HL-E5 Human Brain Label, on a diagram of the brain, the medulla oblongata, cerebellum, hypothalamus, pituitary gland and cerebral hemispheres. Outline the functions of each of the parts of the brain listed in E.5.1. Explain how animal experiments, lesions and FMRI (functional magnetic resonance imaging) scanning can be used in the identification of the brain part involved in specific functions. Explain sympathetic and parasympathetic control of the heart rate, movements of the iris and flow of blood to the gut. Explain the pupil reflex. Discuss the concept of brain death and the use of the pupil reflex in testing for this. Outline how pain is perceived and how endorphins can act as painkillers.

BRAIN Grey matter: makes up the outer part of brain (cell bodies, synapses, groups of unmyelinated neurons) White matter: located in the inner part of brain (myelinated nerve fibers in bundles) Brain is protected by skull.

Brain looks like a boxing glove…

The structure of a living super computer: The human brain The human brain is –more powerful than the most sophisticated computer and –composed of three main parts: 1.forebrain, 2.midbrain, and 3.hindbrain. © 2012 Pearson Education, Inc.

Figure 28.14A Cerebral cortex (outer region of cerebrum) Cerebrum Thalamus Hypothalamus Pituitary gland Midbrain Forebrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord

What is the fundamental role of the brain? First  to coordinate and control the activities of the body Second  thinking

How are those functions achieved? 1- It receives impulses from sensory receptors. It does this from the entire body, through either spinal cord or the 12 pairs of cranial nerves. Connect brain to the sense organs and muscles of the head + VAGUS nerve to the internal organs

2- Interpretation of the impulses (correlated with past experience  stored memory) 3- Answers are sent to the effector organs (muscles and glands) 4- It stores information and builds up the memory bank of past experiences 5- It also initiates impulses  when some ideas suddenly occurs 6- The brain is the center of personality & emotions

Figure 28.14B Left cerebral hemisphere Right cerebral hemisphere Thalamus Basal nuclei Medulla oblongata Corpus callosum Cerebrum Cerebellum

Table 28.14_1

Table 28.14_2

Figure Frontal lobeParietal lobe Occipital lobeTemporal lobe Frontal association area Speech Smell Speech Motor cortex Hearing Reading Vision Visual association area Somatosensory association area Auditory association area Somatosensory cortex

..and there are four main lobes… 1- Temporal lobe: Hearing Recognition Identification & naming objects

2- Frontal lobe Controls muscles in specific parts of the body.

And also has great role on personality…PHINEAS GAGE

Phineas P. Gage (1823 – May 21, 1860) was a railroad construction foreman who suffered a traumatic brain injury when a tamping iron passed through his skull, damaging the frontal lobes of his brain. This injury is supposed to have negatively affected his emotional, social and personal traits—leaving him in a temperamental and unsociable state, so much so that his friends said he was "no longer Gage".1823May traumatic brain injuryfrontal lobesemotionalsocialpersonal

3- Parietal Lobe: Receives touch and pressure throuh thalamus… if you map the body surface which parts do you label??

Cranial Nerves: are the peripheral nerves that do not pass through spinal cord.

Mammal brain and others…

FOREBRAIN: -It is the largest portion of the brain -Has 2 parts a. Cerebrum, b. Diencephalon (thalamus and hypothalamus)

a)Cerebrum Outer layer of the forebrain. Divided into two hemispheres The outer layer is grey matter (unmyelinated nerves), inner white matter myelinated nerves) Hemispheres are connected to each other.

Functions: Coordinates all conscious activities (e.g: speech, writing, calculations comprehension, analytical thought, conceptual non-verbal ideas. The cerebral cortex (outer layer of the cerebrum) has folding structure to increase the surface area. Has 4 main lobes that coordinate activities The interior of the cerebrum forms the limbic system, which is involved in emotional aspects of behavior and memory function.

b) Diencephalon -It includes the thalamus, hypothalamus and posterior pituitary gland. -It is located between the midbrain and the cerebral hemisphere

Functions: THALAMUS: Transmits impulses from the spinal cord, cerebellum and brain stem to the appropriate parts of the cerebral cortex. Filters the info (clearing house) and interpretation of incoming impulses occurs in here

HYPOTHALAMUS: the main control center for autonomic nervous system. Functions are; Keep electrolyte balance (Na, K, Cl..) Control blood pressure Regulate body temp. Control endocrine secretion Sexual response and reproduction Emotional responses (pleasure, pain, fear, anger, love) homeostasis

Hypothalamus is well supplied with blood vessels. WHY?

MIDBRAIN: Located between the diencephalon, pons and cerebellum Visual & auditory reflex center (pupil reflex center, blinking, adjusting ear to the volume of the sound) It filters impulses to prevent overloading the forebrain with too much information.

HINDBRAIN 3 parts; medulla, pons, cerebellum A)Medulla: -It regulates some vital activities (heart rate, blood pressure, respiration rate, swallowing, vomiting, sneezing, coughing) -It receives impulses from inner organs by vagus nerve -The ascending and descending tracts of nerve fibers crossover here so the left side of the brain controls right and vice versa.

B) Pons: -Bridge of white fibers connecting medulla with the upper parts of the brain -It controls respiration. C) Cerebellum: - It coordinates movement of voluntary muscles - It controls posture, hand movement and balance - It coordinates these movements rather than starting them

What about the difference between high and medium inteligence???

We said that cerebellum is important for learning, second languages, calculations, analytical thinking…..etc. What is the importance of analytical thinking? empathy Novel & original ideas Synthesis of new ideas from previous ideas

Figure 28.11A Central nervous system (CNS) Peripheral nervous system (PNS) Spinal cord Cranial nerves Ganglia outside CNS Spinal nerves Brain

Figure 28.12A Peripheral nervous system (to and from the central nervous system) Motor system (voluntary and involuntary; to and from skeletal muscles) Autonomic nervous system (involuntary; smooth and cardiac muscles, various glands) Parasympathetic division (“Rest and digest”) Sympathetic division ( “ Flight and fight ” ) Enteric division (muscles and glands of the digestive system)

Figure 28.12B Brain Parasympathetic division Eye Constricts pupil Lung Constricts bronchi Stimulates saliva secretion Stimulates stomach, pancreas, and intestines Salivary glands Sympathetic division Dilates pupil Inhibits saliva secretion Relaxes bronchi Accelerates heart Heart Liver Stomach Adrenal gland Stimulates epinephrine and norepi- nephrine release Pancreas Intestines Bladder Stimulates glucose release Inhibits stomach, pancreas, and intestines Inhibits urination Slows heart Stimulates urination Spinal cord Genitalia Promotes erection of genitalia Promotes ejacu- lation and vaginal contractions

Figure 28.12B_1 Parasympathetic division Eye Constricts pupil Lung Constricts bronchi Stimulates saliva secretion Salivary glands Dilates pupil Inhibits saliva secretion Relaxes bronchi Accelerates heart Heart Slows heart Sympathetic division

Figure 28.12B_2 Parasympathetic division Sympathetic division Stimulates stomach, pancreas, and intestines Liver Stomach Adrenal gland Stimulates epinephrine and norepi- nephrine release Pancreas Intestines Bladder Stimulates glucose release Inhibits stomach, pancreas, and intestines Inhibits urination Stimulates urination Genitalia Promotes erection of genitalia Promotes ejacu- lation and vaginal contractions

Pupil reflex shows brain death: all brain activities stop

Brain death and cardiac death pupils remain in the mid position, and do not react to light (pupil reflex is absent); the eyes do not blink when touched; the eyes do not rotate in their sockets when the head is moved; the eyes do not move when iced water is placed in the outer ear canal; there is no cough (or gagging) when a suction tube is placed well into the trachea; breathing does not commence when the patient is taken off the ventilator.

Autonomic Nervous System

Brain researches Animal experiments: animals should be alive and different regions of brain are stimulated and response of animals are observed. Think about ethical issues on animals experiments. Lesions (damage in the brain). The change in the ability of a person can be used to deduce the function of that brain.

FMR (Functional Magnetic Resonance Imaging) Detects the differences in oxygenated and deoxygenated blood. Brain cells become active when stimulated and oxygen consumption increases.

Brain

What is the importance of cerebrum?? Animals do whatever their hypothalamus says… But our cerebrum filters the information coming from hypothalamus….