Biological Basis of Behavior Flashcards
Instinctual behavior
Hard coded, shaped by genetics
Heritability
The proportion of variation in a trait (phenotype) that is due to variation in the genotype (0 = purely environmental, 1 = purely genetic)
Epigenetics
Changes that affect how genes work that do not involve changing the actual nucleotide content
Methylation
Adding methyl groups to DNA, silences it
Patellar reflex
Leg jerks in response to tapping on kneecap
Palmar grasp reflex
In babies; they will grab your finger if you stroke along an infant’s palm
Rooting reflexes
Babies will search for an object that brushes against its mouth or cheek
Sucking reflex
A baby will automatically make sucking motions when something grazes the top of its mouth
Moro reflex
Startle reflex in babies in response to sudden movement or loud sounds; baby will throw back its head, extends arms and legs and pulls them back in, and cries
Babinski reflex
Babies will bend up the big toe and fan out the others in response to the bottom of the foot being stroked
Critical period
Period in which early childhood experiences can have lifelong impacts
Adolescence
Transition from childhood to adulthood
Puberty
Biological changes that happen during adolescence
Secondary sex characteristics
Growth of pubic hair and body hair, growth of breasts and wider hips, growth of facial hair and Adam’s apple
Telomeres
Repeating nucleotide sequences at the end of chromosomes that protect them from losing nucleotides during DNA replication
Endocrine system
Network of organs distributed throughout the body that secrete signaling molecules (hormones) into the bloodstream
Direct hormones
Hormones that cause their target cells to make direct changes in some physiological function
Tropic hormones
Hormones that cause other hormones to be released
Thalamus
Information relay station; processes sensory information before sending it to the cerebral cortex for processing
Hypothalamus
Converts input from the nervous system into endocrine signals
Gonadotropin-releasing hormone (GnRH)
Acts on anterior pituitary to trigger the release of LH and FSH to regulate reproduction
Corticotropin-releasing factor
Promotes the release of ACTH from the anterior pituitary to stimulate the adrenal glands to release cortisol
Anterior pituitary
Located directly below the hypothalamus and receives hypothalamic input via hormones released into the hypophyseal portal system
Hypophyseal portal system
Blood vessels connecting the hypothalamus to the anterior pituitary
Hormones secreted by the anterior pituitary
LH, FSH, ACTH, TSH, prolactin, endorphins, and growth hormone
Posterior pituitary
Receives input from the hypothalamus in the form of neuronal signals because it is composed of neurons itself
Thyroid and parathyroid glands
Small organs located in the throat, thyroid releases calcitonin and thyroid hormone
Adrenal glands
Small glands located on top of the kidneys, divided into adrenal cortex and adrenal medulla
Adrenal cortex
Secretes steroid hormones like glucocorticoids and cortisol
Adrenal medulla
Secretes epinephrine and norepinephrine
Estrogen and testosterone
Secreted by ovaries and testes, respectively, help coordinate reproductive processes and orchestrate changes during puberty