Biological Bases of Behaviour Part 1

Brain function and Endocrine System

Endocrine system

• secrete chemical messengers (hormones) into blood

• travel to target organs to bind to specific receptors

Endocrine glands

• H – Hypothalamus

• P – Pituitary

• T – Thyroid

• P – Parathyroid

• A – Adrenal

• P – Pancreas

• G – Gonads (testes/ovaries)

Pineal Gland

• produce melatonin that helps regulate circadian rhythm 

• associated w/ seasonal affective disorder

Hypothalamus 

• Controls the endocrine system by signaling the pituitary gland to release hormones.

Thyroid gland

produces thyroxine which maintains and stimulates metabolic activities

Adrenal glands

atop kidneys

Pancreas

secrets the hormones insulin and glucagon, regulating. blood sugar

Ovaries/Testes

produce hormones necessary for reproduction

Pituitary gland

• Known as the “master gland”

• Releases hormones that regulate growth, metabolism, and reproduction, under the direction of the hypothalamus.

Glial Cells

• Guide growth of neurons

• provide nutrition and get rid of waste

• form insulation

Cell Body/Soma/Cyton

• contains cytoplasm and nucleus

• Processes information

Dendrites

receives info

neurogenesis

growth of new neurons

Glutamate

• major excitatory neurotransmitter

• information processing, especially memory formation in hippocampus

Endorphins

• brains painkillers

• GABA inhibits the firing of these neurons

Norepinephinre

attentiveness, sleeping, dreaming, and learnin

Agonists

bind to receptor site to produce the effect of neurotransmitter

antagonists

block receptor site inhibiting the effect of neurotransmitter

Cerebrum

• Largest part of the brain,

• responsible for higher-order thinking, reasoning, perception, and voluntary movements.

Cerebral Cortex

• Outer layer of the cerebrum

• divided into lobes

• controls thinking, planning, sensory processing, and voluntary movement.

Frontal Lobe

Controls decision-making, problem-solving, planning, personality, and voluntary movement (contains motor cortex)

Parietal Lobe

Processes sensory information like touch, temperature, and pain (contains somatosensory cortex).

Occipital Lobe

Responsible for visual processing.

Temporal Lobe

Processes auditory information and is involved in memory and language.

Cerebellum

controls posture, equilibrium, and movement

Thalamus

directs incoming sensory signals to the correct brain areas (except smell).

Hypothalamus

Regulates hunger, thirst, body temperature, and hormones; links nervous and endocrine systems.

Pituitary Gland

• “Master gland” of the endocrine system

• controls hormone release.

Amygdala

Controls emotions, especially fear and aggression.

Hippocampus

Enables formation of new long term memories

Corpus Callosum

Connects the two hemispheres of the brain, allowing communication between them.

Medulla

Part of brainstem controlling heartbeat, breathing, and reflexes

Pons

Definition: Part of brainstem that helps coordinate movement and sleep/wake cycles

EEG (Electroencepgalogram)

• Measures waves of electrical activity (brain waves) produced by neurons firing on the scalp

• Where and when brain activity occurs

PET (Positron Emission Tomography)

• Shows brain activity by detecting where a radioactive form of glucose goes while the brain performs a task.

• Colored

fMRI (Functional MRI)

• Measures brain activity by detecting changes in blood flow and oxygen levels.

• Shows both structure and function

Magnetic Source Image (MSI)

EEG and MRI data to pinpoint the exact location of brain activity

Central Nervous System

Brain and spinal cord

Peripheral Nervous System

• Somatic nervous system

• Autonomic Nervous System

Somatic Nervous system

stimulate skeletal (voluntary muscle)

Autonomic Nervous system

Stimulate smooth (involuntary) and heart muscle

• antagonistic sympathetic nervous system

• Parasympathetic nervous system

Sympathetic stimulation

• response that help body deal w/ stressful events

• eg dilated pupils, high heart rate, secretion of adrenaline

Parasympathetic stimulation

• Calms body following sympathetic stimulation

• Eg restore digestive function, returning pupil size

Spinal Cord

• protected by membranes (meninges) and spinal column of bony vertebrae

• start at base of back → base of skull → brain