why is it serious?

What covers the Brain and the Spinal Cord?

What will this swelling cause?

In the Brain? In the Spinal Cord?

Cavities within the center of the brain filled with CSF

This fluid is found in the space around the Meningies and the central canal of the spinal cord

Fluid protects and cushions the CNS

Pituitary Gland:Master Gland

ThalamusHypothalamus: Homeostasis

CerebrumCorpus Callosum

Ventricles

Cerebellum

Spinal Cord: sensory impulses upMotor impulses down

Inferior to the Occipital lobes

Posterior to the Pons and Medulla Oblongata

Co-ordinates complex skeletal muscle contractions and relaxation necessary for body movement and balance

Connects the brain to the brain stem

Pituitary gland

Cerebellum

Hypothalamus

Thalamus

Inferior part of brain stem

Contains the vital reflexes◦ Cardiovascular center: force

and rate of the heart rate and changes in smooth muscle of the arteries to regulate Blood Pressure

◦ Respiratory centers: controls diaphragm

◦ Vomiting, hiccupping, swallowing, coughing, sneezing

Medulla Oblongata

Bulging brain stem region

Bridge between the cerebellum and the cerebrum

Works with the medulla oblongata to control breathing (respiration)

Pons

Form important connections between the cerebral cortex and the brainstem and spinal cord to control sensory processes such as vision and movement.

Midbrain

Electrical impulses (messages) travel back & forth between from the PNS to the CNS and then back to the PNS through bundles of neurons which are called nerves

1 Dendrites:◦ Extends out from the

cell body picks up message from synaptic terminal of adjoining neuron

2 Cell Body:◦ Directs all activity of

the neuron

3 Axon:◦ long single fiber that

transmits electrical impulse from cell body to the synaptic terminals

4 Synaptic terminals or axon terminals:◦ Release neurotransmitters

that allows electrical message to travel to the next neuron’s Dendrites or gland or muscle cells

5 myelin sheath covers most

neurons

insulates the axon and helps nerve signals travel faster and farther.

Movement of neurotransmitters

from synaptic terminal of one neuron:

to the dendrites of another neuron◦ Muscle cell : cardiac,

skeletal, smooth◦ gland

For a synapse to occur you need to have a

1.Pre-synaptic cell2.Post-synaptic cell

Acetylcholine – ◦ stimulates muscle contraction

Monoamines - Norepinephrine & Dopamine ◦ sense of feeling good, ◦ low levels = depression

Serotonin◦ Sleepiness◦ Depression

Endorphins◦ reduce pain by inhibit receptors

Neurons in the CNS Brain Spinal cord

White matter: Cell Body

Gray Matter: Axons

Spinal nerve

Central canalGray matter

White matter

Meninges

Spinal nerve

Meningies

Sensory: afferent stimuliDORAL ROOT

Motor: efferent responseVENRAL ROOT

Reflex Arc requires:1.Sensory neuron to

provide afferent input (stimuli) (Dorsal root)

2. Interneuron to process (Gray matter)

3.Motor neuron to send efferent output (response) (Ventral Root)

Nerve messages are sent through the spinal cord to the brain to be processed

Link between brain and rest of body (PNS)

31 pairs of spinal nerves

Reflexes processed directly by spinal cord

Reflex – quick, automatic, involuntary responses

Result of reflex arcs – shortest nerve pathways