A.1 and A.2 IB bio tenth grade

Embryogenesis:

the formation and development of an embryo.

Notochord:

supporting dorsal rod in chordates; the primitive beginning of a backbone.

Ectoderm:

layer of cells that forms skin and neural tissues

Mesoderm:

layer of cells that will become muscle and bone

Endoderm:

layer of cells that forms the inner cells of the digestive and respiratory systems.

Neural groove:

shallow median groove of the neural plate between the neural folds of an embryo.

Neural tube:

a tube formed by the closure of ectodermal tissue in the early vertebrate embryo that later develops into the brain, spinal cord, and nerves.

Spina Bifida:

a type of birth defect called a neural tube defect. It occurs when the bones of the spine (vertebrae) don't form properly around part of the baby's spinal cord. 

Neural patterning:

a process where  all parts of the nervous system as neurons take up their positions and start to establish connections.

Somal migration:

neurons that are produced in the developing brain migrate to different positions; moves by extending a long process from its cell body to the outer region of the brain.

Apoptosis:

cell death that occurs as a result of a regulated sequence of physiological events.

Synaptic plasticity:

the ability of the nervous system to change in both structure and function over a person’s life, as they react to the changes in their environment.

Neurogenesis:

the birth and proliferation of new neurons in the brain.

Basal metabolic rate:

the amount of energy used by the body when at rest

Cerebral Hemispheres:

form the coordinating center for learning, memory, language and reasoning.

Hypothalamus:

controls the autonomic nervous system. It coordinates the endocrine and nervous systems by regulating the secretions of the pituitary gland.

Cerebellum:

coordinates movement, posture and balance.

Medulla oblongata (brain stem):

controls automatic and homeostatic activities such as breathing, swallowing, digestion and heart rate.

Pituitary gland:

has two parts – the posterior lobe stores and releases the hormones oxytocin and ADH from the hypothalamus, while the anterior lobe produces and secretes seven hormones, including FSH.

Cerebrum:

The outer, highly folded area of the brain.

Corpus callosum:

connects two halves of the cerebrum by a band of nerve tissue.

Cerebral cortex:

Outer layer of each hemisphere; a layer of gray matter. Controls functions such as speech, logic and decision making – the so-called higher-order functions of the human brain.

Sensory areas:

receive impulses from sense organs

Association areas:

process the information received

Motor areas:

send impulses to effectors in the body.

Broca’s area:

responsible for speaking and writing.

Wernicke’s area:

responsible for understanding of language.

Nucleus accumbens:

regions that seem to form part of the brain’s ‘pleasure centre’.

Visual cortex:

part of the cerebral cortex that is responsible for processing visual information.

Encephalization quotient (EQ):

is calculated from the ratio between actual brain mass and predicted brain mass for an animal of a given size.

Functional magnetic resonance imaging (fMRI):

scanning technique that monitors blood  flow to different areas of the brain as a subject carries out different tasks.

Peripheral nervous system (PNS):

consists of all the nerves that do not form the central nervous system.

Autonomic nervous system (ANS):

involuntary and regulates internal processes (such as activities of the glands and digestive system, and blood flow) without our awareness.

Sympathetic nervous system:

causes responses that are important in an emergency – the so-called ‘fight or flight’ responses. Excitatory effects.

Parasympathetic nervous system:

controls events in non-urgent, relaxed situations and is inhibitory in its effects.

Pupil reflex:

is a constriction of the pupils caused by contraction of the circular muscles in the iris.

Homunculi:

models that show the relative space that neurons related to different parts of the body occupy in the sensory cortex and motor cortex of the cerebral hemispheres.