The brain: Diencephalon•Hypothalamus – helps maintain homeostasis (hunger, sleep, thirst, body temperature and water balance) and controls pituitary gland•Thalamus – 2 masses of gray matter that receive all sensory input except smell; involved in arousal of the cerebrum. Also has some role in memory and learning.•Pineal gland – secretes melatonin that controls our daily rhythms. (insomnia, puberty onset)

The brain: Cerebellum• Receives and integrates sensory input from

the eyes, ears, joints and muscles about the current position of the body

• Two cerebellar hemispheres joined with each other (lots of invaginations to increase surface area *arbor vitae*)

• Functions to:• Maintains posture & balance• Coordinates voluntary movement• Allows learning of new motor skills

(i.e. playing the piano or hitting a baseball)

The brain: The brain stem• Includes:•Midbrain – relay station between the cerebrum and spinal cord or cerebellum; reflex center for visual and auditory responses.

•Pons – a bridge between cerebellum and the CNS; regulate breathing rate (with medulla oblongata); reflex center for head movements

•Medulla oblongata – reflex centers for regulating breathing, heartbeat and blood pressure, vomiting, sneezing, coughing, hiccupping, swallowing

•Reticular formation – A complex network of nuclei and fibers that extend the length of the brainstem. The reticular activating system (RAS) regulates alertness and wakefulness through activation of the Thalamus. It is stimulated by somatosensory, visual, auditory, olfactory and internal stimuli. (anaesthesia, coma). RAS filters important stimuli before going to cortex (Study with TV on)

مانام حالف ال ما انام لعیونك اسھر عشر اعوام فرا گك الن طیر نومي

تعلمت مشتاگ طبعا اي مشتاگ متعودت على ھیچ فراگ احضنك من یومي

ما چنت اضن تبعد عني وتفارگني ما ترجعلي ما گتلي عن بعدك صعب یكسر گلب لو

گایلي مجروح بعدك اي مجروح لو ادري ما خلیك تروح فراگك ذلني لو طولت اكثربعد اموت احسنلي

وبچاني

حالف ال ما انام -محمد جمال -جعفر الغزال

The limbic system• Joins primitive emotions (i.e. fear, pleasure) with higher functions such as

reasoning

• Can cause strong emotional reactions to situations• Human behavior is the result of Limbic system function (emotion) and

Frontal lobe function (logic conscious thinking)

Includes:•Amygdala – has emotional overtones ( expression of emotions, and read out emotional expressions on faces of others).•Hippocampus – important to learning and memory. Which informations are to be stored, How encoded and in which area of the brain to be stored. ALSO how to be recalled?

Higher mental functions• Learning – It is retaining and using memories, and it is what happens when we

recall and use past memories

• Memory – ability to hold a thought or to recall past events (Hippocampus)

• Short-term memory – retention of information for only a few minutes

• Long-term memory – retention of information for more than a few minutes and include the following: Prefrontal and temporal lobes.

• Episodic memory – persons and events• Semantic memory – facts, numbers and words• Components of memories are stored in different areas of cortex (visual in occipital,

sensory in parietal, auditory in temporal…so on)… recall and collection of these pieces of memories is done by the prefrontal cortex with the help of the hippocampus, to reform (or relive) the total event.

• Skill memory – performing skilled motor activities (i.e. riding a bike) (Cerebellum, Basal Ganglia.)

The peripheral nervous system (PNS)• Includes cranial (12 pr) and spinal nerves (31 pr) and ganglia outside the CNS

- Spinal nerves conduct impulses to and from the spinal cord- Cranial nerves conduct impulses to and from the brain

• Divided into 2 systems:- Somatic- Autonomic

The PNS: Somatic division

• Serves the skin, skeletal muscles and tendons

• Automatic responses are called reflexes

The PNS: Autonomic division

• Regulates the activity of involuntary muscles (cardiac and smooth) and glands

• Divided into 2 divisions:– Sympathetic: coordinates the body for the “fight or flight” response by

speeding up metabolism, heart rate and breathing while down regulating other functions

– Parasympathetic: counters the sympathetic system by bringing up a relaxed state by slowing down metabolism, heart rate and breathing and returning other functions to normal

Symp

Parasymp

EpiNE

ACh

ACh

ACh

The PNS: Autonomic division